Chapter 5 – Geometrical Structure of Single Axons of Visual Corticocortical Connections in the Mouse

Corticocortical connections distribute information from primary sensory areas to more specialized areas of the cere­bral cortex. Complete wiring diagrams of the cortex could provide a basis for better understanding of the functioning of the brain, although the cortical connectome remains poorly known. Network analyses of cortical connectivity use quantitative weighting of cortical connectivity but neglect the morphology of axons. Analysis of corticocortical connections at the single axon level spotlights the many aspects of connectivity that need to be included in network models and connectomes of the cortex. Intra- and inter-cortical axons are diversified in their individual geometry. Axonal diameter, length, the complexity of branching structure, and geometric features at bifurcation points, as well as density of boutons, can be taken as indicators of morphological variations in corticocortical axons, and the consequent potential for very different integration properties.