面部皮下福尔马林注射致大鼠三叉神经脊束核尾侧亚核c-fos和GFAP表达的动态变化

目的：观察福尔马林致炎性鼠中枢三叉神经尾侧亚核（Sp5C）c-fos和胶质原纤维酸性蛋白（glialfibrilary acidic protein GFAP）表达的动态变化。方法：选择体重200-250g健康SD大鼠,在左上唇皮下注射2.5%福尔马林50μl建立炎性痛模型。分别在注射后30,60,120,240,360min等时间点处死,每组6只。免疫荧光染色观察各组大鼠同侧Sp5C核c-fos和GFAP表达的情况。结果：在面部皮下注射福尔马林后,fos阳性（fos-immunoreactivity,Fos-IR）神经元在注射后30分钟即可观察到,120分钟达到峰值,到360分钟观察结束仍有较高的表达。GFAP-IR在福尔马林注射后30分钟即有较高表达,60分钟达峰值后下降,240分钟即恢复到正常水平,二者分布区域相同。结论：在福尔马林致炎性痛模型中Sp5C内神经元和星形胶质细胞共同参与中枢神经系统对炎性疼痛刺激的调节,星形胶质细胞可能对神经元的活动有调节作用。

The dynamic changes of c-fos and GFAP expression of rat spinal trigeminal nucleus after subcutaneous formalin injection

Objective： To observe the changes of c-fos and glial fibrilary acidic protein （GFAP） expression in ipsilateral Sp5C following noxious pain stimulation induced by formalin injection. Methods： Male SD rats weighing 200-350 g, received subcutaneous injection of 2.5% formalin 50μl in the left vibrissa pad to establish the inflammatory pain model. The survival time of animals were 30,60,120,240,360rain after injection with 6 rats for each manipulation at each time point. In addition,6 other rats were sacrificed after subcutaneous injection of normal saline 50 μl and served as control. The c-los and GFAP expressions were detected by immunofluorescence staining. Results： Fos-immunoreactivity （Fos-IR） neurons were presented at 30 min,peaked at 120min and remained at a higher level by 360 min after injection. Meanwhile, expressions of GFAP-IR were observed higher at 30 min ,peaked at 60 min,then declined and returned to normal level by 240 min after injection.Fos-IR and GPAP-IR showed similar distribution. Conclusion： The results suggested that the neurons and astrocytes in the Sp5C might jointly participate in pain modulation in CNS and astrocytes might regulate neuron＇ s function.