DISTRIBUTION AND DENDRITIC FEATURES OF 3 GROUPS OF RAT OLIVOCOCHLEAR NEURONS - A STUDY WITH 2 RETROGRADE CHOLERA-TOXIN TRACERS
DISTRIBUTION AND DENDRITIC FEATURES OF 3 GROUPS OF RAT OLIVOCOCHLEAR NEURONS - A STUDY WITH 2 RETROGRADE CHOLERA-TOXIN TRACERS
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DOI：
10.1007/bf00213596
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发表时间：
1992-01-01
期刊：
影响因子：
--
通讯作者：
MUGNAINI, E
中科院分区：
文献类型：
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作者：
VETTER, DE;MUGNAINI, E
与辣根过氧化物酶缀合的霍乱毒素 B 亚基和未缀合的霍乱毒素 B 亚基是逆行道追踪的有用工具。将任一霍乱毒素制剂单侧注射到耳蜗中都会导致橄榄耳蜗神经元的良好标记，这可以通过细胞体、树突甚至轴突的高尔基样填充来判断。通过这种方法，我们研究了 Sprague-Dawley 大鼠中橄榄耳蜗神经元的光学显微镜细胞学和拓扑分布，并计算了它们的数量。大鼠的橄榄耳蜗系统可分为三个亚组。外侧橄榄耳蜗系统由仅位于同侧外侧上橄榄（相对于测试耳蜗）内的小细胞组成，内侧橄榄耳蜗系统由分布在梯形体腹侧核两侧的大细胞组成，符合之前的地形描述。第三个小组由大约 110 个大单元组成。这里称为壳神经元，被两种示踪剂标记，但在以前的研究中没有得到很好的认识。壳神经元及其树突包围同侧，并在较小程度上包围对侧、外侧上橄榄。外侧橄榄耳蜗神经元不会将其树突投射到外侧上橄榄灰质之外，而属于壳神经元的树突则渗透到该核以及其他听觉脑干核和周围的网状结构中。内侧橄榄耳蜗神经元通常将树突从腹侧投射到梯形体中，并且总是被排除在外侧上橄榄之外。
Cholera toxin B subunit conjugated to horseradish peroxidase, and unconjugated cholera toxin B Subunit are useful tools for retrograde tract tracing. Unilateral injection of either cholera toxin preparation into the cochlea results in excellent labeling of olivocochlear neurons, as judged by the Golgi-like filling of cell bodies, dendrites, and even axons. By this approach, we have studied the light microscopic cytology and topographic distribution of olivocochlear neurons and counted their numbers in Sprague-Dawley rats. The olivocochlear system of rats can be divided into three subgroups. The lateral olivocochlear system, composed of small cells located exclusively within the ipsilateral lateral superior olive (relative to the test cochlea), and a medial olivocochlear system, composed of large cells bilaterally dispersed within the ventral nucleus of the trapezoid body, conformed to previous topographic descriptions. A third subgroup of approximately 110 large cells. herein termed shell neurons, was labeled by both tracers, but was not well recognized in previous studies. Shell neurons and their dendrites surround the ipsilateral, and to a much lesser extent the contralateral, lateral superior olive. Lateral olivocochlear neurons do not project their dendrites outside the gray matter of the lateral superior olive, while dendrites belonging to shell neurons penetrate into that nucleus as well as into other auditory brain stem nuclei and the surrounding reticular formation. Medial olivocochlear neurons usually project dendrites ventrally into the trapezoid body and are always excluded from the lateral superior olive.