摘要
目的研究痕迹性眨眼条件反射建立过程中,小鼠小脑皮层神经元放电活动的动态变化规律。方法将150 ms蓝光作为条件刺激,100 ms角膜吹气作为非条件刺激,进行配对刺激。连续5 d,训练小鼠(n=6)建立痕迹性眨眼条件反射。在条件反射训练过程中,使用tetrode电极记录小鼠小脑皮层内神经元的放电活动。结果通过连续5 d配对刺激训练,小鼠的条件性眨眼反应显著增加(P<0.01),其发生率从第1天的(35.3±10.5)%上升至第5天的(70.9±3.2)%。在小脑皮层记录到两类与痕迹性眨眼条件反射行为相关的神经元放电活动:①刺激间期活动减弱神经元(训练早期:n=11,训练后期:n=23);②刺激间期活动增强神经元(训练早期:n=18,训练后期:n=7)。相对于痕迹性眨眼条件反射的训练早期,训练后期小脑皮层内刺激间期活动减弱的神经元比例增加(早期:16.7%,后期:36.5%),而刺激间期活动增强的神经元比例减少(早期:27.3%,后期:11.2%),放电减弱和增强模式神经元的组成比例发生显著变化(P<0.01)。此外,随着条件反射训练的进行,小脑皮层神经元刺激间期活动变化的起始潜伏期显著后移(P<0.05),但活动强度没有发生显著变化(P>0.05)。结论在痕迹性眨眼条件反射建立过程中,小脑皮层神经元通过群体放电活动从增强向减弱的模式转换来促进痕迹性条件性眨眼反射的建立。
Objective To investigate the dynamic changes of neuronal activity in the cerebellar cortex during the acquisition of trace eyeblink conditioning(tEBC)in mice.Methods A 150-ms pulse of blue light conditioned stimulus(CS)followed by a 100-ms air-puff unconditioned stimulus(US)with a 250-ms trace interval for 5 consecutive training days was performed to train the mice(n=6)to establish tEBC.During daily tEBC training,the neuronal activities in the cerebellar cortex were continuously recorded by tetrode electrodes.Results During the acquisition of tEBC,the incidence of conditioned eyeblink response(CR)in mice was significantly increased(P<0.01),with the incidence increased from(35.3±10.5)%on the 1st day to(70.9±3.2)%on the 5th day.In particular,2 types of learning-related neuronal activities were observed in the cerebellar cortex:①trace interval-decreased firing neurons(early stage:n=11,late stage:n=23)and②trace interval-increased firing neurons(early stage:n=18,late stage:n=7).The proportions of 2 types of cerebellar cortical neurons were significantly different to those at the early-learning stage(P<0.01):the percentage of trace interval-decreased firing neurons was increased(early stage:16.7%,late stage:36.5%),whereas that of trace interval-increased firing neurons was decreased(early stage:27.3%,late stage:11.2%).Moreover,with the acquisition of tEBC response,the latency of CS-evoked decreased firing activity in the cerebellar cortex was significantly prolonged(P<0.05).In contrast,the magnitude of the firing responses failed to change(P>0.05).Conclusion During the acquisition of tEBC,the discharge of neurons in the cerebellar cortex exhibits changed pattern from the enhancement to attenuation,which is highly correlated to the CR acquisition.
作者
章利彬
陈浩
张洁
周安
伍亚民
闫洁
ZHANG Libin;CHEN Hao;ZHANG Jie;ZHOU An;WU Yamin;YAN Jie(State Key Laboratory of Trauma,Burns and Combined Injury,Department 3,Research Institute of Surgery,Chongqing,400042;Department of Physiology,Institute of Brain and Intelligence,College of Basic Medical Sciences,Army Medical University(Third Military Medical University),Chongqing,400038,China;Squadron 7,Battalion 2,Army Medical University(Third Military Medical University),College of Basic Medical Sciences,Army Medical University(Third Military Medical University),Chongqing,400038,China)
出处
《第三军医大学学报》
CAS
CSCD
北大核心
2020年第12期1188-1194,共7页
Journal of Third Military Medical University
基金
高等学校大学生创新创业训练计划项目(201990035045)
陆军军医大学本科学员科学研究培育专项课题(2019XBK35)。
关键词
条件反射
眨眼
小脑皮层
神经元
conditioned reftex
eyeblink
cerebellum
neurons
