Keithley E M, Feldman M L
Hear Res. 1982 Dec;8(3):249-62. doi: 10.1016/0378-5955(82)90017-x.
Hair cells of Sprague-Dawley rats aged 2-33 months were counted in order to assess the magnitude, location and time course of cell degeneration. The mean number of hair cell places (hair cells plus phalangeal scars) was approximately 4700: 960 inner hair cell places and 3470 outer hair cell places. These numbers do not vary systematically with age. Hair cell degeneration was observed in all animals. At 31-33 months of age, animals had inner hair cell losses ranging from 1.6 to 4.2% and outer hair cell losses ranging from 2.1 to 23.3%. The loss of hair cells was greatest in the upper apex, where the 31-33-month-old animals had 3.1-9.2% inner hair cell losses and 7.4-46.8% outer hair cell losses. Outer hair cell losses were also large in the basal end, where inner hair cell losses were small. In the older animals, hair cell losses were consistently most prominent in the third row of outer hair cells. Following examination of the hair cell population, the ganglion cells in the apical region were evaluated in a number of cochleas. No significant correlation was found between the magnitude of inner hair cell and ganglion cell losses.
对2至33月龄的Sprague-Dawley大鼠的毛细胞进行计数，以评估细胞退化的程度、位置和时间进程。毛细胞位（毛细胞加指状瘢痕）的平均数约为4700个：960个内毛细胞位和3470个外毛细胞位。这些数字不会随年龄系统性变化。在所有动物中均观察到毛细胞退化。在31至33月龄时，动物的内毛细胞损失率为1.6%至4.2%，外毛细胞损失率为2.1%至23.3%。毛细胞损失在上部顶点处最为严重，31至33月龄的动物在此处的内毛细胞损失率为3.1%至9.2%，外毛细胞损失率为7.4%至46.8%。外毛细胞在基部末端的损失也很大，而此处内毛细胞损失较小。在较年长的动物中，外毛细胞第三排的毛细胞损失始终最为显著。在对毛细胞群体进行检查后，对多个耳蜗的顶端区域的神经节细胞进行了评估。未发现内毛细胞损失程度与神经节细胞损失之间存在显著相关性。
