Departamento de Neurobiología Conductual y Cognitiva, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro 76230, Mexico.
Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, Qro. 76230, Mexico; División de Ciencias de Biológicas y de la Salud, Universidad Autónoma Metropolitana, Unidad Lerma, Estado de México 52005, Mexico.
Neurobiol Learn Mem. 2021 May;181:107428. doi: 10.1016/j.nlm.2021.107428. Epub 2021 Mar 30.
Typical amnestic treatments are ineffective when administered to subjects trained in aversively-motivated tasks using relatively high foot-shock intensities. This effect has been found when treatments that disrupt neuronal activity are administered to different regions of the brain, including the amygdala. However, the molecular mechanisms induced by this intense training are unknown. We made a detailed mapping of c-Fos-expressing neurons in four regions of the amygdala after moderate and intense one-trial inhibitory avoidance training. Rats were sacrificed 90 min after training or after appropriate control procedures, and their brains were prepared for immunohistochemical c-Fos protein detection in the central, lateral, and in the anterior and posterior parts of the basolateral amygdaloid nucleus. We found a high percentage of neurons expressing c-Fos in the anterior part of the basolateral nucleus after moderate training, and this percentage increased further after intense training. Moderate and intense training did not induce changes in c-Fos expression in the other explored amygdaloid regions. These results show that inhibitory avoidance training produces a localized expression of c-Fos in the basolateral anterior nucleus of the amygdala, which is dependent upon the intensity of training, and indicate that synaptic plastic changes in this region may be required for the formation of memory of moderate and intense aversive learning.
在使用相对较高的足底电击强度对通过厌恶动机任务训练的受试者进行治疗时，典型的遗忘治疗是无效的。当在大脑的不同区域（包括杏仁核）中施用破坏神经元活动的治疗方法时，已经发现了这种效果。然而，这种强烈训练引起的分子机制尚不清楚。我们在中等强度和高强度单次抑制回避训练后对杏仁核的四个区域中的 c-Fos 表达神经元进行了详细映射。在训练后 90 分钟或经过适当的对照程序后，将大鼠处死，并准备其大脑用于检测中央、外侧和基底外侧杏仁核的前、后部分的 c-Fos 蛋白的免疫组织化学检测。我们发现，在中等训练后，基底外侧核的前部有很高比例的神经元表达 c-Fos，而在高强度训练后，这一比例进一步增加。中等和高强度训练不会引起其他探索的杏仁核区域中 c-Fos 表达的变化。这些结果表明，抑制回避训练会导致杏仁核基底外侧前核中 c-Fos 的局部表达，这取决于训练的强度，并表明该区域的突触可塑性变化可能是形成中等和高强度厌恶学习记忆所必需的。
