CHANGES IN THE TONOTOPIC MAP OF THE DORSAL COCHLEAR NUCLEUS FOLLOWING INDUCTION OF COCHLEAR LESIONS BY EXPOSURE TO INTENSE SOUND
CHANGES IN THE TONOTOPIC MAP OF THE DORSAL COCHLEAR NUCLEUS FOLLOWING INDUCTION OF COCHLEAR LESIONS BY EXPOSURE TO INTENSE SOUND
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DOI：
10.1016/0378-5955(92)90118-7
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发表时间：
1992-05-01
期刊：
影响因子：
2.8
通讯作者：
KAPLAN, CR
中科院分区：
文献类型：
--
作者：
KALTENBACH, JA;CZAJA, JM;KAPLAN, CR
将仓鼠暴露于足以引起静纤毛病变的强度（10 kHz）和持续时间。目的是确定耳蜗背核（DCN）的音调图如何重新调整受体敏感性的损失。神经群体阈值和tonotopic组织映射在DCN的表面在正常的未暴露的动物和那些显示色调诱导的病变。结果表明，耳蜗病变的特点主要是损失的静纤毛在有限的一部分Corti器官引起的变化，在相应的区域的tonotopic地图，主要反映的变化的形状和阈值的神经调谐曲线。在许多情况下，病变的中心在DCN中表示为音调分布图中的明显特征频率（CF）间隙，其中反应极弱或不存在。在几乎所有的情况下，代表病变中心的标测图区域都以一个接近恒定CF的扩展区域为边界，这是一个表面上暗示标测图重组的特征。这些扩大的地图地区有异常的提示阈值，并显示其他功能，表明他们的CF已被转移向下的扭曲和恶化的原始提示。这种神经调谐的变化与其他人在听觉神经中观察到的类似，因此似乎具有外周起源。因此，没有必要援引耳蜗核的可塑性变化来解释音调定位图中观察到的变化。
Hamsters were exposed to intense tones (10 kHz) al levels and durations sufficient to cause stereocilia lesions. The purpose was to determine how the tonotopic map of the dorsal cochlear nucleus (DCN) readjusts to loss of receptor sensitivity. Neural Population thresholds and tonotopic organization was mapped over the surface of the DCN in normal unexposed animals and those showing tone-induced lesions. The results indicate that cochlear lesions characterized mainly by loss of stereocilia in a restricted portion of the organ of Corti cause changes in a corresponding region of the tonotopic map which reflect primarily changes in the shape and thresholds of neural tuning curves. In many cases the center of the lesion was represented in the DCN as a distinct characteristic frequency (CF) gap in the tonotopic map in which responses were either extremely weak or absent. In almost all cases the map area representing the center of the lesion was bordered by an expanded region of near-constant CF, a feature superficially suggestive of map reorganization. These expanded map areas had abnormal tip thresholds and showed other features suggesting that their CFs had been shifted downward by distortion and deterioration of their original tips. Such changes in neural tuning are similar to those observed by others in the auditory nerve following acoustic trauma, and thus would seem to have a peripheral origin. Thus, it is not necessary to invoke plastic changes in the cochlear nucleus to explain the changes observed in the tonotopic map.