COCHLEAR PATHOLOGY FOLLOWING CHRONIC ELECTRICAL-STIMULATION OF THE AUDITORY-NERVE .1. NORMAL HEARING KITTENS
COCHLEAR PATHOLOGY FOLLOWING CHRONIC ELECTRICAL-STIMULATION OF THE AUDITORY-NERVE .1. NORMAL HEARING KITTENS
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DOI：
10.1016/0378-5955(92)90203-y
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发表时间：
1992-09-01
期刊：
影响因子：
2.8
通讯作者：
MILLARD, RE
中科院分区：
文献类型：
--
作者：
NI, DF;SHEPHERD, RK;MILLARD, RE
本研究探讨了长期耳壳内电刺激对听力正常的幼年动物的组织病理学影响。将8周龄的小猫植入鼓阶电极阵列，在21-52MUC cm-2geom的电荷密度范围内，使用电荷平衡的双相电流脉冲进行长达1500h的刺激。每一阶段。定期记录短声和电诱发的听觉脑干反应，以监测毛细胞和螺旋神经节细胞群的状态。此外，每天测量刺激电极的阻抗，以监测其在慢性植入过程中的电特性。组织病理学检查显示，与植入的、未受刺激的对照耳蜗相比，没有证据表明刺激对耳蜗结构造成了损害。事实上，与植入对照耳蜗组的相似人群相比，邻近刺激电极的神经节细胞密度在统计学上没有显著差异。此外，毛细胞的丢失仅限于电极阵列附近的区域，不受电刺激程度的影响。这些组织病理学结果与诱发电位记录相一致。最后，电极阻抗数据与鼓阶内观察到的组织生长程度有很好的相关性。目前的研究结果表明，幼年哺乳动物在慢性植入和电刺激后，并不比成年哺乳动物更容易受到耳蜗病的影响。
The present study examines the histopathological effects of long-term intracochlear electrical stimulation in young normal hearing animals. Eight-week old kittens were implanted with scala tympani electrode arrays and stimulated for periods of up to 1500 h using charge balanced biphasic current pulses at charge densities in the range 21-52 muC cm-2 geom. per phase. Both click and electrically evoked auditory brainstem responses were periodically recorded to monitor the status of the hair cell and spiral ganglion cell populations. In addition, the impedance of the stimulating electrodes was measured daily to monitor their electrical characteristics during chronic implantation. Histopathological examination of the cochleas showed no evidence of stimulus induced damage to cochlear structures when compared with implanted, unstimulated control cochleas. Indeed, there was no statistically significant difference in the ganglion cell density adjacent to the stimulating electrodes when compared with a similar population in implanted control cochleas. In addition, hair cell loss, which was restricted to regions adjacent to the electrode array, was not influenced by the degree of electrical stimulation. These histopathological findings were consistent with the evoked potential recordings. Finally, electrode impedance data correlated well with the degree of tissue growth observed within the scala tympani. The present findings indicate that the young mammalian cochlea is no more susceptible to cochlear pathology following chronic implantation and electrical stimulation than is the adult.