Electrical and physiological changes during short-term and chronic electrical stimulation of the normal cochlea
Electrical and physiological changes during short-term and chronic electrical stimulation of the normal cochlea
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DOI：
10.1016/s0378-5955(97)00066-x
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发表时间：
1997-08-01
期刊：
影响因子：
2.8
通讯作者：
Aran, JM
中科院分区：
文献类型：
--
作者：
deSauvage, RC;daCosta, DL;Aran, JM
在听觉通路的电刺激（ES）中，刺激类型和电极/组织界面是方案安全性和有效性的关键参数。在这项研究中，交替脉冲的影响，施加在圆窗和顶点电极之间的长期植入豚鼠，并保持在1和25日期间的2小时（短期和长期实验，分别），进行了研究。ES由+/-70 μ A的双相电流脉冲和300 μ A的持续时间以167/s的速率组成，具有交替的极性。复合动作电位（CAP）听力图，点击诱发CAP的振幅和潜伏期，电诱发听觉反应（EARS）的振幅和潜伏期，和电极阻抗，定期测量外或期间的ES周期。短时间ES对高于正常阈值80 dB的短声反应的CAP阈值、振幅和潜伏期无明显变化，但引起CAP的潜伏期轻微增加和振幅降低，与电极阻抗的指数衰减相关。在长期的基础上，CAP听力图和lavitudes没有显着变化，而CAP振幅和电极阻抗增加，在相互关联。在对照组豚鼠接受无ES，相同的CAP振幅和阻抗的变化，在相同的长期观察。可以通过电极/组织界面的电阻抗的变化来解释电阻抗和CAP的变化。这可能是由于电极周围的电解质在短期变化的ES的影响下发生变化，以及由于长期变化的ES不依赖于纤维组织的电极封装。在本实验的条件下，ES本身对听觉功能没有不良影响，可以安全地用于内耳探查。
In the electrical stimulation (ES) of auditory pathways, the type of stimulus and the electrode/tissue interface are critical parameters for the safety and efficacy of the protocol. In this study the influence of alternate pulses, applied between round window and vertex electrodes in chronically implanted guinea pigs, and maintained during 1 and 25 daily periods of 2 h (short-term and long-term experiments, respectively), was investigated. ES consisted of monophasic current pulses of +/-70 mu A and 300 its in duration at a rate of 167/s, with alternate polarity. Compound Action Potential (CAP) audiograms, amplitudes and latencies of click-evoked CAPs, amplitudes and latencies of electrically-evoked auditory responses (EARs), and electrode impedances, were measured periodically outside or during the ES periods. Short-term ES induced no change in CAP thresholds, amplitude and latency in response to clicks at 80 dB above normal threshold, but induced a slight latency increase and amplitude decrease of the EAR, correlated with an exponential decay of the electrode impedance. On a long-term basis, CAP audiograms and latencies did not change significantly, whereas CAP amplitudes and electrode impedances increased, in correlation with each other. In control guinea pigs receiving no ES, the same CAP amplitude and impedance changes were observed over the same long-term period. The EAR and CAP changes can be explained by a variation of the electrical impedance of the electrode/tissue interface. This is possibly due to a change in electrotytes around the electrode under the influence of the ES for the short-term variation, and to an electrode encapsulation by fibrous tissue independent of the ES for the long-term change. In itself, and under the conditions of this experiment, the ES demonstrated no adverse effects on the auditory function and can be safely used for inner-ear exploration.