NITROOXY ALKYL APOVINCAMINATE MODULATES GABA(A) RECEPTOR IN RAT NEOCORTICAL NEURONS

WE investigated the effects of VA-045 ((+)-eburnamenine-14 carboxylic acid (2-nitroxyethyl) ester) on GABA(A) receptor-mediated Cl- currents in dissociated rat cerebral cortical neurones, using a nystatin-perfo rated patch recording configuration. At a holding potential of - 40 mV , the external application of GABA evoked an inward Cl- current with a n EC(50) value of 5.6 x 10(-6)M. VA-045 increased the GABA response at GABA concentrations below 3.0 x 10(-6)M. The GABA response showed a t ime dependent decay consisting of fast and slow components and VA-045 significantly accelerated both components. The site of action for VA-0 45 was considered to be different from that for benzodiazepines or bar biturates.