Edeline J M, Weinberger N M
Center for the Neurobiology of Learning and Memory, University of California, Irvine.
Behav Neurosci. 1993 Feb;107(1):82-103. doi: 10.1037//0735-7044.107.1.82.
Classical conditioning is known to induce frequency-specific receptive field (RF) plasticity in the auditory cortex (ACx). This study determined the effects of discrimination training on RFs at two levels of task difficulty. Single unit and cluster discharges were recorded in the ACx of adult guinea pigs trained in a tone-shock frequency discrimination paradigm (30 intermixed trials each of positive conditioned stimulus [CS+]-shock and negative CS [CS-] alone) with behavioral performance indexed by the cardiac deceleration conditioned response (CR). After training in an easy task in which subjects developed discriminative CRs, they were trained in a difficult task (reduced frequency distance between CS+ and CS-) in which they failed to discriminate. However, frequency-specific RF plasticity developed at both levels of task difficulty. Responses to the frequency of the CS+ were increased, whereas responses to other frequencies, including the CS- and the prepotent best frequency (BF) were reduced. In many cases, tuning was shifted such that the frequency of the CS+ became the new BF. The effects were present or stronger after a 1-hr retention interval. The role of RF plasticity in the ACx is discussed for behavioral performance and information storage.
已知经典条件作用可在听觉皮层（ACx）中诱导频率特异性感受野（RF）可塑性。本研究确定了辨别训练在两个任务难度水平上对感受野的影响。在成年豚鼠的听觉皮层中记录单个神经元和神经元簇的放电，这些豚鼠接受音调-电击频率辨别范式训练（每次有30次混合试验，分别为阳性条件刺激[CS+]-电击和单独的阴性CS[CS-]），行为表现以心脏减速条件反应（CR）为指标。在完成一个简单任务（在此任务中，实验对象形成了辨别性条件反应）的训练后，它们接受了一个困难任务（CS+和CS-之间的频率距离减小）的训练，在此任务中它们无法进行辨别。然而，在两个任务难度水平上均出现了频率特异性感受野可塑性。对CS+频率的反应增加，而对其他频率（包括CS-和优势最佳频率[BF]）的反应减少。在许多情况下，调谐发生了改变，使得CS+的频率成为新的最佳频率。在1小时的保持间隔后，这些效应依然存在或更强。本文讨论了听觉皮层中感受野可塑性在行为表现和信息存储方面的作用。
