CAJ | 학술논문

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.
목적 탐구대서재속박-침수응격불동시간단,기내측전액협피질(MPFC)내추체신경원적전활동정황.방법 이용다통도재체기록기술,기록대서재속박-침수응격전화응격4h과정중MPFC추체신경원적단위방전활동,진일보분석기방전빈솔、방전간격급폭발식방전활동등지표,연구속박-침수응격대MPFC추체신경원전활동적영향.결과 공채집도료12지대서MPFC내적25개추체신경원적전활동.추체신경원적전활동표현출량충상반추세:(1)A류신경원(72％)기방전활동수응격시간적연장이수도억제,방전솔유응격전적(3.57±0.63) Hz지속강저도응격후제4소시적(0.81±0.11) Hz (P＜0.01);동시족상파적발방솔야유응격전적(10.29±3.04)개/min,지속강저도응격후제4소시적(1.02±0.50)개/min (P＜0.01),폭발식방전소점비례야현저성감소,변화효응여응격시간성정상관.(2)B류신경원(28％)칙표현출단시적흥강효응,기방전솔유응격전적(1.77±0.45) Hz,승고도응격후제2소시적(2.67±0.74) Hz (P＜0.05),평균방전간격야명현축단;족상파적발방솔유응격전적(2.01 ±0.73)개/min,승고도응격후제1소시적(9.04±2.42)개/min(P＜0.05),폭발식방전소점비례야현저성승고,단B류신경원적흥강지속시간교단.결론 속박-침수응격가개변MPFC내추체신경원적전활동,A류추체신경원활동수도억제,B류추체신경원활동증강.
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.