Action of gamma-hydroxybutyrate and GABA on neurones of cultured rat central nervous system.

gamma-Hydroxybutyrate (GHB) and GABA caused a hyperpolarization of cultured spinal, brainstem and cerebellar neurones. When KCl electrodes were used, the hyperpolarizations were reversed to depolarizations, suggesting that the actions of GHB and GABA are associated with an increase in conductance for chloride ions. Both the hyperpolarizations and depolarizations by these compounds were accompanied by an increase in membrane conductance and were reversibly blocked by the GABA antagonist bicuculline. It is suggested that GHB might either exert its effects by mimicking the action of GABA, or act as neurotransmitter or neuromodulator in the mammalian CNS.