Silberfeld Andrew, Roe James M, Ellegood Jacob, Lerch Jason P, Qiu Lily, Kim Yongsoo, Lee Jong Gwan, Hopkins William D, Grandjean Joanes, Ou Yangming, Pourquié Olivier
Department of Genetics, Harvard Medical School, Boston, MA, USA; Department of Pathology, Brigham and Women's Hospital, Boston, MA, USA.
Center for Lifespan Changes in Brain and Cognition (LCBC), Department of Psychology, University of Oslo, Norway.
Neuroimage. 2025 Feb 15;307:121017. doi: 10.1016/j.neuroimage.2025.121017. Epub 2025 Jan 10.
Left-right asymmetry of the human brain is widespread through its anatomy and function. However, limited microscopic understanding of it exists, particularly for anatomical asymmetry where there are few well-established animal models. In humans, most brain regions show subtle, population-average regional asymmetries in thickness or surface area, alongside a macro-scale twisting called the cerebral petalia in which the right hemisphere protrudes past the left. Here, we ask whether neuroanatomical asymmetries can be observed in mice, leveraging 6 mouse neuroimaging cohorts from 5 different research groups (∼3,500 animals). We found an anterior-posterior pattern of volume asymmetry with anterior regions larger on the right and posterior regions larger on the left. This pattern appears driven by similar trends in surface area and positional asymmetries, with the results together indicating a small brain-wide twisting pattern, similar to the human cerebral petalia. Furthermore, the results show no apparent relationship to known functional asymmetries in mice, emphasizing the complexity of the structure-function relationship in brain asymmetry. Our results recapitulate and extend previous patterns of asymmetry from two published studies as well as capture well-established, bilateral male-female differences in the mouse brain as a positive control. By establishing a signature of anatomical brain asymmetry in mice, we aim to provide a foundation for future studies to probe the mechanistic underpinnings of brain asymmetry seen in humans - a feature of the brain with extremely limited understanding.
人类大脑的左右不对称在其解剖结构和功能中广泛存在。然而，人们对其微观层面的了解有限，特别是对于解剖学上的不对称，因为几乎没有成熟的动物模型。在人类中，大多数脑区在厚度或表面积上表现出细微的、群体平均的区域不对称，同时还存在一种称为大脑叶卷曲的宏观扭曲现象，即右半球突出于左半球。在此，我们利用来自5个不同研究小组的6个小鼠神经成像队列（约3500只动物），探究是否能在小鼠中观察到神经解剖学上的不对称。我们发现了一种前后方向的体积不对称模式，即前部区域右侧较大，后部区域左侧较大。这种模式似乎是由表面积和位置不对称的类似趋势驱动的，这些结果共同表明存在一种全脑范围的小扭曲模式，类似于人类的大脑叶卷曲。此外，结果显示与小鼠已知的功能不对称没有明显关系，这凸显了大脑不对称中结构 - 功能关系的复杂性。我们的结果概括并扩展了之前两项已发表研究中的不对称模式，同时作为阳性对照捕捉到了小鼠大脑中已确立的双侧雌雄差异。通过在小鼠中建立大脑解剖学不对称的特征，我们旨在为未来研究探究人类大脑不对称的机制基础提供一个基础——这是一个目前了解极其有限的大脑特征。
