An acetylcholine receptor is an integral membrane protein that responds to the binding of acetylcholine, a neurotransmitter.
A neuromuscular junction is a chemical synapse between a motor neuron and a muscle fiber.
Nicotinic acetylcholine receptors, or nAChRs, are receptor polypeptides that respond to the neurotransmitter acetylcholine. Nicotinic receptors also respond to drugs such as the agonist nicotine. They are found in the central and peripheral nervous system, muscle, and many other tissues of many organisms. At the neuromuscular junction they are the primary receptor in muscle for motor nerve-muscle communication that controls muscle contraction. In the peripheral nervous system: (1) they transmit outgoing signals from the presynaptic to the postsynaptic cells within the sympathetic and parasympathetic nervous system, and (2) they are the receptors found on skeletal muscle that receive acetylcholine released to signal for muscular contraction. In the immune system, nAChRs regulate inflammatory processes and signal through distinct intracellular pathways. In insects, the cholinergic system is limited to the central nervous system.
Snake venom is a highly toxic saliva containing zootoxins that facilitates in the immobilization and digestion of prey. This also provides defense against threats. Snake venom is injected by unique fangs during a bite, whereas some species are also able to spit venom.
Jean-Pierre Changeux is a French neuroscientist known for his research in several fields of biology, from the structure and function of proteins, to the early development of the nervous system up to cognitive functions. Although being famous in biological sciences for the MWC model, the identification and purification of the nicotinic acetylcholine receptor and the theory of epigenesis by synapse selection are also notable scientific achievements. Changeux is known by the non-scientific public for his ideas regarding the connection between mind and physical brain. As put forth in his book, Conversations on Mind, Matter and Mathematics, Changeux strongly supports the view that the nervous system functions in a projective rather than reactive style and that interaction with the environment, rather than being instructive, results in the selection amongst a diversity of preexisting internal representations.
Azemiopinae is a monogeneric subfamily created for the genus Azemiops that contains the viper species A. feae and A. kharini. They are commonly known as Fea's vipers. No subspecies are recognized. The first specimen was collected by Italian explorer Leonardo Fea, and was described as a new genus and new species by Boulenger in 1888. Formerly considered to be one of the most primitive vipers, molecular studies have shown that it is the sister taxon to the pit vipers, Crotalinae. It is found in the mountains of Southeast Asia, in China, southeastern Tibet, and Vietnam. Like all other vipers, they are venomous.
α-Bungarotoxin is one of the bungarotoxins, components of the venom of the elapid Taiwanese banded krait snake. It is a type of α-neurotoxin, a neurotoxic protein that is known to bind competitively and in a relatively irreversible manner to the nicotinic acetylcholine receptor found at the neuromuscular junction, causing paralysis, respiratory failure, and death in the victim. It has also been shown to play an antagonistic role in the binding of the α7 nicotinic acetylcholine receptor in the brain, and as such has numerous applications in neuroscience research.
Bamboo snake may refer to:
The Bornean keeled green pit viper or North Philippine temple pit viper is a venomous pit viper species native to Brunei, Indonesia, Malaysia, and the Philippines. Until 2007, this species was considered part of the Tropidolaemus wagleri species complex.
A nicotinic agonist is a drug that mimics the action of acetylcholine (ACh) at nicotinic acetylcholine receptors (nAChRs). The nAChR is named for its affinity for nicotine.
Bungarotoxins are toxins found in the venom of snakes and kraits. Bites from these animals can result in severe symptoms including bleeding or hemorrhage, paralysis and tissue damage that can result in amputation. The paralytic effects of venom are particularly dangerous as they can impair breathing. These symptoms are the result of bungarotoxin presence in the venom. In actuality, venom contains several distinct bungarotoxins, each varying in which receptors they act on and how powerful they are.
α-Cobratoxin is a substance of the venom of certain Naja cobras. It is a nicotinic acetylcholine receptor (nAChR) antagonist which causes paralysis by preventing the binding of acetylcholine to the nAChR.
The muscle-type nicotinic receptor is a type of nicotinic acetylcholine receptor consisting of the subunit combination (α1)2β1δε (adult receptor) or (α1)2β1δγ (fetal receptor). These receptors are found in neuromuscular junctions, where activation leads to an excitatory postsynaptic potential (EPSP), mainly by increased Na+ and K+ permeability.
Acetylcholine receptor subunit epsilon is a protein that in humans is encoded by the CHRNE gene.
α-Neurotoxins are a group of neurotoxic peptides found in the venom of snakes in the families Elapidae and Hydrophiidae. They can cause paralysis, respiratory failure, and death. Members of the three-finger toxin protein family, they are antagonists of post-synaptic nicotinic acetylcholine receptors (nAChRs) in the neuromuscular synapse that bind competitively and irreversibly, preventing synaptic acetylcholine (ACh) from opening the ion channel. Over 100 α-neurotoxins have been identified and sequenced.
The alpha-3 beta-2 nicotinic receptor, also known as the α3β2 receptor, is a type of nicotinic acetylcholine receptor, consisting of α3 and β2 subunits.
κ-Bungarotoxin is a protein neurotoxin of the bungarotoxin family that is found in the venom of the many-banded krait, a snake found in Taiwan. κ-Bungarotoxin is a high affinity antagonist of nicotinic acetylcholine receptors (nAChRs), particularly of CHRNA3; it causes a post-synaptic blockade of neurotransmission. Although there is significant variability in the clinical effects of snake bites, neuromuscular paralysis and respiratory failure are associated with krait bites.
Three-finger toxins are a protein superfamily of small toxin proteins found in the venom of snakes. Three-finger toxins are in turn members of a larger superfamily of three-finger protein domains which includes non-toxic proteins that share a similar protein fold. The group is named for its common structure consisting of three beta strand loops connected to a central core containing four conserved disulfide bonds. The 3FP protein domain has no enzymatic activity and is typically between 60-74 amino acid residues long. Despite their conserved structure, three-finger toxin proteins have a wide range of pharmacological effects. Most members of the family are neurotoxins that act on cholinergic intercellular signaling; the alpha-neurotoxin family interacts with muscle nicotinic acetylcholine receptors (nAChRs), the kappa-bungarotoxin family with neuronal nAChRs, and muscarinic toxins with muscarinic acetylcholine receptors (mAChRs).
Azemiopsin, a toxin obtained from the Azemiops feae viper venom, is a polypeptide that consists of 21 amino acid residues. It does not contain cysteine residues or disulfide bridges. The polypeptide can block skeletal muscle contraction by blocking nicotinic acetylcholine receptors.
Crotoxin (CTX) is the main toxic compound in the snake venom of the South American rattlesnake, Crotalus durissus terrificus. Crotoxin is a heterodimeric beta-neurotoxin, composed of an acidic, non-toxic and non-enzymatic subunit (CA), and a basic, weakly toxic, phospholipase A2 protein (CB). This neurotoxin causes paralysis by both pre- and postsynaptic blocking of acetylcholine signalling.
