Evolutionary changes in the cochlea and labyrinth: Solving the problem of sound transmission to the balance organs of the inner ear
Evolutionary changes in the cochlea and labyrinth: Solving the problem of sound transmission to the balance organs of the inner ear
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DOI：
10.1002/ar.a.20306
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发表时间：
2006-04-01
期刊：
影响因子：
--
通讯作者：
Amin, N
中科院分区：
文献类型：
--
作者：
Carey, J;Amin, N
这篇综述文章研究了脊椎动物内耳的进化适应，允许选择性激活听觉或前庭毛细胞，尽管两者都被安置在同一个骨囊中。随着对诸如上级管裂开综合征和扩大前庭水管综合征等临床病症的认识，将声刺激与内耳中的前庭终末器官分离的问题最近再次出现。在这些综合征中，耳囊的解剖缺陷改变了听觉和前庭刺激的功能分离，并导致前庭反射响应声音的病理激活。这篇综述表明，虽然部分上级的迷路（椭圆囊和半规管）一直保持相当恒定的整个进化过程中，部分下级（球囊和其他耳石，黄斑，和听觉终末器官）已经看到了相当大的变化，许多适应的发展听觉功能。其中包括一个相对刚性的膜迷路壁，耳囊，浸泡在外淋巴液中的膜迷路，外淋巴管通道的声压变化远离前庭器官，和不同的操作频率前庭与听觉上皮。即使在正常人耳中，迷路对响亮的咔嗒声或音调的声学敏感性也足以在标准临床测试中进行测量，即前庭诱发肌源性电位测试。
This review article examines the evolutionary adaptations in the vertebrate inner ear that allow selective activation of auditory or vestibular hair cells, although both are housed in the same bony capsule. The problem of separating acoustic stimuli from the vestibular end organs in the inner ear has recently reemerged with the recognition of clinical conditions such as superior canal dehiscence syndrome and enlarged vestibular aqueduct syndrome. In these syndromes, anatomical defects in the otic capsule alter the functional separation of auditory and vestibular stimuli and lead to pathological activation of vestibular reflexes in response to sound. This review demonstrates that while the pars superior of the labyrinth (utricle and semicircular canals) has remained fairly constant throughout evolution, the pars inferior (saccule and other otolith, macular, and auditory end organs) has seen considerable change as many adaptations were made for the development of auditory function. Among these were a relatively rigid membranous labyrinth wall, a variably rigid otic capsule, immersion of the membranous labyrinth in perilymph, a perilymphatic duct to channel acoustic pressure changes away from the vestibular organs, and different operating frequencies for vestibular versus auditory epithelia. Even in normal human ears, acoustic sensitivity of the labyrinth to loud clicks or tones is retained enough to be measured in a standard clinical test, the vestibular-evoked myogenic potential test.