Changes in activation of ERK1/2 around injury area following spinal cord hemisection

Objective To study the changes in ERK1/2 activity and the cell types involved following spinal cord hemisection. Methods Rats 3 d after spinal cord hemisection were used to study the changes in phosphorylated ERK1/2 immunoreactivity and its cellular distribution by immunohistochemical and double staining immunofluorescence techniques. Results The phosphorylation level of ERK1/2 in the operated rats 3 d after hemisection was much higher than that in the control rats. The positive cells were located around injury area, having small cell bodies and short processes. Double fluorescent staining proved that most of positive cells were microglia or oligodendrocytes. Conclusion It is showed that ERK1/2 signaling pathway is involved in microglia and oligodendrocytes activation which may play a critical role in the secondary lesion of spinal cord injury 3 d after spinal cord hemisection.