Partially enhanced thalamocortical functional connectivity in autism.
Based on evidence for thalamic abnormalities in autism, impairments of thalamocortical pathways have been suspected. We examined the functional connectivity between thalamus and cerebral cortex in terms of blood oxygen level dependent (BOLD) signal cross-correlation in 8 male participants with high-functioning autism and matched normal controls, using functional MRI during simple visuomotor coordination. Both groups exhibited widespread connectivity, consistent with known extensive thalamocortical connectivity. In a direct group comparison, overall more extensive connectivity was observed in the autism group, especially in the left insula and in right postcentral and middle frontal regions. Our findings are inconsistent with the hypothesis of general underconnectivity in autism and instead suggest that subcortico-cortical connectivity may be hyperfunctional, potentially compensating for reduced cortico-cortical connectivity.
Mizuno
Akiko
A
Brain Development Imaging Laboratory, Department of Psychology, San Diego State University, CA 92120, USA.
Villalobos
Michele E
ME
Davies
Molly M
MM
Dahl
Branelle C
BC
Müller
Ralph-Axel
RA
D000293:Adolescent; D000328:Adult; D001321:Autistic Disorder / Q000473:pathology* / Q000503:physiopathology*; D001931:Brain Mapping; D016022:Case-Control Studies; D002540:Cerebral Cortex / Q000098:blood supply / Q000473:pathology* / Q000503:physiopathology; D007839:Functional Laterality; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D009434:Neural Pathways / Q000098:blood supply / Q000473:pathology* / Q000503:physiopathology; D010775:Photic Stimulation / Q000379:methods; D011597:Psychomotor Performance / Q000502:physiology; D013788:Thalamus / Q000098:blood supply / Q000473:pathology* / Q000503:physiopathology; D014796:Visual Perception / Q000502:physiology