大鼠前庭神经核复合体内5-羟色胺1A受体的分布

为了研究5-羟色胺1A受体(5-HT1AR)亚型在大鼠前庭神经核复合体(VNC)内的分布情况,本文采用免疫组织化学方法,在光学显微镜下对5-HT1AR亚型免疫阳性结构进行了观察。结果显示:5-HT1AR免疫阳性产物在VNC各个核团全长均有分布,主要定位于VNC神经元的胞体和近侧端树突,呈弥散分布,但在胞浆中也观察到许多染色深浅不同、分布不均匀的点状阳性结构。其中5-HT1AR样阳性神经元在前庭内侧核的全长呈密集分布,在前庭下核的尾段呈中等密度分布,在前庭上核、前庭外侧核和X核的全长、前庭下核的吻段和中段以及Y核的中、尾段均呈低密度分布,Y核的吻侧呈稀疏分布。本文结果提示,5-HT1AR阳性结构广泛地分布于大鼠VNC内,它们可能在介导5-HT对神经元活动的调节,参与前庭信息的整合与加工方面发挥重要作用。

DISTRIBUTION OF 5-HT1A RECEPTOR IN THE RAT VESTIBULAR NUCLEAR COMPLEX

To explore the distribution of 5-hydroxytryptamine(5-HT)_ 1A receptor(5-HT_ 1A R) in the rat vestibular nuclear complex (VNC), 5-HT_ 1A R immunoreactive structure were observed by the immunohistochemical technique under the light microscope. The results showed that 5-HT_ 1A R-immunoreactivities were found in all the individual nuclei along the whole rostro-caudal extent of VNC, and the immunoreactive products were diffusely distributed in the cell bodies and proximal dendries. A lot of 5-HT_ 1A R-immunoreactive puncta showing the different density, however, were distributed unevenly in the cytoplasms. The highest density of 5-HT_ 1A R immunoreactive neurons were observed within the whole medial vestibular nucleus, moderate density of 5-HT_ 1A R positive neurons were detected in the caudal part of the inferior vestibular nucleus. The low density of 5-HT_ 1A R immunoreactive neurons were observed in the superior, lateral, X nucleus, the oral-middle segment of the inferior vestibular nucleus and in the middle-caudal portion of Y nucleus. Very weak 5-HT_ 1A R immunoreactivity was found in the rostral part of Y nucleus. The present results indicate that 5-HT_ 1A R immunoreactive products is widely distributed in the rat VNC and might play an important role in regulating the activities of VNC neurons induced by 5-HT, by which participating in the integration and processing of vestibular signals.