Your brain has its own clean-up crew — microglia, the immune cells that patrol for damaged cells and amyloid plaques. But when your circadian rhythm is disrupted, these cells can become "stress-primed" and stop working properly, potentially accelerating dementia. Researchers at Texas A&M University are now testing a new therapy to keep these cells healthy.
The Research
In a study published in 2025, Karienn Souza, a research assistant professor at the Texas A&M University College of Medicine, and her colleague David Earnest investigated how circadian rhythm dysregulation — common in shift workers — affects the brain's immune system. Using an animal model, they found that chronic disruption of sleep-wake cycles caused microglia to change shape. Normal microglia have a branched, tree-like structure, but the team observed "stress-primed" microglia with extra or extended branches, indicating malfunction. These cells failed to clear debris and amyloid plaques, which accumulate and contribute to dementia symptoms.
With a $1.325 million seedling grant from the Dementia & Alzheimer's Research Initiative (DARI), Souza is now testing a therapy developed by Ashok Shetty, a distinguished professor at the same university. The therapy uses extracellular vesicles (EVs) — nano-sized particles derived from stem cells that carry anti-inflammatory signals. In previous work, Shetty showed that EV therapy can prevent microglia from shifting into the stress-primed state, essentially shielding them from circadian-induced damage.
Why It Matters
Globally, dementia cases are projected to reach 139 million by 2050. Souza emphasizes that only about 3% of Alzheimer's risk is genetic — the remaining 97% is environmental. This means lifestyle factors like sleep, exercise, and diet play a huge role. For anyone who works night shifts, has irregular sleep patterns, or struggles with jet lag, this research offers a wake-up call: your brain's clean-up crew may be under stress. While the EV therapy is still in early stages, the findings highlight the importance of protecting your circadian rhythm.
What You Can Do
Prioritize a consistent sleep schedule — even on weekends. Avoid bright screens at least an hour before bed, and keep your bedroom dark and cool. If you're a shift worker, try to maintain a regular sleep routine on days off and use blackout curtains. These steps can help keep your microglia healthy and reduce long-term dementia risk.
Source: Neuroscience News
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