Olivocochlear Neuron Central Anatomy Is Normal in α9 Knockout Mice
Olivocochlear Neuron Central Anatomy Is Normal in α9 Knockout Mice
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DOI：
10.1007/s10162-008-0144-9
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发表时间：
2009-03-01
影响因子：
2.4
通讯作者：
Vetter, Douglas E.
中科院分区：
文献类型：
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作者：
Brown, M. Christian;Vetter, Douglas E.
在α 9烟碱乙酰胆碱受体亚单位缺失的转基因小鼠中研究橄榄耳蜗（OC）神经元。在该α 9基因敲除小鼠中，缺乏OC刺激的外周效应，并且外毛细胞下的OC神经元的外周末梢具有异常形态。为了解释这只小鼠明显正常的听力，有人提出通过耳蜗核的侧支进行中枢补偿。我们通过对OC神经元进行乙酰胆碱酯酶染色并在基因敲除小鼠、相同背景品系的野生型小鼠和CBA/CaJ小鼠中检查其形态来验证这一想法。敲除小鼠在OC神经元数量、树突模式和耳蜗核分支数量方面具有正常的OC系统。分支主要终止于耳蜗核的边缘区，少数终止于核心区，且各品系之间在分布和染色密度方面相似。这些数据表明，在α 9基因敲除小鼠中OC神经元的中枢形态没有明显变化，并且使得在这些小鼠中存在外周受体缺失的中枢补偿的想法不那么有吸引力。
Olivocochlear (OC) neurons were studied in a transgenic mouse with deletion of the alpha 9 nicotinic acetylcholine receptor subunit. In this alpha 9 knockout mouse, the peripheral effects of OC stimulation are lacking and the peripheral terminals of OC neurons under outer hair cells have abnormal morphology. To account for this mouse's apparently normal hearing, it has been proposed to have central compensation via collateral branches to the cochlear nucleus. We tested this idea by staining OC neurons for acetylcholinesterase and examining their morphology in knockout mice, wild-type mice of the same background strain, and CBA/CaJ mice. Knockout mice had normal OC systems in terms of numbers of OC neurons, dendritic patterns, and numbers of branches to the cochlear nucleus. The branch terminations were mainly to edge regions and to a lesser extent the core of the cochlear nucleus, and were similar among the strains in terms of the distribution and staining density. These data demonstrate that there are no obvious changes in the central morphology of the OC neurons in alpha 9 knockout mice and make less attractive the idea that there is central compensation for deletion of the peripheral receptor in these mice.