[Effect of damage to the substantia nigra on conditioned reflex activity in animals]

Effects of the Substantia nigra injury on conditioned activities were studied on rats and cats by defensive and feeding methods, respectively. Bilateral injury of the Substantia nigra led to temporary disappearance of conditioned defensive and feeding motor reflexes, to prolongation of latency and duration of motor reaction. In cats the injury of the Substantia nigra produced a 30--40% decrease of the accuracy of food direction choice. Similar changes were observed following injury of the Nucleus caudatus head.