Thomas Michael Jessell. 2 August 1951—28 April 2019

Abstract

Tom Jessell was a British neuroscientist who made pioneering discoveries in developmental neurobiology. Beginning with a neuropharmacology training in London and Cambridge, Tom moved to Harvard and finally Columbia University. There, Tom embraced the dramatic late twentieth-century developments in molecular biology to unravel the genetic basis of spinal cord neuronal diversity and developmental mechanisms of circuit formation. Combining encyclopaedic knowledge of the classical neurobiology literature with virtuoso molecular genetic, anatomical and electrophysiological techniques, exploited by his team of gifted students, post-docs and collaborators, Tom made seminal contributions to broad areas of neuroscience. Notable contributions included the discovery of extracellular factors that induce distinct neuronal cell types and guide their connectivity, as well as the identification of the transcriptional repertoires that led to neuronal complexity in the developing spinal cord. Important insights into circuitry and behaviour followed these defining studies. At the same time, Tom was heavily involved in neuroscience education and the development of new neuroscience research institutes. For all his Herculean energy for research, he still found great pleasure in fine art, cricket and jazz, and his life was greatly enriched by his partner Jane Dodd, also a Cambridge-trained neuroscientist, and their three daughters. Tom's wit, energy and incisive intelligence will be sorely missed. His legacy is not only a paradigm-shifting body of papers, but also his educational and institutional achievements and the remarkable group of scientists, once his trainees, who, in their turn, continue to advance neuroscience research around the world.