On the surface, the two hemispheres of vertebrate brains look almost perfectly symmetrical, but several motor, sensory, and cognitive systems show a deeply lateralized organization. Importantly, the two hemispheres are connected by various commissures, white matter tracts that cross the brain’s midline and enable cross-hemispheric communication. Cross-hemispheric communication has been suggested to play an important role in the emergence of lateralized brain functions. Here, we review current advances in understanding cross-hemispheric communication that have been made using modern neuroscientific tools in rodents and other model species, such as genetic labeling, large-scale recordings of neuronal activity, spatiotemporally precise perturbation, and quantitative behavior analyses. These findings suggest that the emergence of lateralized brain functions cannot be fully explained by largely static factors such as genetic variation and differences in structural brain asymmetries. In addition, learning-dependent asymmetric interactions between the left and right hemispheres shape lateralized brain functions.

中文翻译：

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跨半球交流：对侧化大脑功能的见解

从表面上看，脊椎动物大脑的两个半球看起来几乎完全对称，但一些运动、感觉和认知系统显示出深度偏侧化的组织。重要的是，两个半球通过各种接合处连接，这些接合处是穿过大脑中线并实现跨半球通信的白质束。跨半球交流被认为在侧化大脑功能的出现中发挥着重要作用。在这里，我们回顾了当前在啮齿动物和其他模型物种中使用现代神经科学工具在理解跨半球通信方面取得的进展，例如基因标记、神经元活动的大规模记录、时空精确扰动和定量行为分析。这些发现表明，侧化大脑功能的出现不能完全用静态因素（例如遗传变异和大脑结构不对称差异）来解释。此外，左右半球之间依赖于学习的不对称相互作用塑造了偏侧化的大脑功能。