Acid-sensing ion channels (ASICs) influence excitability of stellate neurons in the mouse cochlear nucleus
Acid-sensing ion channels (ASICs) influence excitability of stellate neurons in the mouse cochlear nucleus
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DOI：
10.1007/s00359-019-01365-x
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发表时间：
2019-08
期刊：
影响因子：
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通讯作者：
Z. Çakır;Caner Yildirim;İlay Buran;Ebru Önalan;R. Bal
中科院分区：
文献类型：
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作者：
Z. Çakır;Caner Yildirim;İlay Buran;Ebru Önalan;R. Bal
酸敏离子通道(ASIC)是与电压无关的质子门控通道。在这项研究中，我们旨在验证ASICs是否可能参与改变耳蜗核(CN)星状细胞的兴奋性的假说。我们检测了ASIC1、ASIC2和ASIC3在BALB/小鼠CN中的基因表达。采用全细胞膜片钳技术研究星状细胞的ASIC电流。在电压钳实验中，应用pH 50为5.84的2-[N-吗啡-乙磺酸]-正常人工脑脊液(MES-ACSF)记录内向电流。阿米洛利以剂量依赖方式抑制酸诱导的电流。胞外Ca~(2+)和Pb~(2+)(10μ~(-1)M)对ASIC电流的抑制是ASIC_(1a)亚基存在的重要证据。胞外加入锌离子(300μM)可使ASIC电流增加20%(p<； 0.05，n= 13)。在电流钳实验中，应用MES-ACSF可使星状细胞去极化。结果表明，耳蜗核星状细胞的ASIC电流主要由ASIC1a和ASIC2a通道携带。ASIC通道影响星状细胞的兴奋性，因此它们似乎在听觉信息的处理中起作用。
Acid-sensing ion channels (ASICs) are voltage-independent and proton-gated channels. In this study, we aimed to test the hypothesis whether ASICs might be involved in modifying the excitability of stellate cells in the cochlear nucleus (CN). We determined gene expressions of ASIC1, ASIC2 and ASIC3 in the CN of BALB/mice. ASIC currents in stellate cells were characterized by using whole-cell patch-clamp technique. In the voltage-clamp experiments, inward currents were recorded upon application of 2-[N-Morpholino ethanesulfonic acid]-normal artificial cerebrospinal fluid (MES–aCSF), whose pH 50 was 5.84. Amiloride inhibited the acid-induced currents in a dose-dependent manner. Inhibition of the ASIC currents by extracellular Ca2+and Pb2+(10 μM) was significant evidence for the existence of homomeric ASIC1a subunits. ASIC currents were increased by 20% upon extracellular application of Zn2+(300 μM) (p< 0.05,n= 13). In current-clamp experiments, application of MES–aCSF resulted in the depolarization of stellate cells. The results show that the ASIC currents in stellate cells of the cochlear nucleus are carried largely by the ASIC1a and ASIC2a channels. ASIC channels affect the excitability of the stellate cells and therefore they appear to have a role in the processing of auditory information.