Dr ANDREW BENNETT ANDREW.BENNETT@NOTTINGHAM.AC.UK
ASSOCIATE PROFESSOR
Postnatal maturation of endogenous opioid systems within the periaqueductal grey and spinal dorsal horn of the rat
Bennett, Andrew; Kwok, Charlie H.T.; Devonshire, Ian M.; Hathway, Gareth J.
Authors
Charlie H.T. Kwok
Ian M. Devonshire
Professor GARETH HATHWAY gareth.hathway@nottingham.ac.uk
PROFESSOR OF NEUROSCIENCE
Abstract
Significant opioid-dependent changes occur during the fourth postnatal week in supraspinal sites (rostroventral medulla [RVM], periaqueductal grey [PAG]) that are involved in the descending control of spinal excitability via the dorsal horn (DH). Here we report developmentally regulated changes in the opioidergic signalling within the PAG and DH, which further increase our understanding of pain processing during early life. Microinjection of the µ-opioid receptor (MOR) agonist DAMGO (30 ng) into the PAG of Sprague-Dawley rats increased spinal excitability and lowered mechanical threshold to noxious stimuli in postnatal day (P)21 rats, but had inhibitory effects in adults and lacked efficacy in P10 pups. A tonic opioidergic tone within the PAG was revealed in adult rats by intra-PAG microinjection of CTOP (120 ng, MOR antagonist), which lowered mechanical thresholds and increased spinal reflex excitability. Spinal adminstration of DAMGO inhibited spinal excitability in all ages, yet the magnitude of this was greater in younger animals than in adults. The expression of MOR and related peptides were also investigated using TaqMan real-time polymerase chain reaction and immunohistochemistry. We found that pro-opiomelanocortin peaked at P21 in the ventral PAG, and MOR increased significantly in the DH as the animals aged. Enkephalin mRNA transcripts preceded the increase in enkephalin immunoreactive fibres in the superficial dorsal horn from P21 onwards. These results illustrate that profound differences in the endogenous opioidergic signalling system occur throughout postnatal development.
Citation
Bennett, A., Kwok, C. H., Devonshire, I. M., & Hathway, G. J. (2014). Postnatal maturation of endogenous opioid systems within the periaqueductal grey and spinal dorsal horn of the rat. PAIN, 155(1), 168-178. https://doi.org/10.1016/j.pain.2013.09.022
Journal Article Type | Article |
---|---|
Acceptance Date | Sep 20, 2013 |
Publication Date | Jan 1, 2014 |
Deposit Date | Mar 7, 2018 |
Print ISSN | 0304-3959 |
Electronic ISSN | 1872-6623 |
Publisher | Lippincott, Williams & Wilkins |
Peer Reviewed | Peer Reviewed |
Volume | 155 |
Issue | 1 |
Pages | 168-178 |
DOI | https://doi.org/10.1016/j.pain.2013.09.022 |
Public URL | https://nottingham-repository.worktribe.com/output/1094703 |
Publisher URL | https://journals.lww.com/pain/Fulltext/2014/01000/Postnatal_maturation_of_endogenous_opioid_systems.23.aspx |
Related Public URLs | http://dx.doi.org/10.1016/j.pain.2013.09.022 |
You might also like
Integrins as a drug target in liver fibrosis
(2022)
Journal Article
Mixed polymer and bioconjugate core/shell electrospun fibres for biphasic protein release
(2021)
Journal Article
Downloadable Citations
About Repository@Nottingham
Administrator e-mail: discovery-access-systems@nottingham.ac.uk
This application uses the following open-source libraries:
SheetJS Community Edition
Apache License Version 2.0 (http://www.apache.org/licenses/)
PDF.js
Apache License Version 2.0 (http://www.apache.org/licenses/)
Font Awesome
SIL OFL 1.1 (http://scripts.sil.org/OFL)
MIT License (http://opensource.org/licenses/mit-license.html)
CC BY 3.0 ( http://creativecommons.org/licenses/by/3.0/)
Powered by Worktribe © 2024
Advanced Search