Bontempi Pietro, Ricatti Maria Jimena, Sandri Marco, Nicolato Elena, Mucignat-Caretta Carla, Zancanaro Carlo
Department of Computer Science, University of Verona, Strada Le Grazie 15, I-37134 Verona, Italy.
Department of Neuroscience Biomedicine & Movement Sciences, University of Verona, Strada Le Grazie 8, I-37134 Verona, Italy.
Biology (Basel). 2023 Feb 28;12(3):381. doi: 10.3390/biology12030381.
Olfactory areas in mammalian brains are linked to centers that modulate behavior. During aging, sensitivity to odors decreases and structural changes are described in olfactory areas. We explored, in two groups of male mice (young and elderly, 6 and 19 months old, respectively), the link between the changes in olfactory bulb structure, detected with magnetic resonance imaging, and behavioral changes in a battery of tests on motor, olfactory, cognitive performance, and emotional reactivity. The behavioral pattern of elderly mice appears less anxious, being less scared by new situations. Additionally, the olfactory bulb of young and elderly mice differed in two variables derived from magnetic resonance imaging (fractional anisotropy and T2 maps). A random forest approach allowed to select the variables most predictive of the differences between young and elderly mice, and correlations were found between three behavioral variables indicative of anxious behavior and the two magnetic resonance variables mentioned above. These data suggest that in the living mouse, it is possible to describe co-occurring age-related behavioral and structural changes in the olfactory bulb. These data serve as a basis for studies on normal and pathological aging in the mouse, but also open new opportunities for in vivo human aging studies.
哺乳动物大脑中的嗅觉区域与调节行为的中枢相连。在衰老过程中，对气味的敏感度会下降，且嗅觉区域会出现结构变化。我们在两组雄性小鼠（分别为6个月大的年轻小鼠和19个月大的老年小鼠）中，探究了通过磁共振成像检测到的嗅球结构变化与一系列运动、嗅觉、认知能力及情绪反应测试中的行为变化之间的联系。老年小鼠的行为模式似乎焦虑程度较低，对新环境的恐惧较少。此外，年轻小鼠和老年小鼠的嗅球在磁共振成像得出的两个变量（分数各向异性和T2图谱）上存在差异。随机森林方法能够选出最能预测年轻小鼠和老年小鼠之间差异的变量，并且在表明焦虑行为的三个行为变量与上述两个磁共振变量之间发现了相关性。这些数据表明，在活体小鼠中，可以描述嗅球中同时出现的与年龄相关的行为和结构变化。这些数据不仅为小鼠正常衰老和病理衰老的研究提供了基础，也为人体衰老的体内研究开辟了新机遇。
