Socializing the Brain: Decreased Functional Connectivity in those with Autism

A recent study takes an in-depth look at the way communication areas of the brain interact with each other for those with autism and other neurodevelopmental disorders. For the first time, scientists have now determined a way in which this decreased functional connectivity has occurred, according to researchers at the European Molecular Biology Laboratory (EMBL) in Monterondo, Italy.

"We show that a deficit in microglia during development can have widespread and long-lasting effects on brain wiring and behaviour," said Cornelius Gross, who led the study, via a press release. "It leads to weak brain connectivity, decreased social behaviour, and increased repetitive behaviour, all hallmarks of autism."

Researchers note that by trimming surplus connections in the developing brian, microglia can grow stronger and better strengthen signals between brain regions. However, background information from the study also notes that if these cells fail to do their job during a crucial stage of development, communication regions of the brain may become weaker and cause life-long behavioral issues.

The study notes the following regarding findings, via the release: "Yang Zhan, a postdoctoral fellow in Gross' lab at EMBL, analysed the strength of connections between different areas of brain in mice that were genetically engineered to have fewer microglia during development. Working with Alessandro Gozzi's lab at IIT and Davide Ragozzino at La Sapienza University, the EMBL scientists combined this approach with high-resolution fMRI (functional Magnetic Resonance Imaging) scans of the mice's brains, taking full advantage of a novel technique developed at IIT, which enables scientists to obtain detailed, three-dimensional maps of the brain's functional connections. The team found that mice with fewer microglia had weaker connections between neurons, and less cross-talk between different brain regions. When Rosa Paolicelli, a PhD student in Gross' lab, studied the mice's behaviour, she discovered that mice with fewer microglia and decreased connectivity displayed behaviours commonly associated with autism spectrum disorders. These mice spent more time repeatedly grooming themselves, and avoided social interactions."

"This is an exciting time to be studying microglia," Gross concludes: "they're turning out to be major players in how our brain gets wired up."

More information regarding the study can be found via the journal Nature Neuroscience.