Ohi Yoshiaki, Yamazaki Hiromi, Takeda Ryuji, Haji Akira
Department of Pharmacology, Faculty of Medicine, Toyama Medical and Pharmaceutical University, Toyama 930-0194, Japan.
Neurosci Res. 2005 Oct;53(2):201-9. doi: 10.1016/j.neures.2005.06.016.
Projection of the superior laryngeal nerve (SLN) afferent fibers into the nucleus tractus solitarius (NTS) was investigated using a fluorescent tracer in guinea pigs. High density of fluorescence was detected in the ipsilateral NTS extending from 0.5 mm caudal to 1.2 mm rostral to the obex. At coronal slices, the fluorescent granules, lines and patches were located in the interstitial, medial and dorsal regions of NTS. Fluorescence was also found in the dorsal region of contralateral commissural NTS. Microstimulation of the rostral NTS, which corresponded to the region showing the strong fluorescence, induced an increase in the inspiratory discharge of phrenic nerve that was immediately followed by a large burst discharge of the iliohypogastric nerve in decerebrate, paralyzed and artificially ventilated guinea pigs. This serial response of the two nerves was identical to that induced by electrical stimulation of the SLN. Intravenous injection of codeine suppressed both NTS and SLN-induced responses. The SLN-induced response was inhibited by microinjection of codeine into the ipsilateral NTS and abolished by lesion of the ipsilateral NTS. These results suggest that the NTS has an integrative function in production of cough reflex and is possible sites of action of central antitussive agents.
利用荧光示踪剂在豚鼠中研究了喉上神经（SLN）传入纤维向孤束核（NTS）的投射。在从闩尾侧0.5毫米至吻侧1.2毫米的同侧NTS中检测到高密度荧光。在冠状切片上，荧光颗粒、线条和斑块位于NTS的间质、内侧和背侧区域。在对侧连合NTS的背侧区域也发现了荧光。对与显示强荧光区域相对应的吻侧NTS进行微刺激，在去大脑、麻痹并人工通气的豚鼠中，可引起膈神经吸气放电增加，随后立即出现髂腹下神经的大量爆发性放电。这两条神经的这种连续反应与电刺激SLN所诱导的反应相同。静脉注射可待因可抑制NTS和SLN诱导的反应。向同侧NTS微量注射可待因可抑制SLN诱导的反应，同侧NTS损伤则可消除该反应。这些结果表明，NTS在咳嗽反射产生中具有整合功能，并且可能是中枢性镇咳药的作用部位。
