The time interval between administration ofetimizol (3 mg/kg) and the onset of learning varied between 0.5 and 3 h in the several series. Etimizol (Ethymisole) did not facilitate the learning in rats whatever the time of administration and biological modality of reinforcement [1]. After administration of Etimizol (Ethymisole) at doses of 10 or 1 mg/loop mean residence time of etimizol in the loop was 20.1 and 7.6 min, respectively, with mean standard deviation being 3.1 and 0.8, respectively [2]. Extracellular application of 5--10 mM/L Etimizol (Ethymisole) exerted a specific effect on the giant neurons of the Coretus corneus isolated nervous system: action potential duration increased significantly, speed of development of its descending phase decreased, as well as the trace hyperpolarization amplitude [3].