The effects of nicotine on learning and memory: A neuropsychological assessment in young and senescent Fischer 344 rats

The effects of chronic nicotine on the behavioral performance of young (4 month) and old (24 month) Fischer-344 rats were assessed on four behavioral tasks: activity chamber, rotating rod, serial pattern learning, and Morris water maze paradigm. Old and young nicotine-treated rats received an intraperitoneal injection of nicotine (0.20 mg/kg) 15 min prior to all behavioral testing, and old and young saline-treated rats received saline injections 15 min prior to all behavioral testing. Nicotine improved motor coordination and increased the general activity levels of the old rats compared to old saline-treated rats. There were no significant differences in the behaviors of the young rats in these behavioral evaluations. In young rats, nicotine improved the acquisition of a serial pattern, suggesting an improvement in working memory or related processes. Nicotine was found to increase swim speed in a Morris water maze paradigm with a hidden platform; however, no beneficial effects of nicotine in reference memory were obtained for either age group. These results suggests that nicotine may not be as beneficial in attenuating age-related learning and memory deficits as once proposed. (C) 1999 Elsevier Science Inc.