Morphological and Physiological Studies for Age-Related Change in Gerbil's Cochlear Nucleus

沙鼠耳蜗核随年龄变化的形态学和生理学研究

基本信息

批准号：
03454410
负责人：
EDAMATSU Hideo
金额：
$ 2.5万
依托单位：
Kanazawa Medical University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1991
资助国家：
日本
起止时间：
1991 至 1993
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-03454410/
关键词：
GERBIL AGING AUDITORY FUNCTION ABR COCHLEAR NUCLEUS NEURAL DEGENERATION Vacuolation Presbycusis Auditory brainstem response Cochlear microphonics vacuole

项目摘要

A degenerative lesion of the auditory system of mongolian gerbil (Meriones unguiculatus) was reported by K.Morest et al., 1986. The lesion was evaculation confined to the cochlear nucleus (CN) and increased with age. This study was performed to explore an effect of age-related lesion in gerbil's CN on the auditory function. 30 gerbils from 21 days to 2 years and 3 months old were used. They have had no ear infection. The auditory function was electrophysiologically evaluated by recording of cochlear microphonics (CM) and auditory brain stem response (ABR). Then CN and cochlea were microscopically observed. Correlation of the occurrence of lesion was examined with change of CM and ABr.Evaculation in gerbil's CN began to appear at around 7 weeks of age and the lesion increased in number and size with age. Number of vacuoles in average was less than 5 for 7-week-old gerbils and more than 15 for over 4-month-old gerbils. Mean size of each vacuole was smaller than 50 mum^2 for the former ge … More rbils and became larger than 150 mum^2 for the latter. Unlikely with the age-related changes in the cochlear nucleus, no vacuole was seen in cochlea. CM thresholds of gerbils at the frequency range of 1 k - 8kHz increased with aging. The CM thresholds of 4-month-old gerbil were 20-30 dB lower than those of the over 2-year-old gerbils. Similarly with the change of CM thresholds, ABR thresholds increased 15-20 dB with their age. Latencies of ABR waves became elongated along with the increased thresholds. Inter-wave latencies between I and V were also more prolonged in over 2-year-old gerbils than in the younger gerbils. However this delay was almost same with the prolongation of latencies which was caused by the increased thresholds of ABR.The results of CM and ABR in this study showed that auditory function in the cochlea and brain stem pathway of gerbils reached adult levels at about 4 months of age and gradually decreased with age. So far we have not found the direct effect of lesions in the CN on the age-related auditory function of gerbils. Less

K.Morest等人，1986年报告了蒙古语Gerbil（Meriones unguilatus）的听觉系统的变性病变。在局限于人工耳蜗核（CN）上，随着年龄的增长而增加。 - 在Gerbil的CN中相关的病变，通过记录耳蜗麦克风（CM）和听觉脑干响应（ABR），在Gerbil的CN中，通过记录了听觉功能。几周的病变随着年龄的增长而增加。 GE ...后者大于150 MUM^2。 db降低了2岁以上的eSholds。在年轻的沙鼠中，这是战争的延长，这是由于ABR的增加而引起的延长。。