The Medullary Connections of Laryngeal Vagal Neurons of NA in the Rat

大鼠延腦疑核區中喉返迷走神經元之延腦調控神經網路之探討

李裕仁(Yu-Jen Lee) ； 陳瑞芬(R.-F. Chen)

《Acta Zoologica Taiwanica》 14卷2期 (2004/10) Pp. 137-138

https://doi.org/10.6576/AZT.2004.14.(2).24

摘要

本實驗主要目的在研究延腦nucleus tractus solitarius (NTS)中循環呼吸相關區域與nucleus ambiguous (NA)處之呼吸性迷走神經元間的關連性。分別利用biotin-conjugated dextran (BD)注入NTS循環呼吸相關區域之正向追蹤實驗(anterograde tracingex periment)，以及WGA-HRP注入迷走神經、喉部氣管肌肉或喉返神經(recurrent laryngeal nerve, RLN)之逆向追蹤實驗(retrograde tracing experiment)探討之。WGA-HRP逆向追蹤實驗的結果，發現迷走神經元主要分布於延腦之dorsal motor nucleus of the vagus (DMV)與NA區域，而控制喉部氣管肌肉或RLN中的迷走神經元則主要分布於NA區域。微量注射L-Glutamate(10mM)到obex附近NTS中，找到能引起血壓明顯下降、橫隔肌電圖(diaphragm EMG)受抑制之反應點後，再微量注射BD(20-40nl)到此反應點中。十天後，能在延腦NA區域中發現大量染有BD之神經末梢及終鈕之分布，範圍亦涵蓋HRP標定喉頭迷走神經元所分布之NA區域，顯見二者之間極可能有直接之聯結，但尚待同時進行正向及逆向追蹤實驗的直接證明。

並列摘要

In the present study, we examine the projections of respiratory and circulatory area of nucleus tractus solitarius (NTS) to the laryngeal vagal neurons of nucleus ambiguus (NA) in male Wistar rats by anterograde and retrograde tract-tracing methods. WGA-HRP (Sigma, 2.5%) was injected into the cervical vagus, laryngeal muscle or recurrent laryngeal nerve (RLN) separately. After 48-72 hours survival, we found most labeled vagal neurons were located within and ventrolateral to the NA and many other neurons were found in the DMV in the cervical vagus group. But HRP-labeled neurons were located mainly in the NA area in laryngeal muscle or RLN injection groups. Biotin-conjugated dextran (BD, Molecular Probes, 10%, 20-40 nl) was injected into the NTS near the obex level, where profound depressor response and decrease in diaphragm activity were induced by microinjection of glutamate solution (Glu, 10 mM). Ten days later, we found many BD labeled fiber terminals and buttons, which projected from NTS, in the region of NA, bilaterally. Notice that dense fiber terminals existed in the NA area, which containing the HRP-labeled neurons innervating the laryngeal muscles. The data suggested that the NTS might play an important role in controlling the respiratory function by direct projecting to the laryngeal vagal neurons in NA. But it should be proved by anterograde & retrograde experiments in the same animal simultaneously.

並列關鍵字

Nucleus tractus solitarius ； Nucleus ambiguus ； Biotin conjugated dextran ； WGA-HRP ； Rat