LPS激发大鼠前脑神经元Fos和小胶质细胞OX42表达改变

目的 探讨单次腹腔注射LPS后前脑神经元和小胶质细胞的可塑性变化和相互关系。方法 应用抗Fos、抗TH或抗OX42单一、以及抗Fos／抗TH／抗OX42三重免疫组化标记方法，观察大鼠单次腹腔注射LPS后，Fos阳性神经元、Fos／TH阳性神经元、OX42阳性小胶质细胞在脑内的表达分布及时程变化，以及Fos阳性神经元或Fos／TH阳性神经元与OX42阳性小胶质细胞之间的关系。结果：Fos阳性神经元分布在额、顶皮质，扣带回和梨状皮质，外侧隔核腹侧部，杏仁中央核，海马CA2区、CA3区、齿状回，下丘脑室旁核、视上核、下丘脑外侧区和第三脑室周围灰质等。Fos阳性神经元在注射后30min出现表达，注射后1～3h为表达高峰。反应阳性小胶质细胞首先于脑室周围灰质出现，注射后6h达到高峰，胞体变大，突起变粗，OX42呈阳性深染，密集分布于Fos阳性神经元的表达区域。下丘脑Fos／TH／OX42三重染色切片显示：由LPS激活的Fos／TH阳性神经元周围被OX42阳性细胞包绕并接触，表明神经元和小胶质细胞在对LPS刺激的反应中关系密切。结论 在外周免疫刺激下，下丘脑、扣带回、梨状皮质和海马内的神经元和小胶质细胞可能参与免疫调节。

Expression of Fos protein in neurons and OX42 in microglia of rat forebrain after intraperitoneal injection of lipopolysaccharide

Objective To investigate the plastic changes of neurons and microglia and their relationship in rat forebrain after a single intraperineal (IP) injection of lipopolysaccharide (LPS). Methods Single anti-Fos, anti-OX42 and anti-Fos/anti-tyrosine hydroxylase (TH) /anti- OX42 triple-labeling immunohistochemical (ABC) methods were used to observe the expression of Fos protein in neurons and OX42 in microglia in forebrain at different time after injection. Results Anti-Fos-like immunoreaction (-LI) neurons and OX42-LI microglia were distributed in the cingulated cortex, piriform cortex, ventrolateral septal nucleus, supraoptic nucleus, lateral hypothalamic area, paraventricular hypothalamic nucleus (PVN) and the periventricular hypothalamic gray. The quantity of Fos-LI neurons increased after 30 min, and peaked at 1-3 h. OX42-LI microglia was firstly appeared in periventricular hypothalamic gray. It peaked at 6 h and became bigger and ramification. Triple-labeling displayed that the activated Fos/TH-LI neurons were surrounded by OX42-LI microglia and closely contacted. Conclusion Neurons and microglia in hypothalamus, cingulated grus, piriform cortex and hippocampus may participate in the administration of central nervous system to peripheral-immunity stimulated regulation.