中文摘要：

目的 观察大鼠前庭神经核复合体（VNC）内5-羟色胺（5-HT）样阳性终末与表达5-HT1A受体（5-HT1A）的前庭．臂旁核投射神经元之间的联系。方法运用逆行束路追踪和免疫荧光组织化学染色相结合的双重标记技术，在激光共焦显微镜下观察。结果将四甲基罗达明（TMR）注入臂旁核后，在双侧VNC的各个核团内均可观察到许多TMR逆标神经元，但以同侧为主。免疫荧光组织化学染色结果显示，在前庭内侧核（MVe）、前庭下核（SpVe）、前庭上核（SuVe）、前庭外侧核（LVe）、X核以及Y核的一些区域内，许多神经元表达5-HT1AR样免疫阳性，并可观察到大量5-HT样阳性纤维和终末。激光共焦显微镜下可进一步观察到一些TMR逆标神经元同时呈5-HT1A R样免疫阳性，且有部分5-HT样阳性终末与TMR／5-HT1AR双标神经元的胞体或树突形成密切接触。结论 提示5-HT可能通过5-HT1AR对前庭神经核复合体-臂旁核间的信息传递发挥调控作用。

英文摘要：

Objective To observe the relationship between 5-Hydroxytryptamine （5-HT）-like immunoreactive terminals and the vestibulo-parabrachial nucleus projection neurons which may express 5-HT1A receptor in the vestibular nuclear complex （VNC）. Methods Retrograded-tract tracing technique combined with double labeling of immunofluorescence histochemical was used, and the stained sections were observed under a confoeal laser-scarming microscope. Results Following injection of tetramethylrhedamine （TMR） into the parabrachial nucleus, many retrogradely labeled neurons were observed bilaterally within VNC, but with an ipsilateral predominance. histochemical staining showed that many neurons expressed 5-HT1A receptor-like immunoreactivity and a large number of 5-HT immunostained fibers or terminals were found in the medial, spinal, superior, lateral vestibular nucleus （MVe, SpVe, SuVe, LVe）, X nucleus and Y nucleus. Confocal laser-scanning microscopy revealed that some TMR-labeled neurons were 5-HT1AR immunopositive, and some of the cell bodies or dendrites of TMR/5-HT1AR double-labeled neurons were closely apposed by 5-HT-like immunoreactive terminals. Conclusion The present study suggests that 5-HT may modulate vestibular signals along the VNC-parabrachial nucleus pathway via 5-HT1A receptor.