Behavioral effects of nimodipine in animals.

Neuro- and psychopharmacological effects of isopropyl-(2-methoxy-ethyl)-1,4-dihydro-2,6-dimethyl-4-(3-nitrophenyl)-3,5-pyridinedicarboxylate (Bay e 9736, nimodipine) are described using a variety of methods measuring behavior under normal conditions, under the influence of psychotropic drugs, as well as under the influence of ischemia or hypoxia. It has been demonstrated that nimodipine -- although not being very potent when measured in mg/kg -- exerts neuro- and psychopharmacological effects characterized by influences on the extrapyramidal system, aggressive defensive behavior, and chemically induced seizures. Electroencephalographical changes become evident whenever the normal equilibrium between cerebral catecholamine and cerebral serotonin levels is disturbed. When measured under the contingencies of a one trial passive avoidance paradigm, nimodipine is able to prevent the occurrence of retrograde amnesia in rodents after amnesiogenic events such as maximal electroconvulsive seizure or hypoxia. The substance prevents behavioral and electroencephalographic disturbances, elicited by a total cerebral ischemia, which is lethal in non-treated cats. It is concluded that nimodipine besides being a cerebrally vasoactive agent has psychopharmacological properties with a profile of actions hitherto unknown.