title: Examining mechanisms of brain control of bladder function with resting state functional connectivity MRI.
abstract: OBJECTIVE
  This aim of this study is to identify the brain mechanisms involved in bladder control.
  
  
  METHODS
  We used fMRI to identify brain regions that are activated during bladder filling. We then used resting state connectivity fMRI (rs-fcMRI) to assess functional connectivity of regions identified by fMRI with the rest of the brain as the bladder is filled to capacity.
  
  
  RESULTS
  Female participants (n = 20) were between ages 40 and 64 with no significant history of symptomatic urinary incontinence. Main effect of time (MET) fMRI analysis resulted in 20 regions of interest (ROIs) that have significant change in BOLD signal (z = 3.25, P <0.05) over the course of subtle bladder filling and emptying regardless of full versus empty bladder state. Bladder-state by time (BST) fMRI analysis resulted in three ROIs that have significant change in BOLD signal (z = 3.25, P <0.05) over the course of bladder runs comparing full versus empty bladder state. Rs-fcMRI fixed effects analysis identified significant changes in connectivity between full and empty bladder states in seven brain regions (z = 4.0) using the three BST ROIs and sixteen brain regions (z = 7) using the twenty MET ROIs. Regions identified include medial frontal gyrus, posterior cingulate (PCC), inferiolateral temporal and post-central gyrus, amygdale, the caudate, inferior parietal lobe as well as anterior and middle cingulate gyrus.
  
  
  CONCLUSIONS
  There is significant and vast changes in the brain's functional connectivity when bladder is filled suggesting that the central process responsible for the increased control during the full bladder state appears to largely rely on the how distributed brain systems are functionally integrated.
authors.affiliation: Oregon Health and Science University, Portland, Oregon; Kaiser Permanente, Clackamas, Oregon.
authors.forename: Rahel
authors.initials: R
authors.lastname: Nardos
authors.forename: William Thomas
authors.initials: WT
authors.lastname: Gregory
authors.forename: Christine
authors.initials: C
authors.lastname: Krisky
authors.forename: Amanda
authors.initials: A
authors.lastname: Newell
authors.forename: Binyam
authors.initials: B
authors.lastname: Nardos
authors.forename: Bradley
authors.initials: B
authors.lastname: Schlaggar
authors.forename: Damien A
authors.initials: DA
authors.lastname: Fair
mesh_terms: D000328:Adult; D000679:Amygdala / Q000502:physiology; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D002421:Caudate Nucleus / Q000502:physiology; D005260:Female; D059907:Functional Neuroimaging; D006179:Gyrus Cinguli / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009434:Neural Pathways / Q000502:physiology*; D010296:Parietal Lobe / Q000502:physiology; D017397:Prefrontal Cortex / Q000502:physiology; D013702:Temporal Lobe / Q000502:physiology; D001743:Urinary Bladder / Q000502:physiology*
keywords: brain bladder control; brain imaging; functional MRI; overactive bladder; resting state connectivity MRI; urgency incontinence