Over time, the brain gradually loses some of its sharpness. But new research from Texas A&M University suggests that decline may be reversible with a nasal spray.
In a recent study published in the Journal of Extracellular Vesicles, researchers examined “neuroinflammaging,” a slow, chronic inflammation in the brain that builds with age and contributes to memory and cognitive decline. The researchers developed a nasal spray containing microscopic particles derived from neural stem cells. Mice at 18 months of age — roughly equivalent to 60-year-old humans — received the treatment. Compared with untreated mice, those given the spray showed reduced markers of brain inflammation and improvements in memory and cognitive function. The benefits appeared within weeks and persisted for months after just two doses.
“We are seeing the brain’s own repair systems switch on, healing inflammation and restoring itself,” Ashok Shetty, professor of cell biology and genetics at Texas A&M, said in a news release. “As we develop and scale this therapy, a simple, two-dose nasal spray could one day replace invasive, risky procedures or maybe even months of medication.”
With people living longer, age-related brain diseases like dementia and Alzheimer’s are becoming more common. Studies estimate that about 42% of Americans over 55 will develop dementia, and as the population ages, the number of new cases each year is expected to double — from about 514,000 in 2020 to roughly 1 million by 2060.
In Texas, age-related brain diseases such as Alzheimer’s are considered a major public health issue, according to Texas Health and Human Services. The state ranks third in the nation for the number of people living with the disease and second for deaths related to Alzheimer’s. In 2020, about 460,000 Texans 65 and older were living with the disease.
The growing public health burden is one reason scientists are working to counter the inflammation that increases with age. Current treatments, however, have not been effective at stopping or reversing brain changes linked to neuroinflammaging, the Texas A&M researchers said.
Delivering treatments to the brain is difficult because it is protected by a barrier that blocks most drugs from entering — a challenge that often requires invasive procedures or limits how well therapies work. In the new study, though, Shetty and his colleagues used tiny biological packages called extracellular vesicles to carry genetic material known as microRNAs into the brain. These molecules act as regulators, helping control how genes are turned on or off inside cells.
After bypassing the brain’s protective barrier, the microRNAs help switch off signals that drive long-term inflammation in aging brains. They also boost the cells’ energy supply, which may improve mental clarity and support memory and thinking. That latter effect appeared to be reflected in behavioral tests, where treated mice could better recognize familiar objects, detect changes in their environment and adapt more quickly than untreated mice.
The findings are still early, the researchers caution. More research is needed to confirm safety, effectiveness, optimal dosing and how well the therapy would work in humans. Shetty and his colleagues are filing a patent for the nasal spray and hope to move toward developing a version that could eventually be tested in people.
“We aren’t just trying to understand the biological mechanisms,” Shetty said in the news release. “We are translating and developing our findings into real-world therapies that could make a difference.”