Dr. Greenfield, a native New Yorker, graduated from Amherst College Magna Cum Laude in Neuroscience before receiving his M.D. and Ph.D. degrees from the Weill Medical College and Graduate School of Medical Sciences. His laboratory mentor during his PhD was Paul Greengard at The Rockefeller University, who won the Nobel Prize for Medicine in 2000. He completed his Neurosurgery residency at The NewYork-Presbyterian Hospital/Weill Cornell Medical Center and Memorial Sloan Kettering Cancer Center. During residency he was awarded a scientific fellowship with Howard Hughes Scientist Shahin Rafii in Stem Cell Biology at the Ansary Center for Stem Cell Therapeutics.