Hofer M A, Shair H N
Department of Psychiatry, College of Physicians & Surgeons, Columbia University, New York, NY.
Dev Psychobiol. 1992 Nov;25(7):511-28. doi: 10.1002/dev.420250705.
Vocalization in the ultrasonic range (USV) has been reported to occur in young rodents in response to isolation, novelty, handling, and cold. Heretofore these calls have been known to occur only in alert, attentive, or emotionally aroused animals. These studies describe the emission of USV by comatose 9- to 10-day-old rat pups during recovery from deep hypothermia. Calling began at 15-18 degrees C core temperature while pups were virtually unresponsive to stimulation. Experimental results describe the patterns of call production in relation to respiration, cardiac function, colonic temperature, and brown adipose tissue thermogenesis. These vocalizations were 32-42 kHz in frequency, reached peak rates of 50/min at 23 degrees C, and were eliminated by laryngeal denervation, thus resembling isolation-induced vocalizations. However, contact with their dams failed to reduce call rates until pups had warmed above 25 degrees C. Newborn and weanling pups also emitted USV in deep hypothermia, but no USV were observed in pups recovering from general anesthesia. The possible functions and evolution of this behavior are discussed.
据报道，幼鼠在超声范围内的发声（USV）会因隔离、新奇环境、处理和寒冷而出现。迄今为止，已知这些叫声仅在警觉、专注或情绪激动的动物中出现。这些研究描述了9至10日龄昏迷大鼠幼崽在从深度低温恢复过程中发出的USV。当幼崽对刺激几乎无反应时，在核心体温15至18摄氏度时开始发出叫声。实验结果描述了与呼吸、心脏功能、结肠温度和棕色脂肪组织产热相关的叫声产生模式。这些发声频率为32至42千赫兹，在23摄氏度时达到每分钟50次的峰值速率，并通过喉去神经支配而消除，因此类似于隔离诱导的发声。然而，在幼崽体温升至25摄氏度以上之前，与母鼠接触并不能降低叫声频率。新生和断奶幼崽在深度低温时也会发出USV，但在从全身麻醉中恢复的幼崽中未观察到USV。本文讨论了这种行为的可能功能和进化。
