Scarring after spinal cord injury (SCI) consists of glial scar formation followed by fibrotic scar formation.A glial scar is formed by reactive astrocytes during the acute phase of SCI.Reactive astrocytes are formed by astrocyte activation,proliferation and hypertrophy;they highly express glial fibrillary acidic protein,can fill the injured region,limit inflammatory diffusion,secrete and release factors promoting nerve regeneration,and improve the microenvironment surrounding the injury site (Sabelstrom et al.,2013).