Brain deterioration has been assumed for years as an inevitable consequence of the passage of time. It does not occur suddenly, but progresses gradually, associated with inflammatory processes that affect key regions such as the hippocampus and end up eroding memory, learning and the ability to adapt. In its most advanced forms, this same process is linked to diseases such as Alzheimer’s. Scientists call it neuroinflammation. And, until recently, it seemed irreversible.

Now, researchers at Texas A&M University propose something that sounds almost provocative. Brain aging could be partially reversible, at least in experimental models. And the tool is not complex – without resorting to invasive procedures or prolonged treatments – but rather a simple nasal spray.

A nasal spray to address brain aging

The team, led by Dr. Ashok Shetty along with researchers Madhu Leelavathi Narayana and Maheedhar Kodali, developed an aerosol based on extracellular vesicles (EVs), tiny biological particles derived from stem cells that act as communication and transport vehicles between cells within the body.

Its cargo is microRNA, molecules capable of regulating genetic and signaling processes in the brain, which, according to Narayana, “act as master regulators” of multiple cellular pathways.

How it reaches the brain without passing through its defenses

What makes the approach especially notable is the route of administration. When applied through the nose, EVs can partially bypass the blood-brain barrier – which acts as a brain protection mechanism – and facilitate their arrival in regions of the brain, where they are absorbed by resident immune cells.

Once there, microRNAs act by modulating or inhibiting inflammatory systems such as the NLRP3 inflammasome and cGAS-STING pathways, known to fuel chronic inflammation in the aging brain.

Two doses, less inflammation and better memory

The results, published in the journal Journal of Extracellular Vesicles, They are promising. With just two doses, the treatment was associated with a notable reduction in brain inflammation, an improvement in the functioning of mitochondria – responsible for cellular energy production – and a boost in memory performance.

Furthermore, changes were observed in a relatively short term and were maintained for a long period after treatment. “We are giving neurons their spark back,” Narayana said.

Effective in mice, but the jump to humans is missing

It should be noted that the behavioral tests were carried out on 18-month-old laboratory mice – approximately equivalent to a 60-year-old human, according to the study – where the findings were confirmed. Still, the results still need to be validated in humans.

The treated animals showed a clear improvement: they had a greater ability to orient themselves in their environment, recognized familiar stimuli and responded more quickly to new situations compared to the control group. Furthermore, the effects were observed equally in males and females, something unusual in biomedical research. “It’s universal,” Shetty said.

The global challenge of dementia

The need to advance this type of research is clear. According to Alzheimer’s Disease International, around 69.2 million people in the world live with dementia, a figure that could increase to 82 million in 2030 and reach 152 million in 2050. In Europe, cases would rise from 12.71 million in 2020 to 21.64 million in 2050; in Latin America, from 6.41 to 20.55 million in the same period.

“Our goal is successful brain aging: keeping people active, alert and connected. Not just living longer, but living smarter and healthier,” summarized Shetty.

The team has already applied for a patent in the United States and is preparing to move towards human trials. The road is long, but the results open the possibility – yet to be confirmed – of not only slowing down, but perhaps reversing some aspects of brain aging.

The ambition goes beyond a new treatment. “Our approach redefines what it means to age,” said neuroscientist Ashok Shetty.

If these results are confirmed, brain aging could begin to be reconsidered as a potentially modifiable process, rather than as an inevitable destiny. In that scenario, it would not just be about living longer, but – as Shetty himself summarizes – about doing so with a clear mind for longer.