The Changes On The Expression Of Fas And FasL In Central Nervous System Following Spinal Cord Hemisection In The Adult Rhesus

Objective: To investigate the distribution of Fas and FasL in the Central Nervous System (CNS) of adult rhesus and the changes of expression of Fas and FasL in the hemisected spinal cord of adult rhesus.Methods: 18 adult male rhesus were used. They were divided into six groups randomly. Spinal cord hemisection were performed at T11 level. The anaminals were allowed to survive for 7 days, 15 days, 30 days, 60 days, and 90 days. The CNS in control group were obtained in order to investigate the change and distribution of Fas and FasL as well as the spinal cord and moter region of certex in experimental groups. The data were statistically analysed with factorial ANOVA and LSD test.Results: The Fas and FasL immunopositive neurons were observed in many areas. Fas immunoreactivity can be seen in the cytoplasm and processes of Purkinge cells and brain stem nuclei. FasL immunopositive neurons were observed in cerebellar nuclei, diencephalon and brain stem nuclei. Fas and FasL immunoreactivity mainly distributed in motor neurons of spinal ventral horn and neural fibers and glia cells in white matter. Brown staining was observed in the cytoplasm and process.Fas and FasL immunoreactive products deposit in the cytoplasm and processes of stained neurons distributed in the ventral horn of all rhesus and the number reached maximumly 7 days post operation (dpo), then declined and returned to normal up to 2 months post operation in all operated groups.The total number of immunoreactive neurons in the caudal and rostral spinal cord of the rhesus 7dpo and 15dpo on the operative side had significant increase than that ofnormal control group (P<0.05) and that in the contralateral side (P<0.05). There were no statistic difference between the caudal and rostral spinal cord of all rhesus on the operative side (P>0.05). In addition, Fas and FasL had the same expressional trend after the injury.Conclusion: Fas and FasL distributed in various areas of CNS, which indicated that they might play some roles in the immune and physical function of the aforesaid sites.In the ventral horn of hemisection rhesus Fas and FasL had the same expressional trend, that is reached maximumly 7 dpo, then declined and returned to normal up to30 dpo or 60 dpo post operation, which showed that Fas and FasL might involve in the apoptosis and secondary injury in the spinal cord and provide the theory basement for the therapy of spinal cord injury in clinic.