电休克对海马 CA_3区习得性长时程突触增强的影响

每天训练作业结束后对动物进行一次电休克处理,较多的动物(4/6)虽用了比对照组约多一倍的训练次数,但仍未能产生长时程突触增强(LTP),相应地条件反应也未能建立;部分动物(2/6)的突触效应不受影响,能产生LTP,并相应地条件反应亦能建立,且 LTP 发展超前于条件性行为的发展。在条件反应巩固后给大鼠一次电休克,可使它的海马 CA_3区的习得性 LIP—时性地下降,条件反应率也相应地下降。经1—4h,LTP 完全恢复,条件反应率也相应地恢复到电休克前的水平。表明习得性 LTP 受影响,可使条件性行为随之相应改变。它为论证习得性 LTP 可能是记忆的神经基础之一提供了进一步的证据。

EFFECT OF ELECTROSHOCK ON LEARNING-DEPENDENT LONG-TERM POTENTIATION IN RAT HIPPOCAMPAL CA_3 AREA

Population spikes were recorded from hippocampal CA_3 of freely movingrats following stimulation of the perforant path.Six rats were trained to performconditioned drinking behavior.(1)Animals were treated with electroshock inless than 15 minutes after daily training session for a period of 6 consecutive days.Synaptic efficacy did not increase and the conditioned response could not beestablished during the behavioral training in four rats,synaptic efficacy was in-creased,the long-term potentiation(LTP)appeared and the conditioned behaviorwas established in other two rats.(2)After consolidation of conditioned behavior,electroshock temporarily caused suppression of the learning-dependent LTP andthe correlative conditioned response.Both LTP and the correlative conditionedresponse recovered in one to four hours after electroshock.In these cases,themaximal development of LTP preceded the development of conditioned behavior.The results indicated that the learning-dependent LTP might be one of the neuralsubstrates underlying learning and memory.