A subpopulation of neurons in the rat rostral nucleus of the solitary tract that project to the parabrachial nucleus express glutamate-like immunoreactivity
A subpopulation of neurons in the rat rostral nucleus of the solitary tract that project to the parabrachial nucleus express glutamate-like immunoreactivity
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DOI：
10.1016/s0006-8993(98)01270-0
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发表时间：
1999-03-13
期刊：
影响因子：
2.9
通讯作者：
King, MS
中科院分区：
文献类型：
--
作者：
Gill, CF;Madden, JM;King, MS
在啮齿类动物中，味觉信息从孤立束吻侧核（rNST）的二级神经元传递到围栏中的臂旁核（PBN）。这个投影的化学性质是未知的。因此，本研究的目的是确定投射到PEN的rNST神经元是否表达谷氨酸样免疫反应性。将罗丹明填充乳胶微球立体定向注射到7只大鼠的右侧PEN后，对投射神经元进行逆行标记，同时使用免疫过氧化物酶方法在同一组织中观察谷氨酸免疫反应（GLU-IR）结构。测定了每个核细分中位于右（同侧）和左rNST的单标记和双标记神经元的数量以及它们沿rNST的喙尾轴的位置。GLU-IR细胞体遍布rNST。虽然吻侧中央亚核中GLU-IR的比例最高（33.8%），但免疫标记的神经元最集中（亚核数量/亚核面积）在内侧亚核内。rNST吻侧三分之一的GLU-IR细胞体含量最少（20.5%），密度最低。PEN逆行标记的rNST神经元比例最高的是位于脑桥注射部位的同侧（85.4%）、核的中间三分之一（44.2%）和吻侧中央细分内（52.4%）。总的来说，标记的rNST投射神经元中有18%是GLU-IR。双标记神经元的分布反映了投射神经元的分布，其中位于同侧rNST(84.5%)，核中三分之一（40.5%）和吻侧中央细分（64.7%）的神经元数量最多。这些结果表明谷氨酸可能是rNST到PEN上升通路的主要成分。此外，由于GLU-IR神经元遍布rNST，并且大多数没有逆行标记，目前的结果表明谷氨酸可能是髓质中重要的神经递质。(C) 1999 Elsevier Science B.V.版权所有
In rodents, gustatory information is transmitted from second order neurons in the rostral nucleus of the solitary tract (rNST) to the parabrachial nucleus (PBN) in the pens. The chemical nature of this projection is unknown. Therefore, the goal of the current study was to determine if rNST neurons that project to the PEN express glutamate-like immunoreactivity. Projection neurons were retrogradely labeled following stereotaxic injection of rhodamine-filled latex microspheres into the right PEN of seven rats while glutamate-immunoreactive (GLU-IR) structures were visualized in the same tissue using an immunoperoxidase procedure. The number of single- and double-labeled neurons located in the right (ipsilateral) and left rNST, in each of the nuclear subdivisions as well as their position along the rostral-caudal axis of the rNST was determined. GLU-IR cell bodies were located throughout the rNST. Although the rostral central subdivision contained the highest percentage (33.8%) of GLU-IR perikarya, immunolabeled neurons were most concentrated (number/area of subdivision) within the medial subnucleus. The rostral third of the rNST contained the fewest (20.5%) and lowest density of GLU-IR cell bodies. The highest percentage of rNST neurons retrogradely labeled from the PEN were located ipsilateral (85.4%) to the pontine injection site, in the middle third of the nucleus (44.2%) and within the rostral central subdivision (52.4%). Overall, 18% of the labeled rNST projection neurons were GLU-IR. The distribution of double-labeled neurons mirrored that of the projection neurons with the largest number located in the ipsilateral rNST (84.5%), middle third of the nucleus (40.5%) and rostral central subdivision (64.7%). These results indicate that glutamate may be a main component of the ascending pathway from the rNST to the PEN. In addition, since GLU-IR neurons were located throughout the rNST and most were not retrogradely-labeled, the current results suggest that glutamate may be an important neurotrans-mitter within the medulla. (C) 1999 Elsevier Science B.V. All rights reserved.