Chromaproline and Chromaperidine, nicotine agonists, and Donepezil, cholinesterase inhibitor, enhance performance of memory tasks in ovariectomized rats

Chromaproline and Chromaperidine, two recently synthesized and pharmacologically characterized nicotinic agonists, and Donepezil (Aricept), an acetylcholinesterase inhibitor approved for the treatment of memory loss, were evaluated for effects on performance of a visual recognition memory task (object recognition) and a spatial memory task (object placement). Ovariectomized female rats received the drugs chronically via subcutaneous Alzet minipumps. None of the drugs altered activity in the open field or the time spent exploring objects in the field. One week following initiation of treatment, all three drugs enhanced performance of the visual recognition task, but only Donepezil enhanced performance of the spatial memory task. With a longer period of treatment (3 weeks), the nicotinic agonist Chromaproline also enhanced object placement performance. Current results show the memory-enhancing efficacy of Donepezil in two additional memory tasks in rats and suggest that the novel nicotinic agonists, Chromaproline and Chromaperidine, may also be useful new drugs for the treatment of memory impairments/loss.