Whishaw I Q, Flannigan K P, Barnsley R H
Dev Psychobiol. 1979 Nov;12(6):595-605. doi: 10.1002/dev.420120608.
Tonic immobility was studied in rabbit pups varying in age from 1 to 30 days. During the 1st 2 postnatal weeks the rabbits were active in an open field, had difficulty walking and executing a righting response, lost body temperature rapidly, and had no, or only short durations of, tonic immobility. After this age they were less active, hopped and righted well, maintained core temperature, and showed increased durations of tonic immobility. Within the 1st 2 postnatal weeks cooling and warming potentiated; thereafter, cooling disrupted and only warming potentiated tonic immobility. The results suggest that rate of heat loss can act as a stimulus to block tonic immobility and increase activity in neonatal rabbits. With development, cooling produces shivering which can disrupt tonic immobility, whereas warming may raise movement initiation thresholds which can potentiate tonic immobility.
对1至30日龄的兔幼崽进行了紧张性不动研究。在出生后的前两周，兔子在开阔场地活跃，行走和做出翻正反应有困难，体温迅速下降，且没有紧张性不动或只有短暂的紧张性不动。在这个年龄之后，它们活动减少，跳跃和翻正良好，能维持核心体温，并表现出紧张性不动的持续时间增加。在出生后的前两周内，降温与升温有增强作用；此后，降温会干扰紧张性不动，只有升温能增强紧张性不动。结果表明，热量散失速率可作为一种刺激，阻止新生兔的紧张性不动并增加其活动。随着发育，降温会引发颤抖，从而干扰紧张性不动，而升温可能会提高运动起始阈值，从而增强紧张性不动。
