Jehee Janneke F M, Murre Jaap M J
University of Amsterdam, Roetersstraat 15, 1018 WB, Amsterdam, The Netherlands.
Biol Cybern. 2008 May;98(5):439-45. doi: 10.1007/s00422-008-0228-y. Epub 2008 Apr 15.
In this paper, we demonstrate that two characteristic properties of mammalian brains emerge when scaling-up modular, cortical structures. Firstly, the glia-to-neuron ratio is not constant across brains of different sizes: large mammalian brains have more glia per neuron than smaller brains. Our analyses suggest that if one assumes that glia number is proportional to wiring, a particular quantitative relationship emerges between brain size and glia-to-neuron ratio that fits the empirical data. Secondly, many authors have reported that the number of neurons underlying one mm(2) of mammalian cortex is remarkably constant, across both areas and species. Here, we will show that such a constancy emerges when enlarging modular, cortical brain structures. Our analyses thus corroborate recent studies on the mammalian brain as a scalable architecture, providing a possible mechanism to explain some of the principles, constancies and rules that hold across brains of different size.
在本文中，我们证明了在扩大模块化皮质结构时，哺乳动物大脑会出现两个特征性属性。首先，不同大小的大脑中胶质细胞与神经元的比例并非恒定：大型哺乳动物大脑中每个神经元的胶质细胞比小型大脑更多。我们的分析表明，如果假设胶质细胞数量与神经连接成正比，那么大脑大小与胶质细胞与神经元比例之间就会出现一种特定的定量关系，该关系与实验数据相符。其次，许多作者报告称，在不同区域和物种中，每平方毫米哺乳动物皮质下的神经元数量非常恒定。在此，我们将表明，在扩大模块化皮质脑结构时会出现这种恒定性。因此，我们的分析证实了最近关于哺乳动物大脑是一种可扩展结构的研究，为解释适用于不同大小大脑的一些原理、恒定性和规则提供了一种可能的机制。
