Multidisciplinary Pain Center, Aichi Medical University, 1-1 Yazakokarimata, Nagakute, Aichi 480-1195, Japan.
Exp Anim. 2021 Feb 6;70(1):119-125. doi: 10.1538/expanim.20-0111. Epub 2020 Oct 26.
Apart from self and conspecific odors, odors from other species also influence the affective states in laboratory mice (Mus musculus musculus) in their home cages and during experimental procedures, possibly inducing confusion and inconsistency in experimental data. Thus, it is important to detect the types of animal odors associated with housing, husbandry, and laboratory practice that can arouse different types of affective changes in mice. Here, we aimed to test the effectiveness of the acoustic startle reflex (ASR) in detecting changes in the affective states of laboratory mice due to animal-derived-odor as it has a non-zero baseline, and can be enhanced or attenuated by positive or negative affective shifts, respectively. We used ASR to examine the affective changes in mice that were induced by bedding odors and an alarm pheromone. The odor of bedding obtained from the mice' home cages significantly attenuated the ASR, suggesting positive affective shifts in the test mice, whereas that from bedding obtained from rat cages significantly enhanced the ASR, suggesting negative affective shifts. No significant changes in ASR were observed in mice presented with the odor of bedding obtained from cages of unfamiliar conspecifics. In contrast, there was significant ASR enhancement in mice exposed to volatile components of alarm pheromones trapped in water, suggesting negative affective shifts. Thus, our findings show that ASR may be a valuable tool in assessing the effects of odors on the affective states in laboratory mice.
除了自身和同种气味外，来自其他物种的气味也会影响实验室小鼠（Mus musculus musculus）在其笼舍中和实验过程中的情绪状态，可能导致实验数据的混乱和不一致。因此，检测与饲养、管理和实验室实践相关的动物气味类型，以了解这些气味会在多大程度上引起小鼠产生不同类型的情绪变化，这一点非常重要。在这里，我们旨在测试声学惊吓反射（ASR）在检测由于动物源性气味引起的实验室小鼠情绪状态变化方面的有效性，因为它具有非零基线，并且可以分别通过积极或消极的情绪变化来增强或减弱。我们使用 ASR 来检测由垫料气味和警报信息素引起的小鼠情绪变化。来自小鼠笼舍的垫料气味显著减弱了 ASR，表明测试小鼠的情绪发生了积极变化，而来自大鼠笼舍的垫料气味则显著增强了 ASR，表明测试小鼠的情绪发生了消极变化。当向小鼠呈现来自不熟悉同种小鼠笼舍的垫料气味时，ASR 没有明显变化。相比之下，暴露于水中捕获的警报信息素挥发性成分的小鼠的 ASR 显著增强，表明其情绪发生了消极变化。因此，我们的研究结果表明，ASR 可能是评估气味对实验室小鼠情绪状态影响的一种有价值的工具。
