Strain G M, Tucker T A, Graham M C, O'Malley N A
Electroencephalogr Clin Neurophysiol. 1987 Jul;67(1):68-76. doi: 10.1016/0013-4694(87)90165-9.
Brain-stem auditory evoked potentials (BAEPs) were recorded from young alligators (Alligator mississippiensis), and the effects of hypothermia, hyperthermia and hypoxia on the wave forms were determined. The wave form shape was similar to the human BAEP, although extra waves were routinely seen. The responses were highly repeatable and varied in a predictable manner as a function of stimulus frequency, polarity, intensity, and body temperature. Rarefaction clicks produced longer wave form latencies than condensation clicks. BAEPs were present over the entire temperature range studied (0-36 degrees C). In contrast, mammalian BAEPs disappear over the temperature range of 20-27 degrees C, and seizures occur at 20-21 degrees C. At temperatures below 20 degrees C, the alligator BAEP peak amplitudes decreased with decreased temperature, but latencies only decreased slightly. At temperatures above 20 degrees C the peak amplitudes increased, and the latencies decreased with temperature. Peak I was largely unaffected by temperature change, while peaks IIIa and V increased 0.015 and 0.018 msec/degree C, respectively, at temperatures above 24 degrees C. Transient brain hypoxia, achieved by inverting the alligator, produced a progressive decrease in BAEP waves to an isoelectric amplitude without greatly altered latencies. The reverse sequence of changes was seen during recovery. Postural effects on blood flow were documented in two alligators with implanted flow probes. Carotid artery blood flow decreased 43% with body inversion, in both anesthetized and unanesthetized alligators, but no sequelae from the hypoxia could be detected. Metabolic differences between mammals and the alligator may account for the alligator's resistance to hypothermia, hyperthermia and hypoxia.
记录了幼年密西西比鳄的脑干听觉诱发电位（BAEPs），并确定了低温、高温和缺氧对波形的影响。虽然经常能看到额外的波，但波形形状与人类BAEP相似。这些反应具有高度可重复性，并且根据刺激频率、极性、强度和体温以可预测的方式变化。稀疏短声产生的波形潜伏期比压缩短声更长。在所研究的整个温度范围（0-36摄氏度）内都存在BAEPs。相比之下，哺乳动物的BAEPs在20-27摄氏度的温度范围内消失，并且在20-21摄氏度时会发生癫痫发作。在20摄氏度以下的温度时，鳄鱼的BAEP峰振幅随温度降低而降低，但潜伏期仅略有下降。在20摄氏度以上的温度时，峰振幅增加，潜伏期随温度降低。峰I在很大程度上不受温度变化的影响，而在24摄氏度以上的温度时，峰IIIa和峰V分别以0.015和0.018毫秒/摄氏度的速度增加。通过翻转鳄鱼实现的短暂性脑缺氧会导致BAEP波逐渐降低至等电位振幅，而潜伏期没有太大改变。在恢复过程中观察到相反的变化顺序。对两只植入了血流探头的鳄鱼记录了姿势对血流的影响。无论是麻醉的还是未麻醉的鳄鱼，身体翻转时颈动脉血流量都会减少43%，但未检测到缺氧的后遗症。哺乳动物和鳄鱼之间的代谢差异可能解释了鳄鱼对低温、高温和缺氧的耐受性。
