Shimamoto A
Department of Physiology, Nagasaki University School of Medicine.
Nihon Jibiinkoka Gakkai Kaiho. 1990 Apr;93(4):640-50. doi: 10.3950/jibiinkoka.93.640.
The narrow-band action potentials (NAP) and the ordinary electrocochleograms were recorded from the guinea-pig cochlea under normal and pathological conditions in order to study whether the NAP could be a useful measure to detect cochlear dysfunctions. The cochlea damaged either by the administration of kanamycin or by a mechanical lesion of the round window served as pathological materials. Recordings showed that the threshold and amplitude measured for the N1 potential of NAPs ran in parallel with those of the cochlear microphonic potentials (CM), under both normal and pathological conditions of the cochlea. This implies that the CM could be replaced by the NAP when difficulties were present in recording CMs. It may be inferred that the NAP reflects responses of the inner hair-cells and cochlear nerves, while the CM would mainly be derived from responses of the outer hair-cells to the frequency-specific movements of the basilar membrane. If so, the NAP should offer a good means for the objective audiometry. Recording NAPs is also superior to the ordinary electrocochleography in that the method makes it possible to obtain responses generated near the apex of the cochlea, i.e., responses to low-pitch sound stimuli.
为了研究窄带动作电位（NAP）是否可作为检测耳蜗功能障碍的有用指标，在正常和病理条件下从豚鼠耳蜗记录了窄带动作电位和普通耳蜗电图。用卡那霉素给药或圆窗机械损伤造成的耳蜗损伤作为病理材料。记录显示，在耳蜗的正常和病理条件下，NAP的N1电位测量的阈值和幅度与耳蜗微音电位（CM）的阈值和幅度平行。这意味着当记录CM有困难时，CM可以被NAP取代。可以推断，NAP反映了内毛细胞和耳蜗神经的反应，而CM主要来自外毛细胞对基底膜频率特异性运动的反应。如果是这样，NAP应该为客观听力测定提供一个好方法。记录NAP也优于普通耳蜗电图，因为该方法能够获得在耳蜗顶端附近产生的反应，即对低音调声音刺激的反应。
