Prosen C A, Halpern D L, Dallos P
Auditory Physiology Laboratory, Northwestern University, Evanston, Illinois 60201.
J Acoust Soc Am. 1989 Mar;85(3):1302-13. doi: 10.1121/1.397461.
This study assessed normal frequency discrimination ability in the chinchilla and determined how this ability changes as a function of an experimentally induced sensorineural hearing loss. Four chinchillas were trained by the methods of positive reinforcement to report absolute thresholds and frequency difference limens (FDLs). Subjects were then treated with the aminoglycosidic antibiotic amikacin until a 30-dB hearing loss was measured at 10.0 kHz. Absolute and frequency difference thresholds were determined during and after drug treatment. When post-drug thresholds had stabilized, subjects were sacrificed and their cochleas stained, embedded in plastic, microdissected, and viewed with phase contrast microscopy to permit examination of the cochlear tissue. Post-drug data suggest that frequency discrimination at a high frequency is unaffected by a 40- to 45-dB sensorineural hearing loss, considerable hair cell damage, and the resultant disruption of the cochlear micromechanics. The data, in concert with previously published reports, suggest that FDLs may be less affected by a high-frequency sensorineural hearing loss than by a low-frequency sensorineural hearing loss.
本研究评估了绒鼠的正常频率辨别能力，并确定了这种能力如何随实验性诱导的感音神经性听力损失而变化。通过正强化方法训练了四只绒鼠，使其能够报告绝对阈值和频率差异阈（FDL）。然后用氨基糖苷类抗生素阿米卡星对实验对象进行治疗，直到在10.0 kHz处测得30 dB的听力损失。在药物治疗期间和之后测定绝对阈值和频率差异阈值。当药物治疗后的阈值稳定后，处死实验对象并对其耳蜗进行染色、包埋在塑料中、显微解剖，然后用相差显微镜观察，以便检查耳蜗组织。药物治疗后的数据表明，高频处的频率辨别不受40至45 dB感音神经性听力损失、大量毛细胞损伤以及由此导致的耳蜗微机械破坏的影响。这些数据与先前发表的报告一致，表明FDL受高频感音神经性听力损失的影响可能小于受低频感音神经性听力损失的影响。
