Synaptic proteins are tonotopically graded in postnatal and adult type I and type II spiral ganglion neurons.
Synaptic proteins are tonotopically graded in postnatal and adult type I and type II spiral ganglion neurons.
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DOI：
10.1002/cne.22576
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发表时间：
2011-06-01
影响因子：
2.5
通讯作者：
Davis, Robin L.
中科院分区：
文献类型：
--
作者：
Flores-Otero, Jacqueline;Davis, Robin L.
在哺乳动物听觉系统的设计中固有的是将复杂的声音传递给高级神经中枢所必需的精度。这种转换需要Corti器官中独特的专门化，比如毛细胞受体的机械和电子特性是根据它们在信号编码中的特定角色量身定制的。电生理和免疫细胞化学表征表明，这一原理也适用于螺旋神经节的神经元，这一点由支配耳蜗高频区和低频区的神经元的明显不同的放电特征和突触蛋白分布证明。然而，了解这些特性是如何沿着耳蜗隔壁和I型和II型螺旋神经节神经元分布的精细结构，对于充分认识它们的功能意义是必要的。为了解决这一问题，我们通过免疫细胞化学标记在出生后和成人组织中评估了突触后AMPA受体亚基GluR2和GluR3以及突触前蛋白synaptophysin的定位。我们报道这些突触前和突触后蛋白相对于声位图分布相反，并且它们在每个神经元类别中均匀分布，因此从耳蜗的一端到另一端具有整体梯度。对于synaptophysin，一层额外的异质性被叠加在正交于张力轴上。与靠近前庭阶梯的神经元相比，靠近鼓室阶梯的神经元中抗突触素抗体水平最高。此外，我们注意到，在出生后制备中观察到的蛋白质分布模式在成人组织切片中基本上保留了下来，这表明这些特征是完全发育的耳中的螺旋神经节神经元的特征。
Inherent in the design of the mammalian auditory system is the precision necessary to transduce complex sounds and transmit the resulting electrical signals to higher neural centers. Unique specializations in the organ of Corti are required to make this conversion, such that mechanical and electrical properties of hair cell receptors are tailored to their specific role in signal coding. Electrophysiological and immunocytochemical characterizations have shown that this principle also applies to neurons of the spiral ganglion, as evidenced by distinctly different firing features and synaptic protein distributions of neurons that innervate high- and low-frequency regions of the cochlea. However, understanding the fine structure of how these properties are distributed along the cochlear partition and within the type I and type II classes of spiral ganglion neurons is necessary to appreciate their functional significance fully. To address this issue, we assessed the localization of the postsynaptic AMPA receptor subunits GluR2 and GluR3 and the presynaptic protein synaptophysin by using immunocytochemical labeling in both postnatal and adult tissue. We report that these presynaptic and postsynaptic proteins are distributed oppositely in relation to the tonotopic map and that they are equally distributed in each neuronal class, thus having an overall gradation from one end of the cochlea to the other. For synaptophysin, an additional layer of heterogeneity was superimposed orthogonal to the tonotopic axis. The highest anti-synaptophysin antibody levels were observed within neurons located close to the scala tympani compared with those located close to the scala vestibuli. Furthermore, we noted that the protein distribution patterns observed in postnatal preparations were largely retained in adult tissue sections, indicating that these features characterize spiral ganglion neurons in the fully developed ear.
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影响因子：
2.8
作者：
Berglund, AM;Benson, TE;Brown, MC
通讯作者：
Brown, MC
影响因子：
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作者：
Chen, Zhiqiang;Kujawa, Sharon G.;Sewell, William F.
通讯作者：
Sewell, William F.
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3.5
作者：
GAARDSVOLL, H;OBENDORF, D;BOCK, E
通讯作者：
BOCK, E
影响因子：
56.9
作者：
LIBERMAN, MC
通讯作者：
LIBERMAN, MC
影响因子：
2.5
作者：
Adamson, CL;Reid, MA;Davis, RL
通讯作者：
Davis, RL