POTENTIATION OF GABA-INDUCED INHIBITION BY 20-HYDROXYECDYSONE, A NEUROSTEROID, IN CULTURED RAT CORTICAL-NEURONS

Effects of 20-hydroxyecdysone (20-HE), a neurosteroid, on cultured rat cortical neurons were examined using the whole cell recording techniq ue. Under the voltage and current clamp conditions, brief application (5 sec) of 20-HE alone did not produce current changes nor any changes in the membrane potential. However, the chemical dose-dependently pot entiated the GABA-induced current and hyperpolarization, which were bl ocked by bicuculline. These results suggest that 20-HE acts on the mod ulatory site of the GABA, receptor and potentiates GABAergic inhibitio n in rat cortical neurons.