Kameyama T, Nabeshima T, Takahashi K
Nihon Yakurigaku Zasshi. 1978 Apr;74(3):419-26. doi: 10.1254/fpj.74.419.
Determination of auditory threshold was carried out under a response duration schedule of tone and/or light-dipper presentation. This schedule enabled an exact assessment of auditory sensitivity, since the direction and distance from rat to sound source were constant and the rat could thus acquire the conditioned behavior in a short time. The rat has to press the lever and hold it until a CS(tone and/or light) was presented. The animal could get water-reinforcement with release of the lever during the period of CS. The intensity of 3 KHz pure tone was reduced, from 110 dB (starting point), by 2 dB steps in each trial, until the subject made 3 non-response trials (i.e., no dipper approach within 0.7 sec after the tone onset) among 5 trials. The highest tone intensity among non-response trials was taken as the threshold. The auditory sensitivity of the rats with cotton-stuffed ears and the pierced eardrums decreased about 10 and 20 dB, respectively. The auditory sensitivity in rats was decreased by administration of streptomycin sulfate(SM), 300 mg/kg/day, i.m., in combination with ethacrynic acid(EA), 50 mg/kg/day, p.o., for forty days and in combination with EA, 100 mg/kg/day, p.o. for ten days. The auditory sensitivity was not influenced by administration of SM, 300 mg/kg/day, i.m., for forty days.
在音调呈现和/或光杆呈现的反应持续时间程序下进行听觉阈值测定。该程序能够准确评估听觉敏感性，因为大鼠到声源的方向和距离是恒定的，因此大鼠可以在短时间内获得条件性行为。大鼠必须按下杠杆并保持住，直到呈现条件刺激（音调或光）。在条件刺激期间，动物松开杠杆即可获得水强化。3 kHz纯音的强度从110 dB（起始点）开始，每次试验以2 dB的步长降低，直到受试者在5次试验中出现3次无反应试验（即音调开始后0.7秒内无光杆靠近）。无反应试验中的最高音调强度被视为阈值。塞有棉花的耳朵和鼓膜穿孔的大鼠的听觉敏感性分别降低了约10 dB和20 dB。通过肌肉注射硫酸链霉素（SM）300 mg/kg/天，口服依他尼酸（EA）50 mg/kg/天，持续40天，以及口服EA 100 mg/kg/天，持续10天，大鼠的听觉敏感性降低。肌肉注射SM 300 mg/kg/天，持续40天，对听觉敏感性没有影响。
