ISRADIPINE BLOCKS COCAINE ABILITY TO FACILITATE PRESSING FOR INTRACRANIAL STIMULATION

Using rats pressing for rewarding electrical intracranial stimulation of the medial forebrain bundle, it was found that a single administrat ion of isradipine blocked the rate-enhancing effects of cocaine (5.0 m g/kg) at doses of 3.0 and 10.0 mg/kg. Also, when isradipine (3.0 mg/kg ) was administered alone (without cocaine) for 5 consecutive days, pre ssing for intracranial stimulation was not reduced relative to placebo levels. In another experiment, isradipine (3.0 mg/kg) persistently bl ocked the rate-enhancing effects of cocaine (5.0 mg/kg) across 5 conse cutive days. These results support the continued investigation of isra dipine as a useful adjunct to other treatments for cocaine addiction. (C) 1997 Elsevier Science Inc.