Corpus callosum

Function

The corpus callosum is the brain's great bridge: 200 million axons interweaving the two hemispheres in a C-shaped arc of white matter — genu, body, splenium — that is the largest commissure in the human nervous system.

It synchronises attention and transfers learned information between hemispheres within milliseconds. The pioneering split-brain studies of Sperry and Gazzaniga revealed its silent work: after callosotomy, each hemisphere perceives and decides alone, and consciousness divides.

Blood supply

Pericallosal branches of the anterior cerebral arteries; the splenium from the posterior cerebral arteries.

Nerve supply

Composed purely of axons — no synaptic processing of its own.

Clinical relevance

Diffuse axonal injury

Shearing forces of acceleration trauma tear callosal fibres — a major mechanism of coma after road accidents.

Corpus callosum agenesis

Congenital absence often goes unnoticed in isolation — the brain's plasticity routes around it.