Willott J F, Bross L S
Department of Psychology, Northern Illinois University, DeKalb 60115, USA.
Brain Res Dev Brain Res. 1996 Feb 26;91(2):218-26. doi: 10.1016/0165-3806(95)00188-3.
Morphological measurements were made on histological sections of the anteroventral cochlear nucleus (AVCN) in mice of the DBA/2J and C57BL/6J strains to determine the effects of sensorineural cochlear pathology on the number, packing density, and size of neurons and on AVCN volume. Both strains possess alleles that cause progressive cochlear pathology initially affecting the organ of Corti: in DBA mice, hearing loss is evident at 4 weeks of age and progresses rapidly; in C57 mice, hearing loss begins after 2 months of age and progresses more slowly. In both strains AVCN volume decreased, some loss of neurons occurred, and these changes paralleled the progression of peripheral hearing loss. Central changes were rapid in DBA mice, but the ultimate magnitude of the changes in 1-year-old mice did not differ between strains. Both strains differed from well-hearing CBA/J mice which exhibited no changes in the AVCN measures. The findings indicate that pathology of the organ of Corti in adult mice results in degenerative changes in the cochlear nucleus. The data also support earlier findings indicating that, if cochlear pathology does not begin prior to young adulthood, the age of onset and duration of sensorineural impairment have little effect on the ultimate magnitude of central effects.
对DBA/2J和C57BL/6J品系小鼠的前腹侧耳蜗核（AVCN）组织切片进行形态学测量，以确定感音神经性耳蜗病变对神经元数量、堆积密度、大小以及AVCN体积的影响。这两个品系都携带导致进行性耳蜗病变的等位基因，最初影响柯蒂氏器：在DBA小鼠中，4周龄时听力损失明显且进展迅速；在C57小鼠中，2月龄后开始出现听力损失且进展较慢。在这两个品系中，AVCN体积均减小，出现了一些神经元丢失，并且这些变化与外周听力损失的进展情况平行。DBA小鼠的中枢变化迅速，但1岁小鼠中变化的最终程度在两个品系之间并无差异。这两个品系与听力正常的CBA/J小鼠不同，后者的AVCN测量指标未出现变化。研究结果表明，成年小鼠柯蒂氏器的病变会导致耳蜗核发生退行性变化。这些数据也支持了早期的研究结果，即如果耳蜗病变在成年早期之前未开始，感音神经性损伤的发病年龄和持续时间对中枢影响的最终程度影响很小。
