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Hypotonia and Parkinsonism were present in two Turkish siblings, brother and sister. By using exome sequencing, which sequences a selective coding region of the genome, researchers have found a homozygous five-nucleotide deletion in the SPR gene which confirmed both siblings were homozygous. It is predicted that this mutation leads to premature translational termination. Translation is the biological process through which proteins are manufactured. The homozygous mutation of the SPR gene in these two siblings exhibiting early-onset Parkinsonism showcases that SPR gene mutations can vary in combinations of clinical symptoms and movement. These differences result in a wider spectrum for the disease phenotype and increases the genetic heterogeneity causing difficulties in diagnosing the disease. | 0 | Neurochemistry |
Amyotrophic lateral sclerosis ALS is a neurodegenerative disease characterized by progressive muscular paralysis reflecting degeneration of motor neurons in the primary motor cortex, corticospinal tracts, brainstem and spinal cord. One study using the superoxide dismutase 1 (SOD1) mutant mouse, an ALS model which develops severe neurodegeneration, the expression of p75NTR correlated with the extent of degeneration and p75NTR knockdown delayed disease progression. | 0 | Neurochemistry |
Amyloid-beta precursor protein (APP) is an integral membrane protein expressed in many tissues and concentrated in the synapses of neurons. It functions as a cell surface receptor and has been implicated as a regulator of synapse formation, neural plasticity, antimicrobial activity, and iron export. It is coded for by the gene APP and regulated by substrate presentation. APP is best known as the precursor molecule whose proteolysis generates amyloid beta (Aβ), a polypeptide containing 37 to 49 amino acid residues, whose amyloid fibrillar form is the primary component of amyloid plaques found in the brains of Alzheimer's disease patients. | 0 | Neurochemistry |
SoRI-20041 is an "antagonist-like" allosteric modulator of amphetamine-induced dopamine release (in contrast to the related research chemicals SoRI-9804 and SoRI-20040, which are "agonist-like"). SoRI-20041 is believed to be the first example of a drug that separately modulates uptake versus release in the dopamine transporter (possibly showing how inward and outward transport represent distinct operational modes of DAT); it produces the same effects as SoRI-20040 and SoRI-9804 in uptake assays and binding assays, inhibiting the re-uptake of dopamine, but does not modulate d-amphetamine-induced DA release by inhibiting that as well, like agonists of the series do.
This suggests the possibility of simultaneous action and increase of indirect-agonism through the dual action of DRA and DRI efficacy existing together. This increases the inhibition of re-uptake at synaptic dopamine concentrations without interfering in the flow of release of dopamine from amphetaminergic phosphorylation at the affected transporter. This overcomes the obstacle of a compromised binding site that would be rendered unusable through the action of amphetamine. Conventional dopamine re-uptake inhibitors (such as cocaine or methylphenidate) would otherwise ineffectively target such a site on each specific transporter so affected by amphetamine, making this an example of a DRI that does not have a mutually exclusive functionality against DRA action at individual instances of DAT. | 0 | Neurochemistry |
During neuron development neurotrophins play a key role in growth, differentiation, and survival. They also play an important role in the apoptotic programmed cell death (PCD) of neurons. Neurotrophic survival signals in neurons are mediated by the high-affinity binding of neurotrophins to their respective Trk receptor. In turn, a majority of neuronal apoptotic signals are mediated by neurotrophins binding to the p75NTR. The PCD which occurs during brain development is responsible for the loss of a majority of neuroblasts and differentiating neurons. It is necessary because during development there is a massive over production of neurons which must be killed off to attain optimal function.
In the development of both the peripheral nervous system (PNS) and the central nervous system (CNS) the p75NTR-neurotrophin binding activates multiple intracellular pathways which are important in regulating apoptosis. Proneurotrophins (proNTs) are neurotrophins which are released as biologically active uncleaved pro-peptides. Unlike mature neurotrophins which bind to the p75NTR with a low affinity, proNTs preferentially bind to the p75NTR with high affinity. The p75NTR contains a death domain on its cytoplasmic tail which when cleaved activates an apoptotic pathway. The binding of a proNT (proNGF or proBDNF) to p75NTR and its sortilin co-receptor (which binds the pro-domain of proNTs) causes a p75NTR-dependent signal transduction cascade. The cleaved death domain of p75NTR activates c-Jun N-terminal kinase (JNK). The activated JNK translocates into the nucleus, where it phosphorylates and transactivates c-Jun. The transactivation of c-Jun results in the transcription of pro-apoptotic factors TFF-a, Fas-L and Bak. The importance of sortilin in p75NTR-mediated apoptosis is exhibited by the fact that the inhibition of sortilin expression in neurons expressing p75NTR suppresses proNGF-mediated apoptosis, and the prevention of proBDNF binding to p75NTR and sortilin abolished apoptotic action. Activation of p75NTR-mediated apoptosis is much more effective in the absence of Trk receptors due to the fact that activated Trk receptors suppress the JNK cascade.
The expression of TrkA or TrkC receptors in the absence of neurotrophins can lead to apoptosis, but the mechanism is poorly understood. The addition of NGF (for TrkA) or NT-3 (for TrkC) prevents this apoptosis. For this reason TrkA and TrkC are referred to as dependence receptors, because whether they induce apoptosis or survival is dependent on the presence of neurotrophins. The expression of TrkB, which is found mainly in the CNS, does not cause apoptosis. This is thought to be because it is differentially located in the cell membrane while TrkA and TrkC are co-localized with p75NTR in lipid rafts.
In the PNS (where NGF, NT-3 and NT-4 are mainly secreted) cell fate is determined by a single growth factor (i.e. neurotrophins). However, in the CNS (where BDNF is mainly secreted in the spinal cord, substantia nigra, amygdala, hypothalamus, cerebellum, hippocampus and cortex) more factors determine cell fate, including neural activity and neurotransmitter input. Neurotrophins in the CNS have also been shown to play a more important role in neural cell differentiation and function rather than survival. For these reasons, compared to neurons in the PNS, neurons of the CNS are less sensitive to the absence of a single neurotrophin or neurotrophin receptor during development; with the exception being neurons in the thalamus and substantia nigra.
Gene knockout experiments were conducted to identify the neuronal populations in both the PNS and CNS that were affected by the loss of different neurotrophins during development and the extent to which these populations were affected. These knockout experiments resulted in the loss of several neuron populations including the retina, cholinergic brainstem and the spinal cord. It was found that NGF-knockout mice had losses of a majority of their dorsal root ganglia (DRG), trigeminal ganglia and superior cervical ganglia. The viability of these mice was poor. The BDNF-knockout mice had losses of a majority of their vestibular ganglia and moderate losses of their DRG, trigeminal ganglia, nodose petrosal ganglia and cochlear ganglia. In addition they also had minor losses of their facial motoneurons located in the CNS. The viability of these mice was moderate. The NT-4-knockout mice had moderate losses of their nodose petrosal ganglia and minor losses of their DRG, trigeminal ganglia and vestibular ganglia. The NT-4-knockout mice also had minor losses of facial motoneurons. These mice were very viable. The NT-3 knockout mice had losses of a majority of their DRG, trigeminal ganglia, cochlear ganglia and superior cervical ganglia and moderate losses of nodose petrosal ganglia and vestibular ganglia. In addition the NT-3-knockout mice had moderate losses of spinal moroneurons. These mice had very poor viability. These results show that the absence of different neurotrophins result in losses of different neuron populations (mainly in the PNS). Furthermore, the absence of the neurotrophin survival signal leads to apoptosis. | 0 | Neurochemistry |
A photocyte is a cell that specializes in catalyzing enzymes to produce light (bioluminescence). Photocytes typically occur in select layers of epithelial tissue, functioning singly or in a group, or as part of a larger apparatus (a photophore). They contain special structures termed as photocyte granules. These specialized cells are found in a range of multicellular animals including ctenophora, coelenterates (cnidaria), annelids, arthropoda (including insects) and fishes. Although some fungi are bioluminescent, they do not have such specialized cells. | 1 | Bioluminescence |
Voltage-gated ion channels open and close in response to membrane potential.
*Voltage-gated sodium channels: This family contains at least 9 members and is largely responsible for action potential creation and propagation. The pore-forming α subunits are very large (up to 4,000 amino acids) and consist of four homologous repeat domains (I-IV) each comprising six transmembrane segments (S1-S6) for a total of 24 transmembrane segments. The members of this family also coassemble with auxiliary β subunits, each spanning the membrane once. Both α and β subunits are extensively glycosylated.
*Voltage-gated calcium channels: This family contains 10 members, though these are known to coassemble with αδ, β, and γ subunits. These channels play an important role in both linking muscle excitation with contraction as well as neuronal excitation with transmitter release. The α subunits have an overall structural resemblance to those of the sodium channels and are equally large.
**Cation channels of sperm: This small family of channels, normally referred to as Catsper channels, is related to the two-pore channels and distantly related to TRP channels.
*Voltage-gated potassium channels (K): This family contains almost 40 members, which are further divided into 12 subfamilies. These channels are known mainly for their role in repolarizing the cell membrane following action potentials. The α subunits have six transmembrane segments, homologous to a single domain of the sodium channels. Correspondingly, they assemble as tetramers to produce a functioning channel.
*Some transient receptor potential channels: This group of channels, normally referred to simply as TRP channels, is named after their role in Drosophila phototransduction. This family, containing at least 28 members, is incredibly diverse in its method of activation. Some TRP channels seem to be constitutively open, while others are gated by voltage, intracellular Ca, pH, redox state, osmolarity, and mechanical stretch. These channels also vary according to the ion(s) they pass, some being selective for Ca while others are less selective, acting as cation channels. This family is subdivided into 6 subfamilies based on homology: classical (TRPC), vanilloid receptors (TRPV), melastatin (TRPM), polycystins (TRPP), mucolipins (TRPML), and ankyrin transmembrane protein 1 (TRPA).
