Isobe Anna, Kawaguchi Maiko
Lab of Animal Behavior and Environmental Science, Graduate School of Agriculture, Meiji University, 1-1-1, Higashimita, Tama, Kawasaki, Kanagawa 214-8571, Japan.
J Vet Med Sci. 2019 Feb 28;81(2):287-293. doi: 10.1292/jvms.18-0604. Epub 2019 Jan 15.
When rat pups are isolated from their mothers, they emit ultrasonic vocalizations (USVs). Although previous studies have reported that USVs are related to anxiety, others have reported that they are related to simple, nonemotional factors, such as physiological reactions to coldness. In this study, we examined the influence of three maternal separations on rat pups. The number of USVs during 5 min of USV test under maternal separation, latency in the righting reflex as motor function, and body temperature were recorded twice (the first and second tests) before and after the pups were put in various environments for 10 min. The environments were no maternal separation (Control: CON), maternal separation with littermates (LMS), and single maternal separation with a heater (SMS). In the second test, the SMS pups had fewer USVs, a lower body temperature, and a more rapid righting reflex than the CON and LMS pups. In addition, there was no strong correlation between USVs and righting reflex. As a result, pups undergoing 10 min of SMS while being kept warm by the heater showed rapid righting reflex. Thus, by a single maternal separation, the number of USVs decreased but the decrease was unrelated to decrease in motor function.
当幼鼠与母亲分离时，它们会发出超声波叫声（USVs）。尽管先前的研究报告称USVs与焦虑有关，但也有其他研究报告称它们与简单的非情感因素有关，比如对寒冷的生理反应。在本研究中，我们考察了三次母鼠分离对幼鼠的影响。在幼鼠被置于不同环境10分钟前后，分别记录两次（第一次和第二次测试）在母鼠分离情况下USV测试5分钟内的USV数量、作为运动功能的翻正反射潜伏期以及体温。这些环境分别是无母鼠分离（对照：CON）、与同窝幼崽一起母鼠分离（LMS）以及有加热器的单独母鼠分离（SMS）。在第二次测试中，与CON和LMS幼鼠相比，SMS幼鼠的USV数量更少、体温更低且翻正反射更快。此外，USVs与翻正反射之间没有很强的相关性。结果，在加热器保暖的情况下经历10分钟SMS的幼鼠表现出快速的翻正反射。因此，通过单次母鼠分离，USV数量减少，但这种减少与运动功能的下降无关。
