习得性长时程突触增强在学习各阶段中的变化

应用慢性埋植技术以电生理学结合行为学的方法,观察大鼠海马CA_3区锥体细胞在明暗辨别反应的建立、巩固、消退和再建立的连续过程中,突触效应的变化规律。结果:在条件反应的建立过程中,产生突触效应长时程增强(LTP);在条件反应的巩固过程中,LTP继续保持;在条件反应的消退过程中,LTP消退;在条件反应的再建立过程中,再次产生LTP。而这种习得性LTP的发展和变化超前于习得性行为的产生和改变。这是在同一动物身上实现了以往多项工作的连贯性观察,表明在动物学习活动的连贯的迅速改变的各个阶段,海马CA_3区有相应的对条件性行为有制约作用的习得性LTP的发生和改变。它为论证习得性LTP可能是学习和记忆的神经基础之一,提供了新的有力证据。

THE CHANGES OF LEARNING-DEPENDENT LONG-TERM POTENTIATION IN THE VARIOUS PHASES OF LEARNING

The changes of synaptic efficacy in the CA3 region of the rat hippo-campus during establishment, consolidation, extinction and re-estiblish-ment of the conditioned discrimination response have been examined. It is shown that the long-term potentiation (LTP) which appeared inthe CA3 of the hippocampus with the establishment of conditionedresponse, persisted with the consolidation of conditioned response andextinct with the experimental extinction of conditioned response.Yet, it reappeared with the reestablishment of the conditioned response.The development level and alteration of LTP were in advance of the dew- elopment level and alteration of conditioned behavior. The continuous in-vestigation made in one experiment substitutes for several experiments inthe past. The relevant appearance and alteration of the learning-dependentLTP in the CA3 that is a controllable effect on conditioned behavior wasobserved in the various phases of the continuous and rapid alteration inthe learning. All these are fresh and convincing evidences indicating thatthe learning-dependent LTP might be one of the neural substrates of lear-ing and memory.