 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.In 1993, Barres joined the faculty of Neurobiology at the Stanford School of Medicine.