Blumberg M S, Alberts J R
Department of Psychology, Indiana University, Bloomington 47405.
Behav Neurosci. 1990 Oct;104(5):808-17. doi: 10.1037//0735-7044.104.5.808.
Isolated rat pups respond to cold exposure physiologically by increasing metabolic heat production and behaviorally by emitting ultrasound. The relationship between these 2 responses was investigated by monitoring oxygen consumption, heat production by brown adipose tissue, respiratory rate, and ultrasound production during cold exposure in pups 10-12 days of age. All 3 physiological measures increased contemporaneously with the initiation of ultrasound. Pups also exhibited a respiratory pattern characterized by the prolongation of expiratory duration in relation to inspiratory duration. Ultrasound was often detected during these prolonged expirations, suggesting that pups were using laryngeal braking. Laryngeal braking is thought to enhance oxygen uptake in the lungs. Thus, ultrasound may be an acoustic by-product of a respiratory maneuver that increases oxygen delivery to metabolically active tissues during cold exposure.
隔离饲养的大鼠幼崽对寒冷暴露会产生生理反应，即增加代谢产热，行为反应则是发出超声波。通过监测10 - 12日龄幼崽在寒冷暴露期间的耗氧量、棕色脂肪组织产热、呼吸频率和超声波发出情况，研究了这两种反应之间的关系。所有这三项生理指标均与超声波开始发出同时增加。幼崽还表现出一种呼吸模式，其特征是呼气持续时间相对于吸气持续时间延长。在这些延长的呼气过程中经常检测到超声波，这表明幼崽在使用喉部制动。喉部制动被认为可增强肺部的氧气摄取。因此，超声波可能是一种呼吸动作的声学副产品，该呼吸动作在寒冷暴露期间增加了向代谢活跃组织的氧气输送。
