Brain cells protect muscles from wasting away
The head of a roundworm, C. elegans. The glia that regulate the stress response in the worm’s peripheral cells are highlighted. A mere four of these cells, known as CEPsh glial cells, protect the organism from age-related decline. Credit: Ashley Frakes, UC Berkeley

While many of us worry about proteins aggregating in our brains as we age and potentially causing Alzheimer’s disease or other types of neurodegeneration, we may not realize that some of the same proteins are aggregating in our muscles, setting us up for muscle atrophy in old age.

University of California, Berkeley, scientists have now found that help clean up these tangles and prolong life—at least in worms (Caenorhabditis elegans) and possibly mice. This could lead to drugs that improve muscle health or extend a healthy human lifespan.

The research team’s most recent discovery, published Jan. 24 in the journal Science, is that a mere four in the worm’s brain control the in throughout its body and increase the worm’s lifespan by 75%. That was a surprise, since glial cells are often dismissed as mere support cells for the neurons that do the brain’s real work, like learning and memory.

This finding follows a 2013 study in which the UC Berkeley group reported that neurons help regulate the stress response in peripheral cells, though in a different way than glial cells, and lengthen a worm’s life by about 25%. In mice, boosting neuronal regulation increases lifespan by about 10%.

Together, these results paint a picture of the brain’s two-pronged approach to keeping the body’s cells healthy. When the brain senses a stressful environment—invading bacteria or viruses, for example—a subset of neurons sends electrical signals to peripheral cells to get them mobilized to respond to the stress, such as through breaking up tangles, boosting production and mobilizing stored fat. But because produce only a short-lived response, the glial cells kick in to send out a long-lasting hormone, so far unidentified, that maintains a long-term, anti-stress response.

“We have been discovering that if we turn on these responses in the brain, they communicate to the periphery to protect the whole organism from the age onset decline that naturally happens. It rewires their metabolism, it also protects against protein aggregation,” said Andrew Dillin, UC Berkeley professor of molecular and cell biology and Howard Hughes Medical Institute (HHMI) investigator. As a result of the new study, “We think that glia are going to be more important than neurons.”

While the roundworm C. elegans is a long way evolutionarily from humans, the fact that glial cells seem to have a similar effect in mice suggests that