NICOTINE ENHANCES MORRIS WATER MAZE PERFORMANCE OF YOUNG AND AGED RATS

We have recently demonstrated that nicotine administration improves th e acquisition and/or memory retention of aged rats in 17-arm radial ma ze, Lashley III maze, and one-way active avoidance testing. The presen t study extends our evaluation of nicotine's cognition-enhancing poten tial by determining the effect of nicotine on acquisition and retentio n of the Morris water maze in young adult (2 to 3 months old) and aged (25 to 26 months old) Sprague-Dawley rats. For 3 days prior to the on set of testing, and 15 min prior to daily testing, rats were treated I P with 0.2 mg/kg nicotine or saline vehicle. Compared to the performan ce of young adults, vehicle-treated aged rats were impaired in water m aze acquisition. Nicotine substantially enhanced the acquisition of ag ed rats. Furthermore, nicotine significantly improved the memory reten tion of young adult rats. These cognitive improvements may involve a n icotine-receptor induced increase in generalized alertness and/or a fa cilitation of higher integrative function. The results suggest that ni cotine and/or nicotinic agonists may be useful in treating age-associa ted memory impairment and/or Alzheimer's disease.