Perkins R E, Morest D K
J Comp Neurol. 1975 Sep 15;163(2):129-58. doi: 10.1002/cne.901630202.
Cochlear innervation patterns were studied in infant cats and rats with the rapid Golgi method. Examination of thick serial sections and surface preparations with the differential interference contrast microscope (Nomarski optics) allowed direct visualization of individually impregnated spiral ganglion cells, complete with their peripheral processes and endings in the organ of Corti. Individually impregnated efferent fibers could be recognized as heavily varicose axons that project radially to endings beneath inner and outer hair cells after taking a tangential course in the intraganglionic spiral bundle. It was often possible to visualize unimpregnated hair cells in contact with the impregnated endings of both types of fibers. There are at least two types of spiral ganglion cells in the cochlea of the infant cat and rat. One type innervates only inner hair cells by means of radial fibers. These ganglion cells constitute the overwhelming majority of ganglion cells impregnated in our preparations, and each cell typically innervates two inner hair cells. Hence, these ganglion cells establish nearly "point-to-point" connections between the auditory nerve and the organ of Corti. The other type of ganglion cell innervates outer hair cells by means of long spiral fibers; each cell typically innervates many outer hair cells through the numerous angular enlargements and short end branches of its spiral fiber. In addition, a few of these spiral fibers also send branches to inner hair cells by means of short collaterals; it remains to be seen if such fibers also occur in mature cochleas. Efferent fibers have been traced to inner and outer hair cell regions. The simplest pattern is formed by fine beaded axons with only a few branches ending mainly beneath inner hair cells. More complex patterns are formed by larger axons with many branches ending beneath inner or outer hair cells. Many efferent fibers send branches to both inner and outer hair cells. Electrophysiological studies so far have not demonstrated different populations of units that clearly correspond to the spiral and radial fibers. Therefore, the physilogical differences between inner and outer hair cell innervation remain undefined.
采用快速高尔基法对幼猫和幼鼠的耳蜗神经支配模式进行了研究。使用微分干涉相差显微镜（诺马斯基光学系统）检查厚连续切片和表面标本，可直接观察到单个浸染的螺旋神经节细胞，以及它们的外周突及其在柯蒂氏器中的终末。单个浸染的传出纤维可被识别为高度曲张的轴突，这些轴突在螺旋神经节内束中呈切线方向走行后，径向投射至内、外毛细胞下方的终末。通常可以观察到未被浸染的毛细胞与这两种纤维的浸染终末相接触。幼猫和幼鼠的耳蜗中至少存在两种类型的螺旋神经节细胞。一种类型通过径向纤维仅支配内毛细胞。这些神经节细胞在我们的标本中占浸染神经节细胞的绝大多数，每个细胞通常支配两个内毛细胞。因此，这些神经节细胞在听神经和柯蒂氏器之间建立了近乎“点对点”的连接。另一种类型的神经节细胞通过长螺旋纤维支配外毛细胞；每个细胞通常通过其螺旋纤维的众多角状膨大及短的终末分支支配多个外毛细胞。此外，这些螺旋纤维中的一些还通过短的侧支向内毛细胞发出分支；这种纤维是否也存在于成熟耳蜗中还有待观察。传出纤维已被追踪至内、外毛细胞区域。最简单的模式由细的念珠状轴突形成，只有少数分支主要在内毛细胞下方终末。更复杂的模式由较大的轴突形成，有许多分支在内毛细胞或外毛细胞下方终末。许多传出纤维向内毛细胞和外毛细胞都发出分支。到目前为止，电生理研究尚未证明存在明显对应于螺旋纤维和径向纤维的不同单位群体。因此，内、外毛细胞支配的生理差异仍不明确。
