大白鼠脊髓向延髓外侧网状核投射的体部定位——HRP顺行法研究

向大白鼠脊髓的颈、腰膨大和胸髓右侧半分别注入HRP或WGA—HRP,研究了脊髓向延髓外侧网状核的投射。 1.双侧的三叉神经下亚核同时接受颈、胸和腰髓来的投射。 2.大白鼠脊髓主要投射于外侧网状核的尾侧半,有一定的体部定位关系。颈髓投射于双侧大细胞亚核的外侧2/3及与共相邻接的一部分小细胞亚核内,以同侧投射为主。胸髓投射于双侧的大细胞亚核的内侧2/3和与之相邻接的一部分小细胞亚核内,两侧无明显差別。腰髓投射于双侧小细胞亚核和与之相邻接的部分大细胞亚核内,以对侧投射为主。它们相互间有部分重叠。 3.颈、胸和腰髓内外侧网状核投射的神经元位于从背角至腹角的灰质内,越边投射的神经元比不越边投射的神经元位置更靠腹侧。

THE SOMATOTOPICAL LOCALIZATION OF THE SPINAL PROJECTIONS TO THE NUCLEUS LATERALIS RETICULARIS(LRN) IN THE RAT. AN ANTEROGRADE HRP STUDY

HRP or WGA-HRP was injected into the right side of cervical or lumbar enlargemcnt or thoracic segment of 20 adult rats. The antero-gradely labelled terminals and preterminal nerve fibers were examined. The somatotopical localization of the spinal projections to the LRN of the medulla oblongata was observed. 1. The subnucleus subtrigeminalis (Lrs) of both sides received pro-jecting fibers from cervical, thoracic and lumbar cord. 2. The spinal projections terminated somatotopically mainly in the caudal half of the LRN in the rat. The cervical cord projected bila-terally to the lateral 2/3 of the subnueleus magnocellularis (Lrm) and its neighbouring part of the subnucleus parvocellularis(Lrp), ipsilateral side predominating. The thoracic cord projected bilaterally to the medial 2/3 of the Lrm and its neighbouring part of the Lrp. No apparent difference between the two sides was found. The lumbar cord projected bilaterally to the Lrp and its neighbouring part of Lrm, chiefly to the contralateral side. The projections from cervi cal, thoracic, and lumbar cord were partially overlapping with each other. 3. The neurons of the cervical, thoracic and lumbar segments pro jecting to the LRN were situated in the grey matter from dorsal horn to ventral horn of the spinal cord. The contralaterally projecting neurons situated more ventrally than the ipsilatereally projecting neurons.