Up-Regulation of Pain Behavior and Glial Activity in the Spinal Cord after Compression and Application of Nucleus Pulposus onto the Sciatic Nerve in Rats.
- Author:
Masaki NORIMOTO
1
;
Yoshihiro SAKUMA
;
Miyako SUZUKI
;
Sumihisa ORITA
;
Kazuyo YAMAUCHI
;
Gen INOUE
;
Yasuchika AOKI
;
Tetsuhiro ISHIKAWA
;
Masayuki MIYAGI
;
Hiroto KAMODA
;
Gou KUBOTA
;
Yasuhiro OIKAWA
;
Kazuhide INAGE
;
Takeshi SAINOH
;
Jun SATO
;
Junichi NAKAMURA
;
Tomoaki TOYONE
;
Kazuhisa TAKAHASHI
;
Seiji OHTORI
Author Information
- Publication Type:Original Article
- Keywords: Rat; Pain; Nerve; Glia; Spinal cord
- MeSH: Animals; Antibodies; Astrocytes; Calcium; Cytokines; Ganglia, Spinal; Horns; Hyperalgesia; Inflammation; Microglia; Neuroglia; Prostaglandins; Rats*; Sciatic Nerve*; Spinal Cord*; Surgical Instruments; Up-Regulation*
- From:Asian Spine Journal 2014;8(5):549-556
- CountryRepublic of Korea
- Language:English
- Abstract: STUDY DESIGN: Experimental animal study. PURPOSE: To evaluate pain-related behavior and changes in glial activity in the spinal dorsal horn after combined sciatic nerve compression and nucleus pulposus (NP) application in rats. OVERVIEW OF LITERATURE: Mechanical compression and inflammation caused by prostaglandins and cytokines at disc herniation sites induce pain. Structural changes and pain-associated cytokines in the dorsal root ganglia and spinal dorsal horn contribute to prolonged pain. Glial cells in the spinal dorsal horn may also function in pain transmission. METHODS: The sciatic nerve was compressed with NP for 2 seconds using forceps in the NP+nerve compression group; the sham-operated group received neither compression nor NP; and the control group received no operation. Mechanical hyperalgesia was measured for 3 weeks using von Frey filaments. Glial activity in the spinal dorsal horn was examined 7 days and 14 days postsurgery using anti-glial fibrillary acidic protein and anti-Ionized calcium binding adaptor molecule-1 antibodies to detect astrocytes and microglia, respectively. RESULTS: Mechanical hyperalgesia was detected throughout the 14-day observation in the NP+nerve compression group, but not in control or sham-operated groups (p<0.05). Both astrocytes and microglia were significantly increased in the spinal dorsal horn of the NP+nerve compression group compared to control and sham groups on days 7 and 14 (p<0.05). CONCLUSIONS: Nerve compression with NP application produces pain-related behavior, and up-regulates astrocytes and microglia in the spinal dorsal horn, suggesting that these glia may be related to pain transmission.
