Neurotransmitter receptor
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A neurotransmitter receptor is a receptor protein on the surface of a cell that binds to a specific ligand, or receptors on the surface of the postsynaptic cell[[1]], such as a neurotransmitter, receptor antagonist, biogenic amines, etc. with a wide range of differing reactions from the cell receiving the signal, triggering anything from activation to inhibition.One additional characteristic of neurotransmitter receptors is that they are subject to ligand-induced desensitization: That is, they can become unresponsive upon prolonged exposure to their neurotransmitter. Neurotransmitter receptors are present on both postsynaptic neurons and presynaptic neurons with the former being used to receive neurotransmitters and the latter for the purpose of preventing further release of a given neurotransmitter[2]. In addition to being found in neuron cells, neurotransmitter receptors are also found in various immune and muscle tissues[3]. Many neurotransmitter receptors are categorized as a serpentine receptor or G protein-coupled receptor because they span the cell membrane not once, but seven times. Neurotransmitter receptors are known to become unresponsive to the type of neurotransmitter they receive when exposed for extended periods of time. This phenomenon is known as ligand-induced desensitization[4] or downregulation.
Contents |
[edit] table1
Table of Neurotransmitters
Transmitter Molecule |
Derived From |
Site of Synthesis |
Acetylcholine[[5]] |
Choline |
CNS, parasympathetic nerves |
Serotonin[[6]] |
Tryptophan |
CNS, chromaffin cells of the gut, enteric cells |
GABA[[7]] |
Glutamate |
CNS |
Glutamate |
|
CNS |
Aspartate |
|
CNS |
Glycine |
|
spinal cord |
Histamine |
Histidine |
hypothalamus |
Epinephrine[[8]] synthesis pathway[[9]] |
Tyrosine |
adrenal medulla, some CNS cells |
Norpinephrine[[10]] synthesis pathway[[11]] |
Tyrosine |
CNS, sympathetic nerves |
Dopamine[[12]] synthesis pathway[[13]] |
Tyrosine |
CNS |
Adenosine |
ATP |
CNS, periperal nerves |
ATP |
|
sympathetic, sensory and enteric nerves |
Nitric oxide, NO[[14]] |
Arginine |
CNS, gastrointestinal tract |
[edit] Known Neurotransmitter Receptors (table2)[1]
α1A, α1b, α1c, α1d α2a, α2b, α2c, α2d β1, β2, β3
D1, D2, D3, D4, D5
GABAA, GABAB1a, GABAB1δ, GABAB2, GABAC
NMDA, AMPA kainate, mGluR1, mGluR2, mGluR3, mGluR4, mGluR5, mGluR6, mGluR7
H1, H2, H3
Muscarinic: M1, M2, M3, M4, M5 Nicotinic: muscle, neuronal (α-bungarotoxin-insensitive), neuronal (α-bungarotoxin-sensitive)
μ, δ1, δ2, κ
5-HT1A, 5-HT1B, 5-HT1D, 5-HT1E, 5-HT1F, 5-HT2A, 5-HT2B, 5-HT2C, 5-HT3, 5-HT4, 5-HT5, 5-HT6, 5-HT7
Glycine
[edit] See also
- Autoreceptor
- Receptor desensitization has been previously modeled in the context of a two-state mathematical model (see this link [15])
- Synaptic Transmission
- Neuromuscular transmission
- Catecholamines
- Cholinergic Agonists and Antagonists
[edit] Notes and references
- ^ ed. Kebabain, J. W. & Neumeyer, J. L. (1994). "RBI Handbook of Receptor Classification"