EFFECTS OF NICOTINE ON ACTIVE-AVOIDANCE LEARNING IN RATS - SEX-DIFFERENCES

Nicotine, a cognition enhancer and a drug of abuse, exerts its central actions through neuronal nicotinic acetylcholine receptors which show sexual dimorphism. This study tested the effects of nicotine on activ e avoidance learning in male and female rats. Three month-old Sprague- Dawley rats received varying doses of nicotine (0.2, 0.4 and 0.6 mg/kg ) or saline s.c. before active avoidance learning trials (15 trials/da y) for a period of 5 days. Behavioural testing was continued after the termination of nicotine treatment once a week for four weeks. Nicotin e improved acquisition of active avoidance learning in a dose-dependen t manner. fn male rats nicotine was active at all doses tested whereas , in females, learning performance deteriorated at a dose of 0.6 mg/kg . In conclusion, nicotine pre-treatment affects active avoidance in a sexually dimorphic and dose-dependent manner.