Marina Del Fiacco1, Marina Quartu1, Marianna Boi1, M Pina Serra1, Tiziana Melis1, Riccardo Boccaletti2, Elliot Shevel3, Carlo Cianchetti4. 1. Dipartimento di Scienze Biomediche, Sezione di Citomorfologia, University of Cagliari, Cagliari, Italy. 2. Divisione Neurochirurgia, Azienda Ospedaliera, Sassari, Italy. 3. Headache Clinic, Johannesburg, South Africa. 4. Neuropsichiatria Infantile, Azienda Ospedaliero-Universitaria, University of Cagliari, Cagliari, Italy.
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. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
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 humanscalp 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. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
Authors: Elaine D Por; Melody L Sandoval; Chiquita Thomas-Benson; Teresa A Burke; Allison Doyle Brackley; Nathaniel A Jeske; Jeffery M Cleland; Brian J Lund Journal: PLoS One Date: 2017-08-10 Impact factor: 3.240