The human body does a good job of keeping itself clean. We know our immune systems track down and eliminate microscope intruders, kidneys filter the blood and the liver breaks down toxins. But it's now just come to light that cells in the brain, called "microglia", could be going to town on the idle parts of our grey matter, regardless of damage or health.
A New Scientist article on the findings describes microglia as simple "garbage collectors" whose main role is to keep the brain safe; acting as tiny biological vacuums after the organ is damaged. But it turns out they may be a bit more active than previously thought, seeking out underutilised connections in the brain and taking them out.
The discovery was made by a team at the Boston Children's Hospital in the US. As usual, mice were used as test subjects, with one of their eyes made to work less than the other. Using dyes to track brain signals, it was found the synapses for the weaker eye were being "preferentially pruned", despite being perfectly healthy.
It's perhaps a little creepy, yes, but what makes the discovery interesting is that the brain is able to flag parts of itself for deletion... as it were. Figuring out the exact processes involved could help with degenerative diseases, as well as open unexplored pathways for dealing with illnesses that target the organ.
Image: Scott / Flickr