Bakin J S, South D A, Weinberger N M
Department of Psychobiology and Center for the Neurobiology of Learning and Memory, University of California, Irvine 92697-3800, USA.
Behav Neurosci. 1996 Oct;110(5):905-13. doi: 10.1037//0735-7044.110.5.905.
Classical tone conditioning shifts frequency tuning in the auditory cortex to favor processing of the conditioned stimulus (CS) frequency versus other frequencies. This receptive field (RF) plasticity is associative, highly specific, rapidly acquired, and indefinitely retained-all important characteristics of memory. The investigators determined whether RF plasticity also develops during instrumental learning. RFs were obtained before and up to 24 hr after 1 session of successful 1-tone avoidance conditioning in guinea pigs. Long-term RF plasticity developed in all subjects (N = 6). Two-tone discrimination training also produced RF plasticity, like classical conditioning. Because avoidance responses prevent full elicitation of fear by the CS, long-term RF plasticity does not require the continual evocation of fear, suggesting that neural substrates of fear expression are not essential to RF plasticity.
经典音调条件作用会改变听觉皮层中的频率调谐，使其更倾向于处理条件刺激（CS）频率而非其他频率。这种感受野（RF）可塑性具有关联性、高度特异性、快速习得且能无限期保留——这些都是记忆的重要特征。研究人员确定了RF可塑性是否也在工具性学习过程中形成。在豚鼠成功进行1次单音回避条件作用训练前及训练后长达24小时内获取感受野。所有实验对象（N = 6）均出现了长期RF可塑性。双音辨别训练也产生了RF可塑性，与经典条件作用类似。由于回避反应可防止CS充分引发恐惧，所以长期RF可塑性并不需要持续引发恐惧，这表明恐惧表达的神经基质对于RF可塑性并非必不可少。
