Nicotine improvement of Morris water task performance after fimbria-fornixlesion is blocked by mecamylamine

The focus of this study was to analyze the effects of nicotine on behaviour al compensation after fimbria-fornix (FF) lesions in rats tested on the Mor ris water task (MWT). Nicotine (0.3 mg/kg) was injected subcutaneously for 11 consecutive days before, for 11 consecutive days after, or for ii consec utive days before and after a FF lesion. Additionally, a lesion group was i ncluded that was given mecamylamine (1.0 mg/kg), a nicotine antagonist, 10 min before nicotine administration as well as mecamylamine-only, no treatme nt lesion, and sham groups. All drug administration ceased 24 h before thre e consecutive days of behavioural testing on the MWT. Results showed that t he sham group and animals receiving both a pre- and post-lesion treatment o f nicotine performed significantly better than all other groups, and the pr e- and post-lesion nicotine group performed equivalent to sham controls on both acquisition and a probe trial. The compensatory effect of nicotine was blocked by mecamylamine. This study demonstrates that nicotine stimulates recovery from brain damage and the results are discussed in relation to neu ral mechanisms and potential applications. (C) 2001 Published by Elsevier S cience B.V. All rights reserved.