Altered cochlear innervation in developing and mature naked and Damaraland mole rats
Altered cochlear innervation in developing and mature naked and Damaraland mole rats
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DOI：
10.1002/cne.24682
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发表时间：
2019-10-01
影响因子：
2.5
通讯作者：
Pyott, Sonja J.
中科院分区：
文献类型：
--
作者：
Barone, Catherine M.;Douma, Sytse;Pyott, Sonja J.
与许多其他啮齿类动物相比，裸鼹鼠（Heterocephalus glaber）具有较高的听觉阈值，较差的频率选择性和有限的声音定位能力。由于耳蜗负责编码和传递听觉信号到大脑，我们使用免疫荧光和定量图像分析来检测成熟和发育中的裸鼹鼠的耳蜗神经分布，并将其与小鼠（Mus musculus）、沙鼠（Meriones unguiculatus）和达马拉兰鼹鼠（Fukomys damarensis）（另一种地下啮齿动物）进行比较。与小鼠和沙鼠相比，我们观察到裸鼹鼠和达马拉兰鼹鼠的传入和传出神经支配及其发育精细模式的变化。然而，这些变化在裸鼹鼠和达马拉兰鼹鼠之间并不总是相似的。最明显的是，裸鼢鼠和大鼠的内毛细胞传入带密度降低，而外毛细胞传入带密度增加。裸鼹鼠和达马拉兰鼹鼠也表现出外侧和内侧传出终端密度降低。在发育过程中，裸鼹鼠的传入和传出神经在出生后重组减少和延长。达马拉兰鼹鼠没有显示出出生后重组的证据。两种地下啮齿动物之间以及更广泛的啮齿动物之间的耳蜗神经支配差异，为耳蜗增强频率敏感性和声音定位、听觉系统成熟以及对地下环境的进化适应机制提供了深入的了解。
Compared to many other rodent species, naked mole rats (Heterocephalus glaber) have elevated auditory thresholds, poor frequency selectivity, and limited ability to localize sound. Because the cochlea is responsible for encoding and relaying auditory signals to the brain, we used immunofluorescence and quantitative image analysis to examine cochlear innervation in mature and developing naked mole rats compared to mice (Mus musculus), gerbils (Meriones unguiculatus), and Damaraland mole rats (Fukomys damarensis), another subterranean rodent. In comparison to mice and gerbils, we observed alterations in afferent and efferent innervation as well as their patterns of developmental refinement in naked and Damaraland mole rats. These alterations were, however, not always shared similarly between naked and Damaraland mole rats. Most conspicuously, in both naked and Damaraland mole rats, inner hair cell (IHC) afferent ribbon density was reduced, whereas outer hair cell afferent ribbon density was increased. Naked and Damaraland mole rats also showed reduced lateral and medial efferent terminal density. Developmentally, naked mole rats showed reduced and prolonged postnatal reorganization of afferent and efferent innervation. Damaraland mole rats showed no evidence of postnatal reorganization. Differences in cochlear innervation specifically between the two subterranean rodents and more broadly among rodents provides insight into the cochlear mechanisms that enhance frequency sensitivity and sound localization, maturation of the auditory system, and the evolutionary adaptations occurring in response to subterranean environments.