SfN Day 1/Theme C: Altered functional connectivity in autism, as confirmed by MEG

It’s only been Day 1 of Neuroscience 2013, I am already filling up with awesome findings to share (plus my feet are already mad at me). Since my themes are pretty disparate (C: Disorders of the Nervous System & H: History/Teaching/Public Awareness/Societal Impacts) I figured it would be helpful to post on each theme separately throughout the week. So here we go:

SfN Day 1/Theme C – Human Biomarkers of Autism

The first poster I visited turned out to be very relevant to my work as well as pretty interesting. Annette Ye of the University of Toronto took the time to discuss her poster (49.01) on the highly explored topic of altered functional connectivity in adolescents with autism spectrum disorder (ASD), only she looked at this idea using magnetoencephalography (MEG), as opposed to functional magnetic resonance imaging (fMRI). MEG data complements the information provided by fMRI, as it provides a picture of the synchrony of oscillations in neural activity. Using resting state MEG data, Ye and colleagues explored the synchrony between 90 brain regions using different frequency bands. When comparing individuals with ASD to those without ASD, they found several regions, most of which were in the frontal lobe, that exhibited increased inter-regional connectivity in the gamma frequency band. This frequency band is related to local as opposed to long range connections and may be predictive of cognition. Disruption in neural synchrony within this band has been associated with schizophrenia and depression.

When Ye used graph theoretical analysis, in which brain regions are treated as nodes in a connected functional network, the increased functional connectivity among the frontal lobe regions was confirmed by increased node strength and clustering coefficients, indicating stronger inter-regional connections and a greater likelihood of neighboring connections, respectively. These MEG findings replicate previous findings that functional connectivity may be higher in ASD in local areas of the brain, including those related to cognition. Whereas decreased long-range connectivity in ASD has been robustly demonstrated in current literature, the local hyper-connectivity argument has been less defined. However, the findings Ye presented show that this argument definitely warrants further consideration.

Ye’s next steps for this project include collecting more data so she can explore potential relationships between this increased frontal lobe connectivity and the severity of autism symptoms, such as impairments in social communication or restricted, repetitive behaviors. I would guess that this increased frontal lobe connectivity would be related to increased repetitive behaviors, such as resistance to change. I look forward to what Ye finds.


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