A GABA(B) mystery: the search for pharmacologically distinct GABA(B) receptors.

The classification of neurotransmitter receptors into distinct pharmacological subtypes is of major importance in drug discovery. This quest is particularly important for neurotransmitter systems that are widely distributed. Because gamma-aminobutyric acid (GABA) receptors, both GABA(A) and GABA(B), are found throughout the neuroaxis, they are likely involved in all central nervous system functions. Accordingly, the therapeutic promise of GABA(B) receptor manipulation depends upon the identification of subtypes than can be specifically targeted.