Authors: AnneMarie Levy Elena Choleris Francesco Leri
Publish Date: 2009/01/29
Volume: 204, Issue: 3, Pages: 413-
Abstract
Male Sprague–Dawley rats were tested on a social recognition learning task which assesses changes in investigation during repeated exposure to the same rat habituation training four sessions and during exposure to a novel rat dishabituation test In the first experiment rats received 0 03 or 1 mg/kg heroin sc immediately following each training session or 1 mg/kg heroin 2 h posttraining In experiments 2 and 3 rats received 1 mg/kg heroin posttraining after a 7day drugfree period from heroin preexposure achieved through conditioned place preference 1 mg/kg sc 1 injection/day × 4 days or intravenous selfadministration 005 mg/kg/infusion iv 3 h/day × 9 days training In experiment 4 rats received 0 003 03 or 3 mg/kg heroin posttraining after a 7day drugfree period from a regimen of heroin administration ie 1 mg/kg heroin/day sc × 7 days that induced locomotor sensitizationThese results do not support the hypothesis that heroin preexposure leads to sensitization to its effect on memory consolidation of nondrugrelated learning However this requires further testing using alternative heroin preexposure regimens a wider range of posttraining heroin doses as well as other types of learning tasksThis research was supported by a grant from the Natural Sciences and Engineering Research Council The authors wish to thank Dr Norman White for his valuable input on an earlier version of this manuscript and Ms Erin Cummins and Mr Derek Jacklin for their technical assistance
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