Microglia: Cells Linked to Alzheimer's Disease Act Like Construction Crew on Brain Cells, Research Suggests

We don't yet know what causes dementia, but scientists believe immune cells called microglia may play a role. Now, researchers have shed light on what these cells do in our bodies.

Microglia are among the cells that populate the central nervous system and are responsible for protecting the brain and spine by eating up cellular debris and dead neurons. Scientists fear the build-up of brain plaque causes microglia to vacuum up neurons in a way that triggers neurodegenerative diseases such as Alzheimer's, the most common form of dementia.

Microglia's role in how our brains develop in childhood is well-researched, but scientists at the University of Virginia Health System wanted to better understand how they affect the organ into adulthood.

To piece together the study, published in the Journal of Experimental Medicine, researchers created a new approach to watching microglia differentiate between healthy and damaged cells in the brain tissue of mice who experienced acute injury to their nervous systems.

They found that when the central nervous system is injured, microglia jump into action.

Comparing the cells to a construction crew demolishing a damaged building, Dr. Geoffrey Norris, an author of the study, explained in a statement, "If you have a crumbling building after a house fire, you usually take the building away, right?"

"You load it up on dump trucks and take it away," he said. "That's what the microglia are doing with this debris."

"It seems that microglia are very responsive to the job at hand," he said. "So rather than being good or bad, what we're basically seeing is that they're doing what they need to do."

More research is needed to discover whether the microglia clean up debris in a way that triggers neurodegeneration. This in turn could help scientists develop medications for conditions such as Alzheimer's and Parkinson's.

"Whether the microglia activity is detrimental or not is really just starting to be teased out," Norris said.

Dr. James Pickett, head of research at the Alzheimer's Society, told Newsweek: "We know microglia are a vital part of the brain's cleanup system, and this study tells us more about what triggers them." He added, however, that the study was conducted in mice rather than humans, so it's unclear how the results would translate.

Pickett added: "Dementia is the only one of the top 10 killers that we can't cure, prevent or even slow down, so it's vital we explore every avenue to better understand this disease."