Brain Scaling Laws

Bigger brains have lower neuron density, possess a greater number of synapses per neuron, become increasingly convoluted, have disproportionately more white matter, and are compartmentalized into more areas. This article reviews these and many other ways in which large mammalian neocortices differ from small ones. By identifying these allometric scaling laws, we hope to identify fundamental principles that the neocortex obeys across the nearly five orders of magnitude of brain volume change from shrew to whale.