We already know that our brains have a waste disposal system that prevents dead and toxic neurons from clogging our biological pathways. Now, scientists have managed to capture a video of the trial for the first time, in laboratory tests on mice.
There are still many things we don’t know about how dead neurons are eliminated and how the brain reacts to them, so new research could be a significant step forward in understanding this – even if we haven’t yet confirmed that the human brain works exactly. in the same way.
“This is the first time the process has ever been seen in a living mammalian brain,” says neurologist Jaime Grutzendler of the Yale School of Medicine in Connecticut.
Further down, these findings may even inform treatments for age-related brain decline and neurological disorders ̵
The team focused on the glial cells responsible for doing the cleaning job in the brain; they used a technique called 2Phatal to target a single brain cell for apoptosis (cell death) in a mouse and then followed the path of glial cells using fluorescent markers.
“Instead of hitting the brain with a hammer and causing thousands of deaths, inducing a single cell to die allows us to study what’s going on right after the cells start to die and observe the many other cells involved,” says Grutzendler.
“This was not possible before. We can clearly show what exactly is going on and understand the process.”
Three types of glial cells – microglia, astrocytes and NG2 cells – have been shown to be involved in a highly coordinated cell removal process, which has removed both the dead neuron and any pathways connecting with the rest of the brain. The researchers observed that a microglia engulfs the body of the neuron and its main branches (dendrites), while the astrocytes targeted small connection dendrites for removal. They suspect that NG2 may help prevent the spread of dead cell debris.
The researchers also showed that if one type of glial cell were missing the dead neuron for any reason, other cell types would take their role in the waste removal process, suggesting that some sort of communication between glial cells is taking place.
Another interesting finding from the research was that older mouse brains were less efficient at cleaning up dead neuronal cells, although waste removal cells appeared to be just as aware that a dying cell was there.
This is a good opportunity for future research and could provide experts with information on how older brains begin to fail in various ways, as the waste disposal service starts to slow down or even break.
One day new treatments could be developed that can take on this clearing process on behalf of the brain – not only in older people, but also in those who have suffered head trauma, for example.
“Cell death is very common in brain diseases,” says neurologist Eyiyemisi Damisah, of the Yale School of Medicine.
“Understanding the process could provide insights into how to deal with cell death in a brain injured by head injury to stroke and other conditions.”
The research was published in Science advances.