title: Cortical thickness as a contributor to abnormal oscillations in schizophrenia?
abstract: BACKGROUND
  Although brain rhythms depend on brain structure (e.g., gray and white matter), to our knowledge associations between brain oscillations and structure have not been investigated in healthy controls (HC) or in individuals with schizophrenia (SZ). Observing function-structure relationships, for example establishing an association between brain oscillations (defined in terms of amplitude or phase) and cortical gray matter, might inform models on the origins of psychosis. Given evidence of functional and structural abnormalities in primary/secondary auditory regions in SZ, the present study examined how superior temporal gyrus (STG) structure relates to auditory STG low-frequency and 40 Hz steady-state activity. Given changes in brain activity as a function of age, age-related associations in STG oscillatory activity were also examined.
  
  
  METHODS
  Thirty-nine individuals with SZ and 29 HC were recruited. 40 Hz amplitude-modulated tones of 1 s duration were presented. MEG and T1-weighted sMRI data were obtained. Using the sources localizing 40 Hz evoked steady-state activity (300 to 950 ms), left and right STG total power and inter-trial coherence were computed. Time-frequency group differences and associations with STG structure and age were also examined.
  
  
  RESULTS
  Decreased total power and inter-trial coherence in SZ were observed in the left STG for initial post-stimulus low-frequency activity (~ 50 to 200 ms, ~ 4 to 16 Hz) as well as 40 Hz steady-state activity (~ 400 to 1000 ms). Left STG 40 Hz total power and inter-trial coherence were positively associated with left STG cortical thickness in HC, not in SZ. Left STG post-stimulus low-frequency and 40 Hz total power were positively associated with age, again only in controls.
  
  
  CONCLUSIONS
  Left STG low-frequency and steady-state gamma abnormalities distinguish SZ and HC. Disease-associated damage to STG gray matter in schizophrenia may disrupt the age-related left STG gamma-band function-structure relationships observed in controls.
authors.affiliation: The Children's Hospital of Philadelphia and University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: J Christopher
authors.initials: JC
authors.lastname: Edgar
authors.affiliation: The University of New Mexico School of Medicine, Department of Psychiatry, Center for Psychiatric Research, Albuquerque, NM, USA ; New Mexico Raymond G. Murphy VA Healthcare System, Psychiatry Research, Albuquerque, NM, USA.
authors.forename: Yu-Han
authors.initials: YH
authors.lastname: Chen
authors.affiliation: The Children's Hospital of Philadelphia and University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Matthew
authors.initials: M
authors.lastname: Lanza
authors.affiliation: The University of New Mexico School of Medicine, Department of Psychiatry, Center for Psychiatric Research, Albuquerque, NM, USA ; New Mexico Raymond G. Murphy VA Healthcare System, Psychiatry Research, Albuquerque, NM, USA.
authors.forename: Breannan
authors.initials: B
authors.lastname: Howell
authors.affiliation: The Children's Hospital of Philadelphia and University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Vivian Y
authors.initials: VY
authors.lastname: Chow
authors.affiliation: The Children's Hospital of Philadelphia and University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Kory
authors.initials: K
authors.lastname: Heiken
authors.affiliation: The Children's Hospital of Philadelphia and University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Song
authors.initials: S
authors.lastname: Liu
authors.affiliation: The University of New Mexico School of Medicine, Department of Psychiatry, Center for Psychiatric Research, Albuquerque, NM, USA ; New Mexico Raymond G. Murphy VA Healthcare System, Psychiatry Research, Albuquerque, NM, USA.
authors.forename: Cassandra
authors.initials: C
authors.lastname: Wootton
authors.affiliation: The University of New Mexico School of Medicine, Department of Psychiatry, Center for Psychiatric Research, Albuquerque, NM, USA ; New Mexico Raymond G. Murphy VA Healthcare System, Psychiatry Research, Albuquerque, NM, USA.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Hunter
authors.affiliation: The University of California San Diego, Department of Radiology, San Diego, CA, USA ; San Diego VA Healthcare System, Department of Radiology, San Diego, CA, USA.
authors.forename: Mingxiong
authors.initials: M
authors.lastname: Huang
authors.affiliation: University of California, Los Angeles, Department of Psychology, USA.
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Miller
authors.affiliation: The University of New Mexico School of Medicine, Department of Psychiatry, Center for Psychiatric Research, Albuquerque, NM, USA ; New Mexico Raymond G. Murphy VA Healthcare System, Psychiatry Research, Albuquerque, NM, USA.
authors.forename: José M
authors.initials: JM
authors.lastname: Cañive
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D002540:Cerebral Cortex / Q000473:pathology* / Q000503:physiopathology; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D053798:Magnetocardiography; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D012559:Schizophrenia / Q000473:pathology*; D013702:Temporal Lobe / Q000473:pathology* / Q000503:physiopathology; D013997:Time Factors
keywords: Alpha; Auditory; Gamma; Magnetoencephalography; Schizophrenia; Superior temporal gyrus; Theta