THE INNERVATION OF THE ORGAN OF CORTI IN THE RAT
THE INNERVATION OF THE ORGAN OF CORTI IN THE RAT
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DOI：
10.1016/0378-5955(93)90255-y
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发表时间：
1993-03-01
期刊：
影响因子：
2.8
通讯作者：
BRUNS, V
中科院分区：
文献类型：
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作者：
DANNHOF, BJ;BRUNS, V
迄今为止，我们对支配柯蒂氏器的传入和传出神经纤维的基底-顶端分布的了解还很片断。本研究旨在为全面分析耳蜗神经支配奠定基础。使用定量电子显微镜方法，研究了成年大鼠褐家鼠沿耳蜗管整个长度的所有耳蜗纤维的纤维密度。对初级骨螺旋层中的有髓和无髓神经纤维以及柯蒂管中外毛细胞（OHC）的传入和传出神经纤维进行计数。大鼠耳蜗由 19000 个神经纤维支配，其中 79% 为传入纤维，21% 为传出纤维。内毛细胞 (IHC) 由 14000 个传入纤维和 2000 个传出纤维支配。 OHC 由 1000 根传入纤维和 2000 根传出纤维支配。 IHC 传入神经、OHC 传入神经和 IHC 传出神经的最大纤维密度位于耳蜗中部。这对应于最大灵敏度频率范围所在的基底膜区域[8 kHz-31 kHz；凯利和马斯特顿，J. Comp。生理学。心理。 91, 930-936 (1977)]。 OHC 的传出神经纤维由两种不同的形态亚型组成：含有线粒体和神经管的大纤维（I 型）和含有神经丝的小纤维（II 型）。 I 型 OHC 传出神经的纤维密度从基底到顶点递减，对应于沿基底膜的频率色散。 II 型 OHC 传出神经的纤维密度在耳蜗基部和顶端处最大，在耳蜗中部最小。该最小值对应于最大灵敏度频率范围所在的基底膜区域。
To date our knowledge of the baso-apical distribution of the afferent and efferent nerve fibers innervating the organ of Corti is only fragmentary. This study makes an effort to lay the basis for a comprehensive analysis of cochlear innervation. Using a quantitative electronmicroscopic method, the fiber density of all cochlear fibers along the entire length of the cochlear duct was investigated in adult rats, Rattus norvegicus. Myelinated and unmyelinated nerve fibers in the primary osseous spiral lamina and afferent and efferent nerve fibers to the outer hair cells (OHCs) in the tunnel of Corti were counted. The rat cochlea is innervated by 19000 nerve fibers which consist of 79% afferent and 21% efferent fibers, The inner hair cells (IHCs) are innervated by 14000 afferent and 2000 efferent fibers. The OHCs are innervated by 1000 afferent and 2000 efferent fibers. The maximum fiber density of IHC afferents, OHC afferents and IHC efferents was found in the middle of the cochlea. This corresponds to the region at the basilar membrane where the frequency range of maximum sensitivity is located [8 kHz-31 kHz; Kelly and Masterton, J. Comp. Physiol. Psychol. 91, 930-936 (1977)]. The efferent nerve fibers to the OHCs consists of two different morphological sub-types: large fibers containing mitochondria and neurotubules (type I) and small fibers containing neurofilaments (type II). The fiber density of type I OHC efferents decreases from base to apex corresponding to the frequency dispersion along the basilar membrane. The fiber density of type II OHC efferents has maxima at the base and at the apex and a minimum in the middle of the cochlea. This minimum corresponds to the region at the basilar membrane where the frequency range of maximum sensitivity is located.