Brain scaling in mammalian evolution as a consequence of concerted and mosaic changes in numbers of neurons and average neuronal cell size.
Brain scaling in mammalian evolution as a consequence of concerted and mosaic changes in numbers of neurons and average neuronal cell size.
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DOI：
10.3389/fnana.2014.00077
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发表时间：
2014
影响因子：
2.9
通讯作者：
Kaas JH
中科院分区：
文献类型：
--
作者：
Herculano-Houzel S;Manger PR;Kaas JH
现在已经有足够多的物种对其大脑的形态和细胞组成之间的关系进行了系统的定量分析，这些模式开始出现，并揭示了导致哺乳动物大脑多样性的进化路径。基于对 6 个进化枝中 41 个现代哺乳动物物种的共有特征和进化枝特异性特征的分析，并根据它们之间的系统发育关系，我们提出，祖先哺乳动物大脑的细胞组成和规模与现代非洲兽和羚羊的大脑相似：神经元的增加伴随着神经元密度的减少和神经胶质细胞密度的很少改变，这意味着 较大大脑中的平均神经元细胞大小增加，大脑皮层中约 2 个神经元和小脑中约 8 个神经元分配给大脑其余部分。我们还提出，在某些进化枝中，不同大脑结构的尺度已经偏离了共同祖先的布局，这是通过进化枝特异性（或进化枝定义）的变化来实现的，这些变化包括平均神经元细胞质量与每个结构中神经元数量的关系，以及神经元数量相对于大脑其余部分的神经元数量如何差异分配到每个结构的方式。因此，哺乳动物大脑的进化扩张涉及跨结构的协调和马赛克缩放模式。据我们所知，这是第一个解释哺乳动物进化中大小大脑生成的机制模型，它为寻找大脑进化中涉及的细胞途径和基因开辟了新的视野。
Enough species have now been subject to systematic quantitative analysis of the relationship between the morphology and cellular composition of their brain that patterns begin to emerge and shed light on the evolutionary path that led to mammalian brain diversity. Based on an analysis of the shared and clade-specific characteristics of 41 modern mammalian species in 6 clades, and in light of the phylogenetic relationships among them, here we propose that ancestral mammal brains were composed and scaled in their cellular composition like modern afrotherian and glire brains: with an addition of neurons that is accompanied by a decrease in neuronal density and very little modification in glial cell density, implying a significant increase in average neuronal cell size in larger brains, and the allocation of approximately 2 neurons in the cerebral cortex and 8 neurons in the cerebellum for every neuron allocated to the rest of brain. We also propose that in some clades the scaling of different brain structures has diverged away from the common ancestral layout through clade-specific (or clade-defining) changes in how average neuronal cell mass relates to numbers of neurons in each structure, and how numbers of neurons are differentially allocated to each structure relative to the number of neurons in the rest of brain. Thus, the evolutionary expansion of mammalian brains has involved both concerted and mosaic patterns of scaling across structures. This is, to our knowledge, the first mechanistic model that explains the generation of brains large and small in mammalian evolution, and it opens up new horizons for seeking the cellular pathways and genes involved in brain evolution.
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影响因子：
2.9
作者：
Elston GN;Manger P
通讯作者：
Manger P
影响因子：
2.5
作者：
Azevedo, Frederico A. C.;Carvalho, Ludmila R. B.;Herculano-Houzel, Suzana
通讯作者：
Herculano-Houzel, Suzana
DOI：
10.1111/j.1749-6632.1947.tb36165.x
发表时间：
1947-01-01
影响因子：
5.2
作者：
COUNT, EW
通讯作者：
COUNT, EW
影响因子：
2.9
作者：
Herculano-Houzel S;Watson C;Paxinos G
通讯作者：
Paxinos G
影响因子：
2.9
作者：
Herculano-Houzel S
通讯作者：
Herculano-Houzel S