Institute of Medical Psychology and Behavioral Immunobiology, University Hospital Essen, University of Duisburg-Essen, D-45122 Essen, Germany.
Brain Behav Immun. 2011 Oct;25(7):1384-92. doi: 10.1016/j.bbi.2011.04.005. Epub 2011 Apr 18.
The amygdala, a group of nuclei located in the medial temporal lobe, is a key limbic structure involved in mood regulation, associative learning, and modulation of cognitive functions. Functional neuroanatomical studies suggest that this brain region plays also an important role in the central integration of afferent signals from the peripheral immune system. In the present study, intracerebral electroencephalography and microdialysis were employed to investigate the electrophysiological and neurochemical consequences of systemic immune activation in the amygdala of freely moving rats. Intraperitoneal administration of bacterial lipopolysaccharide (100 μg/kg) induced with a latency of about 2 h a significant increase in amygdaloid neuronal activity and a substantial rise in extracellular noradrenaline levels. Activated neurons in the amygdaloid complex, identified by c-Fos immunohistochemistry, were mainly located in the central nucleus and, to a lesser extent, in the basolateral nucleus of the amygdala. Gene expression analysis in micropunches of the amygdala revealed that endotoxin administration induced a strong time-dependent increase in IL-1β, IL-6, and TNF-α mRNA levels indicating that these cytokines are de novo synthesized in the amygdala in response to peripheral immune activation. The changes in amygdaloid activity were timely related to an increase in anxiety-like behavior and decreased locomotor activity and exploration in the open-field. Taken together, these data give novel insights into different features of the acute amygdaloid response during experimental inflammation and provides further evidence that the amygdala integrates immune-derived information to coordinate behavioral and autonomic responses.
杏仁核是位于内侧颞叶的一组核团，是参与情绪调节、联想学习和认知功能调节的关键边缘结构。功能神经解剖学研究表明，这个大脑区域在周围免疫系统传入信号的中枢整合中也起着重要作用。在本研究中，我们采用脑内脑电图和微透析技术来研究全身免疫激活对自由活动大鼠杏仁核的电生理和神经化学后果。腹腔内给予细菌脂多糖（100μg/kg）后，约 2 小时潜伏期内，杏仁核神经元活动显著增加，细胞外去甲肾上腺素水平显著升高。通过 c-Fos 免疫组织化学鉴定，杏仁核复合体中被激活的神经元主要位于中央核，其次是杏仁核基底外侧核。对杏仁核微穿孔的基因表达分析显示，内毒素给药诱导 IL-1β、IL-6 和 TNF-α mRNA 水平的强烈时间依赖性增加，表明这些细胞因子是在对周围免疫激活的反应中在杏仁核中从头合成的。杏仁核活动的变化与焦虑样行为的增加和旷场中运动活性和探索的减少及时相关。总之，这些数据为实验性炎症期间急性杏仁核反应的不同特征提供了新的见解，并进一步证明杏仁核整合免疫衍生信息以协调行为和自主反应。
