Background. Cochlear implant-based electrical stimulation may be an important reason to induce the residual hearing loss after cochlear implantation. In our previous study, we found that charge-balanced biphasic electrical stimulation inhibited the neurite growth of spiral ganglion neurons (SGNs) and decreased Schwann cell density in vitro. In this study, we want to know whether cochlear implant-based electrical stimulation can induce the change of electrical activity in cultured SGNs. Methods. Spiral ganglion neuron electrical stimulation in vitro model is established using the devices delivering cochlear implant-based electrical stimulation. After 48 h treatment by 50 μA or 100 μA electrical stimulation, the action potential (AP) and voltage depended calcium current (I_Ca) of SGNs are recorded using whole-cell electrophysiological method. Results. The results show that the I_Ca of SGNs is decreased significantly in 50 μA and 100 μA electrical stimulation groups. The reversal potential of I_Ca is nearly +80 mV in control SGN, but the reversal potential decreases to +50 mV in 50 μA and 100 μA electrical stimulation groups. Interestingly, the AP amplitude, the AP latency, and the AP duration of SGNs have no statistically significant differences in all three groups. Conclusion. Our study suggests cochlear implant-based electrical stimulation only significantly inhibit the I_Ca of cultured SGNs but has no effect on the firing of AP, and the relation of I_Ca inhibition and SGN damage induced by electrical stimulation and its mechanism needs to be further studied.

中文翻译：

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基于人工耳蜗植入的电刺激对培养的螺旋神经节神经元电生理特性的影响。


背景。人工耳蜗植入电刺激可能是诱发人工耳蜗植入后残余听力损失的重要原因。在我们之前的研究中，我们发现电荷平衡双相电刺激在体外抑制螺旋神经节神经元（SGN）的神经突生长并降低雪旺细胞密度。在这项研究中，我们想知道基于人工耳蜗植入的电刺激是否可以诱导培养的 SGN 的电活动变化。方法。使用基于人工耳蜗植入的电刺激装置建立螺旋神经节神经元电刺激体外模型。 50μA或100μA电刺激处理48小时后，采用全细胞电生理方法记录SGN的动作电位（AP）_和电压依赖性钙电流（ ICa ）。结果。结果表明_， 50μA和100 ​​μA电刺激组SGNs的ICa显着降低。在对照SGN中I _Ca的反转电位接近+80 mV，但在50 μA和100​​ μA电刺激组中反转电位降低至+50 mV。有趣的是，三组中 SGN 的 AP 幅度、AP 潜伏期和 AP 持续时间没有统计学上的显着差异。结论。 我们的研究表明，基于人工耳蜗的电刺激仅显着抑制培养SGN的I _Ca ，但对AP的放电没有影响，并且I _Ca抑制与电刺激引起的SGN损伤的关系及其机制有待进一步研究。