Ameliorative influence of a nootropic drug on motor activity of rats after bilateral carotid artery occlusion

The effects of the peptidergic nootropic drug Cerebrolysin(R) on spatial memory and motor activity were examined in intact and ischemic rats. Ischemic-hypoxic damage was induced by injection of Na-cyanide followed by bilateral occlusion of common carotid arteries. Immediately afterwards Cerebrolysin(R) or saline was administered, either by continous intraventricular (i.v.) infusion or by daily intraperitoneal (i.p.) injection. Rats were tested for spatial memory and motor activity in the Morris water maze on days 3 and 4 post-surgery. The best dose of the substance for i.p. administration was known from previous studies. Therefore we had to investigate the dose-response-relationship and tolerability of the drug after i.v. administration in intact rats. Infusion (i.v.) of a high dose of Cerebrolysin(R) (0.57 mg/day) decreased motor activity and spatial memory of intact rats (p < 0.01 and p < 0.05, respectively) but low dose of Cerebrolysin(R) was well tolerated in the intact animals. Ischemia led to deterioration of motor activity in control rats (p < 0.01). Cerebrolysin(R) significantly counteracted deleterious motor changes due to ischemia up to the level of intact controls after both i.v. infusion (0.0057mg/day) and daily i.p. drug administration (100 mg/kg bw and day) indicating an accelerating recovery after ischemia.