Fig. 3. Novel object recognition test. Vehicle, ketamine, and L-NAME were injected intraperitoneally under warm environmental conditions (25°C) just after the second T1 on day 2. The histogram represents the mean ± SD of 10 rats per treatment group. (A ) Total motor activity. (B ) Total exploration time. (C ) Discrimination index D. *P < 0.05 versus all the other groups (except the ketamine plus L-NAME group, 10 mg/kg); +P < 0.05 versus all the other groups (except the ketamine plus vehicle group).