Effects of Kir2.1 gene transfection in cochlear hair cells and application of neurotrophic factors on survival and neurite growth of co-cultured cochlear spiral ganglion neurons

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• 作者：Qingwei Ruan ; Dong Chen ; Zhengmin Wang ; Fanglu Chi ; Jinchun He ; Jian Wang ; Shankai Yin
• 关键词：Spontaneous activity ; Inwardly rectifying K + Channel kir2.1 transfection ; Hair cells ; Spiral ganglion neurons ; Organ of corti
• 刊名：Molecular and Cellular Neuroscience
• 出版年：2010
• 出版时间：March 2010
• 年：2010
• 卷：43
• 期：3
• 页码：326-339
• 全文大小：6021 K

文摘

Immature inner hair cells (IHCs) produce spontaneous action potentials, which may be associated with the survival of spiral ganglion neurons (SGNs) during early development. Later, this activity ceases in part by the expression of Kir channels. In the present study, SGNs were co-cultured with organ of Corti in which a Kir2.1 channel was over-expressed in an attempt to block the spontaneous activity of IHCs. The over-expression led to a reduced survival and neurite growth accompanied by increased SGN apoptosis. The enhanced activation of apoptosis was consistent with the inhibition of the survival-promoting pathway and the disruption of [Ca²⁺]_i homeostasis. Furthermore, the effect of Kir2.1 over-expression can be reversed by exogenous neurotrophic factors (NTFs). These results are consistent with the hypothesis that the earlier-than-normal expression of Kir2.1 in HCs inhibits their spontaneous activity required for SGN survival and neurite growth.