title: White matter abnormalities of microstructure and physiological noise in schizophrenia.
abstract: White matter abnormalities in schizophrenia have been revealed by many imaging techniques and analysis methods. One of the findings by diffusion tensor imaging is a decrease in fractional anisotropy (FA), which is an indicator of white matter integrity. On the other hand, elevation of metabolic rate in white matter was observed from positron emission tomography (PET) studies. In this report, we aim to compare the two structural and functional effects on the same subjects. Our comparison is based on the hypothesis that signal fluctuation in white matter is associated with white matter functional activity. We examined the variance of the signal in resting state fMRI and found significant differences between individuals with schizophrenia and non-psychiatric controls specifically in white matter tissue. Controls showed higher temporal signal-to-noise ratios clustered in regions including temporal, frontal, and parietal lobes, cerebellum, corpus callosum, superior longitudinal fasciculus, and other major white matter tracts. These regions with higher temporal signal-to-noise ratio agree well with those showing higher metabolic activity reported by studies using PET. The results suggest that individuals with schizophrenia tend to have higher functional activity in white matter in certain brain regions relative to healthy controls. Despite some overlaps, the distinct regions for physiological noise are different from those for FA derived from diffusion tensor imaging, and therefore provide a unique angle to explore potential mechanisms to white matter abnormality.
authors.affiliation: Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, 47405, USA. hucheng@indiana.edu.
authors.forename: Hu
authors.initials: H
authors.lastname: Cheng
authors.affiliation: Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, 47405, USA.
authors.forename: Sharlene D
authors.initials: SD
authors.lastname: Newman
authors.affiliation: Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, 47405, USA.
authors.forename: Jerillyn S
authors.initials: JS
authors.lastname: Kent
authors.affiliation: Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, 47405, USA.
authors.forename: Amanda
authors.initials: A
authors.lastname: Bolbecker
authors.affiliation: Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, 47405, USA.
authors.forename: Mallory J
authors.initials: MJ
authors.lastname: Klaunig
authors.affiliation: Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, 47405, USA.
authors.forename: Brian F
authors.initials: BF
authors.lastname: O'Donnell
authors.affiliation: Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, 47405, USA.
authors.forename: Aina
authors.initials: A
authors.lastname: Puce
authors.affiliation: Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, 47405, USA.
authors.forename: William P
authors.initials: WP
authors.lastname: Hetrick
mesh_terms: D000328:Adult; D001921:Brain / Q000473:pathology* / Q000503:physiopathology*; D001931:Brain Mapping; D056324:Diffusion Tensor Imaging; D005260:Female; D019416:Head Movements; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009434:Neural Pathways / Q000473:pathology / Q000503:physiopathology; D012146:Rest; D012559:Schizophrenia / Q000473:pathology* / Q000503:physiopathology*; D066127:White Matter / Q000473:pathology* / Q000503:physiopathology*
keywords: Physiological noise; Resting state fMRI; Schizophrenia; White matter