Abstract
Cumulating evidence has demonstrated that μ opioid receptor (MOR) agonists promote spinal glial activation, lead to synthesis and release of proinflammatory cytokines and chemokines, and contribute to opioid-induced hyperalgesia and development of opioid tolerance and dependence. However, whether these MOR agonists directly or indirectly act on spinal cord astrocytes and microglial cells in vivo is unclear. In the present study, by combining the techniques of in-situ hybridization of MOR mRNA with immunohistochemistry of glial fibrillary acidic protein (GFAP; an astrocyte marker) and Iba1 (a microglial marker), we examined expression and distribution of GFAP, Iba1, and MOR mRNA in the spinal cord of rats under chronic morphine tolerance conditions. Intrathecal injections of morphine twice daily for 7 days reduced morphine analgesic effect and increased both GFAP and Iba1 immunostaining densities in the spinal cord. Surprisingly, neither GFAP nor Iba1 colocalized with MOR mRNA in spinal cord cells. Our findings indicate that MOR expression is absent from spinal cord astrocytes and microglia, suggesting that these cell types are indirectly activated by MOR agonists under chronic opioid tolerance conditions.
References
Oct 1, 1995·Brain : a Journal of Neurology·V SalanovaL F Quesney
Dec 28, 1995·Brain Research. Molecular Brain Research·B B RuzickaH Akil
Jan 3, 2001·The Journal of Comparative Neurology·H Wang, M W Wessendorf
Sep 26, 2001·Glia·A Stiene-MartinK F Hauser
Feb 9, 2002·Brain : a Journal of Neurology·L F BarcellosUNKNOWN Multiple Sclerosis Genetics Group
Mar 7, 2002·Brain Research·Catherine AbbadieAllan I Basbaum
Dec 12, 2003·Neuroscience·W-J LiawY-X Tao
Aug 16, 2005·Pain·Tatsuro KohnoClifford J Woolf
Nov 9, 2005·DNA and Cell Biology·Ying-Xian Pan
Dec 16, 2005·The AAPS Journal·Kirsten M Raehal, Laura M Bohn
Jan 13, 2006·Brain Research·Yu CuiPei-Xi Chen
Jan 19, 2006·Neuroscience·M NaritaT Suzuki
Feb 16, 2006·Brain : a Journal of Neurology·Francesca MorganteRobert Chen
Apr 4, 2006·Life Sciences·Alan R Gintzler, Sumita Chakrabarti
Aug 21, 2007·Brain Research Reviews·Linda R WatkinsSteven F Maier
Nov 22, 2007·The European Journal of Neuroscience·Takahiro SonomuraTakeshi Kaneko
Dec 5, 2008·Journal of Neurochemistry·Jadwiga Turchan-CholewoAnnadora J Bruce-Keller
Jan 30, 2009·The Journal of Neuroscience : the Official Journal of the Society for Neuroscience·Ryan J Horvath, Joyce A DeLeo
Feb 24, 2010·Brain : a Journal of Neurology·Paolo MissoriAntonio Currà
Apr 20, 2010·Brain Research·Ji-Tain XuYuan-Xiang Tao
May 25, 2010·Neuroscience·R J HorvathJ A DeLeo
Jun 25, 2010·Pain·Ryan J HorvathJoyce A De Leo
Feb 1, 2011·Journal of Neuroscience Methods·Benjamin NehméDidier Mouginot
Citations
Oct 16, 2013·Peptides·Richard J Bodnar
Feb 13, 2013·Pain Research and Treatment·Joel S Goldberg
Jan 3, 2014·The Journal of Clinical Investigation·Ji-Tian XuYuan-Xiang Tao
Apr 25, 2012·Journal of Neurovirology·Seth M DeverKurt F Hauser
Dec 14, 2012·Expert Review of Neurotherapeutics·Jacob Thomas, Mark R Hutchinson
Apr 3, 2015·Headache·Peter M GraceLinda R Watkins
Jul 15, 2015·European Journal of Pharmacology·Maria Domenica SannaNicoletta Galeotti
Jan 21, 2015·Journal of Neuroinflammation·Guilherme D SilvaRosana L Pagano
Aug 31, 2013·Life Sciences·Shinichi HaradaShogo Tokuyama
Feb 12, 2013·European Journal of Pharmacology·Asunción RomeroMargarita M Puig
Feb 5, 2008·Brain Research·J WiedeyL Marson
Jan 17, 2017·Nature Medicine·Gregory CorderGrégory Scherrer
Jul 29, 2018·Journal of Anesthesia·Salim KadhimDavid G Lambert
Oct 16, 2018·European Journal of Pain : EJP·Miriam Martínez-NavarroJosep-E Baños
Jan 20, 2018·Physiological Reviews·Alexei Verkhratsky, Maiken Nedergaard
Aug 23, 2019·Pain·Ruth Drdla-SchuttingJürgen Sandkühler
Apr 8, 2020·Journal of Neuroscience Research·David ReissClaire Gaveriaux-Ruff
Jan 11, 2020·Frontiers in Immunology·Toby K Eisenstein
Jul 28, 2019·Molecular Neurobiology·Maria Domenica SannaNicoletta Galeotti
Jan 22, 2019·Frontiers in Psychiatry·Tando MadunaClaire Gaveriaux-Ruff
Mar 21, 2020·Frontiers in Immunology·Halina Machelska, Melih Ö Celik
Dec 4, 2019·Brain Research Bulletin·Hong ZhangTodd W Vanderah
Feb 15, 2021·Neuroscience and Biobehavioral Reviews·Élora MidavainePhilippe Sarret
Apr 30, 2020·Pain·Viktoria HadschieffJürgen Sandkühler