Timothy Pons
Timothy “Tim” Philip Pons, 49, Professor of Neurosurgery at Wake Forest University School of Medicine, died 19 January 2005, after a long and courageous battle with liver disease. He was a neuroscientist of the first rank.
Tim got his first taste of neuroscience at the University of North Carolina at Greensboro, working with Walter Salinger on adult neural plasticity in the lateral geniculate nucleus, and he met Preston Garraghty, a life-long friend, colleague, and collaborator. Tim went on to do a Ph.D. with Jon Kaas at Vanderbilt University. This work led to extensive publications on area 2 of macaque parietal cortex, and revealed a basis for the sensory plasticity after adult nerve injury previously discovered by Michael Merzenich and others in Kaas's lab.
In 1984, Tim moved to Mortimer Mishkin's laboratory at the N.I.M.H., where he undertook to determine whether the primate somatosensory system shared organizational features with the hierarchically-organized parallel processing streams in the visual system. Tim showed that the second somatosensory area (S-II) of macaques required inputs from primary (S-I) cortex for its activation. This result contrasted with what had been demonstrated in non-simian species, and still stands as a reminder that mice are men only some of the time. His subsequent experiments, conducted after a period of recovery from S-I ablation, revealed that the formerly-deactivated region of S-II had regained responsiveness, but to skin surfaces whose S-I representations remained intact. This finding served as a precursor for experiments that would become the defining nexus of Tim's professional career.
Tim was lead author of a 1991 landmark paper in Science demonstrating that the somatosensory cortices of Ed Taub's Silver Spring monkeys, which had undergone extensive deafferentations of the hand, arm, and upper trunk, were responsive to cutaneous stimulation of the chin and lateral face. This was reorganization an order of magnitude greater than any previously reported. Soon thereafter Vilayanur Ramachandran reported that stimulating the face of human amputees evoked sensations not only on the face, but also on the missing limb. There followed a literal explosion of followup studies in a variety of clinical populations. Tim became the spokesperson for the new view of neural flexibility - that extensive adult neuroplasticity is not only possible, but to be expected.
In 1993, Tim became the Director of Research in the Department of Neurosurgery at Wake Forest University School of Medicine. There he obtained funding for, and directed an interdisciplinary Program Project on recovery from stroke in both monkeys and humans that became a model for translational research. In recent years he collaborated with Sam Deadwyler and Terrence Stanford on several projects involving single-neuron recording in behaving monkeys. But Tim retained his enduring interest in somatosensory cortical plasticity, and continued his investigations of the Silver Spring monkeys in collaboration with E.G. (Ted) Jones.
Tim will be remembered fondly by a vast array of friends and associates in many places, for his optimistic outlook on life, sense of humor, and desire to help others. While one could argue that Tim had greatness thrust upon him by the circumstances surrounding the Silver Spring monkeys, those who knew him appreciated that his greatness was latent, like the novel inputs exposed in the neuroplasticity experiments that followed his seminal Science report.
