离体脊髓同侧中央管周围区电刺激诱发运动神经元突触反应  

Synaptic responses of motoneurons evoked by ipsilateral pericentral canal zone stimulation in spinal cord in vitro

作　　者：秦雯[1] 郑超[1] 王邦安 汪萌芽[1] 

机构地区：[1]皖南医学院细胞电生理研究室

出　　处：《皖南医学院学报》2013年第6期431-435,共5页Journal of Wannan Medical College

基　　金：国家自然科学基金项目(31271155;31200828)

摘　　要：目的:探讨新生大鼠脊髓切片同侧中央管周围区(iPCC)向运动神经元(MN)兴奋性突触传递的细胞电生理特性。方法:应用新生大鼠(8～14 d)脊髓切片MN细胞内记录技术,观察iPCC局部电刺激在MN所诱发的突触反应。结果:在14个测试的MN,观察到iPCC电刺激可在11个MN上诱发兴奋性突触后电位(iPCC-EPSP),在1个MN上诱发抑制性突触后电位(iPCC-IPSP),在2个MN上诱发iPCCEPSP后复合有iPCC-IPSP的反应。iPCC-EPSP不仅具有刺激强度依赖性和膜电位依赖性,而且可以被低钙高镁溶液或TTX(0.1μmol/L)可逆性取消。荷包牡丹碱和士的宁能增大iPCC-EPSP,但谷氨酸受体拮抗剂APV(30μmol/L)和DNQX(1μmol/L)仅部分抑制iPCC-EPSP。结论:iPCC的激活可通过兴奋性突触传递调制MN的活动,其介导递质除谷氨酸外,可能还有其他递质的参与。Objective：To explore the cellular electrophysiological proper-ties of the excitatory synaptic transmissions from the ipsilateral pericentral canal（iPCC）zone to motoneurons（MN）in neonatal rat spinal cord slices. Methods： The intracellular recording techniques were performed in MN of spinal cord slices isolated from neonatal rats（8-14 days old）,and focal e-lectrical stimulation of the iPCC zone was applied to evoke the synaptic responses.Results： In 14 MNs tested, excitatory postsynaptic potentials （ EPSPs） ,inhibitory postsynaptic potentials （ IPSPs） and EPSP followed by IPSP were elicited by iPCC stimulation （ iPCC-EPSPs or iPCC-IPSPs） in 11,1 and 2 MNs, respectively.The iPCC-EPSPs were sensitive to low Ca2＋/high Mg2＋solution or tetrodotoxin and presented with stimulus in-tensity-dependent and membrane potential-dependent properties.The iPCC-EPSPs were increased by bicuculline and strychnine,but only par-tially eliminated by the perfusion of APV（30 mol/L）,and DNQX（1 mol/L） ,the antagonists of glutamate receptors.Conclusion：These results sug-gest that the activation of the iPCC zone may modulate the activities of MN in neonatal rat spinal cord by excitatory synaptic transmissions .Apart from glutamate,additional neurotransmitters may be involved in mediating the iPCC-EPSPs.

关 键 词：突触传递 脊髓 运动神经元 谷氨酸 乙酰胆碱 电生理学 

分 类 号：R338[医药卫生—人体生理学]