On MRI scans of older adults, especially those living with dementia, small fluid-filled spaces often appear surrounding the brain’s blood vessels. These features, called enlarged perivascular spaces, have been showing up on scans for years, but scientists and doctors have not been able to fully understand how or why they form.
New NIH-funded work at the Oregon National Primate Research Center (ONPRC) is starting to change that. A recent study showed that rhesus macaques, a species of monkey closely related to humans, naturally developed these same kinds of perivascular spaces with age. A related study discovered that they can also experience cognitive impairment in old age, similar to humans. This makes monkeys a powerful model for closely mirroring and tracking what doctors see in human brain scans as people age and develop dementia.
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Why Do These Little Spaces Matter?
Many leading theories suggest that Alzheimer’s disease and other related dementias may be driven in part by the brain’s reduced ability to clear waste products, and that enlarged perivascular spaces may be a visible sign of this process. While these spaces do not themselves cause dementia, they are thought to reflect underlying changes in brain health that occur with aging and disease. Brain waste-clearance can’t yet be tracked in people over the years it takes dementia to develop. And the other tools researchers turn to, like rodents, organoids, and computer models, cannot yet reproduce the complexity of an aging primate brain. AI approaches are promising, but they still learn from biological data that has to be measured somewhere first. That leaves a critical gap in dementia research, which monkeys help fill.
How Nonhuman Primates Move Dementia Research Forward
By showing that monkeys naturally develop the same brain and memory changes in old age as humans do, this work gives researchers a way to better understand how and why waste clearance fails and to evaluate potential treatments in ways not currently possible in people before dementia develops. This advance fills a major gap in Alzheimer’s research and exemplifies how responsible, ethical research with monkeys is helping to advance dementia care.
Foundational research like this, on the biology of aging, is essential for turning scientific discoveries into therapies that could delay or prevent dementia, which, in turn, would reduce suffering for patients and families and lower long-term healthcare costs.
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References
- Liguore WA, Schwartz DL, Piantino J, Rajendran A, Jensen G, Karpf JA, Chernov MM, Woltjer RL, Kohama SG, Silbert LC, Weiss AR. Aging macaques bridge the translational gap in perivascular space biology. Scientific Reports. June 15, 2026. https://doi.org/10.1038/s41598-026-52797-w
- Lurye LR, Smith DL, Liguore WA, Kohama SG, Weiss AR. Age-Related Differences in Short Term Spatial Memory in Rhesus Macaques. American Journal of Primatology. April 2026;88(4). https://doi.org/10.1002/ajp.70157