Bold claim: the brain has built-in defenses against Alzheimer’s that may still be working in youth but fade with age. New findings illuminate how the brain protects itself from dangerous calcium surges, offering a potential path to preventing neurodegeneration.
High levels of calcium inside cells are toxic and contribute to neuron loss in Alzheimer’s disease. A recent JCI Insight study from Yale School of Medicine reveals a protective response in younger brains: when calcium runs high, the brain increases the level and activity of Glyoxalase 1 (GLO1), a detoxifying enzyme that helps clear harmful cellular byproducts. This upregulation appears to buffer the brain against calcium-related damage.
Yet this resilience seems to wane with age. The researchers observed that GLO1 activity rises during early life but declines as organisms get older, which could render the aging brain more vulnerable to neurodegenerative processes. Understanding this shift could guide the development of therapeutics aimed at sustaining GLO1 function to slow or prevent disease progression.
Amy Arnsten, a neuroscience professor and co-leading author, explains that the brain possesses an intrinsic mechanism to cope with calcium leakage, one that diminishes with age. If this mechanism can be preserved, it would constitute a brain-native form of protection against degeneration.
The study is a collaboration between Arnsten’s lab and the lab of Lauren Hachmann Sansing, a neurology professor at Yale. The team focused on calcium dysregulation linked to ryanodine receptor 2 (RyR2), a cellular channel that releases calcium from the endoplasmic reticulum. In the brain, RyR2 acts like a faucet that can be turned on and off, directing calcium flow into neurons with numerous downstream effects.
Prior work has shown that age-related changes can keep RyR2 abnormally open, a pattern associated with Alzheimer’s disease and even Long COVID. To explore the brain’s response to chronic calcium influx, the researchers used an animal model with RyR2 engineered to stay in the “on” position, causing persistent calcium leakage.
In this model, GLO1 expression and activity rose in the prefrontal cortex and hippocampus—key regions for cognition and memory. Interestingly, GLO1 levels increased with age up to a point (peaking around 12 months in mice) before declining in older mice.
Behaviorally, older animals with constitutively active RyR2 and reduced GLO1 performed worse on a memory task—a T-shaped maze—than their healthier counterparts, supporting the link between calcium dysfunction and cognitive decline.
The study positions GLO1 as a potential compensatory mechanism against chronic calcium dysregulation. As one study author, Elizabeth Woo, notes, calcium is a powerful neuronal mediator, and GLO1’s detoxifying properties may help counter the long-term effects of calcium imbalance.
Looking ahead, the researchers hope these insights into upstream biology can fuel preventative therapies. While much work focuses on treating Alzheimer’s after onset, clarifying early brain responses to calcium disruption could enable interventions that delay or avert disease.
Funding supported the work from the National Institutes of Health and Yale University. The authors emphasize that the article’s conclusions reflect their findings and do not necessarily represent NIH positions.
Source: Yale Medicine
