Pain behavior and the expression of Fos in the related brain regions of rats with chronic construction injury
10.3760/cma.j.issn.1674-6554.2016.08.004
- VernacularTitle:慢性坐骨神经损伤大鼠痛行为及痛调节相关脑区Fos蛋白表达
- Author:
Jing XU
;
Yugang LU
;
Hao GAO
;
Weifeng YU
- Publication Type:Journal Article
- Keywords:
Anterior cingulate cortex;
Spinal;
Periaqueductal grey;
Rostroventral medulla;
Fos protein
- From:
Chinese Journal of Behavioral Medicine and Brain Science
2016;25(8):687-692
- CountryChina
- Language:Chinese
-
Abstract:
Objective To observe pain behavior and the expression of Fos in the related brain re? gions,including Anterior Cingulate Cortex ( ACC) ,Periaqueductal Gray ( PAG) ,Rostral ventromedial nucle?us ( RVM) in chronic constrictive injury ( CCI) rats and to explore whether ACC modulate spinal nociceptive transmission through endogenous descending facilitatory system. Methods A total of 48 male SD rats were randomly divided into six groups:Naive group,Sham group ( just separated the left sciatic nerves without liga?tion) ,CCI group ( the left sciatic nerve was ligated) ,CCI+P group ( on the 14 th day after surgery,intraper?itoneal injection of 10 mg/kg paroxetine 45 min before behavior test) ,ACC?Sham group ( bilateral microin?jection of 0.9% NaCl in ACC,1μl/each side) and ACC?AP5 group ( bilateral microinjection of AP5 25 mM in ACC,1μl/each side on the 13th day after surgery) . On the 14th day after light?dark transition test,forced swimming test,paw?withdrawal mechanical threshold( PWMT) and paw?withdrawal thermal patency( PWTL) were performed,the rats were terminally anesthetized and ACC,PAG,RVM and the spinal cord was rapidly removed,and then the expression of c?fos was measured by immunohistochemistry. Results ( 1) Rats in CCI group demonstrated nociceptive hypersensitivity and depressive?like behaviors compared with Naive rats, while rats in CCI+P group and in ACC?AP5 group showed less nociceptive hypersensitivity and less depres?sive?like behaviors compared with CCI group. (2)Compared with Naive group,the number of c?fos positive neurons in the bilateral ACC (left,surgery side,4920.6±1053.7;right,2059.3±409.1),VIPAG (9074.8± 2320.3),RVM (6195.4±895.0) and bilateral spinal cord (left,15148.8±3080.2;right,6400.2±1558.4) was significantly enhanced in CCI group, especially in the left side. In contrast, the amount of fos labeled neurons declined in the bilateral ACC (left,2776.4±820.1;right,1120.5±141.4),VIPAG (4002.2± 1171.8),RVM (2938.9±910.3) and bilateral spinal cord (left,8742.0±1131.0;right,3933.1±858.9) in CCI+P group and also declined in the bilateral ACC (left,3623.1±667.4;right,696.5±164.8),VIPAG (5668.8±1403.3),RVM (3972.3±851.7) and bilateral spinal cord (left,10675.4±1725.3;right,3818.3± 1085.1) in ACC?AP5 group. Conclusion Endogenous descending facilitatory system may contribute to ACC modulating spinal nociceptive transmission.
