迷走传入冲动对刺激下丘脑诱发室性期前收缩的抑制作用

用电刺激家免下丘脑乳头体核及其周围区域的方法诱发室性期前收缩(HVE)。用强电流(90～200μA)刺激迷走神经中枢端可使 HVE 数减少,用弱电流(3～10μA)刺激对 HVE 数影响不大.刺激延髓孤束核区域可使 HVE 数减少.刺激延髓最后区、网状结构以及三叉脊束核等区域对 HVE 数影响不大.上述结果提示,刺激下丘脑诱发的期前收缩可被迷走传入冲动所抑制。延髓孤束核区域在此传入通路中起重要作用.

Inhibition of Vagus Nerve Afferent Impulses on Ventricul ar Extrasystol es Induced by Stimulation of Hypothalamus

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.