Microglia (green) with purple representing the P2Y12 receptor which the study shows is a critical regulator in the process of pruning connections between nerve cells.
A new study out today in the journal Nature Communications shows that cells normally associated with protecting the brain from infection and injury also play an important role in rewiring the connections between nerve cells. While this discovery sheds new light on the mechanics of neuroplasticity, it could also help explain diseases like autism spectrum disorders, schizophrenia, and dementia, which may arise when this process breaks down and connections between brain cells are not formed or removed correctly.
“We have long considered the reorganization of the brain’s network of connections as solely the domain of neurons,” said Ania Majewska, Ph.D., an associate professor in the Department of Neuroscience at the University of Rochester Medical Center (URMC) and senior author of the study. “These findings show that a precisely choreographed interaction between multiple cells types is necessary to carry out the formation and destruction of connections that allow proper signaling in the brain.”
The study is another example of a dramatic shift in scientists’ understanding of the role that the immune system, specifically cells called microglia, plays in maintaining brain function. Microglia have been long understood to be the sentinels of the central nervous system, patrolling the brain and spinal cord and springing into action to stamp out infections or gobble up dead cell tissue. However, scientists are now beginning to appreciate that, in addition to serving as the brain’s first line of defense, these cells also have a nurturing side, particularly as it relates to the connections between neurons.