GABA types

Lewis DA, Cho RY, Carter CS, Eklund K, Forster S, et al. 2008. Subunit-selective modulation of GABA type A receptor neurotransmission and cognition in schizophrenia. Am J Psychiatry 165 1585-1593. 

Holden-Dye, L., Krogsgaard-Larsen, P., Neilsen, L. and Walker, R. J. (1989) GABA receptors on the somatic muscle cells of the parasitic nematode, Ascaris suum stereoselectivity indicates similarity to a GABA -type agonist recognition site. Br. J. Pharmacol. 98 841-850. 

GABAergic (releases y-aminobutric acid) GABA type B (GABAb) ... 

Alcohol and benzodiazepines produce synergistic central depression, probably via separate activity on the y-aminobutyric acid (GABA) type A receptor. 

GABAAy2 GABA type-A receptor subunit y2, GADglutamic acid decarboxylase, rGATvesicular GABA transporter, vG/ t2vesicular glutamate transporter 2... 

Synaptic vesicles isolated from brain exhibit four distinct vesicular neurotransmitter transport activities one for monoamines, a second for acetylcholine, a third for the inhibitory neurotransmitters GABA and glycine, and a fourth for glutamate [1], Unlike Na+-dependent plasma membrane transporters, the vesicular activities couple to a proton electrochemical gradient (A. lh+) across the vesicle membrane generated by the vacuolar H+-ATPase ( vacuolar type proton translocating ATPase). Although all of the vesicular transport systems rely on ApH+, the relative dependence on the chemical and electrical components varies (Fig. 1). The... 

By far the most important amino acids are the a-amino acids, in which the —NH2 group is attached to the carbon atom next to the carboxyl group, as in glycine. However, other types of amino acids are common and play an important biological role. For instance, the y-amino acid NH2CH2CH2CH2COOH is the neurotransmitter GABA. 

Expression studies in Xenopus oocytes or transfected cell lines originally suggested that functional GABA-activated chloride channels could be formed by receptor subunits of each class in isolation. However, much better expression occurs with two or more subunit types in combination and it is likely that most native receptors contain at least three different subunits. Co-expression of a and /I subunits results in the assembly of... 

Introduced initially for absence seizures, this drug is now known to be effective in and used to treat tonic lonic seizures and most types of epilepsy. It was found to inhibit GABA transaminase and so elevate GABA concentrations and inhibition. This is achieved, however, over a slower time-course than its anti-seizure effect, especially experimentally, which is now thought to be due to its phenytoin-like, use-dependent block of sodium channels. Since, unlike phenytoin, the full effect of valproate takes some weeks to develop, its slower effect on GABA metabolism and activity should not be ignored. 

---