A new peer-reviewed paper by neuroscientist Dale E. Bredesen proposes a unifying framework that could fundamentally change how researchers understand Alzheimer’s disease and other neurodegenerative disorders.
Published on August 11 in the Journal of Advanced Therapeutic Science, the paper introduces the Pr2 (prion-priion) theory, which views neurodegeneration as a failure of vulnerable neural networks to meet their biological demands.
Rather than treating amyloid, tau and other pathological features as the primary causes of disease, the theory proposes that these proteins may be components of an ancient protective response to threats—including chronic infections, toxins, inflammation and metabolic or vascular stress. Over time, according to the model, persistent threats can push that protective response toward chronic inflammation and loss of neural function.
The theory also offers an explanation for a longstanding puzzle in Alzheimer’s research: why some cognitively healthy people accumulate substantial amounts of amyloid without developing dementia. Under the Pr2 framework, amyloid and related proteins may initially serve protective, anti-infective or signaling functions before becoming associated with damaging inflammation and neurodegeneration under sustained stress.
The paper further argues that different neurodegenerative diseases may reflect vulnerabilities in different neural networks. In Alzheimer’s disease, those vulnerabilities may involve networks supporting neuroplasticity and may be influenced by factors including metabolic dysfunction, sleep apnea, chronic infection, air pollution and other sources of inflammation or impaired energetic support. Similar network-specific vulnerabilities are proposed for Parkinson’s disease, ALS and other disorders.
Importantly, the theory points toward a precision-medicine approach: identifying and addressing the combination of factors contributing to an individual patient’s neurological decline rather than relying on a single therapeutic target.
According to the paper, initial clinical translation of this approach has produced encouraging results, including findings from two proof-of-concept studies and reports of sustained cognitive improvement in some patients. The authors emphasize the need for further research and clinical testing to determine how broadly these findings can be replicated.
The Pr2 theory does not simply offer another explanation for Alzheimer’s – it proposes a different question: Instead of asking only how to remove the pathology, can we identify what caused the brain to enter a protective state in the first place – and restore the conditions needed for healthy neural function?
Dr. Dale Bredesen is an internationally recognized neurologist, neuroscientist, and expert in neurodegenerative disease, best known for his pioneering work in Alzheimer’s disease research and prevention. Over the course of his career, Dr. Bredesen has focused on understanding the complex mechanisms that contribute to cognitive decline and developing precision-medicine approaches designed to identify and address its underlying drivers.
Dr. Bredesen has held faculty positions at leading academic institutions, including the University of California, San Francisco (UCSF) and the University of California, Los Angeles, and served as founding president and CEO of the Buck Institute for Research on Aging. His research has contributed to the scientific understanding of neurodegeneration and the molecular mechanisms involved in Alzheimer’s disease.
He is the author of several books on brain health and cognitive decline, including the New York Times bestseller The End of Alzheimer’s. Through his research, writing, and clinical collaborations, Dr. Bredesen continues to advocate for earlier identification of cognitive decline and personalized, multi-factor approaches to supporting brain health.
Dr. Bredesen currently serves as the Chief Scientific Officer at Apollo Health and Senior Director of Precision Brain Health at Pacific Neuroscience Institute.
