束缚-浸水应激对大鼠内侧前额叶皮质锥体神经元放电活动的影响  

The influence of restraint water-immersion stress on firing activities of pyramidal neurons in the medial prefrontal cortex in rats

作　　者：祝建平[1] 耿希文 李敏[1] 王敏[1] 艾洪滨[1] 

机构地区：[1]山东师范大学生命科学学院,济南250014

出　　处：《中华行为医学与脑科学杂志》2015年第9期779-783,共5页Chinese Journal of Behavioral Medicine and Brain Science

基　　金：山东省自然科学基金项目（ZR2011CM029,ZR2014CM019）

摘　　要：目的 探究大鼠在束缚-浸水应激不同时间段,其内侧前额叶皮质（MPFC）内锥体神经元的电活动情况.方法 利用多通道在体记录技术,记录大鼠在束缚-浸水应激前和应激4h过程中MPFC锥体神经元的单位放电活动,进一步分析其放电频率、放电间隔及爆发式放电活动等指标,研究束缚-浸水应激对MPFC锥体神经元电活动的影响.结果 共采集到了12只大鼠MPFC内的25个锥体神经元的电活动.锥体神经元的电活动表现出两种相反趋势：（1）A类神经元（72％）其放电活动随应激时间的延长而受到抑制,放电率由应激前的（3.57±0.63） Hz持续降低到应激后第4小时的（0.81±0.11） Hz （P＜0.01）;同时簇状波的发放率也由应激前的（10.29±3.04）个/min,持续降低到应激后第4小时的（1.02±0.50）个/min （P＜0.01）,爆发式放电所占比例也显著性减少,变化效应与应激时间成正相关.（2）B类神经元（28％）则表现出短时的兴奋效应,其放电率由应激前的（1.77±0.45） Hz,升高到应激后第2小时的（2.67±0.74） Hz （P＜0.05）,平均放电间隔也明显缩短;簇状波的发放率由应激前的（2.01 ±0.73）个/min,升高到应激后第1小时的（9.04±2.42）个/min（P＜0.05）,爆发式放电所占比例也显著性升高,但B类神经元的兴奋持续时间较短.结论 束缚-浸水应激可改变MPFC内锥体神经元的电活动,A类锥体神经元活动受到抑制,B类锥体神经元活动增强.Objective To explore the effects of restraint water-immersion stress （RWIS） on the firing activities of pyramidal neurons in the medial prefrontal cortex （MPFC） of rats.Methods Multi-channel in vivo recording techniques were used to record firing activities of pyramidal neurons before and during 4-h RWIS in rats.Firing rates,inter-spike intervals and burst firing rates were taken as indices to study the influence of RWIS on neuronal firing activities.Results Twenty-five pyramidal neurons of 12 rats were recorded.The opposite patterns of firing activities were observed in two different classes of neurons,type A and type B neurons which account for 72% and 28%,respectively.In type A neurons,inhibited firing activities were in direct proportion to the stress-exposure.Mean firing rates and mean burst firing rates were significantly reduced to （0.81 ± 0.11） Hz and （1.012 ± 0.50） counts/min after 4h constant RWIS compared with those before RWIS,（3.57 ± 0.63） Hz and （10.29 ± 3.04） counts/min.However,in type B neurons,firing activities were enhanced.After 2h constant RWIS,mean firing rates and mean burst firing rates were increased from （1.77±0.45） Hz and （2.01±0.73） counts/min to （2.67±0.74）Hz and （9.04±2.42） counts/min,respectively.Moreover,the percentage of spikes in bursts was significantly increased and mean inter-spike intervals were remarkably shortened.Interestingly,the effect of RWIS on type B neurons lasted for shorter time compared with its effect on type A neurons.Conclusion RWIS differentially affects the firing activity of pyramidal neuron in the MPFC,i.e.,inhibiting the firing activity of type A neurons,but enhancing the firing activity of type B neurons.

关 键 词：内侧前额叶皮质 锥体神经元 束缚-浸水应激 神经元电活动 

分 类 号：R338[医药卫生—人体生理学]