*Hyperpolarization-activated cyclic nucleotide-gated channels: The opening of these channels is due to hyperpolarization rather than the depolarization required for other cyclic nucleotide-gated channels. These channels are also sensitive to the cyclic nucleotides cAMP and cGMP, which alter the voltage sensitivity of the channel's opening. These channels are permeable to the monovalent cations K and Na. There are 4 members of this family, all of which form tetramers of six-transmembrane α subunits. As these channels open under hyperpolarizing conditions, they function as pacemaking channels in the heart, particularly the SA node.
*Voltage-gated proton channels: Voltage-gated proton channels open with depolarization, but in a strongly pH-sensitive manner. The result is that these channels open only when the electrochemical gradient is outward, such that their opening will only allow protons to leave cells. Their function thus appears to be acid extrusion from cells. Another important function occurs in phagocytes (e.g. eosinophils, neutrophils, macrophages) during the "respiratory burst." When bacteria or other microbes are engulfed by phagocytes, the enzyme NADPH oxidase assembles in the membrane and begins to produce reactive oxygen species (ROS) that help kill bacteria. NADPH oxidase is electrogenic, moving electrons across the membrane, and proton channels open to allow proton flux to balance the electron movement electrically. | 0 | Neurochemistry |
GFP can be used to analyse the colocalization of proteins. This is achieved by "splitting" the protein into two fragments which are able to self-assemble, and then fusing each of these to the two proteins of interest. Alone, these incomplete GFP fragments are unable to fluoresce. However, if the two proteins of interest colocalize, then the two GFP fragments assemble together to form a GFP-like structure which is able to fluoresce. Therefore, by measuring the level of fluorescence it is possible to determine whether the two proteins of interest colocalize. | 1 | Bioluminescence |
All bacterial species that have been reported to possess bioluminescence belong within the families Vibrionaceae, Shewanellaceae, or Enterobacteriaceae, all of which are assigned to the class Gammaproteobacteria.
(List from Dunlap and Henryk (2013), "Luminous Bacteria", The Prokaryotes ) | 1 | Bioluminescence |
The serotonin created by the brain comprises around 10% of total body serotonin. The majority (80-90%) is found in the gastrointestinal (GI) tract. It travels around the brain along the medial forebrain bundle and acts on serotonin receptors. In the peripheral nervous system (such as in the gut wall) serotonin regulates vascular tone. | 0 | Neurochemistry |
*Orexins (-A and -B) are involved in a number of cognitive processes, including appetite, arousal, and reward, among many others.
*Neurohypophysial hormones:
**Arginine-vasopressin
**Oxytocin regulates social cognition (e.g., trust and pair-bonding) and modulates maternal behavior.
*Endogenous opioids:
**Dynorphins
**Endorphins
**Endomorphins
**Enkephalins
* Neurotrophic factors are biomolecules – nearly all of which are peptides or small proteins – that support the growth, survival, and differentiation of both developing and mature neurons. Examples of notable neurotrophic factors include:
** Insulin-like growth factor-1 (IGF-1)
** Glial cell line-derived neurotrophic factor (GDNF)
** Vascular endothelial growth factor (VEGF)
** Brain-derived neurotrophic factor (BDNF)
** Nerve growth factor
** Neurotrophin-3
** Neurotrophin-4
** Ephrins
** Neuregulins | 0 | Neurochemistry |
Macro-scale biological processes, such as the spread of virus infections, can be followed using GFP labeling. In the past, mutagenic ultra violet light (UV) has been used to illuminate living organisms (e.g., see) to detect and photograph the GFP expression. Recently, a technique using non-mutagenic LED lights have been developed for macro-photography. The technique uses an epifluorescence camera attachment based on the same principle used in the construction of epifluorescence microscopes. | 1 | Bioluminescence |
In Amphipholis squamata, bioluminescence has been observed to come from the spines emanating from the arms from photocytes within the spinal ganglia. Acetylcholine has been found to be able to stimulate the photocytes to produce light. | 1 | Bioluminescence |
Also known as ionotropic receptors, this group of channels open in response to specific ligand molecules binding to the extracellular domain of the receptor protein. Ligand binding causes a conformational change in the structure of the channel protein that ultimately leads to the opening of the channel gate and subsequent ion flux across the plasma membrane. Examples of such channels include the cation-permeable nicotinic acetylcholine receptors, ionotropic glutamate-gated receptors, acid sensing ion channels (ASICs), ATP-gated P2X receptors, and the anion-permeable γ-aminobutyric acid-gated GABA receptor.
Ion channels activated by second messengers may also be categorized in this group, although ligands and second messengers are otherwise distinguished from each other. | 0 | Neurochemistry |
Pancuronium remains one of the few muscle relaxants logically and rationally designed from structure-action / effects relationship data. A steroid skeleton was chosen because of its appropriate size and rigidness. Acetylcholine moieties were inserted to increase receptor affinity. Although having many unwanted side-effects, a slow onset of action and recovery rate it was a big success and at the time the most potent neuromuscular drug available. Pancuronium and some other neuromuscular blocking agents block M2-receptors and therefore affect the vagus nerve, leading to hypotension and tachycardia. This muscarinic blocking effect is related to the acetylcholine moiety on the A ring on pancuronium. Making the N atom on the A ring tertiary, the ring loses its acetylcholine moiety, and the resulting compound, vecuronium, has nearly 100 times less affinity to muscarin receptors while maintaining its nicotinic affinity and a similar duration of action. Vecuronium is, therefore, free from cardiovascular effects. The D ring shows excellent properties validating Beers and Reich's rule with great precision. As a result, vecuronium has the greatest potency and specificity of all mono-quaternary compounds. | 0 | Neurochemistry |
The endocannabinoid system has been shown to have a homeostatic role by controlling several metabolic functions, such as energy storage and nutrient transport. It acts on peripheral tissues such as adipocytes, hepatocytes, the gastrointestinal tract, the skeletal muscles and the endocrine pancreas. It has also been implied in modulating insulin sensitivity. Through all of this, the endocannabinoid system may play a role in clinical conditions, such as obesity, diabetes, and atherosclerosis, which may also give it a cardiovascular role. | 0 | Neurochemistry |
The hammerhead titanothere (Angtsìk in Navi) is a large hexapodal herbivore whose massive, low-slung head features bony projections on either side of the skull, similar to those of hammerhead sharks and their bodies resemble the Brontotheres of Earth. These protrusions are often used to push and destroy objects: a single sideways thrust of the neck being sufficient to down a significantly sized tree. The titanothere has exceedingly thick, gray skin. There is a small "fan" feather structure on the head that it flares up as a warning symbol seen in the film and in the video game. The creature, which resembles a cross between a rhinoceros and a hammerhead shark, is easily aroused. Its hide is impervious to small arms fire, though firing on it is known to anger it. This massive, grazing creature travels in moderately large herds or packs of 10–20 animals. Avatar creature designer Yuri Bartoli explained about the creatures colorful threat display: "Originally, the hammerhead just had to be a huge creature, big enough that even a thanator would think twice about attacking one. A threat display is meant to be seen, so it required bright colors that would stand out against its more muted body". It is moderately social, but also extremely territorial and hierarchical. A soft ungulate mouth is protected by a rigid, beak-like jaw structure. The species is scientifically known as Titanotheris hammercephalis. In the climax of the film, a group of hammerhead titanothere assist the Navi in their battle against Colonel Miles Quaritch's army. | 1 | Bioluminescence |
Many PAFPs have been engineered from existing fluorescent proteins or identified from large-scale screens in the wake of Kaede's discovery. Many of these undergo green-to-red photoconversion, but other colors are available. Some proteins take part in irreversible photoconversion reactions while other reactions can be reversed using light of a specific wavelength. | 1 | Bioluminescence |
There are many GFP-like proteins that, despite being in the same protein family as GFP, are not directly derived from Aequorea victoria. These include dsRed, eqFP611, Dronpa, TagRFPs, KFP, EosFP/IrisFP, Dendra, and so on. Having been developed from proteins in different organisms, these proteins can sometimes display unanticipated approaches to chromophore formation. Some of these, such as KFP, are developed from naturally non- or weakly-fluorescent proteins to be greatly improved upon by mutagenesis. When GFP-like barrels of different spectra characteristics are used, the excitation spectra of one chromophore can be used to power another chromophore (FRET), allowing for conversion between wavelengths of light.
FMN-binding fluorescent proteins (FbFPs) were developed in 2007 and are a class of small (11–16 kDa), oxygen-independent fluorescent proteins that are derived from blue-light receptors. They are intended especially for the use under anaerobic or hypoxic conditions, since the formation and binding of the Flavin chromophore does not require molecular oxygen, as it is the case with the synthesis of the GFP chromophore.
Fluorescent proteins with other chromophores, such as UnaG with bilirubin, can display unique properties like red-shifted emission above 600 nm or photoconversion from a green-emitting state to a red-emitting state. They can have excitation and emission wavelengths far enough apart to achieve conversion between red and green light.
