Research On The Development Of Functional Brain Networks In Autism Spectrum Disorder

Autism spectrum disorder(ASD)is a widespread neurodevelopmental disorder that may be caused by a variety of reasons.Its core symptoms consist of social communication disorders,speech communication disorders,and repetitive stereotyped behaviors.Although there have been a large number of neuroimaging studies about autism,its pathogenesis is still unclear.Meanwhile,at present,there is no effective treatment and prognostic means.Previous resting-state f MRI studies on autism have revealed that many functional brain networks of autism are abnormal,but inconsistencies exist in the regional specificity across these studies.Based on multi-center,large-sample resting-state functional magnetic resonance brain imaging data,our study conducted the following research on the abnormal development of autism gray matter and white matter brain functional networks:In the first study,we used independent component analysis(ICA)to select high-level cognitive networks including the default mode network(DMN),salience network(SAN),and frontal-parietal network(FPN),as well as primary sensory perceptual networks including auditory network(AN),sensory motor network(SMN),and visual network(VN).The functional connectivity and curve fitting were utilized to delineate the developmental trajectory of the high-level cognitive networks and primary sensory perceptual networks of autism and typical development(TD).Comparing the network development trajectories of autism and TD,we found that both the primary sensory perceptual networks and high-level cognitive networks have a developmental pattern shifting from hyper-connectivity to hypo-connectivity in autism.In general,this mode of transformation appears in pre-adolescence in all six networks,but the mode of transformation in the primary sensory perceptual networks is often earlier than the high-level cognitive networks.Our study described the developmental trajectory of grey matter functional networks in autism and typical development ranging from childhood to adulthood,and provided a basis for explaining the inconsistency of previous studies on the same functional network.Previous studies on the functional networks of autism mostly focused on the gray matter functional networks.However,recent studies have revealed the white matter functional signals are in highly physiological significance.Therefore,in the second study,we constructed twelve white matter functional networks using K-means clustering.Comparing with TD,we found that there is a significantly higher connection between the frontal and temporal lobe networks of the superficial network,and a significantly lower connection between the middle and deep networks in autism.Further analysis of different age groups,we found that autism did not show significant differences from typical development in childhood,while the adolescent group showed a decreased connection,and the adult group showed an increased connection.Next,we also used the curve fitting method to describe the developmental trajectory of the white matter functional networks of autism and TD.It is regrettable that we did not find a clear "hypo-to hyper-connectivity" development pattern in the white matter functional networks of autism.Our research found abnormalities in the grey and white matter functional networks of autism,and described the networks development trajectories of autism and TD from the gray matter and white matter.Our works completed the research on the functional networks of autism,helped us understand the neuropathological mechanism of autism,and provided a new perspective for clinical diagnosis and exploring the possible treatments.