Recent findings in Professor Gerald Schneider's laboratory challenge the dominant theory explaining the failure of axonal regeneration after injury in the adult mammalian brain. These findings suggest that programmed changes in the neuronal cells of origin, rather than negative influences in the tissue environment, are the major cause of decline in regenerative ability of axons in the central nervous system. This research has significance for understanding mechanisms of brain repair after injury or trauma.
Professor William Quinn's laboratory has characterized a peptide transmitter with an evident role in middle term memory. Antibodies generated to this peptide have led to the functional localization in the Drosophila brain of cells producing the peptide. The antibodies may also facilitate the search for mammalian versions of the peptide, with implications for human memory and learning.
Professor Richard Wurtman's lab has discovered that glutamate, a brain neurotransmitter which is especially abundant in brain regions (like cortex and hippocampus) that are involved in memory and learning, and which is deficient in brains of people with Alzheimer's Disease, normally controls the metabolism of the brain protein APP. In the presence of normal glutamate levels, this protein is metabolized in a a way which does not lead to the formation of the amyloid plaques characteristic of Alzheimer's Disease. However in the absence of glutamate, APP is broken down to yield A-beta peptides, which can form amyloid. The glutamate acts via metabotropic glutamate receptors. These findings are important for understanding and possibly treating Alzheimer's Disease.
Professor Mriganka Sur's laboratory has used optical imaging techniques to record the activity of neuronal populations in visual cortex. The activity of cortical neurons can be regulated in dynamic fashion by long-range connections within cortex. This work provides an important basis for context-dependent effects in vision, and more generally, for the cortical processing of visual information.
Professor Edward Adelson has developed models for the analysis of transparent motion and motion segementation. This work has applications in modeling human vision as well as in computer vision and image coding.
Professor Mary Potter's lab has focused on the deployment of attention when events occur rapidly in vision, audition, or both. Her lab demonstrated that a visual "attention blink" makes it difficult to encode the second of two visual targets among distractors, within a 50 ms window. Professor Potter has recently shown that no such attentional bottleneck arises with rapid auditory targets, and work on mixtures of auditory and visual targets is under way.
Nine students complete the Ph.D. during the past year. One has accepted a faculty position at Yale, and the others have opted for postdoctoral fellowships.
Suzanne Corkin was awarded the Smith College Medal.
Ann M. Graybiel was awarded the Walter A. Rosenblith Professorship in Neuroscience and elected to the Institute of Medicine of the National Academy of Sciences.
Steven Pinker won the William James Book Award of the American Psychological Association. The New York Times Book Review, London Times Book Review and Boston Globe Book Review chose The Language Instinct as one of the ten best books of 1994.
Matthew Wilson was named an Alfred P. Sloan Research Fellow and Edward J. Poitras Associate Professor of Human Biology and Experimental Medicine. He also received the Seaver Award.
Richard Wurtman was named Cecil B. Green Distinguished Professor.
Emilio Bizzi, M.D.
MIT Reports to the President 1994-95