Université Paris 13, Sorbonne Paris Cité, Laboratoire d'Ethologie Expérimentale et Comparée EA 4443, F-93430, Villetaneuse, France.
Université Paris 13, Sorbonne Paris Cité, Laboratoire d'Ethologie Expérimentale et Comparée EA 4443, F-93430, Villetaneuse, France.
Behav Brain Res. 2019 Dec 30;376:112194. doi: 10.1016/j.bbr.2019.112194. Epub 2019 Aug 29.
Animals of different behavioral types typically show associated differences in their physiological stress response, including differential reactivity of the sympathetic nervous system. Infrared thermography offers the possibility to explore this link in a non-invasive way via the quantification of fine-scale changes in peripheral body temperature due to changes in cutaneous blood flow. We used this technique to investigate the association between exploration tendency, a behavioral trait frequently used to phenotype mammals and birds, and short-term thermal responses to challenge in a small rodent of wild origin, the mound-building mouse (Mus spicilegus). We applied a brief handling procedure consisting in the transfer of subjects into a small arena. This procedure led to a significant increase in subjects' maximum peripheral body temperature (mainly reflecting the temperature of the eyes) and to significant decreases in maximum temperatures at different positions on the tail. Maximum peripheral body and tail temperatures showed significant individual-level consistencies in response to repeated applications of the handling procedure, suggesting stable individual differences in the animals' sympathetic activity. We then compared the thermal responses to handling between 'fast' and 'slow' explorers, who were phenotyped through repeated open field and novel object tests. Fast explorers showed significantly lower tail temperatures than slow explorers shortly after handling, suggesting a stronger sympathetic reactivity in the former. Comparisons within sibling groups kept in different cages showed that the differences between explorer types were particularly pronounced during the first minute after handling, and increased in magnitude along the first millimeters distal to the tail base.
不同行为类型的动物通常在其生理应激反应方面表现出相关差异，包括交感神经系统的不同反应性。红外热成像技术通过量化由于皮肤血流变化引起的外周体温的细微变化，提供了一种非侵入性的方法来探索这种联系。我们使用这种技术来研究探索倾向（一种常用于表型哺乳动物和鸟类的行为特征）与来自野外的小型啮齿动物——冢鼠（Mus spicilegus）短期热应激反应之间的关联。我们应用了一个简短的处理程序，包括将实验对象转移到一个小竞技场中。该程序导致实验对象的最大外周体温显著升高（主要反映眼睛的温度），尾巴不同位置的最大温度显著降低。最大外周体温和尾巴温度在重复应用处理程序时表现出显著的个体水平一致性，这表明动物的交感活动存在稳定的个体差异。然后，我们比较了通过重复开放场和新物体测试表型的“快速”和“慢速”探索者对处理的热反应。处理后不久，快速探索者的尾巴温度明显低于慢速探索者，这表明前者的交感反应性更强。在不同笼子中饲养的同窝兄弟姐妹组内的比较表明，在处理后的前一分钟，探索者类型之间的差异特别明显，并且沿着尾巴基部向远端的第一毫米处，差异程度增加。
