Systemic minocycline differentially influences changes in spinal microglial markers following formalin-induced nociception

Li, Kai; Fu, Kai-Yuan; Light, Alan R.; Mao, Jianren

doi:10.1016/j.jneuroim.2010.02.003

« Previous Next »Journal of Neuroimmunology
Volume 221, Issue 1 , Pages 25-31, 15 April 2010

Systemic minocycline differentially influences changes in spinal microglial markers following formalin-induced nociception

Kai Li
- Center for TMD & Orofacial Pain, Peking University School & Hospital of Stomatology, Beijing 100081, PR China
Kai-Yuan Fu
- Center for TMD & Orofacial Pain, Peking University School & Hospital of Stomatology, Beijing 100081, PR China
- Corresponding author. Center for TMD & Orofacial Pain, Peking University School & Hospital of Stomatology, Zhong Guan Cun South Avenue 22, Beijing 100081, PR China. Tel.: +86 10 62179977; fax: +86 10 62173402.
Alan R. Light
- Department of Anesthesiology, University of Utah, Salt Lake City, UT 84132-2304, USA
Jianren Mao
- MGH Center for Translational Pain Research, WACC 324, Department of Anesthesia and Critical Care, Massachusetts General Hospital, Harvard Medical School, 15 Parkman Street, Boston, MA 02114, USA

Received 17 December 2009; received in revised form 2 February 2010; accepted 2 February 2010. published online 08 March 2010.

Abstract

In the present study, intraperitoneal administration of minocycline attenuated enhancing nociceptive behaviors in those rats receiving dual formalin injections (5% formalin followed at 7days later by 1% formalin). The minocycline treatment did not prevent the increase in OX-42 and MHC class I labeling and morphological changes, but significantly attenuated upregulation of phospho-p38 in activated microglia. These results suggest that the later days of microglial activation with upregulated immune markers in the spinal cord contributes to enhancing long-term pain response by a pathway of p38 activation in microglia.

Keywords: Microglia, OX-42, MHC class I, p38 MAPK, Minocycline, Formalin