ENHANCEMENT OF HIPPOCAMPAL ACETYLCHOLINE-RELEASE BY THE NEUROSTEROID DEHYDROEPIANDROSTERONE-SULFATE - AN IN-VIVO MICRODIALYSIS STUDY

The effect of dehydroepiandrosterone sulfate (DHEAS) administered i.p. on the release of acetylcholine (ACh) from the hippocampus of anesthe tized rats was examined using in vivo microdialysis. DHEAS significant ly increased ACh release above the pre-treatment levels for all doses tested. The administration of 100 mg/kg significantly enhanced ACh rel ease greater than 4-fold when compared to the saline-treated group 80 min following drug administration. This study is the first to demonstr ate that the neurosteroid DHEAS, a negative allosteric modulator of th e GABA(A) receptor, can enhance the release of ACh from neurons in the hippocampus.