Look up: GABA receptor

1. GABA receptor
   Member of a family of receptors for neurotransmitters that includes those for glycine and the nicotinic acetylcholine receptor. Opened by g -amino butyric acid (GABA). There are two main classes; GABA A and GABAC receptors are ionotropic, GABAB receptor is metabotropic. 1. GABAA receptor (ca 250 kD) is a ligand-gated chloride channel specifically blocked by bicuculline and picrotoxin, a hetero-oligomer with (probably) five subunits, generally two pairs of a and b subunits and a g subunit, but there are multiple isoform and splicing variants of these and some additional tissue-specific isoforms. The a chains (53 kD) are needed for binding of benzodiazepine, though the site is probably shared with the g subunit, and the bchains (58 kD) bind GABA. The subunits are thought to form a tight group with the chloride channel in the centre. There is considerable protein sequence similarity between GABAA receptor and the nicotinic acetylcholine receptor. Properties of the receptor can be modified by phosphorylation. Insect GABA receptor resemble vertebrate GABAA but do not bind bicuculline and have significantly different pharmacological profiles. 2. The GABAB receptor (80 kD) is a G-protein-coupled receptor found in the brain and differs from the GABAA receptor both in agonist specificity (baclofenis a specific agonist) and its effects on cells. It is negatively coupled to adenylate cyclase through a G o-protein and thus acts indirectly on N-type calcium channels. Inhibitory effects mediated through this receptor are due to a reduction in catecholamine release. Has sequence similarity with metabotropic glutamate receptors. 3. The GABAC receptor resembles GABAA but is restricted to the retina.
   Found on http://www.encyclo.co.uk/visitor-contrib
   
   
2. GABA receptor
   Synonym for gamma aminobutyric acid receptor ... <physiology> Ligand gated chloride ion channel forming receptor opened by gamma aminobutyric acid. Two distinct types: A and B. ... A receptor: One of a family of neurotransmitter receptors with fast intrinsic ion channels that includes the glyc...
   Found on http://www.mondofacto.com/facts/dictiona
   
   
3. GABAA receptor
   The `GABA<sub>A</sub> receptor` (`GABA<sub>A</sub>R`) is an ionotropic receptor and ligand-gated ion channel. Its endogenous ligand is γ-aminobutyric acid (GABA), the major inhibitory neurotransmitter in the central nervous system. Upon activation, the GABA_A receptor ...
   Found on http://en.wikipedia.org/wiki/GABAA_recep
   
   
4. GABAA-rho receptor
   The `GABA<sub>A</sub>-rho receptor` (previously known as the `GABA<sub>C</sub> receptor`) is a subclass of GABA_A receptors composed entirely of rho (ρ) subunits. GABA_A receptors including those of the ρ-subclass are ligand-gated ion channels respon...
   Found on http://en.wikipedia.org/wiki/GABAA-rho_r
   
   
5. GABAB receptor
   `GABA<sub>B</sub> receptors` (GABA_BR) are metabotropic transmembrane receptors for gamma-aminobutyric acid (GABA) that are linked via G-proteins to doi=10.1016/j.brainresbull.2005.07.004-->--> These receptors are found in the central and peripheral autonomic nervous system.<...
   Found on http://en.wikipedia.org/wiki/GABAB_recep