Effect of hypothalamic lesions on the responses to cold and immobilization in the monkey.

Abstract

Monkeys with bilateral lesions in the rostral hypothalamus show a loss of the hyperglycemic response to immobilization but retain normal eosinopenic and lymphopenic reactions and granulocytosis. Monkeys with bilateral caudal lesions involving the medial and lateral structures show when immobilized, a complete loss of the hyperglycemic response, depressed eosinopenic and lymphopenic reactions and a normal granulocytosis. With lesions involving only the more medial structures of the premammillary area, the hyperglycemic response to immobilization is intact, and the blood cells reactions identical to that of the preceding group. These results suggest that the rostral hypothalamus belongs to a nervous circuit originating in the rhinencephalic structures and whose function is to activate epinephrine release from the suprarenal medulla during emotional reactions.