Nicotine impairs acquisition of radial maze performance in rats

The effects of nicotine (NIC) and scopolamine (SCOP) on radial maze acquisition were examined using an 8-arm radial maze. In Experiment 1, food-deprived Sprague-Dawley rats were trained to eat food pellets located at the ends of each arm of the radial maze without repeating arm choices. Both NIC (0.45 mg/kg, SC) and SCOP (0.25 mg/kg, IP) impaired acquisition when they were administered before, but not after the daily training sessions. Experiment 2 examined the effect of nicotine on working and reference memory in rats trained to a criterion of 3 correct choices out of the first 4 choices with only 4 of the 8 arms baited. NIC (0.1-0.45 mg/kg) had no effect on working memory (reentry into baited arms) or reference memory (entry into unbaited arms) errors. It is concluded that NIC impairs processes involved in the acquisition but not maintenance of radial maze performance. Neither NIC nor SCOP affects post-training consolidation processes.