大鼠传出性前庭神经元的定量研究

Quantitative study of efferent vestibular system neurons in wistar rat

目的利用逆行荧光示踪剂研究前庭传出性神经元在脑干的分布、大小、数量和形态。方法 Wistar大鼠20只随机分为二组,实验组10只动物,在外周前庭注射红色逆行荧光示踪剂;对照组10只动物在外周前庭注射生理盐水。5d后处死动物,行脑干连续冰冻切片,在荧光显微镜及激光共聚焦显微镜下观察荧光细胞的分布、大小、数量及形态。结果 Wistar大鼠前庭传出神经元主要分布于双侧面神经膝的背外侧、内侧和桥脑网状结构核区,还有小部分位于面神经膝的腹侧;注射对侧脑干的细胞数目多于同侧。结论前庭传出性神经元在Wistar大鼠脑干呈散在分布。

Objective To study the morphology,distribution and the number of efferent vestibular neurons in wistar rat brainstems. Methods Totally 20 wistar rats were divided into experiment group（ 10 Wistar rats） and control group （ 10 wistar rats）. A retrograde neuron tracing method using micro- flurosphere（MFS） was delivered into the oval window. Five days after surgery, the animals were sacrificed by intracardial perfusion of saline followed by mixed aldehyde fixative. The brainstem were extracted, pastfixed for 2 hours and stored overnight. By means of a vibratome, the section were obtained and observed under the fluorescence microscope and the laser scanning eonfocal microscopy. Results The efferent vestibular neurons located bilaterally, with more somas in the brainstem contralateral to the labyrinth injection site. The distribution of the Micro - florosphere labelled neuron cell were mainly observed in three location. The first location was in the lateral portion of the facial nerve genu, the neurons was shaped mainly in oval shape and the size was mainly in 10 - 15μm. The second location was in the medial of the facial nerve genu ,the neurons was shaped mainly in oval or round shape and the size was mainly in 5 - 15μm. The third location is in the reticular nucleus, the neurons was shaped mainly in polygonal shape and the size was mainly in 20 - 30μm. Conclusions The distribution of efferent vestibular neurons was mainly in the lateral and medial portion of the facial nerve genu and the reticular nucleus.