title: TRPV1, CGRP and SP in scalp arteries of patients suffering from chronic migraine.
abstract: OBJECTIVE
  The transient receptor potential vanilloid type-1 receptor (TRPV1) and the neuropeptides calcitonin gene-related peptide (CGRP) and substance P (SP) appear to be differently involved in migraine pain. A role of neurovascular scalp structures is also suggested by several data. We performed a quantitative study of TRPV1-like immunoreactive (LI), CGRP-LI and SP-LI innervation of scalp arterial samples from patients affected with chronic migraine (CM).
  
  
  METHODS
  Short segments of scalp arteries were collected from 17 participants undergoing vascular surgery for treatment-resistant CM and from 6 controls who underwent neurosurgery for various indications. The immunoreactivity of the arterial innervation to TRPV1, CGRP, SP and to the pan-neuronal marker protein gene product 9.5 (PGP9.5) was examined. Immunoreactive nerve fibres in vessel cross-sections were quantified by computerised image analysis.
  
  
  RESULTS
  A significant increase of TRPV1-LI nerve fibres was found in the arterial wall from CM compared with control patients (p<0.05), while no significant difference was found for CGRP and SP.
  
  
  CONCLUSIONS
  This study yields the first evidence for the existence of a TRPV1-LI innervation in human scalp arteries and provides the first quantitative assessment of the TRPV1-LI, CGRP-LI and SP-LI innervation of those vessels. The increase of TRPV1-LI periarterial nociceptive fibres of scalp arteries may represent, at least in some participants, a structural condition favouring CM (and possibly migraine), for example, by causing a higher sensitivity to algogenic agents.
authors.affiliation: Dipartimento di Scienze Biomediche, Sezione di Citomorfologia, University of Cagliari, Cagliari, Italy.
authors.forename: Marina
authors.initials: M
authors.lastname: Del Fiacco
authors.affiliation: Dipartimento di Scienze Biomediche, Sezione di Citomorfologia, University of Cagliari, Cagliari, Italy.
authors.forename: Marina
authors.initials: M
authors.lastname: Quartu
authors.affiliation: Dipartimento di Scienze Biomediche, Sezione di Citomorfologia, University of Cagliari, Cagliari, Italy.
authors.forename: Marianna
authors.initials: M
authors.lastname: Boi
authors.affiliation: Dipartimento di Scienze Biomediche, Sezione di Citomorfologia, University of Cagliari, Cagliari, Italy.
authors.forename: M Pina
authors.initials: MP
authors.lastname: Serra
authors.affiliation: Dipartimento di Scienze Biomediche, Sezione di Citomorfologia, University of Cagliari, Cagliari, Italy.
authors.forename: Tiziana
authors.initials: T
authors.lastname: Melis
authors.affiliation: Divisione Neurochirurgia, Azienda Ospedaliera, Sassari, Italy.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Boccaletti
authors.affiliation: Headache Clinic, Johannesburg, South Africa.
authors.forename: Elliot
authors.initials: E
authors.lastname: Shevel
authors.affiliation: Neuropsichiatria Infantile, Azienda Ospedaliero-Universitaria, University of Cagliari, Cagliari, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Cianchetti
mesh_terms: D000328:Adult; D000368:Aged; D001158:Arteries / Q000378:metabolism*; D015740:Calcitonin Gene-Related Peptide / Q000235:genetics* / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008881:Migraine Disorders / Q000235:genetics* / Q000378:metabolism*; D009412:Nerve Fibers / Q000378:metabolism; D012039:Regional Blood Flow; D012535:Scalp / Q000098:blood supply*; D013373:Substance P / Q000235:genetics* / Q000378:metabolism*; D050916:TRPV Cation Channels / Q000235:genetics* / Q000378:metabolism*; D055815:Young Adult
chemical_list: D050916:TRPV Cation Channels; C494482:TRPV1 protein, human; D013373:Substance P; D015740:Calcitonin Gene-Related Peptide
keywords: HEADACHE; MIGRAINE