title: Extended cortical activations during evaluating successive pain stimuli.
abstract: Comparing pain is done in daily life and involves short-term memorizing and attention focusing. This event-related functional magnetic resonance imaging study investigated the short-term brain activations associated with the comparison of pain stimuli using a delayed discrimination paradigm. Fourteen healthy young volunteers compared two successive pain stimuli administered at a 10 s interval to the same location at the nasal mucosa. Fourteen age- and sex-matched subjects received similar pain stimuli without performing the comparison task. With the comparison task, the activations associated with the second pain stimulus were significantly greater than with the first stimulus in the anterior insular cortex and the primary somatosensory area. This was observed on the background of a generally increased stimulus-associated brain activation in the presence of the comparison task that included regions of the pain matrix (insular cortex, primary and secondary somatosensory area, midcingulate cortex, supplemental motor area) and regions associated with attention, decision making, working memory and body recognition (frontal and temporal gyri, inferior parietal lobule, precuneus, lingual cortices). This data provides a cerebral correlate for the role of pain as a biological alerting system that gains the subject's attention and then dominates most other perceptions and activities involving pain-specific and non-pain-specific brain regions.
authors.affiliation: Pharmazentrum Frankfurt/ZAFES, Institute of Clinical Pharmacology, Goethe-University, Theodor Stern Kai 7, 60590 Frankfurt am Main, Germany. j.loetsch@em.uni-frankfurt.de
authors.forename: Jörn
authors.initials: J
authors.lastname: Lötsch
authors.forename: Carmen
authors.initials: C
authors.lastname: Walter
authors.forename: Lisa
authors.initials: L
authors.lastname: Felden
authors.forename: Christine
authors.initials: C
authors.lastname: Preibisch
authors.forename: Ulrike
authors.initials: U
authors.lastname: Nöth
authors.forename: Till
authors.initials: T
authors.lastname: Martin
authors.forename: Sandra
authors.initials: S
authors.lastname: Anti
authors.forename: Ralf
authors.initials: R
authors.lastname: Deichmann
authors.forename: Bruno G
authors.initials: BG
authors.lastname: Oertel
mesh_terms: D000328:Adult; D001921:Brain / Q000473:pathology / Q000503:physiopathology*; D001931:Brain Mapping; D002245:Carbon Dioxide / Q000009:adverse effects; D002540:Cerebral Cortex / Q000503:physiopathology*; D018592:Cross-Over Studies; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009297:Nasal Mucosa / Q000294:innervation; D010146:Pain / Q000209:etiology / Q000473:pathology*; D011597:Psychomotor Performance / Q000502:physiology; D055815:Young Adult
chemical_list: D002245:Carbon Dioxide