A new class of fluorescent protein was evolved from a cyanobacterial (Trichodesmium erythraeum) phycobiliprotein, α-allophycocyanin, and named small ultra red fluorescent protein (smURFP) in 2016. smURFP autocatalytically self-incorporates the chromophore biliverdin without the need of an external protein, known as a lyase. Jellyfish- and coral-derived GFP-like proteins require oxygen and produce a stoichiometric amount of hydrogen peroxide upon chromophore formation. smURFP does not require oxygen or produce hydrogen peroxide and uses the chromophore, biliverdin. smURFP has a large extinction coefficient (180,000 M cm) and has a modest quantum yield (0.20), which makes it comparable biophysical brightness to eGFP and ~2-fold brighter than most red or far-red fluorescent proteins derived from coral. smURFP spectral properties are similar to the organic dye Cy5.
Reviews on new classes of fluorescent proteins and applications can be found in the cited reviews. | 1 | Bioluminescence |
There are a number of disorders which disrupt normal functioning of ion channels and have disastrous consequences for the organism. Genetic and autoimmune disorders of ion channels and their modifiers are known as channelopathies. See :Category:Channelopathies for a full list.
* Shaker gene mutations cause a defect in the voltage gated ion channels, slowing down the repolarization of the cell.
* Equine hyperkalaemic periodic paralysis as well as human hyperkalaemic periodic paralysis (HyperPP) are caused by a defect in voltage-dependent sodium channels.
* Paramyotonia congenita (PC) and potassium-aggravated myotonias (PAM)
* Generalized epilepsy with febrile seizures plus (GEFS+)
* Episodic ataxia (EA), characterized by sporadic bouts of severe discoordination with or without myokymia, and can be provoked by stress, startle, or heavy exertion such as exercise.
* Familial hemiplegic migraine (FHM)
* Spinocerebellar ataxia type 13
* Long QT syndrome is a ventricular arrhythmia syndrome caused by mutations in one or more of presently ten different genes, most of which are potassium channels and all of which affect cardiac repolarization.
* Brugada syndrome is another ventricular arrhythmia caused by voltage-gated sodium channel gene mutations.
* Polymicrogyria is a developmental brain malformation caused by voltage-gated sodium channel and NMDA receptor gene mutations.
* Cystic fibrosis is caused by mutations in the CFTR gene, which is a chloride channel.
* Mucolipidosis type IV is caused by mutations in the gene encoding the TRPML1 channel
* Mutations in and overexpression of ion channels are important events in cancer cells. In Glioblastoma multiforme, upregulation of gBK potassium channels and ClC-3 chloride channels enables glioblastoma cells to migrate within the brain, which may lead to the diffuse growth patterns of these tumors. | 0 | Neurochemistry |
HCN4 is the main isoform expressed in the sinoatrial node, but low levels of HCN1 and HCN2 have also been reported.
The current through HCN channels, called the pacemaker current (I), plays a key role in the generation and modulation of cardiac rhythmicity, as they are responsible for the spontaneous depolarization in pacemaker action potentials in the heart. HCN4 isoforms are regulated by cCMP and cAMP and these molecules are agonists at I. | 0 | Neurochemistry |
The resting potential of photocytes was found to exist in a range between 50 and 65 millivolts. It is generally accepted that the emission of light was found to occur after depolarization of the photocyte membrane although some have argued that the depolarization follows the emission of light. The depolarization of the membrane results in an increase of the rate of diffusion of ions across it. The depolarization of the photocyte was found to occur 0.5 seconds following nervous impulse culminating at one second with the maximum degree of depolarization observed. A higher frequency of nervous stimulation was associated with a smaller depolarization event. Exposure to neurotransmitters including epinephrine, norepinephrine, and synephrine, results in the emission of light but without any corresponding depolarization of the photocyte membrane. | 1 | Bioluminescence |
The ionotropic glutamate receptors bind the neurotransmitter glutamate. They form tetramers, with each subunit consisting of an extracellular amino terminal domain (ATD, which is involved tetramer assembly), an extracellular ligand binding domain (LBD, which binds glutamate), and a transmembrane domain (TMD, which forms the ion channel). The transmembrane domain of each subunit contains three transmembrane helices as well as a half membrane helix with a reentrant loop. The structure of the protein starts with the ATD at the N terminus followed by the first half of the LBD which is interrupted by helices 1,2 and 3 of the TMD before continuing with the final half of the LBD and then finishing with helix 4 of the TMD at the C terminus. This means there are three links between the TMD and the extracellular domains. Each subunit of the tetramer has a binding site for glutamate formed by the two LBD sections forming a clamshell like shape. Only two of these sites in the tetramer need to be occupied to open the ion channel. The pore is mainly formed by the half helix 2 in a way which resembles an inverted potassium channel. | 0 | Neurochemistry |
The turtapede (Mawup in Navi) is a Pandoran creature that resembles a cross between a turtle, a platypus and a starfish. With its large dorsal fin and long tail, the turtapede is agile underwater. When emerging from the water, mesmerizing colors start to shimmer in the translucent area on its shell. They first appear in the musical Toruk – The First Flight'. | 1 | Bioluminescence |
Light production may first be triggered by nerve impulses which stimulate the photocyte to release the enzyme luciferase into a "reaction chamber" of luciferin substrate. In some species the release occurs continually without the precursor impulse via osmotic diffusion. Molecular oxygen is then actively gated through surrounding tracheal cells which otherwise limit the natural diffusion of oxygen from blood vessels; the resulting reaction with the luciferase and luciferin produces light energy and a by-product (usually carbon dioxide). The reaction occurs in the peroxisome of the cell.
Researchers once postulated that ATP was the source of reaction energy for photocytes, but since ATP only produces a fraction the energy of the luciferase reaction, any resulting light wave-energy would be too small for detection by a human eye. The wavelengths produced by most photocytes fall close to 490 nm; although light as energetic as 250 nm is reportedly possible.
The variations of color seen in different photocytes are usually the result of color filters that alter the wavelength of the light prior to exiting the endoderm, thanks to the other parts of the photophore. The range of colors vary between bioluminescent species.
The exact combinations of luciferase and luciferin types found among photocytes are specific to the species to which they belong. This would seem to be the result of consistent evolutionary divergence. | 1 | Bioluminescence |
Push–pull perfusion is an in vivo sampling method most commonly used for measuring neurotransmitters in the brain. Developed by J.H. Gaddum in 1960,
this technique replaced the cortical cup technique for observing neurotransmitters. The advent of concentric microdialysis probes in the 1980s resulted in push-pull sampling falling out of favor, as such probes require less monitoring, and are less invasive than the higher flow rate push-pull probes (>10 microliter/min), which could result in lesions if flow is unbalanced.
With the advent of microfluidics and miniaturized probes, low-flow push–pull sampling was developed in 2002. By using flow rates of ~50 nL/min, this technique minimizes tissue damage while providing finer spatial resolution than microdialysis sampling. | 0 | Neurochemistry |
The chemical reaction catalyzed by firefly luciferase takes place in two steps:
* luciferin + ATP → luciferyl adenylate + PP
* luciferyl adenylate + O → oxyluciferin + AMP + light
Light is produced because the reaction forms oxyluciferin in an electronically excited state. The reaction releases a photon of light as oxyluciferin goes back to the ground state.
Luciferyl adenylate can additionally participate in a side reaction with O to form hydrogen peroxide and dehydroluciferyl-AMP. About 20% of the luciferyl adenylate intermediate is oxidized in this pathway.
Firefly luciferase generates light from luciferin in a multistep process. First, D-luciferin is adenylated by MgATP to form luciferyl adenylate and pyrophosphate. After activation by ATP, luciferyl adenylate is oxidized by molecular oxygen to form a dioxetanone ring. A decarboxylation reaction forms an excited state of oxyluciferin, which tautomerizes between the keto-enol form. The reaction finally emits light as oxyluciferin returns to the ground state. | 1 | Bioluminescence |
Since EosFP can be used in fusion constructs while maintaining functionality of the protein of interest, it is a popular choice for multi-colour labelling studies. In a dual-colour labelling experiment to map the stages of mitosis, HEK293 cells were first stably transfected with tubulin-binding protein cDNA fused to EGFP for visualization of the spindle apparatus. Then, transient transfection of recombination signal-binding protein (RBP) fused to d2EosFP was used to visualize the beginning of mitosis. Photoconversion was completed by fluorescent microscopy and highlighted the separation between two sets of chromosomes during anaphase, telophase and cytokinesis. | 1 | Bioluminescence |
Location of M receptors is not well known.
Like the M and M muscarinic receptor, M receptors are coupled with G proteins of class G that upregulate phospholipase C and, therefore, inositol trisphosphate and intracellular calcium as a signaling pathway. | 0 | Neurochemistry |
Alzheimer's disease (AD) is a neurodegenerative disease resulting from synaptic plasticity failure. BC200 RNA plays a role in the dendrites of neurons thought to modulate synthesis of proteins that influence this plasticity. Researchers posit that upregulation of BC200 RNA results in an inadequate delivery of RNA to the neuronal synapses, thus resulting in neurodegeneration. In comparing healthy brains with those with AD, it was determined that BC200 RNA is upregulated in the brains of people with AD, most notably in areas of the brain that correspond to the disease. A direct relationship was observed here, the more severe the disease, the higher the levels of BC200 RNA there were. This is in contrast to a normal aging brain where a steady decrease of this RNA is observed between the ages of 49 and 86. | 0 | Neurochemistry |
Overall, the evolution of light producing cells (photocytes) is believed to have happened twice in sharks through convergence. Evidence suggests that the bioluminescent properties of the shark, Etmopterus spinax, came about as a mechanism of camouflage. It is thought that luminescence has other functions as well due to camouflage not being a logical explanation for the luminescence on the lateral sides of the shark. Bioluminescence is believed to have only evolved in sharks among the cartilaginous fishes. The function of bioluminescence among sharks has not been fully ascertained. | 1 | Bioluminescence |
The Puerto Mosquito Bioluminescent Bay (), or Mosquito Bio Bay, is a bay in the island of Vieques famous for its bioluminescence produced by the dinoflagellate Pyrodinium bahamense, which glows blue when agitated. This species of phytoplankton is found in bays in the Virgin Islands, Puerto Rico and The Bahamas. | 1 | Bioluminescence |
The GLIC receptor is a bacterial (loeobacter) igand-gated on hannel, homolog to the nicotinic acetylcholine receptors. It is a proton-gated (the channel opens when it binds a proton, ion), cation-selective channel (it selectively lets the positive ions through). Like the nicotinic acetylcholine receptors is a functional pentameric oligomer (the channel normally works as an assembly of five subunits). However while its eukaryotic homologues are hetero-oligomeric (assembled from different subunits), all until now known bacteria known to express LICs encode a single monomeric unit, indicating the GLIC to be functionally homo-oligomeric (assembled from identical subunits).
