家兔延髓单位放电与颈动脉窦压力感受性反射

在22只家兔延髓共记录到220个自发放电单位。可分四型:同步血压相关型(37.3％)、非同步血压相关型(20.5％)、血压呼吸相关型(1.8％)、非血压相关型(40.5％)。同步血压相关型与非同步血压相关型在压力感受器加压反射与减压反射时均可见到单位放电与血压呈同相变化和反相变化两种反应类别。其放电频率的变动值均显示有显著意义(P<0.001)。同步血压相关型神经元单位较其他型更为靠近延髓腹外侧区。结果表明延髓中调控心血管活动的神经元单位的紧张性与压力感受器传入有关。延髓腹外侧区为心血管调节的紧张性冲动来源之一。

DISCHARGE OF MEDULLAR NEURON-UNIT AND CAROTID SINUS BARORECEPTOR REFLEX IN RABBIT

Experiments are performed on 22 rabbits and the total of 220 spontaneous firing neuron units are recorded in the definite area of medulla. Four types of the neuron units may be divided, in which there are synchronous blood pressure related type (37.3%), nonsynchronous blood pressure related type (20.5%), repiratory blood pressure related type (1.8%) and blood pressure nonrelated type (40.5%). It can be found that two responsive kinds, co-direction and centra-direction, exist between the unit discharge change and the arterial blood pressure change during baroreceptor press reflex and depress reflex. The value of the firing rate change is very significant in the synchronous and nonsynchronous blood pressure related type. The neurons of synchronous blood pressure related type units which exist more closer to ventro-lateral area of the medulla than the others. The results suggest that the units of neuron, responsible for regulation and control of cardiovascular function, indeed exist in medulla oblongata and that their tonicity is correlated with baroreceptor input. It is generally believed that the medulla oblongata is the one of the tonicity sources of cardiovascular regulation.