EFFERENT CONTROL OF COCHLEAR INNER HAIR CELL RESPONSES IN THE GUINEA-PIG
EFFERENT CONTROL OF COCHLEAR INNER HAIR CELL RESPONSES IN THE GUINEA-PIG
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DOI：
10.1113/jphysiol.1984.sp015396
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发表时间：
1984-01-01
影响因子：
5.5
通讯作者：
NUTTALL, AL
中科院分区：
文献类型：
--
作者：
BROWN, MC;NUTTALL, AL
在麻醉豚鼠耳蜗内毛细胞的细胞内记录过程中，电刺激传出交叉橄榄耳蜗束（COCB）。刺激COCB的作用是降低由特征频率的纯音诱发的内毛细胞去极化成分（DC）和交流成分（AC）受体电位的幅度。在低压水平下，COCB刺激引起的受体电位降低相当于降低9-24 dB的声音强度。刺激COCB通常对听神经的复合动作电位有类似的影响。内毛细胞膜电阻的变化，在中等水平的声音测量单独的声音，当声音伴随着COCB刺激。单独的声音产生了更大的膜电阻变化比声音与COCB刺激，在相同的条件下，成比例的DC受体电位。COCB效应的时间过程是缓慢的，完全效应和恢复需要50-250 ms。改变电刺激的频率和电压对DC受体电位和复合动作电位的影响是相似的。对于高水平的声音和低于特征频率的频率，COCB刺激在降低受体电位方面效果较差。在连续COCB刺激的间隔期间拍摄的DC受体电位的频率调谐曲线显示主要在调谐曲线的尖端段中的灵敏度降低。当不存在声音刺激时，静息膜电位在COCB刺激期间相对不变。静息膜电阻在COCB刺激期间没有改变。由于COCB主要支配外毛细胞，这些结果强烈表明，外毛细胞活性的变化可以影响内毛细胞的受体电位，从而改变声反应的传输到中枢神经系统。
The efferent crossed olivocochlear bundle (COCB) was electrically stimulated during intracellular recordings from cochlear inner hair cells in anesthetized guinea-pigs. The effect of COCB stimulation was to decrease the magnitude of the inner hair cell depolarizing component (DC) and alternating component (AC) receptor potentials evoked by tone bursts at the characteristic frequency. At low pressure levels, the decrease in receptor potentials caused by COCB stimulation was equivalent to decreasing the sound intensity by 9-24 dB. COCB stimulation usually had a similar effect on the compound action potential of the auditory nerve. The change in inner hair cell membrane resistance during moderate-level sound was measured for sound alone and when sound was accompanied by COCB stimulation. Sound alone produced a greater membrane resistance change than sound with COCB stimulation, in proportion to the DC receptor potential during the same conditions. The time course of the COCB effect was slow, with 50-250 ms required for a full effect and for recovery. The effects of varying the frequency and voltage of electrical stimulation were similar for the DC receptor potential and for the compound action potential. For sounds of high level and for frequencies well below the characteristic frequency, COCB stimulation was less effective in reducing receptor potentials. Frequency tuning curves for the DC receptor potential taken during intervals of continuous COCB stimulation showed decreases in sensitivity primarily in the tip segment of the tuning curve. When no sound stimulus was present, the resting membrane potential was relatively unaltered during COCB stimulation. The resting membrane resistance did not change during COCB stimulation. Since the COCB innervates mainly the outer hair cells, these results strongly suggest that changes in outer hair cell activity can influence the receptor potentials of inner hair cells and thus alter the transmission of acoustic responses to the CNS.