Chorda tympani nerve stimulation evokes Fos expression in regionally limited neuron populations within the gustatory nucleus of the solitary tract
Chorda tympani nerve stimulation evokes Fos expression in regionally limited neuron populations within the gustatory nucleus of the solitary tract
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DOI：
10.1016/s0006-8993(01)02449-0
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发表时间：
2001-06-15
期刊：
影响因子：
2.9
通讯作者：
Harrison, TA
中科院分区：
文献类型：
--
作者：
Harrison, TA
采用免疫组织化学方法观察了电刺激大鼠鼓索神经后，孤束核（rNST）内对舌前区味觉刺激有反应的神经元的分布。Fos免疫反应（Fos-IR）神经元的地图进行了比较，在一个单独的动物组的跨神经节运输罗丹明-葡聚糖标记的CT传入终末字段的分布。Fos-ir神经元的主要浓度定位在注册的主要终端领域的CT传入纤维，在中央三分之一的吻侧1.0毫米的NST同侧的刺激神经。Fos-ir神经元和传入TT终端的位置和程度的标记类似的对应关系，观察到在同侧背侧三叉神经脊束复合体（Sp 5）部尾侧，obex附近，和Sp 5部口侧附近的喙极的rNST。因此，在具有化学感觉或伤害感受功能的CT神经的脑干目标中Fos上调的幅度与CT传入输入的相对密度成比例。这种对应关系，以及已知是一个额外的突触远离传入输入味觉或口腔反射通路内的神经元中的标记的情况下，表明所获得的细胞图主要代表通过初级传入突触从CT纤维直接激活的神经元。的可用性的方法来组织化学确定一个群体的推定的二级味觉神经元将有助于分析这些神经元的细胞/分子特性和突触电路中的rNST。(C)2001 Elsevier Science B. V.保留所有权利。
The distribution of neurons in the rostral nucleus of the solitary tract (rNST) that respond to gustatory input from the anterior tongue was visualized by Fos protein immunohistochemistry following electrical stimulation of the chorda tympani (CT) nerve in rats. Maps of Fos-immunoreactive (Fos-ir) neurons were compared with the distribution of CT afferent terminal fields labeled by transganglionic transport of rhodamine-dextran in a separate group of animals. The primary concentration of Fos-ir neurons localized in register with the major terminal fields of CT afferent fibers, in the central third of the rostral 1.0 mm of the NST ipsilateral to the stimulated nerve. A similar correspondence in location and degree of labeling of Fos-ir neurons and afferent tt terminals was observed in the ipsilateral dorsal spinal trigeminal complex (Sp5) pars caudalis, near the obex, and the Sp5 pars oralis near the rostral pole of the rNST. Thus, the magnitude of Fos upregulation in brainstem targets of the CT nerve having chemosensory or nociceptive function, was proportional to the relative density of the CT afferent input. This correspondence, and the absence of labeling in neurons known to be one additional synapse away from the afferent input within gustatory or oral reflex pathways, suggests that the cell map obtained represents mainly neurons that are directly activated via primary afferent synapses from CT fibers. The availability of a method to histochemically identify a population of putative second-order taste neurons will facilitate analysis of the cellular/molecular properties of these neurons and of synaptic circuitry in the rNST. (C) 2001 Elsevier Science B.V. All rights reserved.