杏仁核参与大鼠哮喘发作及其机制探讨

Study on the activities of amygdala in the models of asthma and its mechanisms

为探讨杏仁核是否参与大鼠哮喘发作及其机制,采用卵蛋白致敏哮喘大鼠模型,运用WGA-HRP逆行追踪与免疫组织化学染色相结合的双重标记方法,在光镜下观察向下丘脑室旁核(PVN)发出投射的杏仁核神经元内Fos蛋白的表达情况。结果显示:杏仁核内可观察到三种阳性细胞,即HRP逆标神经元、Fos阳性神经元和HRP/Fos双标神经元。Fos阳性细胞呈双侧分布,主要分布在杏仁核的内侧亚核(MeA)和中央亚核(CeA);HRP逆标神经元和HRP/Fos双标神经元分布在注射区同侧的内侧杏仁核,内侧杏仁核内HRP/Fos双标神经元占HRP单标神经元的33.55%。本研究结果提示,哮喘大鼠发作时,杏仁核、下丘脑室旁核的神经元兴奋,且杏仁核到下丘脑室旁核的直接投射可能参与了哮喘发作的调控。

To investigate the activities of amygdala and its mechanisms during the acute asthmatic attack, the model of asthmatic rat induced by sensitizing and challenging with OVA was used. The combined method of the wheat germ agglutinin-conjugated horseradish peroxidase （WGA-HRP） retrograde tracing technique and immunohistochemistry staining was used, and the expression of Fos proteins in the neurons of amygdala projecting to the hypothalamic paraventricular nucleus （PVN） was identified under light microscope. The results showed that three kinds of labeled neurons which were HRP-labeled neurons, Fos-immunoreactive neurons and HRP/Fos double-labeled neurons were observed in the amygdala. The Fos-immunoreactive neurons distributed bilaterally in the medial and central subdivisions of the amygdala, and the HRP-labeled neurons and HRP/Fos double-labeled neurons distributed dominantly in the ipsilateral medial amygdala to the injection site. The proportion of HRP/Fos double-labeled neurons was about 33.55% of total population of HRP-labeled neurons. The results suggest that amygdala and PVN of the hypothalamus are excited during the acute asthmatic attack in rat brain, and the direct projection from amygdaloid complex to PVN of the hypothalmus maybe involved in the regulation of the asthmatic attack.