Bakin J S, Weinberger N M
Department of Psychobiology, University of California, Irvine 92717.
Brain Res. 1990 Dec 17;536(1-2):271-86. doi: 10.1016/0006-8993(90)90035-a.
To determine if classical conditioning produces general or specific modification of responses to acoustic conditioned stimuli (CS), frequency receptive fields (RF) of neurons in guinea pig auditory cortex were determined before and up to 24 h after fear conditioning. Highly specific RF plasticity characterized by maximal increased responses to the CS frequency and decreased responses to the pretraining best frequency (BF) and other frequencies was observed in 70% of conditioning cases. These opposing changes were often sufficient to produce a shift in tuning such that the frequency of the CS became the new BF. CS frequency specific plasticity was maintained as long as 24 h. Sensitization training produced general increased responses across the RF without CS specificity. The findings indicate that associative processes produce systematic modification of the auditory system's processing of frequency information and exemplify the advantages of combining receptive field analysis with behavioral training in the study of the neural bases of learning and memory.
为了确定经典条件作用是否会对听觉条件刺激（CS）的反应产生一般性或特异性改变，在恐惧条件作用前及之后长达24小时内，测定了豚鼠听觉皮层神经元的频率感受野（RF）。在70%的条件作用案例中观察到了高度特异性的RF可塑性，其特征为对CS频率的反应最大程度增加，而对训练前最佳频率（BF）及其他频率的反应降低。这些相反的变化通常足以使调谐发生偏移，从而使CS频率成为新的BF。CS频率特异性可塑性可维持长达24小时。敏化训练使整个RF的反应普遍增加，且无CS特异性。这些发现表明，联想过程会对听觉系统处理频率信息的方式产生系统性改变，并例证了在学习和记忆神经基础研究中，将感受野分析与行为训练相结合的优势。
