大鼠前庭脊核和X细胞群向脑桥核的直接投射

Direct projection from the spinal vestibular nucleus and nucleus X to the pontine nuclei in rat

目的：应用菜豆白细胞凝集素（PHA-L）顺行追踪和荧光金（FG）逆行追踪技术研究前庭脊核和X细胞群向脑桥核的直接投射.方法：SD大鼠随机分为PHA-L注射组和FG注射组.将顺行神经追踪剂PHA-L电泳至前庭脊核和X细胞群,逆行神经追踪剂FG分别电泳至脑桥核的外侧亚核和内侧亚核,动物存活7 d,灌流固定后,脑干作冠状冷冻切片,然后进行免疫组织化学显色.结果：PHA-L注射于前庭脊核后,顺行标记纤维和终末主要分布在对侧脑桥核的外侧亚核、内侧亚核及脑桥网状被盖核;FG分别注射于脑桥核的外侧和内侧亚核后,逆行标记细胞仅分布在对侧前庭脊核和X细胞群.结论：前庭脊核和X细胞群向对侧脑桥核的外侧和内侧亚核有直接的纤维投射,该投射可能与前庭-眼反射的调节有关.

Objective： To study the direct projection from the spinal vestibular nucleus and nucleus X to the pontine nuclei by using phaseolus vulgaris leucoagglutinin （PHA-L） anterograde tracing and fluorogold （FG） retrograde tracing. Methods： Total 12 adult rats were divided into PHA-L injection group and FG injection group. By using electrophoreses methods, PHA-L was injected into the spinal vestibular nucleus and nucleus X and FG was injected into the lateral pontine nucleus and medial pontine nucleus. The animals were allowed to survive for 7 days, and then perfusion-fixed. The brain stems were transversely sectioned and stained by immunohistochemistry. Results： The PHA-L labelled fibers and terminals were mainly found in the contralateral lateral pontine nucleus and medial pontine nucleus, and reticulotegmental nucleus of pons. The FG labelled neurons were only distributed in the contralateral spinal vestibular nucleus and nucleus X. Conclusion： The results show that the spinal vestibular nucleus and nucleus X have direct projections to the contralateral lateral pontine nucleus and medial pontine nucleus. The direct projections could be involved in the regulation of vestibulo-ocular reflex.