Effects of Hearing Preservation on Psychophysical Responses to Cochlear Implant Stimulation
Effects of Hearing Preservation on Psychophysical Responses to Cochlear Implant Stimulation
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DOI：
10.1007/s10162-009-0194-7
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发表时间：
2010-06-01
影响因子：
2.4
通讯作者：
Pfingst, Bryan E.
中科院分区：
文献类型：
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作者：
Kang, Stephen Y.;Colesa, Deborah J.;Pfingst, Bryan E.
先前的研究表明，残余声学听力补充了人工耳蜗的功能，以改善噪声中的语音识别以及对音乐的感知。目前的研究有两个主要目标。首先，我们试图确定耳蜗植入和电刺激在14至21个月的时间内如何影响耳蜗结构，如毛细胞和螺旋神经节神经元。其次，我们试图研究提供听觉的结构是否也影响电刺激的感知。我们比较了两组成年豚鼠对人工耳蜗刺激的心理生理反应。组I（11只动物）在先前未处理的耳朵中接受人工耳蜗植入，而组II（10只动物）在先前已注入新霉素以破坏听力的耳朵中接受人工耳蜗植入。心理物理阈值测量脉冲串和正弦刺激。对所有第I组动物和第II组动物子集进行组织学分析。11只I组动物中有9只显示Corti器官和螺旋神经节神经元与电极阵列相邻。所有组I动物均显示出这些元素在电极阵列顶端区域中的存活。第II组动物进行组织学检查，显示在邻近和顶端的电极阵列和严重的螺旋神经节神经元损失的区域的Corti器官的完全损失，与以前的报告一致的新霉素治疗的耳朵。在行为上，第II组动物的阈值显着低于第I组动物在100 Hz的正弦刺激。然而，I组动物对脉冲串刺激的反应阈值显著低于II组动物（0.02 ms/相位; 156至5，000 pps）。此外，两组显示出不同的阈值与脉率函数。我们假设组间检测阈值的差异是由第I组动物毛细胞的电激活和/或螺旋神经节神经元状况的组间差异引起的。
Previous studies have shown that residual acoustic hearing supplements cochlear implant function to improve speech recognition in noise as well as perception of music. The current study had two primary objectives. First, we sought to determine how cochlear implantation and electrical stimulation over a time period of 14 to 21 months influence cochlear structures such as hair cells and spiral ganglion neurons. Second, we sought to investigate whether the structures that provide acoustic hearing also affect the perception of electrical stimulation. We compared psychophysical responses to cochlear implant stimulation in two groups of adult guinea pigs. Group I (11 animals) received a cochlear implant in a previously untreated ear, while group II (ten animals) received a cochlear implant in an ear that had been previously infused with neomycin to destroy hearing. Psychophysical thresholds were measured in response to pulse-train and sinusoidal stimuli. Histological analysis of all group I animals and a subset of group II animals was performed. Nine of the 11 group I animals showed survival of the organ of Corti and spiral ganglion neurons adjacent to the electrode array. All group I animals showed survival of these elements in regions apical to the electrode array. Group II animals that were examined histologically showed complete loss of the organ of Corti in regions adjacent and apical to the electrode array and severe spiral ganglion neuron loss, consistent with previous reports for neomycin-treated ears. Behaviorally, group II animals had significantly lower thresholds than group I animals in response to 100 Hz sinusoidal stimuli. However, group I animals had significantly lower thresholds than group II animals in response to pulse-train stimuli (0.02 ms/phase; 156 to 5,000 pps). Additionally, the two groups showed distinct threshold versus pulse rate functions. We hypothesize that the differences in detection thresholds between groups are caused by the electrical activation of the hair cells in group I animals and/or differences between groups in the condition of the spiral ganglion neurons.