CNRS, UPS, Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), Université de Toulouse, Toulouse, France.
Sci Rep. 2024 Oct 25;14(1):25323. doi: 10.1038/s41598-024-76884-y.
Innate defensive behaviors are essential for species survival. While these behaviors start to develop early in an individual's life, there is still much to be understood about how they evolve with advancing age. Considering that aging is often accompanied by various cognitive and physical declines, we tested the hypothesis that innate fear behaviors and underlying cerebral mechanisms are modified by aging. In our study we investigated this hypothesis by examining how aged mice respond to a looming visual threat compared to their younger counterparts. Our findings indicate that aged mice exhibit a different fear response than young mice when facing this imminent threat. Specifically, unlike young mice, aged mice tend to predominantly display freezing behavior without seeking shelter. Interestingly, this altered behavioral response in aged mice is linked to a distinct pattern of functional brain connectivity compared to young mice. Notably, our data highlights a lack of a consistent brain activation following the fear response in aged mice, suggesting that innate defensive behaviors undergo changes with aging.
先天防御行为对物种生存至关重要。虽然这些行为在个体生命的早期就开始发展，但对于它们如何随着年龄的增长而进化，仍有很多需要了解。考虑到衰老通常伴随着各种认知和身体机能的下降，我们测试了一个假设，即先天恐惧行为和潜在的大脑机制会随着年龄的增长而改变。在我们的研究中，我们通过观察年老小鼠与年轻小鼠相比对即将到来的视觉威胁的反应来检验这一假设。我们的研究结果表明，年老小鼠在面对这种迫在眉睫的威胁时，表现出与年轻小鼠不同的恐惧反应。具体来说，与年轻小鼠不同，年老小鼠在没有寻求庇护的情况下往往主要表现出冻结行为。有趣的是，与年轻小鼠相比，年老小鼠这种行为反应的改变与大脑功能连接的特定模式有关。值得注意的是，我们的数据突出表明，年老小鼠在恐惧反应后缺乏一致的大脑激活，这表明先天防御行为随着年龄的增长而发生变化。
