Ubiquitous lognormal distribution of neuron densities across mammalian cerebral cortex

Abstract

Numbers of neurons and their spatial variation are fundamental organizational features of the brain. Despite the large corpus of data available in the literature, the statistical distributions of neuron densities within and across brain areas remain largely uncharacterized. Here, we show that neuron densities are compatible with a lognormal distribution across cortical areas in several mammalian species. We find that this also holds true for uniformly sampled regions across cortex as well as within cortical areas. Our findings uncover a new organizational principle of cortical cytoarchitecture. The ubiquitous lognormal distribution of neuron densities adds to a long list of lognormal variables in the brain.