CURRENTS EVOKED BY GABA AND GLYCINE IN ACUTELY DISSOCIATED NEURONS FROM THE RAT MEDIAL PREOPTIC NUCLEUS

The responses of acutely dissociated medial preoptic neurons to applic ation of GABA and glycine were studied using the perforated-patch whol e-cell recording technique under voltage-clamp conditions. GABA, at a concentration of 1 mM, evoked outward currents in all cells (n = 33) w hen studied at potentials positive to -80 mV. The I-V relation was rou ghly linear. The currents evoked by GABA were partially blocked by 25- 75 mu M picrotoxin and were also partially or completely blocked by 10 0-200 mu M bicuculline. Glycine, at a concentration of 1 mM, did also evoke outward currents in all cells (n = 12) when studied at potential s positive to -75 mV. The I-V relation was roughly linear. The current s evoked by glycine were largely blocked by 1 mu M strychnine. In conc lusion, the present work demonstrates that neurons from the medial pre optic nucleus of rat directly respond to the inhibitory transmitters G ABA and glycine with currents that can be attributed to GABA(A) recept ors and glycine receptors respectively. (C) 1997 Elsevier Science B.V.