Abstract

Binding of the neurosteroid dehydroepiandrosterone sulfate (DHEAS) to rat brain synaptosomal membranes was studied in vitro, and the interaction of DHEAS with the GABAA receptor was tested using biochemical and electrophysiological assays. DHEAS bound to two populations of sites, and its binding was inhibited by barbiturates. DHEAS interfered with barbiturate-mediated enhancement of benzodiazepine binding. In cultured neurons from ventral mesencephalon, DHEAS reversibly blocked GABA-induced currents, behaving as an allosteric antagonist of the GABAA receptor.