The effect of restraint stress on masseter mechanical hyperalgesia and the activity of neurons and astrocytes in the spinal trigeminal nucleus caudalis in rats
10.3760/cma.j.issn.1002-0098.2017.04.012
- VernacularTitle: 束缚应激对大鼠咬肌区域痛觉敏感及三叉神经脊束核神经元和星形胶质细胞的影响
- Author:
Wenqing LIN
1
,
2
,
3
;
Min ZHANG
1
,
2
,
3
;
Yinhua ZHAO
1
,
2
,
3
;
Qiang LI
1
,
2
,
3
;
Jian WANG
4
;
Yongjin CHEN
1
,
2
,
3
Author Information
1. Department of General Dentistry and Emergency, School of Stomatology, The Fourth Military Medical University & State Key Laboratory of Military
2. Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi International Joint Research Center for Oral Diseases, Xi&apos
3. an 710032, China
4. Department of Cardiovascular Surgery, Chengdu Military General Hospital, Chengdu 610083, China
- Publication Type:Journal Article
- Keywords:
Stress, psychological;
Masseter muscle;
Hyperalgesia;
Proto-oncogene proteins c-fos
- From:
Chinese Journal of Stomatology
2017;52(4):254-258
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the effect of restraint stress on masseter mechanical hyperalgesia and the activity of neurons and astrocytes in the spinal trigeminal nucleus caudalis (Vc).
Methods:The animals were randomly divided into the control group, 1-, 3-, 5-, 7-, 9-, 11-and 14-day stress groups, with 10 rats in each group. The body weight increase and behavior tests were used to testify the animal model. The mechanical sensitivity of masseter of the rat before and after the stress was measured with Von Frey filaments. Histological examinations were used to evaluate the expression of neuronal c-fos and astrocytic glial fibrillary acidic protein (GFAP).
Results:Restraint stress resulted in remarkable mechanical allodynia in the masseter muscle. The head withdrawal threshold was significantly lower in the 7-, 9-, 11-and 14-day stress groups ([0.071±0.011], [0.059±0.020], [0.052±0.011], [0.033±0.011] N) than that in the control group ([0.120±0.025] N) (P<0.05). Compared to the control group, the rats in the 1-day stress group showed a significant increase of c-fos in neurons of the Vc and then declined to normal level after 1 week gradually. The GFAP expression in astrocytes of the Vc was significantly increased in the 7-, 9-, 11-and 14-day stress groups (4.3±1.0, 4.5±0.6, 4.6±0.5, 4.8±1.3) compared with the control group (2.0±0.8) (P<0.05).
Conclusions:Chronic restraint stress could lower the threshold of mechanical allodynia in the masseter muscle and activate the neurons and astrocytes in Vc. The activation of neurons and astrocytes plays an important role in the masseter hyperalgesia induced by restraint stress in rats.
