Rajan R, Johnstone B M
Department of Physiology, University of Western Australia, Nedlands.
Hear Res. 1988 Oct;36(1):75-88. doi: 10.1016/0378-5955(88)90138-4.
This report demonstrates that electrical stimulation of the efferents at the round window reduces temporary threshold shifts in a protective manner. For a standard set of stimulating parameters greatest reductions in TTS were found to exposures that caused the greatest amounts of TTS to occur. Low level exposures that caused low levels of TTS from which the cochlea could recover relatively quickly were not affected by the standard electrical stimulus. Intermediate reductions were obtained to intermediate levels of exposure, resulting in intermediate levels of TTS. Increasing current levels or duration of stimulation did not produce reductions in the low level TTS; a higher rate of stimulation was, however, able to reduce the low level TTS. Even with the higher rate of stimulation, greatest reductions in TTS occurred at the higher levels of exposure. These results are identical to the effects of COCB stimulation at the level of the brainstem and argue for viewing the COCB as a protective pathway.
本报告表明，在圆窗处对传出神经进行电刺激能以一种保护方式减少暂时性阈移。对于一组标准的刺激参数，发现对导致最大量暂时性阈移的暴露，暂时性阈移的减少最为显著。导致低水平暂时性阈移且耳蜗能相对快速恢复的低水平暴露不受标准电刺激影响。对中等水平的暴露可获得中等程度的减少，从而产生中等水平的暂时性阈移。增加电流水平或刺激持续时间并不能减少低水平的暂时性阈移；然而，更高的刺激频率能够减少低水平的暂时性阈移。即使采用更高的刺激频率，暂时性阈移的最大减少仍出现在更高水平的暴露时。这些结果与在脑干水平进行耳蜗传出复合束刺激的效果相同，支持将耳蜗传出复合束视为一条保护通路的观点。
