Kraus N, Smith D I, McGee T
Siegel Institute, Michael Reese Medical Center, Ill.
Audiology. 1987;26(5):257-68. doi: 10.3109/00206098709081554.
Auditory middle-latency responses (MLRs) were obtained from 71 unanesthetized gerbils ranging in age from 10 to greater than 90 days. Effects of age, stimulation rate, high- and lowpass filter settings and filter slope were examined. MLR amplitude decreased significantly with increased stimulation rate at all ages, at rates up to 40/s. The detection of MLR waves (presence or absence) varied inversely with the rate of stimulation only in immature subjects. The amplitude of waves B (15 ms) and C (25 ms) was significantly larger with a highpass filter setting of 3 Hz as compared to 10 and 30 Hz. This effect was significantly more pronounced in developing animals as compared to adults. MLR amplitude was greater with a filter slope of 6 dB/octave as compared to 48 dB/octave, (10-2,000 Hz) and this effect was also significantly greater in developing animals than in adults. There was no interaction between lowpass filter setting and age (100 vs. 2,000 Hz). A prominent positive wave occurring at approximately 50 ms was present in the 48 dB/octave condition although it was not observed with 6 dB/octave filtering. The clinical use of the MLR requires a better understanding of the effects of stimulus and recording procedures on the response, and how they vary as a function of subject age.
从71只年龄在10至90多天不等的未麻醉沙鼠身上获取听觉中潜伏期反应（MLR）。研究了年龄、刺激率、高通和低通滤波器设置以及滤波器斜率的影响。在所有年龄段，当刺激率高达40次/秒时，MLR振幅随刺激率增加而显著降低。仅在未成熟受试者中，MLR波的检测（存在或不存在）与刺激率呈反比。与10 Hz和30 Hz相比，高通滤波器设置为3 Hz时，波B（15毫秒）和波C（25毫秒）的振幅显著更大。与成年动物相比，这种效应在发育中的动物中更为明显。与48 dB/倍频程（10 - 2000 Hz）相比，滤波器斜率为6 dB/倍频程时MLR振幅更大，并且这种效应在发育中的动物中也比成年动物显著更大。低通滤波器设置与年龄（100 Hz与2000 Hz）之间没有相互作用。在48 dB/倍频程条件下，大约在50毫秒时出现一个明显的正波，尽管在6 dB/倍频程滤波时未观察到。MLR的临床应用需要更好地理解刺激和记录程序对反应的影响，以及它们如何随受试者年龄而变化。
