【摘要】 本研究在麻醉并制动的大鼠上观察了电刺激巨细胞网状核（Gi）对小脑浦肯野细胞（PC）自发及诱发简单锋电位的影响。结果如下:（1）刺激Gi可使PC的简单锋电位出现潜伏期小于20ms的抑制性或兴奋性反应,并以抑制性反应为主。抑制性反应持续40-100ms,而兴奋性反应的时程可达200ms以上;（2）注射5-HT₂型受体阻断剂methysergide可以减弱或阻断电刺激Gi对PC自发简单锋电位的抑制作用;（3）条件性Gi刺激可以显著压抑或加强由刺激对侧大脑皮层感觉运动区引起的PC诱发简单锋电位反应。以上结果说明:在大鼠存在Gi-小脑通路,这一通路中的部分纤维是5-HT能的。Gi-小脑纤维可能通过突触和/或非经典突触的化学传递方式对PC的电活动产生某种调制性的影响。推测Gi-小脑传入纤维投射可能在某些小脑功能活动,如肌紧张及姿势的调节等方面发挥重要作用。更多还原

【Abstract】 In anesthetized and paralyzed rats, the effect of stimulation of GigantocellularsReticular Nucleus （Gi） on spontaneous and evoked simple spike discharges of cerebel-lar Purkinje cells （PCs） was examined. The result were as follows: （1） Stimulationof Gi elicited either inhibitory or excitatory effect on spontaneous simple spikes of PCswith latency less than 20 ms, being inhibitory in the most cases. The inhibitory re-sponses lasted for 40--100 ms, while the excitatory ones were sometimes longer than200 ms; （2） Injection of 5--HT₂ recptor antagonist methypergide could reversibly at-tenuate or block the inhibitory effect of Gi stimulation on spontaneous simple spike dis-charges of PCs; （3） The evoked simple spike responses of PCs elicited by stimulatingthe contralateral cerebral sensorimotor cortex could be markedly suppressed or poenti-ated by the conditioning Gi stimulation. The results demonstrated that Gi--cerebellar pathways exists, with some fibers be-ing serotonergic. Gi-cerebellar afferent fibers may have certain modulatory effects onPCs through synaptic and/or non--classical chemical synaptic transmission. The Gi-cerebellar afferent fiber projection may play important roles in some cerebellar func-tions, such as regulating myotonia and posture.更多还原