大鼠初级听皮层神经元对声刺激反应的膜电位特征  

Membrane potential characteristics of intracellular responses of rat primary auditory cortex neurons to acoustic stimulation in vivo

作　　者：韩磊[1] 张永海[1] 肖雄健 熊鹰[2] 

机构地区：[1]第三军医大学基础医学部,生理学教研室,重庆400038 [2]第三军医大学基础医学部,神经生物学教研室,重庆市神经生物学重点实验室,重庆400038

出　　处：《第三军医大学学报》2011年第6期550-553,共4页Journal of Third Military Medical University

基　　金：国家自然科学基金(30770681,30911120490);教育部回国人员启动基金(200920481);重庆市自然科学基金(CSTC2008BB5020)~~

摘　　要：目的探讨大鼠初级听皮层单个神经元对声刺激反应的膜电位特征。方法运用在体细胞内微电极记录技术观察麻醉大鼠初级听皮层单个神经元对声音刺激的细胞内反应,分析声音引发的各种兴奋性和抑制性反应的成分及其膜电位特征。结果在大鼠初级听皮层共记录到64个神经元,声音刺激引起其中33个神经元产生兴奋性听觉反应,24个产生抑制性反应,2个产生"on-off"双相听觉反应,其余5个神经元对声音刺激反应不明显。根据声音诱发的兴奋性突触后电位(EPSP)/抑制性突触后电位(IPSP)以及动作电位(AP)的特点,兴奋性听觉反应可分为4型:长时程EPSP型、短时程EPSP型、规律放电型、阈下EPSP型;抑制性听觉反应也可分为4型:AP-IPSP型、EPSP-IPSP型、IPSP型、AP-超极化型。声音诱发的IPSP的潜伏期(46.3±20.5)m s和上升相时程(10.1±4.4)m s显著长于EPSP[分别为(15.1±4.7)、(6.1±3.5)m s,P<0.05,P<0.01]。且"on-off"双相听觉反应的放电间隔与声音时长高度一致。结论大鼠初级听皮层神经元对相同自然声刺激可以产生多种类型的反应,且各型反应的成分和膜电位特征各异,这可能是初级听皮层神经元功能多样性的基础。Objective To investigate the membrane potential characteristics of intracellular responses of individual rat primary auditory cortex neurons to the acoustic stimulation in vivo.Methods The intracellular responses of individual primary auditory cortex neurons to the acoustic stimulation in vivo were observed in anesthetized rats using the intracellular microelectrode recording technique.Results Sixty-four neurons were recorded in the primary auditory cortex of rats,of which thirty-three responded to the acoustic stimulation with excitatory auditory responses,twenty-four with inhibitory auditory responses,two with on-off auditory responses,and the remaining five without obvious responses.According to the characteristics of sound-evoked excitatory postsynaptic potential（EPSP）/inhibitory postsynaptic potential（IPSP） as well as action potential（AP）,the excitatory auditory responses could be classified into 4 patterns： long-term EPSP pattern,short-term EPSP pattern,regular spike pattern and subthreshold EPSP pattern;the inhibitory auditory responses could also be classified into 4 patterns： AP-IPSP pattern,EPSP-IPSP pattern,IPSP pattern and AP-hyperpolarization pattern.The latency [（46.3±20.5）ms] and rising phase duration [（10.1±4.4）ms] of sound-evoked IPSP were significantly longer than those [（15.1±4.7）ms,（6.1±3.5）ms] of EPSP（P0.05,P0.01）.The spike intervals and sound durations of on-off auditory responses were in a phase-locking mode.Conclusion Different patterns of auditory responses can be induced in the primary auditory cortex neurons of rats by the same natural acoustic stimulation.Besides,the components and membrane potential characteristics of each pattern are various,which may lay a basis for the functional diversity of primary auditory cortex neurons.

关 键 词：初级听皮层 在体 细胞内记录 声音刺激 听觉反应 

分 类 号：R338.25[医药卫生—人体生理学] R338.3[医药卫生—基础医学]