[Functional state of the positive reward system of the hypothalamus in arterial hypertension].

Effects of acute and chronic arterial hypertension on self-stimulation operant behaviour were studied in cats and rats. Small doses of noradrenaline facilitated the self-stimulation, whereas high doses depressed or stopped it. The depressive effect was accompanied by an obvious increase in the blood pressure. Chronic neurogenic hypertension can be induced by means of overloading the higher nervous system. A marked suppression of self-stimulation behaviour was found in chronic hypertensive rats. Decrease of the arterial pressure induced with an anti-hypertensive drug (catapresan) resulted in a temporary recovery of self-stimulation reaction. Baroafferent mechanisms of inhibition of positive emotional structures of the hypothalamus are discussed.