Dumitru Magda L, Frugård Opdal Anders Martin
Department of Biological Sciences, University of Bergen, Bergen, Norway.
Ann N Y Acad Sci. 2024 Dec;1542(1):58-66. doi: 10.1111/nyas.15267. Epub 2024 Nov 25.
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.
比较动物研究发现，随着大脑变大，存在一种向更全局化结构组织发展的趋势，这表明脑区如大脑进化的协同模型所预测的那样同步生长。与此同时，大脑可塑性研究发现环境会引发局部脑结构的增强，这表明脑区如镶嵌模型所预测的那样独立生长。然而，尚不清楚环境是否也能引发向更全局化脑结构的转变，也就是说，表型可塑性是否以协同的方式进行。在这里，我们研究了截然不同的饲养环境对一种硬骨鱼——三刺鱼（Gasterosteus aculeatus）脑组织结构的影响。我们计算了在两种环境中饲养的不同组别的局部和全局脑结构的新指标，并将它们作为脑和身体大小差异的预测指标。局部脑结构的变化预测了身体和脑大小的差异，而全局脑结构的变化仅预测了脑大小的差异。我们的研究结果凸显了群体中大脑可塑性以局部和全局变化的形式出现，且这两种变化都与协同模型相符。
