Transplantation of neural stem cells (NSCs) is a potential strategy for the treatment of
spinal cord transection (SCT). Here we investigated whether transplanted NSCs would improve motor function of rats with SCT and explored the underlying mechanism. First, the rats were divided into
sham, SCT, and NSC groups. Rats in the SCT and NSC groups were all subjected to SCT in T10, and were administered with media and NSC
transplantation into the lesion site, respectively. Immunohistochemistry was used to label
Nestin-, TUNEL-, and NeuN-positive cells and reveal the expression and location of type I
insulin-like growth factor receptor (IGF-1 R). Locomotor function of hind limbs was assessed by Basso, Beattie, Bresnahan (BBB) score and inclined plane test. The conduction velocity and amplitude of spinal nerve fibers were measured by electrophysiology and the anatomical changes were measured using magnetic resonance imaging. Moreover, expression of
IGF-1 R was determined by real-time polymerase chain reaction and Western blotting. The results showed that NSCs could survive and differentiate into neurons in vitro and in vivo. SCT-induced deficits were reduced by NSC
transplantation, including increase in NeuN-positive cells and decrease in apoptotic cells. Moreover, neurophysiological profiles indicated that the latent period was decreased and the peak-to-peak amplitude of spinal nerve fibers conduction was increased in transplanted rats, while morphological measures indicated that fractional anisotropy and the number of nerve fibers in the site of
spinal cord injury were increased after NSC
transplantation. In addition,
mRNA and
protein level of
IGF-1 R were increased in the rostral segment in the NSC group, especially in neurons. Therefore, we concluded that NSC
transplantation promotes motor function improvement of SCT, which might be associated with activated
IGF-1 R, especially in the rostral site. All of the above suggests that this approach has potential for clinical treatment of
spinal cord injury.