大鼠发育过程中视皮层神经元电学特性的研究  

The electrophysiological properties of neurons in the developing visual cortex in rats

作　　者：涂娅莉[1] 刘应兵[2] 张莉[3] 赵妍君[2] 

机构地区：[1]第三军医大学附属西南医院眼科,重庆400038 [2]四川大学华西医学院生理学教研室,成都610041 [3]四川大学华西医学院药理学教研室,成都610041

出　　处：《第三军医大学学报》2003年第18期1632-1635,共4页Journal of Third Military Medical University

基　　金：国家自然科学基金资助项目 ( 30 0 70 2 54 )

摘　　要：目的　研究大鼠发育过程中视皮层神经元的电生理学特性 ,探讨相邻神经元之间的相互作用和局部神经元网络的整合功能。方法　应用脑片膜片钳全细胞记录技术 (盲法 )获得 4～ 2 8d龄SD大鼠视皮层神经元的全细胞记录 ,在电压钳下应用强度为 0 1～ 1 0mA刺激来引起神经元的突触后电流 (Postsynapticcurrents ,PSCs)。结果　 15 6个大鼠视皮层神经元的PSCs可分为无反应型、单突触反应型和多突触反应型 3种类型。大鼠睁眼后多突触反应型细胞所占的百分率显著增加。某些细胞在不同的刺激强度下有不同的突触反应 ;个别细胞在相同刺激强度下 ,多突触反应的曲线不同。双脉冲刺激视皮层神经元引起的时间整合作用的形式表现为突触反应增强型、压抑型和无影响型 3种类型。结论　多突触反应的神经元可接受两个或多个延时不同的突触输入。视皮层神经元在出生后发育过程中 ,其功能的成熟表现为在视觉刺激下 ,视觉依赖性突触的重新分布 。Objective To investigate the electrophysiological characteristics of neurons in developing visual cortex and to observe the reciprocal connection and the function of integration between adjacent neurons. Methods Whole cell recordings of the visual cortex from SD rats (4～28 d old) were obtained by using 'blind' whole cell patch clamp recording technique. Bipolar stimulating electrodes were placed in the white border under the visual cortex. Postsynaptic currents(PSCs) were evoked by using stimulation of 0 1 Hz. Results There were three types of PSCs recorded in 156 cells in the first developmental month: irresponse, monosynaptic response and polysynaptic response. The incidence of polysynaptic PSCs increased from 12 36% before eye opening to 31 34% after eye opening ( P <0 05). There were different synaptic responses evoked by different stimulus intensities. Some neurons showed different polysynaptic responses evoked by the same stimulus intensity. There were three types of the paired pulse integration of neurons in the visual cortex: synaptic facilitation, synaptic suppression and non effective synaptic response. Conclusion The polysynaptic neurons can receive two or more than two synaptic inputs with different delayed time. The functional maturity of neurons in visual cortex during the developmental course is presented as the redistribution of activity dependent synapses, showing the reciprocal connection between adjacent neurons and the integration in local neuronal networks.

关 键 词：全细胞记录 膜片钳 脑片 视皮层 多突触反应 

分 类 号：R33-33[医药卫生—人体生理学]