Henson M M, Xie D H, Wynne R H, Wilson J L, Henson O W
Department of Surgery, University of North Carolina, Chapel Hill 27599, USA.
Hear Res. 1996 Dec 1;102(1-2):99-115. doi: 10.1016/0378-5955(96)00153-0.
The course and distribution of medial olivocochlear (MOC) nerve fibers were studied in the cochlea of the mustached bat. This animal is of interest because of the very sharp tuning of the ear and fine frequency resolution in small frequency bands near 60 and 90 kHz. The MOC fibers arise from about 400 cells in the dorsomedial periolivary (DMPO) nucleus and they are distributed to approximately 4500 outer hair cells (OHCs), resulting in an average OHC unit size of 11.25. Individual fibers appear to have a small number of branches and each branch entering the tunnel of Corti terminates on a patch of OHCs. The patch size is typically 1-3 OHCs with the smallest average patch sizes in the regions tuned to 60 and 90 kHz. The majority of the MOC terminals are derived from the contralateral DMPO. Contralateral vs. ipsilateral projecting fibers are not preferentially distributed within any of the three rows of OHCs or within specific regions throughout most of the cochlea. It can be concluded that the main differences between the mustached bat's MOC system and that of most other mammals are: (1) origin from a single nucleus; (2) relatively small sizes of the patches; (3) a single terminal on each OHC; (4) a gradient in the size of the terminals but not in the number of terminals from row to row or from base to apex.
对髭蝠耳蜗内的内侧橄榄耳蜗（MOC）神经纤维的走行和分布进行了研究。这种动物备受关注，因为其耳朵具有非常敏锐的调谐能力以及在60和90千赫兹附近的小频段内具有精细的频率分辨率。MOC纤维起源于背内侧橄榄周核（DMPO）中的约400个细胞，并分布到大约4500个外毛细胞（OHC），导致平均每个OHC单元的大小为11.25。单个纤维似乎有少量分支，并且每个进入柯蒂氏管的分支都终止于一片OHC上。这片OHC的大小通常为1 - 3个细胞，在调谐到60和90千赫兹的区域平均片层大小最小。大多数MOC终末来自对侧的DMPO。在大多数耳蜗中，对侧与同侧投射纤维在三排OHC中的任何一排内或特定区域内都没有优先分布。可以得出结论，髭蝠的MOC系统与大多数其他哺乳动物的MOC系统之间的主要差异在于：（1）起源于单个核；（2）片层相对较小；（3）每个OHC上有单个终末；（4）终末大小存在梯度，但从一排到另一排或从基部到顶部终末数量没有梯度。
