A DIENCEPHALIC MECHANISM FOR THE EXPRESSION OF RAGE WITH SPECIAL REFERENCE TO THE SYMPATHETIC NERVOUS SYSTEM

Abstract

Almost immediately after removal of the cerebral cortex in cats there develops spontaneously, or as the result of the slightest disturbance, a remarkable group of activities such as are commonly regarded as expressive of anger. This behavior closely resembles that of the infuriated normal animal; it is best described as a sham rage. It includes struggling, clawing, snarling, biting, tail lashing, erection of hair, sweating, widening of eyes and pupils, with retraction of nictitating membranes and large increments in arterial pressure and heart rate. This investigation was directed toward the delimitation of the subcortical region responsible for the sham rage. The method used was that of ablation of varying portions of the brain stern after decortication. In a total of 52 acute experiments it was found that the typical decorticate rage regularly developed after removal of all parts of the brain cranial to the middle of the diencephalon; it also developed after ablation of hemispheres, corpora striata and the dorsal parts of the diencephalon, but it invariably failed to appear after transactions which separated the diencephalon from the midbrain. From this it is concluded that the expression of anger in the cat is dependent upon central mechanisms located in the ventral and caudal parts of the lower half of the dien-cephalon. The intense and widespread sympathetic discharge so characteristic of strong emotional excitement is a prominent and invariable feature of the sham rage. The relation of the diencephalon to the sympathetic nervous system is discussed in the light of this and other work, and the view is advanced that the dien-cephalic representation of the sympathetic consists of a dominant central mechanism which is responsible for the widespread sympathetic discharge which occurs under conditions of stress (anger, fear, exposure to cold).