Donaldson G S, Rubel E W
Department of Otolaryngology, University of Virginia Health Sciences Center, Charlottesville.
Electroencephalogr Clin Neurophysiol. 1990 Nov-Dec;77(6):458-70. doi: 10.1016/0168-5597(90)90006-y.
The ABR wave forms of 16-day-old and adult Mongolian gerbils were evoked by click stimuli presented at rates ranging from 1 to 80/sec. Wave I and wave IV thresholds were determined for each of 5 click rates. Amplitudes and latencies of waves I and IV were measured at each of 7 click rates and 3 intensity levels (15, 40 and 65 dB above threshold). Thresholds for waves I and IV in the adult gerbil and wave I in the 16 day gerbil were unaffected by changes in stimulus repetition rate. Neonatal wave IV thresholds were unaffected by click rate for rates below 25/sec but increased approximately 7 dB/decade increase in click rate when rate exceeded 25/sec. Increasing click rate produced greater reductions in ABR amplitude among neonates than adults for both waves I and IV. Decreases in amplitude due to increasing rate were independent of intensity level in both neonatal and adult subjects. Increasing rate produced similar increases in wave I latency among 16 day and adult subjects, but produced much greater increases in wave IV latency among neonates. Stimulus intensity level and click rate acted independently on wave I and wave IV latency in adult subjects and wave I latency in neonates. However, an interaction between rate and intensity was observed with respect to neonatal wave IV latency.
对16日龄和成年蒙古沙鼠施加每秒1至80次的短声刺激，引出听觉脑干反应（ABR）波形。针对5种短声频率中的每一种，测定I波和IV波阈值。在7种短声频率和3种强度水平（高于阈值15、40和65分贝）下，测量I波和IV波的振幅和潜伏期。成年沙鼠的I波和IV波阈值以及16日龄沙鼠的I波阈值不受刺激重复率变化的影响。当短声频率低于25次/秒时，新生沙鼠的IV波阈值不受短声频率影响，但当频率超过25次/秒时，每增加10倍的短声频率，IV波阈值大约增加7分贝。对于I波和IV波，短声频率增加时，新生沙鼠ABR振幅的降低幅度比成年沙鼠更大。在新生和成年实验对象中，频率增加导致的振幅降低与强度水平无关。短声频率增加时，16日龄和成年实验对象的I波潜伏期增加幅度相似，但新生沙鼠的IV波潜伏期增加幅度更大。在成年实验对象的I波和IV波潜伏期以及新生沙鼠的I波潜伏期方面，刺激强度水平和短声频率的作用相互独立。然而，在新生沙鼠IV波潜伏期方面，观察到频率和强度之间存在相互作用。
