大鼠延腦吻端腹外側與呼吸循環相關核區之神經徑路研究

Study of Projections from the Rostral Ventrolateral Medulla of the Rat to the Respiratory and Cardiovascular Related Nuclei

陳玉玲(Yu-Ling Chen)

指導教授 ： 黃基礎 博士 ； 嚴震東 博士

國立臺灣師範大學/理學院/生物學系/碩士(1999年)

摘要

摘要
本研究的目的在於藉由神經追蹤的方法，來探討大白鼠之延腦吻端腹外側與疑核及其他與呼吸、循環相關的延腦及脊髓核區的神經徑路連結。實驗分成兩個部分進行：（一）從喉返神經作逆向神經追蹤；（二）從延腦吻端腹外側進行正向追蹤。
第一部份實驗是自喉返神經打入逆向追蹤劑WGA-HRP，再以TMB法呈色。結果發現大鼠的喉返神經運動神經元細胞本體均位於同側的疑核及其周邊區域，在延腦長軸上呈現雙峰分佈。第二部分的實驗則是先以麩胺酸鈉（sodium glutamate, 50mM）在延腦吻端腹外側進行化學刺激，顯示出血壓上升、橫膈吸氣活動受抑制的區域，再由此區域注射入正向追蹤劑BDA(biotinylated dextran amine)。結果顯示上述的延腦吻端腹外側區域有投射至延腦兩側的疑核(nucleus ambiguus)、舌下神經核(hypoglossal nucleus)、孤獨徑核(nucleus of the tracts solitarius)和迷走背運動神經核(dorsal motor nucleus of the vagus)，亦投射至脊髓中的膈運動神經核(phrenic motor nucleus)以及胸髓中的間質外側柱(intermediolateral column)等與循環、呼吸功能有相關的核區。我們進一步比較投射至膈運動神經核和間質外側柱的突觸密度是否與生理反應具有相關性。經統計分析之後，發現投射至膈運動神經核的突觸密度和化學刺激後橫膈受抑制的程度具有顯著的正相關(p＜0.01)，而投射至間質外側柱的突觸密度與血壓的上升幅度則相關性未達顯著程度（p＞0.05）。
本研究結果證明大鼠的延腦吻端腹外側可能藉由投射至與呼吸、循環相關的核區，來調控其呼吸與循環的功能。

關鍵字

延腦吻端腹外側 ； 疑核 ； 膈運動神經核 ； 間質外側柱 ； 喉返神經 ； 舌下神經核 ； 孤獨徑核腹外側 ； 迷走背運動神經核

並列摘要

Abstract
The aim of the present study was to examine the projections from the rostral ventrolateral medulla (RVLM) of the rat to the nucleus ambiguous (NA), and to other respiratory and cardiovascular related nuclei in the medulla and spinal cord by tract-tracing methods. Two experiments were performed. In the first experiment, retrograde tracer WGA- HRP was injected into the recurrent laryngeal nerves of three rats. 3 days lateral, HRP-labeled neurons were detected mainly in the ipsilateral NA and its neighborhood. These cells distributed along the longitudinal axis of NA with two major peaks.
Nine rats were used in the second anterograde tracing experiment. First, the RVLM were activated with microinjection of glutamate solution（50mM）to locate an area which produced significant decreases in diaphragm activity and increase in blood pressure. Then BDA, an anterograde tracer, was injected into the same area. 10 to 14 days later, fiber terminals radiated from these RVLM injection sites were found in the bilateral NA, the hypoglossal nucleus, the solitary tract nucleus, the dorsal motor nucleus of the vagus, the phrenic motor nucleus (PMN) in the cervical spinal cord, and the intermediolateral cell column (IML) in the thoracic spinal cord, all these nuclei related to respiratory and cardiovascular function. The correlation between terminal density in the PMN and IML from the RVLM versus glutamate- induced functional changes, i.e., diaphragm activity depression (for PMN) or blood pressure increase (for IML), were examined with linear regression statistics. Significant correlation was found between the terminal density in the PMN and the suppression of diaphragm muscle EMG. The correlation between terminal density in the IML and blood pressure increase did not reach statistically significant level.
Findings of the present study suggest that RVLM play an important role in modulating or controlling respiratory and cardiovascular functions by direct projections to respiratory and cardiovascular related nuclei.

並列關鍵字

RVLM ； NA ； phrenic motor nucleus ； intermediolateral column ； recurrent laryngeal nerve ； hypoglossal nucleus ； vlNTS ； DMV

參考文獻

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