[Effect of unilateral extirpation of the superior cervical sympathetic ganglion and electric stimulation of the posterior hypothalamus on the rate of reflex conditioning in the dog].

The influence of the sympathetic nervous system and the posterior hypothalamus on the rate of conditioning and the magnitude of conditioned reflexes was studied on dogs by motor defensive method. Extirpation of the superior cervical sympathetic ganglion reduced the conditioned reflex magnitude, delayed the elaboration of positive reflexes facilitating the formation of the inhibitory process. Stimulation of the posterior hypothalamus with electrical current of medium strength (50 mcA) promoted the enhancement of positive conditioned reflexes, and while not substantially affecting the rate of their formation, facilitated elaboration of internal inhibition.