What if we could mitigate age-related cognitive decline with a simple nasal spray? Researchers at Texas A&M University in the United States presented an innovative treatment in February 2026 that protects cognition in aging mice. Their approach, published in the Journal of Extracellular VesiclesIt targets neuroinflammation caused by age or neurodegenerative diseases. In doing so, it could slow memory loss associated with dementia, extending healthy life expectancy.
Reducing brain inflammation to protect cognition
Neuroinflammation is characteristic of neurodegenerative diseases. It is caused by a dysfunction of the mitochondria (the cells' energy factories), which leads to an increase in the production of oxidative stress in the brain. This triggers a pro-inflammatory signaling cascade, including the activation of inflammasomes, protein complexes that cause inflammation.
One potential solution to this chronic inflammation is to treat the brain with stem cells, which artificially "rejuvenate" it. However, this stem cell treatment would be very complex to perform in humans and, for the moment, only works in animal models. The approach of the Texas researchers bypasses these difficulties by using not whole stem cells, but molecules produced by them, which are easier to introduce into the brain. These molecules are encapsulated in extracellular vesicles, which can be administered simply via nasal spray, reaching the brain quickly. "Intranasal administration allows us to reach and treat the brain directly without the need for invasive interventions," summarized in a press release Maheedhar Kodali, one of the authors of the study.
The molecules in the nasal spray improve mitochondrial function in the hippocampus.
Thanks to the nasal spray, these vesicles reach almost all regions of the mouse brain in less than six hours. There, they are absorbed by neurons and microglial cells, the immune cells responsible for neuroinflammation when they are overactivated. This is particularly the case in the hippocampus, a brain structure that plays a central role in the memoryMicroglial cells in the hippocampus responded rapidly to the treatment and showed reduced overactivation compared to those in untreated mice, thereby decreasing the production of pro-inflammatory signals. As a result, inflammasomes were less activated, reducing the inflammatory state of the brain.
This protective effect is due to improved mitochondrial function: the molecules contained in the vesicles increased the expression of several genes necessary for the proper functioning of the respiratory chain, a protein complex responsible for energy production. This treatment therefore had a "rejuvenating" effect on the mitochondria, which worked more efficiently (producing more energy and less oxidative stress) despite the advanced age of the cells.
Improving mitochondrial function protects memory
And when mitochondria function better, cells function better and the brain is healthier. This molecular "rejuvenation" resulted in improved memory in 20-month-old mice (which is equivalent to over 60 years in humans). "What we are showing is that brain aging can be reversed, and that we can help the brain stay sharp," "Ashok Shetty, the study's director, is thrilled." Our goal is not just for us to live longer, but for us to stay intelligent and healthy. It remains to be seen whether this nasal spray also works in humans… or if only mice will benefit from it.
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