大鼠前庭核向脑干呕吐区的间接投射

INDIRECT PROJECTION FROM THE VESTIBULAR NUCLEUS TO THE EMETIC AREA IN BRAINSTEM IN THE RAT

前庭信息调节内脏活动的神经通路是产生运动病的结构基础,但至今尚未明了。本研究旨在探讨接受初级前庭传入信息的前庭核到脑干呕吐中枢的神经通路。向大鼠前庭内侧核和前庭下核内注入顺行追踪剂生物素化葡聚糖胺(BDA),向脑干呕吐区注入逆行追踪剂荧光金(FG),用荧光组织化学方法显示BDA顺行标记纤维和终末,在荧光显微镜下观察BDA顺行标记纤维和终末与荧光金逆行标记细胞的重叠区域。结果发现在延髓背侧巨细胞旁核(DPGi)、巨细胞网状核(Gi)和小细胞网状核(PCRt)有顺行标记纤维与逆行标记细胞的重叠。表明前庭核可能经DPGi、Gi和PCRt向呕吐区有间接投射,此结果为进一步揭示前庭信号引发恶心、呕吐的神经机制提供了形态学依据。

The pathway which the vestibular signals regulate the visceral function is the structural foundation of motion sickness. However, it is unclear up to now. This study aimed to investigate the pathway from vestibular nucleus which receives the primary vestibular signals to the emetic area. Anterograde tracer BDA was injected into the medial vestibular nucleus and inferior vestibular nucleus and the retrograde tracer FG was injected into the emetic area, and then the BDA-labeled fibers and terminals were visualized by fluorescence techniques. The overlapping area of the BDA-labelled fibers and FG-labelled neurons were detected under the fluorescent microscopy. As a result, the overlapping areas of the BDA-labelled fibers and FG-labelled neurons were found in the dorsal paragigantecellular nucleus （DPGi） ,gigantocellular reticular nucleus （Gi） and parvecellular reticular nucleus （PCRt）. The result shows that the DPGi, Gi and PCRt may serve as an important relay for the indirect projection from the vestibular nucleus to the emetic area in brainstem. The result of the present study may be helpful for elucidating the mechanism of the vestibular signals triggering nausea and vomiting.