The similarity of amino-acid sequence to the eukaryotic LGICs is not localized to any single or particular tertiary domain, indicating the similar function of the GLIC to its eukaryotic equivalents. Regardless, the purpose of regulating the threshold for action potential excitation in the nerve signal transmission of multicellular organisms cannot translate to single-cell organisms, thereby not making the purpose of bacterial LGICs immediately obvious. | 0 | Neurochemistry |
The induction of NMDA receptor-dependent long-term potentiation (LTP) in chemical synapses in the brain occurs via a fairly straightforward mechanism. A substantial and rapid rise in calcium ion concentration inside the postsynaptic cell (or more specifically, within the dendritic spine) is most possibly all that is required to induce LTP. But the mechanism of calcium delivery to the postsynaptic cell in inducing LTP is more complicated. | 0 | Neurochemistry |
The photocytes present in Amphipholis squamata have been found to contain a golgi apparatus and rough endoplasmic reticulum. They have also been found to contain up to six different kinds of vesicles within their cytoplasm. | 1 | Bioluminescence |
The Tulkun is a whale-like creature native to Pandoras ocean. They are similar to Earths whales and possess a form of sentience with their own language, laws, and philosophy which makes them capable of bonding with Navi in a more spiritual way than other animals. Each member of the Metkayina Clan forms a life-long bond with a tulkun as a spirit brother/sister. Once violent creatures who continually warred with one another, they are now completely pacifistic, refusing to kill even to defend themselves. As such they banish those who commit violence. They are introduced in Avatar: The Way of Water, in which humans have begun hunting them to harvest their brain enzymes for creating anti-aging remedies called amrita. Jake Sullys son, Lo'ak, bonds with an outcast tulkun named Payakan after he is banished for killing the whalers who killed his mother. | 1 | Bioluminescence |
In its anionic form, the green chromophore has an absorption maxima at 506 nm and an emission maxima at 516 nm. It is formed autocatalytically from amino acids His-62, Tyr-63 and Gly-64. Immediately surrounding the chromophore there is a cluster of charged or polar amino acids as well as structural water molecules. Above the plane of the chromophore, there is a network of hydrogen bond interactions between Glu-144, His-194, Glu-212 and Gln-38. Arg-66 and Arg-91 participate in hydrogen bonding with the carbonyl oxygen of green Eos's imidazolinone moiety. The His-62 side chain lies in an unpolar environment. Conversion from the green to red form depends on the presence of a histidine in the first position of the tripeptide HYG that forms the chromophore. When this histidine residue is substituted with M, S, T or L, Eos only emits bright green light and no longer acts as a photoconvertible fluorescent protein. | 1 | Bioluminescence |
In laboratory experiments, activation of cannabinoid receptors had an effect on the activation of GTPases in macrophages, neutrophils, and bone marrow cells. These receptors have also been implicated in the migration of B cells into the marginal zone and the regulation of IgM levels. | 0 | Neurochemistry |
The great leonopteryx (Toruk in Navi, meaning last shadow) is the apex airborne predator native to Pandora. It is scientifically known as Leonopteryx rex, meaning "king lion-wing". The fierce beauty and nobility of the leonopteryx gave the species a place central to Navi lore and culture. The leonopteryx is scarlet with black stripes and a midnight blue crest on top of the head and on the lower jaw. It is celebrated in dance and song; elaborate totems symbolize both the fear and respect accorded to the creature. The leonopteryx is considered crucial to the Navi sense of destiny and interconnectedness. Prior to the events of the film, it had only been tamed five times, and Neytiri tells Jake that the riders (Toruk Makto) brought peace among the Pandoran tribes. This makes Jake the sixth Toruk Makto. He manages to capture one by jumping on it from above from his banshee but releases it after the battle with the humans has ended. The great leonopteryx and the banshee were designed with bright colors. Page based the colors on Earths birds, poison dart frogs, and monarch butterflies, though he altered the patterns so that their inspirations would not be so conspicuous to moviegoers. The skull and crest shapes appear to be derived from pterosaurs from the genus Tapejara. | 1 | Bioluminescence |
The Akula is a Dunkleosteus like creature. They have 3 sets of jaws and is the apex predator of the Pandoran ocean. They are introduced in Avatar: The Way of Water, where Jakes son Loak fights of one after he is stranded in the ocean, before being saved by Payakan. | 1 | Bioluminescence |
The Glowing Plant project was the first crowdfunding campaign for a synthetic biology application. The project was started by the Sunnyvale-based hackerspace Biocurious as part of the DIYbio philosophy. According to the projects goals, funds were used to create a glowing Arabidopsis thaliana' plant using firefly luminescence genes. Long-term ambitions (never realized) included the development of glowing trees that can be used to replace street lights, reducing CO emissions by not requiring electricity. | 1 | Bioluminescence |
An autoluminograph is a photograph produced by placing a light emitting object directly on a piece of film. A famous example is an autoluminograph published in Science magazine in 1986 of a glowing transgenic tobacco plant bearing the luciferase gene of fireflies placed on Kodak Ektachrome 200 film. | 1 | Bioluminescence |
GFP has a beta barrel structure consisting of eleven β-strands with a pleated sheet arrangement, with an alpha helix containing the covalently bonded chromophore 4-(p-hydroxybenzylidene)imidazolidin-5-one (HBI) running through the center. Five shorter alpha helices form caps on the ends of the structure. The beta barrel structure is a nearly perfect cylinder, 42Å long and 24Å in diameter (some studies have reported a diameter of 30Å), creating what is referred to as a "β-can" formation, which is unique to the GFP-like family. HBI, the spontaneously modified form of the tripeptide Ser65–Tyr66–Gly67, is nonfluorescent in the absence of the properly folded GFP scaffold and exists mainly in the un-ionized phenol form in wtGFP. Inward-facing sidechains of the barrel induce specific cyclization reactions in Ser65–Tyr66–Gly67 that induce ionization of HBI to the phenolate form and chromophore formation. This process of post-translational modification is referred to as maturation. The hydrogen-bonding network and electron-stacking interactions with these sidechains influence the color, intensity and photostability of GFP and its numerous derivatives. The tightly packed nature of the barrel excludes solvent molecules, protecting the chromophore fluorescence from quenching by water. In addition to the auto-cyclization of the Ser65-Tyr66-Gly67, a 1,2-dehydrogenation reaction occurs at the Tyr66 residue. Besides the three residues that form the chromophore, residues such as Gln94, Arg96, His148, Thr203, and Glu222 all act as stabilizers. The residues of Gln94, Arg96, and His148 are able to stabilize by delocalizing the chromophore charge. Arg96 is the most important stabilizing residue due to the fact that it prompts the necessary structural realignments that are necessary from the HBI ring to occur. Any mutation to the Arg96 residue would result in a decrease in the development rate of the chromophore because proper electrostatic and steric interactions would be lost. Tyr66 is the recipient of hydrogen bonds and does not ionize in order to produce favorable electrostatics. | 1 | Bioluminescence |
The endocannabinoid system (ECS) is a biological system composed of endocannabinoids, which are endogenous lipid-based retrograde neurotransmitters that bind to cannabinoid receptors, and cannabinoid receptor proteins that are expressed throughout the vertebrate central nervous system (including the brain) and peripheral nervous system. The endocannabinoid system remains under preliminary research, but may be involved in regulating physiological and cognitive processes, including fertility, pregnancy, pre- and postnatal development, various activity of immune system, appetite, pain-sensation, mood, and memory, and in mediating the pharmacological effects of cannabis. The ECS plays an important role in multiple aspects of neural functions, including the control of movement and motor coordination, learning and memory, emotion and motivation, addictive-like behavior and pain modulation, among others.
Two primary cannabinoid receptors have been identified: CB1, first cloned (or isolated) in 1990; and CB2, cloned in 1993. CB1 receptors are found predominantly in the brain and nervous system, as well as in peripheral organs and tissues, and are the main molecular target of the endogenous partial agonist, anandamide, as well as exogenous tetrahydrocannabinol, the most known active component of cannabis. Endocannabinoid 2-arachidonoylglycerol (2-AG), which was found to be two and three orders of magnitude more abundant in mammalian brain than anandamide, acts as a full agonist at both CB receptors.
The endocannabinoid system is sometimes referred to as the endocannabinoidome or expanded endocannabinoid system. | 0 | Neurochemistry |
Muscarinic acetylcholine receptors, or mAChRs, are acetylcholine receptors that form G protein-coupled receptor complexes in the cell membranes of certain neurons and other cells. They play several roles, including acting as the main end-receptor stimulated by acetylcholine released from postganglionic fibers in the parasympathetic nervous system.
