Shvarev Y N, Canlon B
Behavioral Phenogenetics Laboratory, Institute for Cytology & Genetics, Siberian Division of the Russian Academy of Sciences, Novosibirsk.
Acta Physiol Scand. 1998 Feb;162(2):155-64. doi: 10.1046/j.1365-201X.1998.0286f.x.
The receptor potential as a function of stimulus amplitude and frequency was studied with the patch-clamp technique in isolated outer hair cells (OHCs) with a length ranging from 30 to 87 microm during direct mechanical stimulation of the stereocilia. The amplitude and frequency of the stimulation were varied from 125 nm to 2 microm and from 100 Hz to 2.5 kHz, respectively. The mean resting membrane potential before stimulation was -64.25 +/- 1.4 mV (mean +/- SE, n = 26). Irrespective of the frequency used, stereocilia stimulation produced a combination of AC and DC responses, and both components showed saturation with increasing stimulation. Frequency responses appeared to be a function of intensity and resembled a low-pass filter with a time constant ranging from 0.2 to 2.0 ms. With increasing stereocilia stimulation, the relative contribution of high frequencies to the AC component decreased, suggesting a decrease of the corner frequency. The saturated amplitude of the AC component for low-frequency stimulation (100 Hz) was proportional to cell length and increased with a mean rate of 0.014 mV microm(-1). A relationship between the DC response of the receptor potential and the pre-stimulus membrane potential was found. Recordings with more negative membrane potentials had greater DC components, while more depolarized recordings demonstrated smaller DC components. These fluctuations seemed to be defined by the interaction between the probe and stereocilia bundle and could be in the range of the transfer function for each cell.
运用膜片钳技术，在长度为30至87微米的离体外侧毛细胞（OHC）中，于对静纤毛进行直接机械刺激期间，研究了感受器电位作为刺激幅度和频率的函数。刺激的幅度和频率分别在125纳米至2微米以及100赫兹至2.5千赫兹范围内变化。刺激前的平均静息膜电位为-64.25±1.4毫伏（平均值±标准误，n = 26）。无论使用何种频率，静纤毛刺激都会产生交流（AC）和直流（DC）反应的组合，并且随着刺激增强，这两种成分均表现出饱和现象。频率反应似乎是强度的函数，类似于时间常数在0.2至2.0毫秒范围内的低通滤波器。随着静纤毛刺激增强，高频对交流成分的相对贡献降低，表明截止频率降低。低频刺激（100赫兹）时交流成分的饱和幅度与细胞长度成正比，平均增长率为0.014毫伏·微米⁻¹。发现了感受器电位的直流反应与刺激前膜电位之间的关系。膜电位更负的记录具有更大的直流成分，而膜电位去极化程度更高的记录显示直流成分更小。这些波动似乎由探头与静纤毛束之间的相互作用所决定，并且可能处于每个细胞传递函数的范围内。
