Neural stem cell conditioned culture medium promotes corticospinal axons regeneration in injured rat spinal cord

Objective Study the action of Neural stem cell (NSC) conditioned culture medium on promoting corticospinal tract (CST) in rats with injured spinal cord (SCI).Methods 30 adult Wister rats were randomly divided into two groups:NSC-conditioned medium group and medium control group.A sterile laminectomy was performed at T11 and spinal cord was transected in all rats.In NSC-conditioned medium group,5μl/week NSC-conditioned medium was administered into the spinal cord via an Ommaya tube which was fixed subcutaneously.Medium in which NSC hadn't been cultured was administered as control. Hindlimb motor function was assessed using the BBB Locomotor Rating Scale.Assess the regeneration of BDA positive CST and synaptophysin expression distal to the lesion.Results Locomotor function of these paraplegic rats improved in NSC medium group rats,BDA traces regenerated fibers across the lesion site and into the caudal part of the spinal cord.Minimal histological and functional changes were found in control group.Synaptophysin expression was found colocalized with BDA positive axons and neurons distal to the injury site in the treatment group,there was no synaptophysin expressing in control group.Conclusions NSC-conditioned medium could promote CST regeneration in SCI rats and anatomical reeonnection between sprouting CST fibers and distal spinal cord neurons.Treating of NSCs on SCI is mainly through the supporting effect but not substitute effect.