Neurotransmitter receptor

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Figure 1. The seven transmembrane α-helix structure of a G-protein-coupled receptor.
Figure 1. The seven transmembrane α-helix structure of a G-protein-coupled receptor.

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]]
5-Hydroxytryptamine (5-HT)

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

[edit] Notes and references

  1. ^ ed. Kebabain, J. W. & Neumeyer, J. L. (1994). "RBI Handbook of Receptor Classification"

[edit] External links


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