Pharmacological restoration of scopolamine-impaired memory.

In training for passive avoidance using a device of the step-down type, the nootropic agents piracetam (60 mg/kg orally) and centrophenoxine (100 mg/kg, i. p.) do not facilitate learning, while the ergot alkaloid elymoclavine (1 mg/kg, i. p.) tends to have a positive effect on learning and memory. The muscarine cholinergic receptor blocker scopolamine (2 mg/kg, i. p.) substantially deteriorates short-term memory in passive avoidance training. Piracetam in a dose of 600 mg/kg does not change the negative effect of scopolamine on the memory, while centrophenoxine (100 mg/kg) and elymoclavine (1 mg/kg) eliminate it in view of the fact that the impairment of the short-term memory in the reported experiments was induced by the cholinolytic agent scopolamine, it should be assumed that the observed effects of piracetam, centrophenoxine and elymoclavine are due to definite interactions between the cerebral cholinergic and monoaminergic mechanisms.