Postnatal Changes in the Afferent Innervation of Hair Cells in the Rodent Cochlea

成年哺乳动物耳蜗内至少含有两种形态的螺旋神经节神经元。I型螺旋神经节细胞通过粗大的放射状纤维与内毛细胞联系，而II型螺旋神经节细胞通过较细的外螺旋纤维与外毛细胞联系。然而，在新生耳蜗中，螺旋神经节细胞看起来是一个均匀的群体，一些螺旋神经节细胞似乎接触内毛细胞和外毛细胞。本研究以豚鼠和仓鼠为对象，从单细胞水平研究外毛细胞的螺旋神经节细胞神经支配。这项研究的总体目标是通过广泛研究II型神经元的解剖发育来获得对其在听力中的作用的更多见解。这样一项系统的研究将有助于进一步解决成人神经支配模式的产生。

The adult mammalian cochlea contains at least two morphological types of spiral ganglion neurons. Type-I spiral ganglion cells contact inner hair cells via thick radial fibers while type-II spiral ganglion cells contact outer hair cells via thinner outer spiral fibers. However, in newborn cochlea spiral ganglion cells appear as a homogeneous population, and some spiral ganglion cells appear to contact both inner and outer hair cells. This research on guinea pigs and hamsters will focus on the spiral ganglion cell innervation of outer hair cells at a single- cell level. The overall objective of this research is to gain additional insights into the role of type-II neurons in hearing by extensively studying their anatomical development. Such a systematic study will help to further resolve how adult innervation patterns arise.