The GABA A receptor
GABA is the major inhibitory neurotransmitter in the central nervous system. The GABA A receptor is composed of five sub-units – two alpha, two beta and one gamma sub-unit. Two molecules of GABA activate the receptor by binding to the alpha sub-units. Once activated the receptor allows the passage of negatively charged ions into the cytoplasm, which results in hyperpolarization and the inhibition of neurotransmission.
Click the image to view high resolution version
References
Sedative-hypnotic drugs. In: Basic and clinical pharmacology, 8th edition. Katzung BG. USA: The McGraw Hill Companies, Inc, 2001:364–381.