The behavioral experiments using a passive avoidance learning model showed that the new cognition-enhancing acyl-prolyn containing dipeptide GVS-111 promotes recovery of the test performance in animals with a long-term memory deficit caused by the M-cholinolytic scopolamine (1 mg/kg/day scopolamine for 20 days, followed by 0.5 mg/kg/day GVS-111 for 10 days). At the same time, GVS-111 increased the duration of tremor induced by the M-cholinomimetic arecoline. The results of electrophysicological experiments showed that GVS-111 in a concentration range from 10(-11) to 10(-9) M increased amplitude of the neural response to acetylcholine (Ach) microappications in 75% of the isolated neurons of Helix Pomatum and produced a predominantly facilitating effect upon the endoneuronal pacemaker activity. The effect of GVS-111 upon the Ach response in a part of neurons was attenuated or even blocked by scopolamine, and in the other neurons--by the N-cholinolytic d-tubocurarine. This fact indicates that both muscarinic and nicotinic receptors are involved in the mechanism of the cholino-sensitizing action of GVS-111 upon the neuronal activity.