[Effect of destruction of the amygdaloid complex on the cardiac and motor components of a conditioned defense reaction].

The effect of bilateral ablation of the amygdala complex basolateral part on heart and motor components of conditioned defensive reaction was studied in chronic experiments on rats. After 10 presentations of the tone during habituation procedure the elaboration of conditioned reaction in operated and control animals was achieved in one session (10 pairings of the tone with electrical pain stimulation in a minute). The analysis of the changes in the heart rate of amygdalectomized rats immediately after the elaboration revealed a shorter time of retention of the heart rate tachycardiac changes elicited by aversive stimulation. In tests one hour and 24 hours after the elaboration, the operated animals showed no conditioned bradycardiac reaction to the tone. This fact suggests a severe impairment of the conditioned emotional reaction of fear. The absence of the emotional component of the conditioned reaction seems to result in the disturbance of reproduction of its motor component.