title: Unique, common, and interacting cortical correlates of thirst and pain.
abstract: This study used positron-emission tomography to establish the patterns of brain activity involved in the isolated and concurrent experiences of thirst and pain. Ten subjects were scanned while experiencing pain evoked with noxious pressure, while experiencing thirst after the infusion of hypertonic saline, and while experiencing pain when thirsty. After the onset of thirst, noxious pressure evoked more intense sensations of pain. Noxious pressure did not change subjective ratings of thirst. Thirst caused activation in the anterior cingulate (Brodmann area 32) and the insula. Enhanced pain responses were associated with increased activity in cortical regions that are known to correlate with pain intensity, and also with unique activity in the pregenual anterior cingulate and ventral orbitofrontal cortex. These findings suggest a role for limbic and prefrontal cortices in the modulation of pain during the experience of thirst.
authors.affiliation: Howard Florey Institute, Centre for Neuroscience, and Department of Physiology, University of Melbourne, Parkville, Victoria 3010, Australia. m.farrell@hfi.unimelb.edu.au
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Farrell
authors.forename: Gary F
authors.initials: GF
authors.lastname: Egan
authors.forename: Frank
authors.initials: F
authors.lastname: Zamarripa
authors.forename: Robert
authors.initials: R
authors.lastname: Shade
authors.forename: John
authors.initials: J
authors.lastname: Blair-West
authors.forename: Peter
authors.initials: P
authors.lastname: Fox
authors.forename: Derek A
authors.initials: DA
authors.lastname: Denton
mesh_terms: D000328:Adult; D001519:Behavior / Q000502:physiology; D002540:Cerebral Cortex / Q000000981:diagnostic imaging / Q000502:physiology* / Q000503:physiopathology; D006801:Humans; D008032:Limbic System / Q000000981:diagnostic imaging / Q000502:physiology / Q000503:physiopathology; D008297:Male; D010146:Pain / Q000000981:diagnostic imaging / Q000503:physiopathology*; D049268:Positron-Emission Tomography; D017397:Prefrontal Cortex / Q000000981:diagnostic imaging / Q000502:physiology / Q000503:physiopathology; D012462:Saline Solution, Hypertonic / Q000008:administration & dosage; D013894:Thirst / Q000502:physiology*
chemical_list: D012462:Saline Solution, Hypertonic