Chronic Administration of Donepezil in Inhibitory and Spatial Learning and Memory in Male Rats

Background: Cholinergic dysfunction is involved with age-related cognitive deficits and Alzheimer’s disease. Donepezil is a reversible acetylcholinesterase inhibitor. Objectives: The present study examined the ability of chronic supplementation with donepezil on the cognition of the healthy young rats. Materials and Methods: Twenty young male Wistar rats (140-160 g) were divided into the control and experimental groups. The rats received the oral administration of saline or 0.3 mg/kg of donepezil for 30 consecutive days. Then, they were trained and tested with Inhibitory Avoidance (IA) and 8-radial Arm Maze (RAM) tasks. Results: There was neither significant difference in the number of trials to acquisition in the IA nor the number of baited food arms in RAM tasks between the groups. In the IA retrieval test, the time spent in the dark compartment in the donepezil-treated group was significantly less than the saline-treated group. Also, in the RAM retrieval test, the number of total memory and working memory errors of donepezil-treated rats was significantly less than that of the saline-treated ones. Conclusion: The chronic administration of donepezil (0.3 mg/kg) had no significant effect on the learning process, but it can improve memory performance in normal rats.