Muscarinic receptors are so named because they are more sensitive to muscarine than to nicotine. Their counterparts are nicotinic acetylcholine receptors (nAChRs), receptor ion channels that are also important in the autonomic nervous system. Many drugs and other substances (for example pilocarpine and scopolamine) manipulate these two distinct receptors by acting as selective agonists or antagonists. | 0 | Neurochemistry |
Neuroproteomics is the study of the protein complexes and species that make up the nervous system. These proteins interact to make the neurons connect in such a way to create the intricacies that nervous system is known for. Neuroproteomics is a complex field that has a long way to go in terms of profiling the entire neuronal proteome. It is a relatively recent field that has many applications in therapy and science.
So far, only small subsets of the neuronal proteome have been mapped, and then only when applied to the proteins involved in the synapse. | 0 | Neurochemistry |
Due to the special property of photo-switchable fluorescence, Kaede protein possesses several advantages as an optical cell marker.
After the photoconversion, the photoconverted Kaede protein emits bright and stable red fluorescence. This fluorescence can last for months without anaerobic conditions. As this red state of Kaede is bright and stable compared to the green state, and because the unconverted green Kaede emits very low intensity of red fluorescence, the red signals provides contrast.
Besides, before the photoconversion, Kaede emits bright green fluorescence which enables the visualization of the localization of the non-photoacivated protein. This is superior to other fluorescent proteins such as PA-GFP and KFP1, which only show low fluorescence before photoactivation.
In addition, as both green and red fluorescence of Kaede are excited by blue light at 480 nm for observation, this light will not induce photoconversion. Therefore, illumination lights for observation and photoconversion can be separated completely. | 1 | Bioluminescence |
The broad scope of the available raw neuronal proteins to map requires that initial studies be focused on small areas of the neurons. When taking samples, there are a few places that interest neurologists most. The most important place to start for neurologists is the plasma membrane. This is where most of the communication between neurons takes place. The proteins being mapped here include ion channels, neurotransmitter receptors, and molecule transporters. Along the plasma membrane, the proteins involved in creating cholesterol-rich lipid rafts are being studied because they have been shown to be crucial for glutamate uptake during the initial stages of neuron formation. As mentioned before, vesicle proteins are also being studied closely because they are involved in disease.
Collecting samples to study, however, requires special consideration to ensure that the reproducibility of the samples is not compromised. When taking a global sample of one area of the brain for example, proteins that are ubiquitous and relatively unimportant show up very clear in the SDS PAGE. Other unexplored, more specific proteins barely show up and are therefore ignored. It is usually necessary to divide up the plasma membrane proteome, for example, into subproteomes characterized by specific function. This allows these more specific classes of peptides to show up more clearly. In a way, dividing into subproteomes is simply applying a magnifying lens to a specific section of a global proteome’s SDS PAGE map. This method seems to be most effective when applied to each cellular organelle separately. Mitochondrial proteins, for example, which are more effective at transporting electrons across its membrane, can be specifically targeted effectively in order to match their electron-transporting ability to their amino acid sequence. | 0 | Neurochemistry |
The great austrapede (Tsawltsping in Navi) is a bipedal, flightless, bird-like creature resembling the emu, ostrich, or the extinct Phorusrhacids that live in Pandoran savannah, and can be tamed and ridden as a mount by certain Navi clans. It has dark grey skin with blue-grey striping on its body and yellow markings on its wings, which it uses for threat displays and the long-clawed fingers at the ends for hunting and battling rivals. Great austrapedes stand slightly taller than their genetic cousin, the austrapede, and is a far more imposing creature overall. They first appear in the musical Toruk – The First Flight. | 1 | Bioluminescence |
Methods for estimating the degree of neuromuscular block include valuation of muscular response to stimuli from surface electrodes, such as in the train-of-four test, wherein four such stimuli are given in rapid succession. With no neuromuscular blockade, the resultant muscle contractions are of equal strength, but gradually decrease in case of neuromuscular blockade. It is recommended during use of continuous-infusion neuromuscular blocking agents in intensive care. | 0 | Neurochemistry |
The dopamine or dopaminergic system consists of several pathways, originating from the ventral tegmentum or substantia nigra as examples. It acts on dopamine receptors.
Parkinson's disease is at least in part related to dropping out of dopaminergic cells in deep-brain nuclei, primarily the melanin-pigmented neurons in the substantia nigra but secondarily the noradrenergic neurons of the locus coeruleus. Treatments potentiating the effect of dopamine precursors have been proposed and effected, with moderate success. | 0 | Neurochemistry |
The Skimwing ("Tsurak" in Navi) is a large Flying Fish like creature. They are primarily ridden by the Metkayina Clan in place of Banshee into battle. They do not form long-term bonds like the Mountain Banshee. They are first introduced in Avatar: The Way of Water', where Jake Sully tames one for battle. | 1 | Bioluminescence |
The woodsprite (Atokirina in Navi) is an animal, also called seed, of the "holy tree", appearing similar to airborne jellyfish. Neytiri describes them as very pure spirits, and slaps Jake for shooing two of them away. The Omaticaya Clan plants one of these seeds on the body of a deceased Navi, so the Navis consciousness will become part of Eywa. | 1 | Bioluminescence |
All SK channels can be pharmacologically blocked by quaternary ammonium salts of a plant-derived neurotoxin bicuculline. In addition, SK channels (SK1-SK3) but not SK4 (IK) are sensitive to blockade by the bee toxin apamin, and the scorpion venoms tamapin and charybdotoxin (ChTx), all via competitive antagonism for access to the mouth of the pore formation. All known blockers compete for roughly the same binding site, the pore, in all subtypes. This provides a physical blockage to the channel pore. Since all blockers are universal to all three types of SK channels, there is an incredibly narrow therapeutic window that does not allow for blocking of a specific SK channel subtype. Quaternary ammonium salts like bicuculline and tetraethylammonium (TEA) enter the pore via the selectivity filter by acting as a potassium mimic in the dehydration step of pore permeation.
The following molecules are other toxins and organic compounds that also inhibit all three small SK channel subtypes to any (even minimal) degree:
*Dequalinium
*d-Tubocurarine
*UCL-1684
*UCL-1848
*Cyproheptadine
*Fluoxetine, the active ingredient in Prozac
*NS8593
*Scyllatoxin (Leiurotoxin-I)
*Lei-Dab7
*N-methyl-laudanosine
*N-Me-bicuculline
*Pancuronium
*Atracurium
*1-ethyl-1H-benzo[d]imidazol-2(3H)-on
*6,7-dichloro-3-(hydroxyimino)indolin-2-one
*N-cyclohexyl-2-(3,5-dimethyl-1H-pyrazol-1-yl)-6-methylpyrimidin-4-amine
*(R)-N-(1,2,3,4-tetrahydronaphthalen-1-yl)-1H-benzo[d]imidazol-2-amine | 0 | Neurochemistry |
Amyloid precursor protein has been shown to interact with:
* APBA1,
* APBA2,
* APBA3,
* APBB1,
* APPBP1,
* APPBP2,
* BCAP31,
* BLMH
* CLSTN1,
* CAV1,
* COL25A1,
* FBLN1,
* GSN,
* HSD17B10, and
* SHC1.
APP interacts with reelin, a protein implicated in a number of brain disorders, including Alzheimer's disease. | 0 | Neurochemistry |
HCN channel was first identified in 1976 in the heart by Noma and Irisawa and characterized by Brown, Difrancesco and Weiss | 0 | Neurochemistry |
In chronobiology, an ultradian rhythm is a recurrent period or cycle repeated throughout a 24-hour day. In contrast, circadian rhythms complete one cycle daily, while infradian rhythms such as the menstrual cycle have periods longer than a day. The Oxford English Dictionarys definition of Ultradian' specifies that it refers to cycles with a period shorter than a day but longer than an hour.
The descriptive term ultradian is used in sleep research in reference to the 90–120 minute cycling of the sleep stages during human sleep.
There is a circasemidian rhythm in body temperature and cognitive function which is technically ultradian. However, this appears to be the first harmonic of the circadian rhythm of each and not an endogenous rhythm with its own rhythm generator.
Other ultradian rhythms include blood circulation, blinking, pulse, hormonal secretions such as growth hormone, heart rate, thermoregulation, micturition, bowel activity, nostril dilation, appetite, and arousal. Ultradian rhythms of appetite require antiphasic release of neuropeptide Y (NPY) and corticotropin-releasing hormone (CRH), stimulating and inhibiting appetite ultradian rhythms. Recently, ultradian rhythms of arousal lasting approximately 4 hours were attributed to the dopaminergic system in mammals. When the dopaminergic system is perturbed either by use of drugs or by genetic disruption, these 4-hour rhythms can lengthen significantly into the infradian (> 24 h) range, sometimes even lasting for days (> 110 h) when methamphetamine are provided.
According to a study published in 1996: Ultradian mood states in bipolar disorder cycle much faster than rapid cycling; the latter is defined as four or more mood episodes in one year, sometimes occurring within a few weeks. Ultradian mood cycling is characterized by cycles shorter than 24 hours. | 0 | Neurochemistry |
Luciferase can function in two different pathways: a bioluminescence pathway and a CoA-ligase pathway. In both pathways, luciferase initially catalyzes an adenylation reaction with MgATP. However, in the CoA-ligase pathway, CoA can displace AMP to form luciferyl CoA.
