Knippenberg J M J, van Luijtelaar E L J M, Maes J H R
University of Nijmegen, Department of Biological Psychology, P.O. Box 9104, 6500 HE Nijmegen, The Netherlands.
Neural Plast. 2002;9(4):261-72. doi: 10.1155/NP.2002.261.
Male Wistar rats were subjected to a differential Pavlovian fear conditioning procedure in which one of two tones (6 or 10 kHz) was followed by an electric shock (CS+) and the other was not (CS-). Before and after fear conditioning, we recorded the evoked potentials elicited by CS+ and CS- from electrodes aimed at the lateral nucleus of the amygdala. Before conditioning, a slow, negative component with peak amplitude around 150 ms was present in the evoked potentials. This component was sensitive to habituation. After fear conditioning, both CS+ and CS- elicited the same late component, albeit with a larger amplitude. This enhancement was temporary: decreasing amplitude was observed in the course of CS test presentations under extinction. Prior research revealed a comparable slow component in the amygdala of the cat under similar experimental conditions. The collective results indicate that the large late component in the amygdala is enhanced by fear conditioning, suggesting that such enhancement reflects the anticipation of a biologically significant event.
将雄性Wistar大鼠置于一种差异巴甫洛夫恐惧条件反射程序中，在此程序中，两个音调（6千赫或10千赫）中的一个之后会伴随电击（条件刺激+），另一个则不会（条件刺激-）。在恐惧条件反射前后，我们从针对杏仁核外侧核的电极记录了由条件刺激+和条件刺激-引发的诱发电位。在条件反射之前，诱发电位中存在一个缓慢的负成分，其峰值幅度约在150毫秒左右。该成分对习惯化敏感。恐惧条件反射后，条件刺激+和条件刺激-均引发相同的晚期成分，但幅度更大。这种增强是暂时的：在消退条件下的条件刺激测试呈现过程中观察到幅度减小。先前的研究在类似实验条件下在猫的杏仁核中发现了类似的缓慢成分。总体结果表明，杏仁核中的大晚期成分通过恐惧条件反射得到增强，这表明这种增强反映了对具有生物学意义事件的预期。
