The link between structural brain asymmetry and the dimensions of the corpus callosum: A systematic review.

Cerebral asymmetry is a defining feature of the human brain, but some controversy exists with respect to the relationship between structural brain asymmetry and the dimensions of the corpus callosum, the brain's major inter-hemispheric commissure. On the one hand, more asymmetric brains might house a proportionally smaller corpus callosum (negative link), potentially due to intra-hemispheric connections dominating over inter-hemispheric connections. On the other hand, asymmetric brains may contain a proportionately larger corpus callosum (positive link), to facilitate a possibly enhanced demand of interhemispheric communication, either through excitatory or inhibitory channels.

Aberrant callosal morphology in ex-smokers.

Background: Cigarette smoking is associated with widespread structural alterations in both brain hemispheres as well as of the corpus callosum (i.e., the brain's main interhemispheric white matter pathway).