Fatty acyl-CoA synthetase similarly activates fatty acids with ATP, followed by displacement of AMP with CoA. Because of their similar activities, luciferase is able to replace fatty acyl-CoA synthetase and convert long-chain fatty acids into fatty-acyl CoA for beta oxidation. | 1 | Bioluminescence |
Phylogenetic analyses performed by Zhang et al. (2020) suggest that the luciferses of the Lampyridae, Rhagopthalmidae, and Phenogodidae families diverged from the Elateridae family 205 Mya. According to phylogenetic data, the emergences of these two luciferases appeared even before the families could diverge– indicating their analogous nature due phenotypic convergences. | 1 | Bioluminescence |
The NMDA receptor (NMDAR) does not, in resting or near-resting membrane potential conditions, contribute significant current to the EPSP. Following the presynaptic release of the glutamate that binds to and opens the AMPAR, the NMDAR also binds this glutamate and opens. However, current does not flow through the NMDAR ion channel because it is instantaneously blocked by a magnesium ion (Mg) that binds to a site "inside" the open pore of the NMDAR channel. Magnesium has access to this binding site only when the NMDAR channel is opened by glutamate binding, a so-called open channel block. | 0 | Neurochemistry |
Although the native biological role of APP is of obvious interest to Alzheimers research, thorough understanding has remained elusive. Experimental models of Alzheimers disease are commonly used by researchers to gain better understandings about the biological function of APP in disease pathology and progression. | 0 | Neurochemistry |
Administration of neuromuscular blocking agents (NMBA) during anesthesia can facilitate endotracheal intubation. This can decrease the incidence of postintubation hoarseness and airway injury.
Short-acting neuromuscular blocking agents are chosen for endotracheal intubation for short procedures (< 30minutes), and neuromonitoring is required soon after intubation. Options include succinylcholine, rocuronium or vecuronium if sugammadex is available for rapid reversal block.
Any short or intermediate acting neuromuscular blocking agents can be applied for endotracheal intubation for long procedures (≥ 30 minutes). Options include succinylcholine, rocuronium, vecuronium, mivacurium, atracurium and cisatracurium. The choice among these NMBA depends on availability, cost and patient parameters that affect drug metabolism.
Intraoperative relaxation can be maintained as necessary with additional dose of nondepolarizing NMBA.
Among all NMBA, Succinylcholine establish the most stable and fastest intubating conditions, thus is considered as the preferred NMBA for rapid sequence induction and intubation (RSII). Alternatives for succinylcholine for RSII include high dose rocuronium (1.2mg/kg which is a 4 X ED95 dose), or avoidance of NMBAs with a high dose remifentanil intubation. | 0 | Neurochemistry |
The biosynthesis of BC200 RNA occurs at the cell body of a neuron and requires upstream promoter elements, downstream internal promoter elements (intragenic A and B boxes), at least two transcription factor binding sites, a TATA-like sequence, TATA-box binding protein (TBP), and RNA polymerase III.
There is a deletion of sequences between -100 and -1 in the DNA that blocks transcription activity, revealing that the transcription complex must interact with this 100-bp sequence of the upstream region for proper synthesis of BC200 RNA. The TATA-box binding protein (TBP) binds here, and when inhibited, BC200 RNA levels decrease, indicating that the 100 base pair region and TBP are critical players in the biosynthesis of BC200 RNA.
In addition to upstream elements, there is an upstream TATGAAA sequence (similar to TATA box sequence) at positions -28 to -22 which, when deleted, compromises transcription, revealing this TATA-like sequence as another critical player in the synthesis of BC200 RNA. However, transcription is not dependent on the TATA-box binding protein binding to the TATA-like sequence.
Both upstream and internal promoter elements are also essential for BC200 RNA synthesis. There are two types of upstream promoter elements in the 100 base pair region: one proximal to the transcription start site and associated with downstream transcription factor binding sites, and the other between nucleotides -36 and -100 and not associated with downstream binding sites. The internal promoter elements are intragenic A and B boxes with A located at position +5 to +15 and B located at position +78 to +88. Any mutation in these boxes can result in a decrease of BC200 RNA.
Because BC200 RNA acts as a translational regulator, it is then transported to the dendrites to bind to specific proteins involved in translation and inhibit their activity (see next section). | 0 | Neurochemistry |
Coelenterazine is a luciferin, a molecule that emits light after reaction with oxygen, found in many aquatic organisms across eight phyla. It is the substrate of many luciferases such as Renilla reniformis luciferase (Rluc), Gaussia luciferase (Gluc), and photoproteins, including aequorin, and obelin. All these proteins catalyze the oxidation of this substance, a reaction catalogued EC 1.13.12.5. | 1 | Bioluminescence |
p75NTR is a type I transmembrane protein, with a molecular weight of 75 kDa, determined by glycosylation through both N- and O-linkages in the extracellular domain.
It consists of an extracellular domain, a transmembrane domain and an intracellular domain. The extracellular domain consists of a stalk domain connecting the transmembrane domain and four cysteine-rich repeat domains, CRD1, CRD2, CRD3, and CRD4; which are negatively charged, a property that facilitates Neurotrophin binding. The intracellular part is a global-like domain, known as a death domain, which consists of two sets of perpendicular helixes arranged in sets of three. It connects the transmembrane domain through a flexible linker region N-terminal domain. It is important to say that, in contrast to the type I death domain found in other TNFR proteins, the type II intracellular death domain of p75NTR does nor self-associated. This was an early indication that p75NTR does nor signal death through the same mechanism as the TNFR death domains, although the ability of the p75NTR death domain to activate other second messengers is conserved.
The p75ECD-binding interface to NT-3 can be divided into three main contact sites, two in the case of NGF, that are stabilized by hydrophobic interactions, salt bridges, and hydrogen bonds. The junction regions between CDR1 and CDR2 form the site 1 that contains five hydrogen bonds and one salt bridge. Site 2 is formed by equal contributions from CDR3 and CRD4 and involves two salt bridges and two hydrogen bonds. Site 3, in the CRD4, includes only one salt bridge. | 0 | Neurochemistry |
Light production in Photurius pennsylvanica (Photuris pennsylvanica) larvae occurs in the roughly 2,000 photocytes located in the heavily innervated light organ of the insect which is much simpler than that of the adult organism. The transparent photocytes of the larvae are clearly distinguishable from the opaque dorsal layer cells that cover them. Nervous and intracellular mechanisms contribute to light production in the photocytes. Nervous and intracellular mechanisms contribute to light production in the photocytes.It has been shown that fireflies can modify the amount of oxygen that travels through their trachea system to the light organ which plays a role in oxygen availability for light production. They do this by modifying the amount of fluid present within the trachea system. Because oxygen diffuses more slowly through water than in a gaseous form, this allows fireflies to effectively change the amount of oxygen reaching the photocytes. Spiracles can be opened and closed to control the amount of air that is able to pass through the tracheal system, but this control mechanism is only used as a response to a stressor. | 1 | Bioluminescence |
D-luciferin is the substrate for firefly luciferases bioluminescence reaction, while L-luciferin is the substrate for luciferyl-CoA synthetase activity. Both reactions are inhibited by the substrates enantiomer: L-luciferin and D-luciferin inhibit the bioluminescence pathway and the CoA-ligase pathway, respectively. This shows that luciferase can differentiate between the isomers of the luciferin structure.
L-luciferin is able to emit a weak light even though it is a competitive inhibitor of D-luciferin and the bioluminescence pathway. Light is emitted because the CoA synthesis pathway can be converted to the bioluminescence reaction by hydrolyzing the final product via an esterase back to D-luciferin.
Luciferase activity is additionally inhibited by oxyluciferin and allosterically activated by ATP. When ATP binds to the enzymes two allosteric sites, luciferases affinity to bind ATP in its active site increases. | 1 | Bioluminescence |
Meanwhile, geneticists and molecular biologists have characterised five genes that appear to encode muscarinic receptors, named m1-m5 (lowercase m; no subscript number). They code for pharmacologic types M-M. The receptors m1 and m2 were determined based upon partial sequencing of M and M receptor proteins. The others were found by searching for homology, using bioinformatic techniques. | 0 | Neurochemistry |
ACh is always used as the neurotransmitter within the autonomic ganglion. Nicotinic receptors on the postganglionic neuron are responsible for the initial fast depolarization (Fast EPSP) of that neuron. As a consequence of this, nicotinic receptors are often cited as the receptor on the postganglionic neurons at the ganglion. However, the subsequent hyperpolarization (IPSP) and slow depolarization (Slow EPSP) that represent the recovery of the postganglionic neuron from stimulation are actually mediated by muscarinic receptors, types M and M respectively (discussed below).
Peripheral autonomic fibers (sympathetic and parasympathetic fibers) are categorized anatomically as either preganglionic or postganglionic fibers, then further generalized as either adrenergic fibers, releasing noradrenaline, or cholinergic fibers, both releasing acetylcholine and expressing acetylcholine receptors. Both preganglionic sympathetic fibers and preganglionic parasympathetic fibers are cholinergic. Most postganglionic sympathetic fibers are adrenergic: their neurotransmitter is norepinephrine except postganglionic sympathetic fibers to the sweat glands, piloerectile muscles of the body hairs, and the skeletal muscle arterioles do not use adrenaline/noradrenaline.
The adrenal medulla is considered a sympathetic ganglion and, like other sympathetic ganglia, is supplied by cholinergic preganglionic sympathetic fibers: acetylcholine is the neurotransmitter utilized at this synapse. The chromaffin cells of the adrenal medulla act as "modified neurons", releasing adrenaline and noradrenaline into the bloodstream as hormones instead of as neurotransmitters. The other postganglionic fibers of the peripheral autonomic system belong to the parasympathetic division; all are cholinergic fibers, and use acetylcholine as the neurotransmitter. | 0 | Neurochemistry |
The BC200 RNA is the product of an unprocessed monomeric Alu sequence. It is 200 nucleotides long and non-translatable.
