Effects of Glucocorticoids on c-fos Express in the Brain of Rats Following Acute Inflammative Pain

Objective To provide the morphologic information about glucocorticosteriod(GCS) effect on brain neurons.Methods Observation of animal ethology,nerve cells staining by immunohistochemistry and morphometry methods was performed.Results 2.5% formalin(20μl) injection into the plantar surface of rat hind paw could induce acute durative inflammation near area of the injection.After 1 hour the total number of fos-like immunoreactive(fos-LI) neurone in thalamencephalon and cerebral cortex increased obviously.But the number of FLI neuron was significantly reduced after 2 hours carulon pretreatment,and it was dose dependent.The number of FLI neuron had the positive correlation to the edema in peripheral tissue and the pain behavior.RU486,the blocking agent of glucocorticoid receptor,could reverse partly the effect of GCS.Conclusion ①c-fos is expressed widely in central nervous system after the nocuous stimulation;②GCS induced effect on central nervous system of c-fos expression is different