Comparative animal studies have identified a trend toward a more global structural organization as brains become larger, suggesting that brain regions grow in sync as predicted by the concerted model of brain evolution. At the same time, brain plasticity studies have identified a boost in local brain structure triggered by the environment, suggesting that brain regions grow independently, as predicted by the mosaic model. Nevertheless, it is unclear whether the environment can also trigger shifts toward a more global brain structure, that is, whether phenotypic plasticity proceeds in a concerted fashion. Here, we examined the impact of radically different rearing environments on brain organization in a teleost fish, the three‐spined stickleback (Gasterosteus aculeatus). We computed novel indices of local and global brain structure across groups reared in the two environments and entered them as predictors of differences in brain and body sizes. Changes in local brain structure predicted differences in both body and brain sizes, whereas changes in global brain structure only predicted differences in brain size. Our findings highlight the emergence of brain plasticity in a population as local and global changes that are both compatible with the concerted model.

中文翻译：

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超越大脑进化的马赛克模型：饲养环境定义了局部和全局可塑性


比较动物研究已经确定了随着大脑变得更大，结构组织更加全球化的趋势，这表明大脑区域按照大脑进化的协调模型所预测的那样同步增长。与此同时，大脑可塑性研究发现，环境触发了局部大脑结构的增强，这表明正如马赛克模型所预测的那样，大脑区域是独立生长的。然而，目前尚不清楚环境是否也能触发向更全面的大脑结构的转变，即表型可塑性是否以协调一致的方式进行。在这里，我们研究了截然不同的饲养环境对硬骨鱼 （Gasterosteus aculeatus） 大脑组织的影响。我们计算了在两种环境中饲养的各组的局部和整体大脑结构的新指数，并将它们作为大脑和身体大小差异的预测因子。局部大脑结构的变化预测了身体和大脑大小的差异，而整体大脑结构的变化仅预测了大脑大小的差异。我们的研究结果强调了种群中大脑可塑性的出现，因为局部和全球变化都与协同模型兼容。