大鼠胸腰段脊髓向下橄榄核的定位投射

目的　探讨大鼠胸腰段脊髓向下橄榄核的定位投射。方法　将菜豆白细胞凝集素 (PHA L)分别注入T5到L5的不同脊髓节段 ,顺行追踪脊髓到下橄榄核的投射。实验分为三个组 ,分别是T5 7、T8 10 、L2 5组。结果　T5 7组可以在MAO尾侧半近中间的位置观察到标记末梢 ,T8 10 组的标记末梢位于其稍外侧 ,L2 5组的标记末梢位于MAO尾侧半的末端 ;在DAO ,T5 7组的标记末梢出现在DAO的中间位置 ,T8 10 组的标记末梢位于其稍外侧 ,L2 5组的标记末梢出现在DAO的末端。结论　胸腰段脊髓到下橄榄核的投射存在着明确的定位投射关系 ,T5 L5段脊髓到MAO尾侧半和DAO的投射 ,表现出从胸段到腰段 ,标记末梢依次由内侧向外侧排列的规律。结合先前所做的胸腰段脊髓向小脑中央核的投射的研究 ,讨论了胸腰段脊髓、下橄榄核和小脑中央核之间的联系

Somatotopic Termination of the Thoracic and Lumber Segments of the Spino-olivary Fibers in the Rat

Objective Terminal sites of the spino olivary fibers (SOFs) were examined by the anterograde transport of phaseolus vulgaris leucoagglutinin (PHA L) in the rat. Methods The tracer was injected at varous spinal cord levels from T 5 to L 5. We divided the species into three groups, namely T 5 7 segments, T 8 10 segments and L 2 5 segments. The SOFs derived from the T 5 7 segments terminated the middle part of the caudal of the medial accessory olive (MAO), whereas the SOFs derived from the T 8 10 terminated slightly laterally, and the SOFs from the L 2 5 terminated more laterally. Results In the dorsal accessory olived (DAO), the SOFs derived from the T 5 7 segments terminated the middle of the dorsal accessory olived (DAO), followed laterally by those from the T 8 10 . Further laterally, the SOFs derived from the L 2 5 segments occupied the most lateral part of the DAO. Conclusion The present study suggests that there is a distinct somatotopic termination of the SOFs in the mediolateral order in the caudal MAO and the DAO. Associating with the previous study we have done about the projection from the thoracic and lumber cord to the cerebellar nuclie in the rat, we explore the relation between the thoracici and lumber cord, the inferior olivary and the cerebellar nuclei.