Nicotine improves AF64A-induced spatial memory deficits in Morris water maze in rats

Ethylcholine mustard aziridinium ion (AF64A) is a neurotoxic derivative of choline that produces not only long-term presynaptic cholinergic deficits, but also various memory deficits in rats similar to some characteristics observed in Alzheimer's disease patients. This study investigated whether nicotine (NCT) administration attenuated spatial learning deficits induced by intracerebroventricular AF64A treatment. AF64A (6 nmol/6 μl)-or saline (SAL)-treated rats were trained in Morris water maze task. NCT (0.025-0.25 mg/kg) was subcutaneously injected 5 min before the training every day. The results showed that moderate dose (0.10 mg/kg) of NCT attenuated AF64A-induced prolongation of escape latency. Furthermore, NCT dose-dependently recovered the AF64A-induced decrease of time spent in the target quadrant in the probe test. These results suggest that NCT improves AF64A-induced spatial memory deficits, and thus it is a potential therapeutic agent for the treatment of memory deficits in dementia.