家兔前庭核与脊髓的联系——HRP法研究

将HRP注入家兔颈、胸或腰髓的一侧灰质内,追踪前庭四核内的逆行标记细胞和顺行标记终支。发现同侧外侧核内标记细胞数量甚多,且具有体部定位规律。内侧核及降核的尾段标记细胞也较多,内侧核者甚为密集,它们投射到双侧脊髓的颈、胸、腰段,对侧多于同侧,无体部定位关系。降核的头段及在此平面的内侧核内也有一定数量的标记细胞,也投射到颈、胸、腰髓,同侧为主,无体部定位关系。上核内只有极少量标记细胞,主要投射到对侧颈髓。顺行标记终支于降核、内侧核的见端小范围内及外侧核的尾端背面较为恒定,颈、腰注射例在降核和内侧核的尾端尤为密集。

CONNECTIONS BETWEEN THE VESTIBULAR NUCLEI AND SPINAL CORD IN THE RABBIT——A STUDY WITH THE HRP METHOD

HRP was injected into the gray matter of the cervical, thoracic, or lumbar spinal cord unilaterally in rabbits and the labeled cells and terminal arborizations were traced in the four main vestibu- lar nuclei. It was found that the labeled cells in the ipsilateral lateral vestibular nucleus were quite numerous, and showed somato- topical arrangement. The number of labeled cells in caudal parts of the medial and inferior vestibular nuclei was also large, and those in the medial vestibular nucleus were denser. Axons from these cells projected to the cervical, thoracic and lumbar spinal cord on both sides, with contralateral predominance. No somatotopic relations were found. The number of labeled cells of the rostal part of the inferior vestibular nucleus and the part of the medial vestibular nucleus at the same level was less than those in the parts mentioned above.These labeled cell axons also projected bilaterally to the cervical, thoracic and lumbar spinal cord, with ipsilateral predominance, and also showed no somatotopical arrangement. A few labeled cells were found in the superior vestibular nucleus, which projected predominently to the contralateral cervical spinal cord, although they could be found to project to the whole length of the spinal cord bilaterally. The anterogradely labeled terminal arborizations were constantly discovered in small localized regions of the caudal end of the medial and inferior vestibular nucleus, and the dorsal portion of the caudal part of the lateral vestibular nucleus. In the cervical and lumbar cord injected cases dense anterogradely labeled terminal arboriza- tion areas were found in the caudal end of the inferior and medial vestibular nuclei.