title: Fronto-striatal circuitry and inhibitory control in autism: findings from diffusion tensor imaging tractography.
abstract: BACKGROUND
  Repetitive behaviour and inhibitory control deficits are core features of autism; and it has been suggested that they result from differences in the anatomy of striatum; and/or the 'connectivity' of subcortical regions to frontal cortex. There are few studies, however, that have measured the micro-structural organisation of white matter tracts connecting striatum and frontal cortex.
  
  
  OBJECTIVE
  To investigate differences in bulk volume of striatum and micro-structural organisation of fronto-striatal white matter in people with autism; and their association with repetitive behaviour and inhibitory control.
  
  
  METHODS
  We compared the bulk volume of striatum (caudate nucleus, putamen and nucleus accumbens) and white matter organisation of fronto-striatal tracts using (respectively) structural magnetic resonance imaging (sMRI) and tract specific diffusion tensor imaging (DTI) measures in 21 adults with autism and 22 controls. We also assessed performance on a cognitive inhibition (go/nogo) task.
  
  
  RESULTS
  Bulk volume of striatal structures did not differ between groups. However, adults with autism had a significantly smaller total brain white matter volume, lower fractional anisotropy of white matter tracts connecting putamen to frontal cortical areas, higher mean diffusivity of white matter tracts connecting accumbens to frontal cortex and worse performance on the go/nogo task. Also, performance on the go/nogo task was significantly related to anatomical variation when both groups were combined; but not within the autism group alone.
  
  
  CONCLUSIONS
  These data suggest that autism may be associated with differences in the anatomy of fronto-striatal white matter tracts.
authors: Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, King's College London, UK. m.langen@umcutrecht.nl
authors: Marieke
authors: M
authors: Langen
authors: Alexander
authors: A
authors: Leemans
authors: Patrick
authors: P
authors: Johnston
authors: Christine
authors: C
authors: Ecker
authors: Eileen
authors: E
authors: Daly
authors: Clodagh M
authors: CM
authors: Murphy
authors: Flavio
authors: F
authors: Dell'acqua
authors: Sarah
authors: S
authors: Durston
authors: Declan G M
authors: DG
authors: Murphy
mesh_terms: D000328:Adult; D001321:Autistic Disorder / Q000473:pathology* / Q000503:physiopathology / Q000523:psychology; D001479:Basal Ganglia / Q000473:pathology / Q000503:physiopathology; D003342:Corpus Striatum / Q000473:pathology* / Q000503:physiopathology; D056324:Diffusion Tensor Imaging; D005625:Frontal Lobe / Q000473:pathology* / Q000503:physiopathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D038801:International Classification of Diseases; D008279:Magnetic Resonance Imaging; D008297:Male; D009412:Nerve Fibers / Q000502:physiology; D009415:Nerve Net / Q000473:pathology* / Q000503:physiopathology; D009483:Neuropsychological Tests; D012919:Social Behavior; D055815:Young Adult