title: Validation of a model of itch induction for brain positron emission tomography studies using histamine iontophoresis.
abstract: Skin-brain signalling in itch reactions has been demonstrated with neuroimaging techniques showing specific brain activation. With positron emission tomography (PET), the itch model used must be adapted to technical and practical constraints. The technique of itch induction by histamine iontophoresis enables modulation of the sensation via the electrical charge applied. This itch model was validated on normal forearm skin of 56 subjects, with itch visual analogue scores peaking to approximately 1.0 cm after 3-4 min, falling to 0.2 cm at 15 min, with no influence of sex, zone, or order. Subsequently, the model was used in a PET study on 14 male volunteers, comparing histamine with physiological saline (control). The results show that the brain is able to discriminate these two conditions, with activated areas similar to those described previously, with, in addition, the anterior cingulate cortex and the insula being positively correlated with the intensity of the sensation.
authors.affiliation: INSERM, Imagerie Cérébrale et Handicaps Neurologiques UMR, CHU Purpan, France.
authors.forename: Laure
authors.initials: L
authors.lastname: Bergeret
authors.forename: David
authors.initials: D
authors.lastname: Black
authors.forename: Jennifer
authors.initials: J
authors.lastname: Theunis
authors.forename: Laurent
authors.initials: L
authors.lastname: Misery
authors.forename: Nicolas
authors.initials: N
authors.lastname: Chauveau
authors.forename: Florent
authors.initials: F
authors.lastname: Aubry
authors.forename: Hélène
authors.initials: H
authors.lastname: Gros
authors.forename: Gérard
authors.initials: G
authors.lastname: Viallard
authors.forename: Pierre
authors.initials: P
authors.lastname: Celsis
mesh_terms: D000279:Administration, Cutaneous; D000328:Adult; D000704:Analysis of Variance; D001921:Brain / Q000000981:diagnostic imaging*; D001931:Brain Mapping / Q000379:methods*; D004192:Discrimination, Psychological; D005260:Female; D005542:Forearm; D005602:France; D006632:Histamine / Q000008:administration & dosage*; D006801:Humans; D007478:Iontophoresis; D008297:Male; D049268:Positron-Emission Tomography; D011237:Predictive Value of Tests; D011537:Pruritus / Q000139:chemically induced* / Q000000981:diagnostic imaging* / Q000523:psychology; D015203:Reproducibility of Results; D012720:Severity of Illness Index
chemical_list: D006632:Histamine