下丘脑室旁核经迷走神经复合体对哮喘大鼠的神经调控研究

为探讨下丘脑室旁核对哮喘大鼠的神经调控途径,取健康雄性SD大鼠制备哮喘模型并诱发哮喘发作,运用WGA-HRP逆行追踪法与免疫组织化学染色法(ABC法)相结合的双重标记方法,在光镜下观察向迷走神经复合体(DVC)发出投射的下丘脑室旁核(PVN)神经元内Fos蛋白的表达情况。结果显示:PVN内有三种阳性细胞,即HRP逆行标记神经元、Fos样免疫阳性神经元和HRP/Fos双标神经元。这些神经元主要见于PVN小细胞部的内侧亚核和外侧亚核,散在分布于背侧亚核,在前小细胞亚核内未见阳性反应;Fos样免疫阳性细胞呈双侧分布,且HRP逆标神经元,HRP/Fos双标神经元也为双侧分布,但以注射区同侧占优势。HRP/Fos双标神经元占HRP标记细胞的44.22%。本研究结果提示,哮喘大鼠发作时中枢内包括下丘脑PVN、延髓DVC的多个脑区内神经元兴奋,且两者之间通过直接投射联系参与哮喘的调控。

THE STUDY OF HYPOTHALAMIC PARAVENTRICULAR NUCLEUS REGULATES THE ACUTE ASTHMATIC ATTACK IN ASTHMATIC RATS THROUGH THE DORSAL VAGAL COMPLEX

In order to investigate the regulating pathway of the hypothalamic paraventricular nucleus (PVN) during the acute asthmatic attack, the experiment was carried out in the SD male rats of asthmatic model. The double-labeling method combining the wheat germ agglutinin-conjugated horseradish peroxidase (WGA-HRP) retrograde tracing technique with immunohistochemical staining (ABC method) was used, then the expression of Fos proteins in neurons in PVN projecting to the dosal vagal complex (DVC) was identified under the light microscope. The results showed that three kinds of labeled neurons which were HRP-labeled neurons, Fos-like immunoreactive neurons and HRP/Fos double-labeled neurons were observed in PVN. These neurons were mainly in the medial and lateral pavocellular subdivisions of PVN, and scattered in the dorsal subdivisions, but not in the anterior parvocellular subnucleus. Fos immunoreactive neurons distributed bilaterally in PVN as well as HRP-labeled neurons and HRP/Fos double-labeled neurons. However, HRP-labeled neurons and HRP/Fos double-labeled neurons distributed dominantly in the ipsilateral injection site. The percentage of HRP/Fos double-labeled neurons in HRP-labeled neurons was 44.22%. The results suggest that many regions in rat brain including PVN and DVC were excited during the acute asthmatic attack, and the PVN and DVC could regulate the pathological development of asthmatic rats by their direct projecting pathway.