Effects of the novel compound NIK-247 on impairment of passive avoidance response in mice.

The effects of NIK-247 [9-amino-2,3,5,6,7,8-hexahydro-1H-cyclopenta(b)-quinoline monohydrate hydrochloride] were studied on a model involving various types of drug- and electroconvulsive shock (ECS)-induced amnesia. The step-down type passive avoidance task in mice was used for comparison of the effects with those of tacrine, a 4-aminopyridine derivative which has an antiamnesic action. NIK-247 administered pre- and post-training or pre-retention test (24 h after training) prevented the disruption of memory induced by cycloheximide administered immediately after training. In addition, NIK-247 protected from the amnesia induced by treatment with ECS, phencyclidine and picrotoxin immediately after training. Tacrine failed to protect from ECS- and PCP-induced amnesia at the doses effective on cycloheximide-induced amnesia. The results indicate that NIK-247 improves cognitive functions at different phases of the learning and memory processes such as acquisition, consolidation, and retrieval in drug- and ECS-induced amnesia. NIK-247 may produce its antiamnesic effects via the cholinergic and GABAergic neuronal systems.