 During his residency, Barres noted the lack of knowledge about the causes or cures of neurodegeneration.In studying pathology reports, he noticed a correlation between neural degeneration and irregular patterns of glial cells in the brain and, intrigued, resigned his residency to pursue research in neuroscience at Harvard.He completed a PhD in Neurobiology there in 1990, then did postdoctoral training at University College London under Martin Raff.