GABA (A) receptors are ligand-gated chloride channels that play a role as inhibitory neurotransmitters. They are known targets for certain classes of environmental and pharmaceutical compounds because a number of drugs interact with binding sites on GABA (A). Some of these drugs include benzodiazepines, anticonvulsants, and anesthetics. GABA (A) Receptors are comprised of subunits and these are further classified into 3 major groups (alpha, beta, and gamma). The subunits determine the pharmacological characteristics.