Characterized by shared differences in motor and social behaviors, autism spectrum disorder (ASD) is a condition that affects individuals uniquely. Identifying features in the brain that can account for its diverse manifestations and commonalities across all ages has been a goal for scientists seeking to understand its cause.
It’s often difficult to do this kind of analysis in living people – so much of the existing data we have is based on older post-mortem subjects – but new image capturing and processing technology now allows us to see how the brain is wired in younger people.
“We’ve spent many years describing the larger characteristics of brain regions, such as thickness, volume, and curvature,” says neuroscientist Zachary Christensen from the University of Rochester.
“However, newer techniques in the field of neuroimaging, for characterizing cells using MRI [magnetic resonance imaging], unveil new levels of complexity throughout development.”
The comparisons revealed lower neuron densities in certain regions of the cerebral cortex thought to be responsible for our ability to learn, reason, problem-solve, and successfully form memories.
In other areas, there was increased neuron density. This was the case in a region known as the amygdala, which scientists believe helps to process emotions. Furthermore, when comparing autistic children to those with ADHD and anxiety, these differences appeared to be specific to autism.
It’s too early to say what these differences in density mean, but they could help explain some characteristics of autism. Importantly, the new imaging methods allow us to track the condition as it develops.
“If we can reliably and easily characterize unique deviations in neuron structure in those with autism, it opens many opportunities to understand how autism develops,” says Christensen.
“These measures may be used to identify individuals with autism who could benefit from more specific therapeutic interventions.”
Non-invasive brain scans with high accuracy and detail have only recently become possible, and efforts are already underway to follow individuals with autism over extended periods to better understand the brain changes associated with their unique perceptions of the world.
“It is truly transforming what we know about brain development as we follow this group of children from childhood into early adulthood,” says neuroscientist John Foxe from the University of Rochester.
The research has been published in Autism Research.