Study shines light on mysteries of senility

Millions of Americans above the age of 65 suffer from dementia, a disorder of mental processes associated with loss of memory or perception skills that may impact a person’s ability to perform everyday tasks.  A novel study, conducted at OHSU and published in the Annals of Neurologyprovides new insights into the origins of vascular dementia in maturing adults, now recognized as the second leading cause of dementia.

Through the analysis of human blood vessels, the research team – led by Stephen Back, M.D., Ph.D. – determined that aging white matter, or the areas of the central nervous system that affect learning and brain function, has a more vulnerable blood supply than other parts of the brain, making it more susceptible to injury.

Further, the study found that when the brain’s white matter becomes injured and attempts to repair itself, it fails to do so, and instead creates a significant increase in oligodendrocyte progenitor cells, which – typically – give rise to myelin-forming cells critical for the conduction of information across the brain.

These OPCs fail to mature into myelin-forming cells, which means that the injured white matter has a block in the pathways that allow myelin to form. This is a potential explanation of why some adults may experience senility as they age.

Additional research, currently underway, works to identify the source of myelin formation block, potentially leading way for future targeted therapy options.

Dieter Brandner, B.A., Phuong Le, B.A., David McNeal, Ph.D., and Xi Gong, M.D., of the OHSU Department of Pediatrics, and Thuan Ngyuen, M.D., Ph.D., of the OHSU Department of Preventive Medicine also contributed to this work in collaboration with investigators at the University of Washington School of Medicine, the Medical College of Georgia and Stanford University School of Medicine.

The research was supported by grants from the National Institute on Aging, (AG031892, AG006781, and AG05136), the National Institute of Neurological Disorders and Stroke (NS054044), a Huebner Family Post-Doctoral Training Fellowship, and by the Nancy and Buster Alvord Endowment.

— Written by Tracey Brawley