BC200 has three distinct structural domains. The 5 region of the RNA defines one domain and consists of Alu repeat elements. The other two structural domains are a central A-rich region, and a C-rich 3 region specific to BC200. The 5 end of this molecule has both primary and secondary structure that is very similar to 7SL RNA, a signal recognition particle RNA (SRP) which also includes a 5 Alu domain.
The BC200 RNA gene has two pseudogenes: BC200 beta and BC200 gamma. These two pseudogenes each have a single gene in the genome, located on separate chromosomes. The beta pseudogene is composed of a BC200 RNA gene and additional Alu sequences. The gamma pseudogene contains an inverted long interspersed nuclear element (LINE). They both have transpositional ability, but the exact mechanism is unknown. | 0 | Neurochemistry |
The Cys-loop ligand-gated ion channel superfamily is composed of nicotinic acetylcholine, GABA, GABA-ρ, glycine, 5-HT, and zinc-activated (ZAC) receptors. These receptors are composed of five protein subunits which form a pentameric arrangement around a central pore. There are usually 2 alpha subunits and 3 other beta, gamma, or delta subunits (some consist of 5 alpha subunits).
The name of the family refers to a characteristic loop formed by 13 highly conserved amino acids between two cysteine (Cys) residues, which form a disulfide bond near the N-terminal extracellular domain.
Cys-loop receptors are known only in eukaryotes, but are part of a larger family of pentameric ligand-gated ion channels. Only the Cys-loop clade includes the pair of bridging cysteine residues. The larger superfamily includes bacterial (e.g. GLIC) as well as non-Cys-loop eukaryotic receptors, and is referred to as "pentameric ligand-gated ion channels", or "Pro-loop receptors".
All subunits consist of a large conserved extracellular N-terminal domain, three highly conserved transmembrane domains, a cytoplasmic loop of variable size and amino acid sequence, and a fourth transmembrane region with a relatively short and variable extracellular C-terminal domain.
Neurotransmitters bind at the interface between subunits in the extracellular domain.
Each subunit contains four membrane-spanning alpha helices (M1, M2, M3, M4). The pore is formed primarily by the M2 helices. The M3-M4 linker is the intracellular domain that binds the cytoskeleton. | 0 | Neurochemistry |
Apamin is the smallest neurotoxin polypeptide known, and the only one that passes the blood-brain barrier. Apamin thus reaches its target organ, the central nervous system. Here it inhibits small-conductance Ca-activated K channels (SK channels) in neurons. These channels are responsible for the afterhyperpolarizations that follow action potentials, and therefore regulate the repetitive firing frequency.
Three different types of SK channels show different characteristics. Only SK2 and SK3 are blocked by apamin, whereas SK1 is apamin insensitive. SK channels function as a tetramer of subunits. Heteromers have intermediate sensitivity. SK channels are activated by the binding of intracellular Ca to the protein calmodulin, which is constitutively associated to the channel. Transport of potassium ions out of the cell along their concentration gradient causes the membrane potential to become more negative. The SK channels are present in a wide range of excitable and non-excitable cells, including cells in the central nervous system, intestinal myocytes, endothelial cells, and hepatocytes.
Binding of apamin to SK channels is mediated by amino acids in the pore region as well as extracellular amino acids of the SK channel. It is likely that the inhibition of SK channels is caused by blocking of the pore region, which hinders the transport of potassium ions. This will increase the neuronal excitability and lower the threshold for generating an action potential. Other toxins that block SK channels are tamapin and scyllatoxin. | 0 | Neurochemistry |
The endocannabinoid transporters (eCBTs) are transport proteins for the endocannabinoids. Most neurotransmitters are water-soluble and require transmembrane proteins to transport them across the cell membrane. The endocannabinoids (anandamide, AEA, and 2-arachidonoylglycerol, 2-AG) on the other hand, are non-charged lipids that readily cross lipid membranes. However, since the endocannabinoids are water immiscible, protein transporters have been described that act as carriers to solubilize and transport the endocannabinoids through the aqueous cytoplasm. These include the heat shock proteins (Hsp70s) and fatty acid-binding proteins for anandamide (FABPs). FABPs such as FABP1, FABP3, FABP5, and FABP7 have been shown to bind endocannabinoids. FABP inhibitors attenuate the breakdown of anandamide by the enzyme fatty acid amide hydrolase (FAAH) in cell culture. One of these inhibitors (SB-FI-26), isolated from a virtual library of a million compounds, belongs to a class of compounds (named the "truxilloids') that act as an anti-nociceptive agent with mild anti-inflammatory activity in mice. These truxillic acids and their derivatives have been known to have anti-inflammatory and anti-nociceptive effects in mice and are active components of a Chinese herbal medicine ((−)-Incarvillateine Incarvillea sinensis) used to treat rheumatism and pain in human. The blockade of anandamide transport may, at least in part, be the mechanism through which these compounds exert their anti-nociceptive effects.
Studies have found the involvement of cholesterol in membrane uptake and transport of anandamide. Cholesterol stimulates both the insertion of anandamide into synthetic lipid monolayers and bilayers, and its transport across bilayer membranes, suggest that besides putative anandamide protein-transporters, cholesterol could be an important component of the anandamide transport machinery, and as cholesterol-dependent modulation of CB1 cannabinoid receptors in nerve cells. The catalytic efficiency (i.e., the ratio between maximal velocity and Michaelis–Menten constant) of the AEA membrane transporter (AMT) is almost doubled compared with control cells, demonstrate that, among the proteins of the “endocannabinoid system,” only CB1 and AMT critically depend on membrane cholesterol content, an observation that may have important implications for the role of CB1 in protecting nerve cells against (endo)cannabinoid-induced apoptosis. This can be a reason, why the use of drugs to lower cholesterol is tied to a higher depression risk, and the correlation between levels and increased death rates from suicide and other violent causes.
Activation of CB1 enhances AMT activity through increased nitric oxide synthase (NOS) activity and subsequent increase of NO production, whereas AMT activity instead is reduced by activation of the CB2 cannabinoid receptor, which inhibits NOS and NO release, also suggesting the distribution of these receptors may drive AEA directional transport through the blood–brain barrier and other endothelial cells.
As reviewed in 2016; "Many of the AMT (EMT) proposals have fallen by the wayside." To date a transmembrane protein transporter has not been identified. | 0 | Neurochemistry |
Research has shown that applying 5 to 15 volts of electricity for 50 ms to the segmental nerve that innervates the light organ leads to a glow 1.5 seconds after that lasts for five to ten seconds. Stimulation of the segmental nerve has been found to lead to several different nerve impulses, and frequency of nervous impulses has been found to be proportional to the intensity of the stimulus applied. A high frequency of nervous impulse was found to lead to a constant latency. The light organ is inactive in the absence of nerve impulses. Constant nerve signaling was shown to coincide with constant emission of light from the light organ with a higher frequency coinciding with a higher amplitude of light emitted up to 30 impulses per second. Impulses beyond this frequency were not found to be associated with a more intense glow. The fact that the frequency of nerve impulses was able to exceed beyond the maximum intensity of light emission suggests some limitations in the mechanism either arising from the synapse or the cell's light producing process. Additionally, a series of action potentials have been shown to lead to the sporadic, discontinuous emission to light. It was also found that a higher frequency of action potentials lead to a higher likelihood of any emission of light. Nerve impulses are associated with a depolarization of the photocyte which plays a role in its light emitting mechanism, and greater depolarization events were found to be associated with more intense lightning. The nerve innervating the light organ containing photocytes has only two axons, but they branch repeatedly allowing the numerous photocytes to be innervated with each cell being associated with several nerve terminals with each terminal possibly being associated with several synapses.
It was found that the junction between at the end of the neuron innervating the light organ differs from the kind of junction found between two different neurons or between neurons and muscles in the neuromuscular junction. The depolarization of the photocyte following nervous stimulation was found to be one-hundred times slower than the with the other two kinds of junctions and this slow response cannot be attributed to the rate of diffusion because the synapse between the neuron and photocyte is relatively small. It has been found that the neurons that control the light mechanism terminate at the tracheal cells rather than the photocytes themselves. | 1 | Bioluminescence |
Adenosinergic means "working on adenosine".
An adenosinergic agent (or drug) is a chemical which functions to directly modulate the adenosine system in the body or brain. Examples include adenosine receptor agonists, adenosine receptor antagonists (such as caffeine), and adenosine reuptake inhibitors. | 0 | Neurochemistry |
Many different fusion proteins have been created using EosFP and its engineered variants. These fusion proteins allow for the tracking of proteins within living cells while retaining complex biological functions like protein-protein interactions and protein-DNA interactions. Eos fusion constructs include those with recombination signal-binding protein (RBP) and cytokeratin. Studies have shown that it is favourable to attach the protein of interest to the N-terminal side of the EosFP label. These fusion constructs have been used to visualize nuclear translocation with androgen receptors, dynamics of the cytoskeleton with actin and vinculin and intranuclear protein movement with RBP. | 1 | Bioluminescence |
Neuromuscular blocking agents need to fit in a space close to 2 nanometres, which resembles the molecular length of decamethonium. Some molecules of decamethonium congeners may bind only to one receptive site. Flexible molecules have a greater chance of fitting receptive sites. However, the most populated conformation may not be the best-fitted one. Very flexible molecules are, in fact, weak neuromuscular inhibitors with flat dose-response curves. On the other hand, stiff or rigid molecules tend to fit well or not at all. If the lowest-energy conformation fits, the compound has high potency because there is a great concentration of molecules close to the lowest-energy conformation. Molecules can be thin but yet rigid. Decamethonium for example needs relatively high energy to change the N-N distance.
