[Mechanism of the effect of the ventromedial, paraventricular and dorsomedial nuclei of the hypothalamus on the heart].

The influence of electrical stimulation of ventromedial, paraventricular and dorsomedial nuclei of the hypothalamus on polycardiographic data and on the serotonin level in the blood was studied in anesthetized rabbits as well as the unit activity of the above nuclei. The nuclei of the hypothalamus seem to be involved in the change of the myocardium functional state. The role of the serotonin content change in the blood was shown in making these nuclei influence the heart. Neuropharmacological analysis revealed the role of the adrenergic substrate of rostral part of the reticular formation in actualization of the hypothalamo-cardial effects. Pressor, depressor and "neutral" neurons of the above hypothalamic nuclei are identified.