Cousillas H, Patuzzi R B, Johnstone B M
Department of Physiology, University of Western Australia, Nedlands.
Hear Res. 1988 Oct;36(1):21-39. doi: 10.1016/0378-5955(88)90135-9.
Glass micro-electrode recordings from the spiral ganglion of the basal turn of the guinea pig cochlea have been obtained before, during and after negative (cathodic) current injection into scala tympani. Electrical stimulation with currents between 100 microA and 900 microA produced a marked increase in firing rate of the afferent neurons for the first 3 min of electrical stimulation. This was followed by a fall in firing rate to rates near or below the pre-stimulatory spontaneous rate if stimulation continued. Continuous electrical stimulation lasting 5 or 10 min reduced neural sensitivity to acoustic stimulation. Although threshold elevation was greatest for sound frequencies near the characteristic frequency of each neuron, thresholds could also be elevated at lower frequencies on the tail of the frequency-threshold tuning curve. After electrical stimulation a fall in the amplitude of the low-frequency microphonic recorded at the round window was also observed, indicating a disruption of the outer hair cell transduction. These effects were highly localized in the basal turn near the site of current injection, and were not associated with any significant structural changes in the organ of Corti, except after stimulation with very high current intensities.
在向豚鼠耳蜗底转鼓阶注入负（阴极）电流之前、期间和之后，已从螺旋神经节获得玻璃微电极记录。用100微安至900微安之间的电流进行电刺激，在电刺激的前3分钟内，传入神经元的放电率显著增加。如果刺激持续，随后放电率会下降至接近或低于刺激前的自发率。持续5或10分钟的连续电刺激会降低神经对声刺激的敏感性。尽管对于每个神经元特征频率附近的声音频率，阈值升高最为明显，但在频率-阈值调谐曲线尾部的较低频率处，阈值也可能升高。电刺激后，还观察到圆窗处记录的低频微音器电位幅度下降，表明外毛细胞转导受到破坏。这些效应高度局限于注入电流部位附近的底转，并且除了用非常高的电流强度刺激后，与柯蒂氏器的任何显著结构变化无关。
