Facilitation of miniature GABAergic currents by chlorpromazine in culturedrat hippocampal cells

THE whole cell configuration of the patch clamp technique was used to study the effects of chlorpromazine (CPZ), a widely used antipsychotic drug, on miniature GABAA-mediated synaptic currents (mIPSCs) in hippocampal cells in culture. CPZ (10-30 mu M) induced a clear dose-dependent increase of mIPSC s frequency that was associated with a decrease in amplitude and with an ac celeration of their decay kinetics. When applied in a calcium-free medium, CPZ was less effective in enhancing mIPSCs frequency, suggesting that this effect was partially calcium dependent. While a low (10 mu M) CPZ concentra tion induced a 2-fold increase in the total charge transfer a higher (30 mu M) dose of this drug produced no changes, indicating that the presynaptic effect was counterbalanced by the postsynaptic one. NeuroReport 10:2251-225 4 (C) 1999 Lippincott Williams & Wilkins.