中文摘要：

目的探讨猫橄榄耳蜗神经元的分布和向内耳的投射特征。方法11只成年猫随机分为两组，实验组8只，左侧耳蜗鼓阶内注射1％霍乱毒素B亚单位，右侧耳蜗鼓阶注射5％荧光金，对照组3只，双侧耳蜗均注射生理盐水。动物饲养7d后处死，脑干连续冰冻切片，免疫荧光处理，荧光显微镜观察被标记的橄榄耳蜗神经元。结果实验组每只动物被霍乱毒素B亚单位和荧光金标记的橄榄耳蜗神经元平均总数为（3210±168）个，分为外侧橄榄耳蜗神经元[（2298±120）个]和内侧橄榄耳蜗神经元[（913±64）个]。根据投射特征可将被标记的神经元分为三种不同类型：只投射到同侧耳蜗的神经元，只投射到对侧耳蜗的神经元，既向同侧又向对侧耳蜗投射的双标记神经元，其中双标记神经元在外侧橄榄耳蜗神经元和内侧橄榄耳蜗神经元中分别占3．9％和15．1％。对照组未观察到被标记的橄榄耳蜗神经元。结论猫的橄榄耳蜗系统中存在三种不同投射特征的神经元，其中双侧投射的神经元在外侧橄榄耳蜗神经元和内侧橄榄耳蜗神经元中均有分布。

英文摘要：

Objective To investigate the distribution and projective feature of cat olivocochlear neurons. Methods Eleven adult cats were divided into two groups randomly. The experimental group of eight cats was injected of 1% cholera toxin B （CTB） to the left cochlea, while injected of 5% fluoro gold （FG） to the right cochlea. The control group of three cats was injected of saline to bilateral cochlea. After a survival time of 7 days, serial frozen sections were cut in the cat brainstem. All the sections were processed by immunofluorescent procedure for CTB and FG, and the labeled olivocochlear neurons were observed by fluorescent microscope. Results In the experimental group, the mean total of olivocochlear neurons labeled by CTB and FG was 3210 ±168, including lateral olivocochlear neurons （LOC, 2298 ±120） and medial olivocochlear neurons （MOC, 913 ±64 ）. The labeled neurons were divided into three different types according to their feature of projection： neurons which only projected to the ipsilateral cochlea, neurons which only projected to the contralateral cochlea, and double-labeled neurons which projected both to the ipsilateral and contralateral cochlea, but the double-labeled neurons comprised 3.9% and 15.1% in the LOC and MOC system respectively. No labeled neurons were found in the control group. Conclusions There are three types of neurons in the cat olivocochlear system cochlea may distribute both in the LOC and MOC system.