Fujisaki M, Hashimoto K, Iyo M, Chiba T
Department of Anatomy and Neurobiology, Graduate School of Medicine, Chiba University, Japan.
Neuroscience. 2004;124(1):247-60. doi: 10.1016/j.neuroscience.2003.11.022.
Using pre- and post-training lesions of the amygdalo-hippocampal transition area (AHi), the role of the AHi in the fear conditioning of rats was examined. Pretraining lesions by N-methyl-d-aspartate led to the enhancement of freezing behavior in auditory fear conditioning and contextual conditioning. However, the freezing of post-training-lesioned rats did not differ from that of the sham-lesioned rats. There were several regions of the brain observed in this study in which c-Fos and/or Egr-1 immunoreactive-positive cell expression changed in diverse manners after the test session. In the pretraining lesioned rats that were trained for auditory conditioning, the number of c-Fos and Egr-1 decreased in the infralimbic cortex (IL) and the number of Egr-1 increased in the basomedial amygdaloid nucleus (BM). In the pretraining AHi-lesioned rats that were trained for contextual conditioning, the number of c-Fos increased in the lateral periaqueductal gray (LPAG) and the number of Egr-1 increased in the BM. These results suggest that the AHi plays an important role in the acquisition of memory during conditioning alone, whereas it is improbable that the AHi had an effect on consolidation, retrieval, and expression in the case of either auditory or contextual fear conditioning. The findings also suggest that the freezing behavior was related to the changes in c-Fos and/or Egr-1 in the IL, BM, and LPAG. As in the case of the BM, the number of Egr-1 immunoreactive-positive cells was increased in both experiments, and it was possible that the activation of neurons with high basal levels of expression might be associated with memory retrieval or expression as a freezing behavior observed in the test session.
利用杏仁核 - 海马过渡区（AHi）训练前和训练后的损伤，研究了AHi在大鼠恐惧条件反射中的作用。N - 甲基 - D - 天冬氨酸造成的训练前损伤导致听觉恐惧条件反射和情境条件反射中僵住行为增强。然而，训练后损伤大鼠的僵住行为与假手术损伤大鼠并无差异。在本研究中观察到大脑的几个区域，在测试环节后，c - Fos和/或Egr - 1免疫反应阳性细胞表达以不同方式发生变化。在接受听觉条件反射训练的训练前损伤大鼠中，边缘下皮质（IL）中c - Fos和Egr - 1的数量减少，基底内侧杏仁核（BM）中Egr - 1的数量增加。在接受情境条件反射训练的训练前AHi损伤大鼠中，外侧导水管周围灰质（LPAG）中c - Fos的数量增加，BM中Egr - 1的数量增加。这些结果表明，AHi仅在条件反射过程中记忆的获取中起重要作用，而在听觉或情境恐惧条件反射的情况下，AHi对巩固、检索和表达不太可能有影响。研究结果还表明，僵住行为与IL、BM和LPAG中c - Fos和/或Egr - 1的变化有关。与BM的情况一样，在两个实验中Egr - 1免疫反应阳性细胞的数量均增加，并且在测试环节中观察到，高基础表达水平神经元的激活可能与作为僵住行为的记忆检索或表达相关。
