Trichloroethanol impairs NMDA receptor function in rat mesencephalic and cortical neurones

The effects of 2,2,2-trichloroethanol, the active compound of the sedative- hypnotic chloral hydrate, were investigated on N-methyl-D-aspartate (NMDA)- induced increases in intracellular Ca2+ concentration ([Ca2+](i)) in cultur ed mesencephalic and cortical neurones by means of the fura-2 method. Trich loroethanol inhibited the NMDA response in a concentration-dependent manner in cortical (IC50 = 2.76 mM) and mesencephalic neurones (IC50 = 1.12 mM), with a maximum effect of approximately 85 and 94 %, respectively. Ethanol w as considerably less potent than trichloroethanol. In conclusion, the trich loroethanol-induced impairment of NMDA receptor function may contribute to the sedative-hypnotic properties of chloral hydrate. (C) 1999 Elsevier Scie nce B.V. All rights reserved.