Abstract: Experiments were performed on rabbits anaesthetized with urethane.The animals were immobilized with gallamine triethiodide and maintained by artificial ventilation.Ventricular extrasystoles (HVE) were produced by electrical stimulation of mamillary nucleus of the hy-pothalamus and its surrounding regions.The number of hypothalamic stimulation-induced ventricular extrasystoles (NHVE) was decreased by stimulation of the vagus nerve with a current of high intensity (90～200μA),but it was not decreased by low intensity (3～10 μA).NHVE was decreased by stimulation of the solitary tracr nucleus at the level of the obex,but it was not decreased by the stimulation of postrena area,the reticular formation and spinal trigeminal nucleus.These observations suggest that NHVE could be inhibited by the afferent impulses of vagus nerve.The solitary tract nucleus at the level of the obex may have important effect in the afferent path.

Key words: hypothalamus, ventricular extrasystoles, vagus, solitary tract nucleus