In general, molecular rigidity contributes to potency, while size affects whether a muscle relaxant shows a polarizing or a depolarizing effect. Cations must be able to flow through the trans-membrane tube of the ion-channel to depolarize the endplate. Small molecules may be rigid and potent but unable to occupy or block the area between the receptive sites. Large molecules, on the other hand, may bind to both receptive sites and hinder depolarizing cations independent of whether the ion-channel is open or closed below. Having a lipophilic surface pointed towards the synapse enhances this effect by repelling cations. The importance of this effect varies between different muscle relaxants and classifying depolarizing from non-depolarizing blocks is a complex issue. The onium heads are usually kept small and the chains connecting the heads usually keep the N-N distance at 10 N or O atoms. Keeping the distance in mind the structure of the chain can vary (double bonded, cyclohexyl, benzyl, etc.)
Succinylcholine has a 10-atom distance between its N atoms, like decamethonium. Yet it has been reported that it takes two molecules, as with acetylcholine, to open one nicotinic ion channel. The conformational explanation for this is that each acetylcholine moiety of succinylcholine prefers the gauche (bent, cis) state. The attraction between the N and O atoms is greater than the onium head repulsion. In this most populated state, the N-N distance is shorter than the optimal distance of ten carbon atoms and too short to occupy both receptive sites. This similarity between succinyl- and acetyl-choline also explains its acetylcholine-like side-effects.
Comparing molecular lengths, the pachycurares dimethyltubocurarine and d-tubocurarine both are very rigid and measure close to 1.8 nm in total length. Pancuronium and vecuronium measure 1.9 nm, whereas pipecuronium is 2.1 nm. The potency of these compounds follows the same rank of order as their length. Likewise, the leptocurares prefer a similar length. Decamethonium, which measures 2 nm, is the most potent in its category, whereas C11 is slightly too long. Gallamine despite having low bulk and rigidity is the most potent in its class, and it measures 1.9 nm. Based on this information one can conclude that the optimum length for neuromuscular blocking agents, depolarizing or not, should be 2 to 2.1 nm.
The CAR for long-chain bisquaternary tetrahydroisoquinolines like atracurium, cisatracurium, mivacurium, and doxacurium is hard to determine because of their bulky onium heads and large number of rotatable bonds and groups. These agents must follow the same receptive topology as others, which means that they do not fit between the receptive sites without bending. Mivacurium for example has a molecular length of 3.6 nm when stretched out, far from the 2 to 2.1 nm optimum. Mivacurium, atracurium, and doxacurium have greater N-N distance and molecular length than d-tubocurarine even when bent. To make them fit, they have flexible connections that give their onium heads a chance to position themselves beneficially. This bent N-N scenario probably does not apply to laudexium and decamethylene bisatropium, which prefer a straight conformation. | 0 | Neurochemistry |
An ionotropic effect is the effect of a transmitter substance or hormone that activates or deactivates ionotropic receptors (ligand-gated ion channels). The effect can be either positive or negative, specifically a depolarization or a hyperpolarization respectively. This term is commonly confused with an inotropic effect, which refers to a change in the force of contraction (e.g. in heart muscle) produced by transmitter substances or hormones. | 0 | Neurochemistry |
Some drugs enhance or inhibit the response to NMBAs which require the dosage adjustment guided by monitoring. | 0 | Neurochemistry |
Bacterial luciferin is two-component system consisting of flavin mononucleotide and a fatty aldehyde found in bioluminescent bacteria. | 1 | Bioluminescence |
SK channels are expressed throughout the central nervous system. They are highly conserved in mammals as well as in other organisms such as Drosophila melanogaster and Caenorhabditis elegans. SK channels are specifically involved in the medium afterhyperpolarizing potential (mAHP). They affect both the intrinsic excitability of neurons and synaptic transmission. They are also involved in calcium signaling. SK channel activation can mediate neuroprotection in various models of cell death. SK channels control action potential discharge frequency in hippocampal neurons, midbrain dopaminergic neurons, dorsal vagal neurons, sympathetic neurons, nucleus reticularis thalamic neurons, inferior olive neurons, spinal and hypoglossal motoneurons, mitral cells in the olfactory bulb, and cortical neurons. | 0 | Neurochemistry |
A neuromuscular non-depolarizing agent is a form of neuromuscular blocker that does not depolarize the motor end plate.
The quaternary ammonium muscle relaxants belong to this class. Quaternary ammonium muscle relaxants are quaternary ammonium salts used as drugs for muscle relaxation, most commonly in anesthesia. It is necessary to prevent spontaneous movement of muscle during surgical operations. Muscle relaxants inhibit neuron transmission to muscle by blocking the nicotinic acetylcholine receptor. What they have in common, and is necessary for their effect, is the structural presence of quaternary ammonium groups, usually two. Some of them are found in nature and others are synthesized molecules.
Below are some more common agents that act as competitive antagonists against acetylcholine at the site of postsynaptic acetylcholine receptors.
Tubocurarine, found in curare of the South American plant Pareira, Chondrodendron tomentosum, is the prototypical non-depolarizing neuromuscular blocker. It has a slow onset (>5 min) and a long duration of action (30 mins). Side-effects include hypotension, which is partially explained by its effect of increasing histamine release, a vasodilator, as well as its effect of blocking autonomic ganglia. It is excreted in the urine.
This drug needs to block about 70–80% of the ACh receptors for neuromuscular conduction to fail, and hence for effective blockade to occur. At this stage, end-plate potentials (EPPs) can still be detected, but are too small to reach the threshold potential needed for activation of muscle fiber contraction.
The speed of onset depends on the potency of the drug, greater potency is associated with slower onset of block. Rocuronium, with an ED of 0.3 mg/kg IV has a more rapid onset than Vecuronium with an ED of 0.05mg/kg. Steroidal compounds, such as rocuronium and vecuronium, are intermediate-acting drugs while Pancuronium and pipecuronium are long-acting drugs.
In larger clinical dose, some of the blocking agent can access the pore of the ion channel and cause blockage. This weakens neuromuscular transmission and diminishes the effect of acetylcholinesterase inhibitors (e.g. neostigmine). Nondepolarizing NBAs may also block prejunctional sodium channels which interfere with the mobilization of acetylcholine at the nerve ending. | 0 | Neurochemistry |
The photocytes of Renilla köllikeri were found to have a diameter of eight to ten micrometers. The mitochondria of the photocytes were found to be very large with abnormally organized cristae surrounding the nucleus of the cell. The rough endoplasmic reticulum of the photocytes were found to exist close to the cell membrane. Several small vesicles, on the order of 0.25 micrometers, were found in the cell, and differently shaped granules containing diverse contents were also observed. | 1 | Bioluminescence |
All bioluminescent bacteria share a common gene sequence: the lux operon characterized by the luxCDABE gene organization. LuxAB codes for luciferase while luxCDE codes for a fatty-acid reductase complex that is responsible for synthesizing aldehydes for the bioluminescent reaction. Despite this common gene organization, variations, such as the presence of other lux genes, can be observed among species. Based on similarities in gene content and organization, the lux operon can be organized into the following four distinct types: the Aliivibrio/Shewanella type, the Photobacterium type, theVibrio/Candidatus Photodesmus type, and the Photorhabdus type. While this organization follows the genera classification level for members of Vibrionaceae (Aliivibrio, Photobacterium, and Vibrio), its evolutionary history is not known.
With the exception of the Photorhabdus operon type, all variants of the lux operon contain the flavin reductase-encoding luxG gene. Most of the Aliivibrio/Shewanella type operons contain additional luxI/luxR regulatory genes that are used for autoinduction during quorum sensing. The Photobacterum operon type is characterized by the presence of rib genes that code for riboflavin, and forms the lux-rib operon. TheVibrio/Candidatus Photodesmus operon type differs from both the Aliivibrio/Shewanella and the Photobacterium operon types in that the operon has no regulatory genes directly associated with it. | 1 | Bioluminescence |
A variety of organisms regulate their light production using different luciferases in a variety of light-emitting reactions. The majority of studied luciferases have been found in animals, including fireflies, and many marine animals such as copepods, jellyfish, and the sea pansy. However, luciferases have been studied in luminous fungi, like the Jack-O-Lantern mushroom, as well as examples in other kingdoms including bioluminescent bacteria, and dinoflagellates. | 1 | Bioluminescence |
A melatonergic agent (or drug) is a chemical which functions to directly modulate the melatonin system in the body or brain. Examples include melatonin receptor agonists and melatonin receptor antagonists. | 0 | Neurochemistry |
Neuromodulators may alter the output of a physiological system by acting on the associated inputs (for instance, central pattern generators). However, modeling work suggests that this alone is insufficient, because the neuromuscular transformation from neural input to muscular output may be tuned for particular ranges of input. Stern et al. (2007) suggest that neuromodulators must act not only on the input system but must change the transformation itself to produce the proper contractions of muscles as output. | 0 | Neurochemistry |
Bioluminescence imaging (BLI) is a technology developed over the past decades (1990's and onward). that allows for the noninvasive study of ongoing biological processes Recently, bioluminescence tomography (BLT) has become possible and several systems have become commercially available. In 2011, PerkinElmer acquired one of the most popular lines of optical imaging systems with bioluminescence from Caliper Life Sciences. | 1 | Bioluminescence |