Expression of the Kv3.1 potassium channel in the avian auditory brainstem
Expression of the Kv3.1 potassium channel in the avian auditory brainstem
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DOI：
10.1523/jneurosci.21-02-00485.2001
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发表时间：
2001-01-15
影响因子：
5.3
通讯作者：
Perney, TM
中科院分区：
文献类型：
--
作者：
Parameshwaran, S;Carr, CE;Perney, TM
肖氏钾通道Kv3.1是一种具有高激活阈值的延迟整流器，在鸟类听觉脑干的时间编码核中表达。Kv3.1 mRNA在家鸽和鸡耳蜗大细胞核（NM）和板层核（NL）均有表达。Western印迹分析表明，针对大鼠Kv3.1（rKv3.1）的合成肽序列提出的抗体特异性地识别大鼠和鸡突触体制剂中相同的92 kDa蛋白条带。使用该抗rKv3.1抗体的免疫组织化学分析揭示了Kv3.1免疫反应性沿着仓鸮NM和NL的tonotopic轴的显著梯度和在鸡中的不太显著的梯度。Kv3.1免疫产物的精确定位通过电子显微镜解决。在猫头鹰和鸡中，Kv3.1在NM和NL的突触后被靶向。Kv3.1蛋白在两种鸟之间的定位的主要差异是Kv3.1在仓鸮NL区域的NM轴突和终末中的表达。Kv3.1通道的这种位置支持其在侵入突触前末梢时减少动作电位宽度的假设功能。突触前定位可能是一种特殊化，使猫头鹰NM神经元传输高频的时间信息，几乎没有抖动。
The Shaw-like potassium channel Kv3.1, a delayed rectifier with a high threshold of activation, is expressed in the time coding nuclei of the bird auditory brainstem. In both barn owls and chickens, Kv3.1 mRNA was expressed in the cochlear nucleus magnocellularis (NM) and the nucleus laminaris (NL). Western blot analysis showed that an antibody raised against the synthetic peptide sequence of rat Kv3.1 (rKv3.1) specifically recognized the same 92 kDa protein bands in both rat and chicken synaptosomal preparations. Immunohistochemical analyses using this anti-rKv3.1 antibody revealed a prominent gradient in Kv3.1 immunoreactivity along the tonotopic axis of the barn owl NM and NL and a less prominent gradient in the chicken. The precise localization of the Kv3.1 immunoproduct was resolved by electron microscopy. In both the owl and the chicken, Kv3.1 was targeted postsynaptically in NM and NL. The major difference in localization of Kv3.1 protein between the two birds was the expression of Kv3.1 in the NM axons and terminals in the region of the barn owl NL. This location of Kv3.1 channels supports its postulated function in reducing the width of action potentials as they invade the presynaptic terminal. The presynaptic localization may be a specialization for enabling neurons in owl NM to transmit high-frequency temporal information with little jitter.