Has the Brain Maximized its Information Storage Capacity?

Learning and memory may rely on the ability of neuronal circuits to reorganize by dendritic spine remodeling. We have looked for geometrical parameters of cortical circuits, which maximize information storage capacity associated with this mechanism. In particular, we calculated optimal volume fractions of various neuropil components. The optimal axonal and dendritic volume fractions are not significantly different from anatomical measurements in the mouse and rat neocortex, and the rat hippocampus. This has led us to propose that the maximization of information storage capacity associated with dendritic spine remodeling may have been an important driving force in the evolution of the cortex.