The AXYOM project deals with the building of a population-based atlas of the diameter and length of the callosal axons with diffusion imaging tractography.

The 25-years old work of Aboitiz et al. (1992) still remains the main description of the fiber composition of the human corpus callosum (CC) obtained in histology. Today, the length but also the axonal diameter of white matter fibers can, in principle, be obtained from in vivo diffusion imaging tractography.

The first goal of AXYOM is to optimize the AxTract tool developed by the Sherbrooke Connectivity Imaging Lab (SCIL, Université de Sherbrooke, Canada, Dir. Prof. M. Descoteaux) to provide a quantitative examination of axonal diameter and length of the callosal fibers.
The second goal of AXYOM is to test if the variability of callosal axon sizes accounts for other determinants of the human brain organization such as the handedness, the cognitive skills and the hemispheric lateralization for language and spatial attention.

This project is supported by the Intiative d’Excellence of the University of Bordeaux through its 2016 campaign of International Doctorat. As such, Mr. Alexandre Gauvin is conducting his thesis in co-supervision between the Universities of Bordeaux and Sherbrooke under the co-direction of MM. Laurent Petit (GIN-IMN) and Maxime Descoteaux (SCIL).