Downs A M, Bond C E, Hoover D B
Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, USA.
Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, USA.
Neuroscience. 2014 Apr 25;266:178-85. doi: 10.1016/j.neuroscience.2014.02.011. Epub 2014 Feb 20.
Electrical stimulation of the vagus nerve attenuates tumor necrosis factor (TNF) synthesis by macrophages and reduces the systemic inflammatory response. Current evidence suggests that the α7 nicotinic acetylcholine receptor present in the celiac/superior mesenteric ganglia is a key component in vagus nerve signaling to the spleen; however, there is currently no direct anatomical evidence that the α7 receptor is present in the murine celiac/superior mesenteric ganglia. Our study addresses this deficiency by providing anatomical evidence that the α7 receptor is expressed within the celiac/superior mesenteric ganglia and splenic nerve fibers using immunohistochemistry and quantitative polymerase chain reaction (qPCR). α7 receptor mRNA is highly expressed in the celiac/superior mesenteric ganglia and at low levels in the spleen compared to the brain. Double-labeling for α7 and tyrosine hydroxylase shows that α7 receptor protein is present on noradrenergic neurons within the ganglia and prejunctionally on noradrenergic nerve fibers within the spleen. The α7 receptor in the ganglia provides a possible location for the action of α7-selective agonists, while prejunctional α7 receptor expressed on splenic nerves may induce an increase in norepinephrine release in a positive feedback system enhanced by lymphocyte-derived acetylcholine.
迷走神经电刺激可减弱巨噬细胞合成肿瘤坏死因子(TNF)并减轻全身炎症反应。目前的证据表明,腹腔神经节/肠系膜上神经节中存在的α7烟碱型乙酰胆碱受体是迷走神经向脾脏发出信号的关键组成部分;然而,目前尚无直接的解剖学证据表明α7受体存在于小鼠腹腔神经节/肠系膜上神经节中。我们的研究通过使用免疫组织化学和定量聚合酶链反应(qPCR)提供解剖学证据,证明α7受体在腹腔神经节/肠系膜上神经节和脾神经纤维中表达,从而解决了这一缺陷。与脑相比,α7受体mRNA在腹腔神经节/肠系膜上神经节中高表达,在脾脏中低表达。α7与酪氨酸羟化酶的双重标记显示,α7受体蛋白存在于神经节内的去甲肾上腺素能神经元上,以及脾脏内去甲肾上腺素能神经纤维的节前部位。神经节中的α7受体为α7选择性激动剂的作用提供了一个可能的位点,而脾神经上表达的节前α7受体可能在淋巴细胞衍生的乙酰胆碱增强的正反馈系统中诱导去甲肾上腺素释放增加。