三叉神经初级传入纤维与孤束核的联系——HRP跨越神经节追踪研究

THE CONNECTION OF PRIMARY AFFERENT FIBERS OF THE TRIGEMINAL NERVE WITH THE NUCLEUS TRACTUS SOLITARII——A STUDY USING THE HRP TRANSGANGLIONIC TRACING TECHNIQUE

本文用HRP跨节追踪技术在光镜下观察了猫的眶上神经、眶下神经、耳颞神经、颊神经、舌神经和下牙槽神经的初级传入纤维向孤束核的投射状况。另外,向舌咽、迷走和鼓索神经也注入HRP进行了观察和对比。结果表明,上述三叉神经各分支中只有舌神经和下牙槽神经向孤束核投射。舌神经的标记出现于孤束核的闩以上部分,以三叉神经吻侧亚核尾段水平的部位最为浓密,标记终末多分布于腹外侧亚核、中间亚核和内侧亚核。下牙槽神经只有少量标记终末呈斑块状局限分布于闩附近的孤束核间质亚核区,小部分投射于连合核。舌咽神经投射至孤束核全长,以内侧亚核区为最多。迷走神经的大量纤维主要投射于极间亚核平面的孤束核。鼓索神经大部投射至孤束核吻极段。本文对比分析了三叉神经初级传入与Ⅶ、Ⅸ、Ⅹ神经内脏传入在孤束核分布的相互关系,结合文献讨论了投射到孤束核的三叉初级传入神经的性质。

With the HRP transganglionic tracing technique, central projections of the primary afferent fibers of the superior orbital, inferior orbitat, aurieulotemporal, buccal, lingual and inferior alveolar nerves of cat to nueleus tractus solitarii(NTS)were observed under light microscope. The observation was compared with that of glossopharyngeal, vagus and chorda tympani separately injected with HRP. The results demonstrated: in the trigeminal system, only did lingual and inferior alveolar nerves of trigeminal nerves project to nucleus tractus solitarii. After the lingual nerve was injected with HRP, the labeled terminals were found in the part of NTS above obex and the terminals were densely located in the part of NTS at the level corresponding to the caudal segment of subnucleus oralis of the trigeminal nerve. Most terminals were distributed in the ventrolateral, intermediate and medial subnucleus of NTS. After the inferior alveolar nerve was injected with HRP, a little amount of labeled terminals appeared as definite patches in the area of interstitial subnucleus of NTS close to the obex. Another small group of terminals was located in the commissural nucleus. In contrast, fibers of glossopharyngeal nerve projected to the whole length of NTS and the terminals were highly concentrated in the medial subnucleus. Most of the vagus fibers projected mainly to NTS below the level of the oral part of interpolar subnucleus of trigeminal nerve. The terminal projection of the chorda tympani to NTS could be seen at the level slightly oral to the obex, while most of the projections went to the oral segment of NTS.The relationship of distribution of primary afferent fibers of the trigeminal and visceral nerves was analyzed and the function of the projection of primary afferent of trigeminal nerve to NST was discussed.