Dennis J. Selkoe (born September 25, 1943) is an American neurologist and neuroscientist known for his research on the molecular mechanisms underlying Alzheimer's disease. He is the Vincent and Stella Coates Professor of Neurologic Diseases at Harvard Medical School and a senior neurologist at Brigham and Women's Hospital. Selkoe's research helped establish the role of amyloid-ò peptides in Alzheimer's etiology and pathogenesis and contributed significantly to the development of the amyloid cascade hypothesis, a dominant framework for understanding and treating the disease. He is also a Fellow of the AAAS and a member of the National Academy of Medicine.
Selkoe was born in New York City, United States. He earned a Bachelor of Arts degree from Columbia University in 1965 and received his Doctor of Medicine degree from the University of Virginia School of Medicine in 1969. He undertook postgraduate training in internal medicine at the Hospital of the University of Pennsylvania and in neurology at teaching hospitals of Harvard Medical School (Peter Bent Brigham, Children's, and Beth Israel Hospitals).
Selkoe joined the faculty of Harvard Medical School in 1975 as Instructor in Neurology, later becoming a professor of neurology and neuroscience. In 1985, he co-founded and became co-director of the Center for Neurologic Diseases at Brigham and women's Hospital, and in 1990 he received an endowed chair as the Vincent and Stella Coates Professor of Neurologic Diseases at Harvard Medical School. He has held clinical appointments at Brigham and Women's Hospital and Massachusetts General Hospital, where he has practiced neurology while directing a laboratory focused on neurodegenerative disease research, principally Alzheimer's and Parkinson's diseases.
He was the principal founding scientist of the biotechnology company Athena Neurosciences in 1986. Subsequently, he served on the boards of the biotech companies Athena, Elan, and Prothena. Selkoe also co-founded the Harvard Center for Neurodegeneration and Repair in 2001, reflecting his involvement in translational research initiatives aimed at developing therapies for neurologic diseases.
He has an h-index of 183 according to Semantic Scholar.
Selkoe's laboratory identified amyloid-ò (Aò) peptides as critical pathogenic agents in AD and showed that these peptides are produced naturally throughout life from the amyloid precursor protein (APP) in essentially all cells. He and collaborators demonstrated that mutations in APP and later in the presenilin genes increase the production and accumulation of the toxic Aò42 peptide and cause familial, early-onset Alzheimer's disease, establishing a genetic link between APP processing and neurodegeneration. In 1999, Selkoe's group identified presenilin as the catalytic component of the ó-secretase complex, the enzyme responsible for processing APP into Aò throughout life, advancing understanding of pathogenic events in brain aging and AD.
Selkoe contributed significantly to the formulation and refinement of the amyloid cascade hypothesis, which proposes that accumulation and misprocessing of Aò is an early driver of AD pathology, triggering downstream processes including tau pathology, synaptic dysfunction, and cognitive decline. His laboratory also provided evidence that soluble Aò oligomers, rather than insoluble plaques alone, can impair synaptic function and memory, linking specific molecular abnormalities to cognitive deficits. He emphasized that an imbalance in Aò production and clearance, particularly increased levels of Aò42, plays a central role in initiating AD pathology long before its clinical symptoms appear.
Selkoe's research and conceptual advances extend beyond AD to protein misfolding and aggregation in other neurodegenerative disorders, including Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis, exploring partly shared pathways of cytotoxicity and abnormal protein clearance. His work emphasizes the interplay between misfolded proteins, synaptic dysfunction, cellular stress responses, inflammation, and neuronal death, contributing to a systems-level understanding of neurodegeneration.
Building on original molecular insights, Selkoe has been involved in translating basic science into therapeutic strategies, including amyloid-targeting immunotherapies and modulation of secretase activity, although clinical progress has been challenging. He has also published perspectives on how emerging Alzheimer's treatments could fundamentally alter the trajectory of human aging and dementia.
Selkoe has authored numerous articles in journals such as Nature, Science, Neuron, Annals of Neurology, EMBO Molecular Medicine, and JAMA Neurology, covering APP biology, Aò dynamics, synaptic pathology, genetic determinants of AD, and therapeutic challenges. His work is highly cited and has influenced multiple generations of AD research, from fundamental biochemical processes to translational approaches in drug development. A bibliometric analysis published in 2009 concluded that Selkoe was the most cited author in the field of Alzheimer's disease research.