DEVELOPMENTAL ALTERATIONS IN THE FREQUENCY MAP OF THE MAMMALIAN COCHLEA
DEVELOPMENTAL ALTERATIONS IN THE FREQUENCY MAP OF THE MAMMALIAN COCHLEA
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DOI：
10.1038/341147a0
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发表时间：
1989-09-14
期刊：
影响因子：
64.8
通讯作者：
DALLOS, P
中科院分区：
文献类型：
--
作者：
ECHTELER, SM;ARJMAND, E;DALLOS, P
听毛细胞沿着耳蜗长度的位置决定了它对声音频率最敏感。位于耳蜗近端（基部）附近的感受器受到高频声音的最大刺激;那些依次占据更远（顶端）位置的感受器对逐渐降低的频率反应最好1。目前，还不清楚这个频率位置图是如何与耳蜗的发育相关的。根据对发育中的小鸡进行的声损伤实验2和对发育中的沙鼠进行的耳蜗电位记录3 - 5，有人提出，这种映射可能是通过耳蜗沿着频率空间编码的系统性变化而产生的。其他人从发育中的哺乳动物6和鸡7的耳蜗神经记录中得出的频率调谐曲线推断，耳蜗频率位置图在整个发育过程中保持稳定。我们分析了从沙鼠螺旋神经节细胞在基底耳蜗内的恒定位置获得的频率调谐曲线，并在这里报告说，这些细胞在出生后的第二和第三周之间的最佳响应频率显著增加（高达1.5倍频程）。这些录音提供了哺乳动物耳蜗的tonotopic组织的发展变化的直接证据。
THE position of an auditory hair cell along the length of the cochlea determines the sound frequency to which it is most sensitive. Receptors located near the proximal end (base) of the cochlea are maximally stimulated by high-frequency sounds; those occupying successively more distal (apical) positions respond best to progress-ively lower frequencies1. At present, it is unclear how this frequency place map emerges with respect to the development of the cochlea. It has been suggested, on the basis of acoustic trauma experiments with developing chicks2and cochlear potential recordings3–5from developing gerbils, that this map may arise through systematic changes in the spatial encoding of frequency along the cochlea. Others have inferred from frequency tuning curves derived from auditory-nerve recordings in developing mammals6and chicks7, that the cochlear frequency-place map remains stable throughout development. We analysed frequency tuning curves obtained from gerbil spiral ganglion cells at a constant location within the basal cochlea, and report here that these cells undergo significant increases (up to 1.5 octaves) in their best-response frequencies between the second and third weeks of postnatal life. These recordings provide direct evidence for developmental changes in the tonotopic organization of the mammalian cochlea.