This Memory Enzyme Could Keep Aging Brains Sharp

A newfound memory enzyme may explain why some older brains stay sharp despite damage that should erode them. The protein, PLA2G2F, appears to switch on in the aging brain and protect neurons by calming inflammation and keeping memory circuits intact. The findings were reported on 15 October in the journal Nature Neuroscience.

The discovery came out of a hunt for genes that respond to neural breakdown. Cinzia Vicidomini and Amar Sahay of Massachusetts General Hospital, Harvard Medical School, the Harvard Stem Cell Institute and the Broad Institute, working with Gaurav Chopra of Purdue University, screened mouse brains for genes that flare up when connections between neurons begin to fail. One rose above the rest: Pla2g2f, which produces PLA2G2F, a phospholipase that breaks down fatty compounds.

A defence that wakes up with age

In young adult mice the gene is essentially silent, according to the researchers, with barely any detectable activity in the brain. That changes as the animals grow older. Just as the synapses feeding the hippocampus begin to erode, Pla2g2f reactivates in a sparse set of neurons, as though the brain had flipped on an emergency repair system. The enzyme seems to act "as a compensatory cognitive-resilience mechanism", says Sahay.

The team tested the idea by engineering mice to lack the gene entirely. As those animals aged, their brains developed markedly more inflammation and lost more neurons than the brains of unaltered controls. Mice given extra copies of the gene told the opposite story: less inflammation, healthier neural connections, and better scores on spatial memory tests in old age. The knockout mice also scored lower than controls on memory tests by middle age.

"This is a fantastic, very thoughtful approach to get at what could be protecting neurons," says Timothy Hohman, a neuroscientist and geneticist at Vanderbilt University who was not involved in the study. "This is a great example of how you can use a model system to get at some of these resilience mechanisms that are super challenging to study in humans."

The protection appears to work through the brain's fat chemistry. Chronic inflammation in the aging brain is partly driven by lipid droplets accumulating inside microglia, the brain's immune cells, which then struggle to clear waste and support synapses. By breaking down those fatty compounds, PLA2G2F eases the inflammatory load and helps preserve the balance of excitation and inhibition in the hippocampus that memory relies on.

The human connection

The researchers looked for the same signal in people. Analysing two large gene-expression data sets compiled by other scientists, they found that PLA2G2F activity in the human brain rises with age. They then examined gene-expression data from the brains of 13 deceased donors who had all undergone cognitive testing before death. Activity was highest in so-called resilient individuals, whose thinking stayed intact even though their brains carried deposits of amyloid-beta, a protein associated with Alzheimer's disease.

Thirteen brains make a clue rather than a conclusion, and the human findings can only show correlation. But set alongside the mouse experiments, they suggest the brain's backup system is conserved across species. "These findings show that Pla2g2f can be used to shift the trajectory of pathological ageing in mice," Sahay adds.

Why it matters

Most dementia research chases the brain's destroyers: amyloid plaques, tau tangles, runaway inflammation. This study starts from the opposite end and asks what the brain does right when it manages to hold on. Drugs that strengthen a natural protective process could one day complement medicines that clear toxic proteins, and the resilience angle is drawing growing interest among neuroscientists. The finding also fits a wider push to understand how the whole body ages, a line of research that recently produced a sweeping atlas of how exercise reshapes the human body.

There is a long way to go. The core evidence comes from mice, and the genetic techniques used to raise enzyme levels are not something that could be given to a patient. The researchers are exploring ways to safely increase the enzyme's activity in the aging brain, according to a statement reported by news-medical.net, but further studies will be needed to determine whether the approach can ever become a therapy for people.

For now, the enzyme joins a short list of natural factors that help keep memories alive with age. The peer-reviewed paper is published in Nature Neuroscience (doi:10.1038/s41593-026-02465-z), and Sahay's team continues to investigate how the molecule interacts with the brain's own repair machinery. Other fields are moving quickly as well: physicists reported finding a missing piece of the superconductivity puzzle.