GABA neurons

Gamma-aminobutyric acid neurons (GABA)

GABA is synthesized by transforming glutamate into GABA via the glutamic acid decarboxylase enzyme. It is then stored in the axon for release. There are 2 different GABA receptors (A and B). The more common GABA-A is a ligand-gated chloride channel and the GABA-B is a G-protein linked receptor. These receptors can be further subtyped, but the functionality of the different subtypes

has yet to be made clear.

GABA produces its inhibitory response when it binds to the GABA-A receptor, causing a influx of chloride ion and decreasing the membrane potential further away from threshold (see graph). Several CNS-active drugs bind to this receptor and enhance GABA's binding effects.

The GABA-B receptor effects are much weaker than that of GABA-A.

1

There are relatively few GABA producing neurons, thus their influence is limited. 

2

GABA-A and -B receptors can be found in the membranes of serotonin, norepinephrine and dopamine neurons. 

3

GABA-B receptors increase the influx of calcium ions into the cell.