Regional specificity of aberrant thalamocortical connectivity in autism.
Preliminary evidence suggests aberrant (mostly reduced) thalamocortical (TC) connectivity in autism spectrum disorder (ASD), but despite the crucial role of thalamus in sensorimotor functions and its extensive connectivity with cerebral cortex, relevant evidence remains limited. We performed a comprehensive investigation of region-specific TC connectivity in ASD. Resting-state functional MRI and diffusion tensor imaging (DTI) data were acquired for 60 children and adolescents with ASD (ages 7-17 years) and 45 age, sex, and IQ-matched typically developing (TD) participants. We examined intrinsic functional connectivity (iFC) and anatomical connectivity (probabilistic tractography) with thalamus, using 68 unilateral cerebral cortical regions of interest (ROIs). For frontal and parietal lobes, iFC was atypically reduced in the ASD group for supramodal association cortices, but was increased for cingulate gyri and motor cortex. Temporal iFC was characterized by overconnectivity for auditory cortices, but underconnectivity for amygdalae. Occipital iFC was broadly reduced in the ASD group. DTI indices (such as increased radial diffusion) for regions with group differences in iFC further indicated compromised anatomical connectivity, especially for frontal ROIs, in the ASD group. Our findings highlight the regional specificity of aberrant TC connectivity in ASD. Their overall pattern can be largely accounted for by functional overconnectivity with limbic and sensorimotor regions, but underconnectivity with supramodal association cortices. This could be related to comparatively early maturation of limbic and sensorimotor regions in the context of early overgrowth in ASD, at the expense of TC connectivity with later maturing cortical regions.
Brain Development Imaging Laboratory, Department of Psychology, San Diego State University, San Diego, California.|Joint Doctoral Program in Clinical Psychology, San Diego State University and University of California, San Diego, California.
Aarti
A
Nair
Brain Development Imaging Laboratory, Department of Psychology, San Diego State University, San Diego, California.|Department of Neuroscience, University of California, San Diego, California.
Ruth A
RA
Carper
Brain Development Imaging Laboratory, Department of Psychology, San Diego State University, San Diego, California.
Angela E
AE
Abbott
Brain Development Imaging Laboratory, Department of Psychology, San Diego State University, San Diego, California.
Colleen P
CP
Chen
Brain Development Imaging Laboratory, Department of Psychology, San Diego State University, San Diego, California.
Seraphina
S
Solders
Brain Development Imaging Laboratory, Department of Psychology, San Diego State University, San Diego, California.
Sarah
S
Nakutin
Brain Development Imaging Laboratory, Department of Psychology, San Diego State University, San Diego, California.|Department of Cognitive Science, University of California, San Diego, California.
Michael C
MC
Datko
Brain Development Imaging Laboratory, Department of Psychology, San Diego State University, San Diego, California.
Inna
I
Fishman
Brain Development Imaging Laboratory, Department of Psychology, San Diego State University, San Diego, California.
Ralph-Axel
RA
Müller
D000293:Adolescent; D000067877:Autism Spectrum Disorder / Q000473:pathology / Q000503:physiopathology*; D002540:Cerebral Cortex / Q000473:pathology / Q000503:physiopathology*; D002648:Child; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D059907:Functional Neuroimaging / Q000379:methods*; D006801:Humans; D008297:Male; D009415:Nerve Net / Q000473:pathology / Q000503:physiopathology*; D013788:Thalamus / Q000473:pathology / Q000503:physiopathology*
autism; diffusion tensor imaging; functional connectivity MRI; thalamus