John O'Keefe

University College London

John O'Keefe is an American-British neuroscientist and Emeritus Professor at University College London. He shared the 2014 Nobel Prize in Physiology or Medicine with May-Britt Moser and Edvard Moser for the discovery of cells constituting a positioning system in the brain—specifically, the discovery of place cells in the hippocampus. In landmark 1971 recordings from freely moving rats, O'Keefe discovered that specific neurons in the hippocampus—which he termed place cells—fire preferentially when an animal occupies a particular location in its environment. Different neurons fire at different locations, collectively forming a cognitive map of the spatial environment. This discovery provided the first clear cellular mechanism for spatial navigation and memory and transformed our understanding of hippocampal function. O'Keefe's cognitive map theory proposed that the hippocampus functions as a spatial map that the brain uses to navigate and record experiences. This framework has since been enormously generalized: the hippocampus is now understood to encode not just physical space but also conceptual and temporal relationships, serving as a fundamental substrate for episodic memory. O'Keefe's research program has continued to characterize the properties of place cells under various conditions and to connect spatial navigation circuits to learning and memory disorders including Alzheimer's disease, where hippocampal place cell degradation may underlie early spatial disorientation symptoms. He is a Fellow of the Royal Society and has received the Kavli Prize in Neuroscience.