title: The organization of intrinsic brain activity differs between genders: a resting-state fMRI study in a large cohort of young healthy subjects.
abstract: OBJECTIVE
  To investigate, using resting state (RS) functional MRI (fMRI), gender-related differences of functional connectivity (FC) and functional network connectivity (FNC) of the human brain.
  
  
  METHODS
  One-hundred and four young healthy subjects (48/56 men/women), aged between 20 and 29 years, underwent a 10-min RS fMRI acquisition. Independent component analysis (ICA) and statistical parametric mapping were used to assess gender-related differences in RSNs, with and without correction for regional gray matter (GM) volume. The relationships among all RSNs was also assessed using a FNC method.
  
  
  RESULTS
  For all networks, significant between-group differences of RS activity were found. Between-group comparisons of RSNs changed when adjusting for GM volume, as follows: (1) there was only marginal effect on the analysis of sensory (i.e., sensorimotor, visual, and auditory) networks; and (2) there was a significantly increased difference when cognitive networks (apart from one related to attention) were considered. Compared with women, men experienced increased FC in parietal and occipital regions in most RSNs, whereas women experienced a higher RS FC in frontal and temporal regions, and in the cerebellum. When compared to women, increased FNC was found in men between several cognitive and sensory networks, whereas women showed an increased FNC only between attention and right working-memory networks.
  
  
  CONCLUSIONS
  The organization of intrinsic FC and FNC differ between genders. The detected differences could contribute to the understanding of the known between-gender variation in task-related recruitments, and the patterns of abnormalities detected in neurologic and psychiatric diseases with a gender prevalence.
authors.affiliation: Neuroimaging Research Unit, Institute of Experimental Neurology, Scientific Institute and Vita-Salute University, Hospital San Raffaele, Milan, Italy. m.filippi@hsr.it
authors.forename: Massimo
authors.initials: M
authors.lastname: Filippi
authors.forename: Paola
authors.initials: P
authors.lastname: Valsasina
authors.forename: Paolo
authors.initials: P
authors.lastname: Misci
authors.forename: Andrea
authors.initials: A
authors.lastname: Falini
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Comi
authors.forename: Maria A
authors.initials: MA
authors.lastname: Rocca
mesh_terms: D000328:Adult; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009434:Neural Pathways / Q000502:physiology; D012146:Rest / Q000502:physiology*; D012727:Sex Characteristics; D055815:Young Adult