O'Keefe, John
John O'Keefe, 1939–, British-American neuroscientist, b. New York, N.Y., Ph.D. McGill Univ., 1967. O'Keefe has spent his entire career at University College London, beginning as a postdoctoral fellow in 1967 and becoming a professor in 1987; he was a pioneer in the study of the hippocampus region in the brain. In 2014 he was the recipient of the Nobel Prize in Physiology or Medicine with Edvard and May-Britt Moser for their discoveries of cells that constitute a positioning system in the brain. O'Keefe, who was awarded half of the prize, discovered the first element in this positioning system in rats in 1971. He identified nerve cells in the hippocampus region of the brain that were always activated when a rat was at certain locations in maze. O'Keefe's work, which was done when the hippocampus was very poorly understood, was not initially widely recognized. The place cells he identified, combined with the grid cells later identified by the Mosers, allow animals to navigate complex environments through the establishment of mental maps.