Abstract
Neurotrophic factor (NF) and Trk signaling mechanisms underlying the promotion of motor recovery following acute spinal cord injury (SCI) in rats were investigated. Thirty-six adult Sprague-Dawley rats of both genders were randomly divided into three groups: Sham-operated, model, and NF/Trk. Each group consisted of 12 rats, with four subgroups in each group: 1, 3, 5 and 7 days. Sham-operated rats received a laminectomy without SCI, while in model group rats, SCI was induced using an improved version of the Allen's method. After analepsia, sham-operated and model group rats were given normal saline via gavage, while the NF/Trk group received NFs and Trk. Lower limb function was measured using the Basso, Beattie and Bresnahan scale 1, 3, 5 and 7 days before and after surgery. Results were analyzed statistically. Six rats from each group were randomly selected for sacrifice at 1, 3, 5 and 7 days after the operation. Morphological changes in motor neurons in the anterior gray column were observed by hematoxylin and eosin, and Nissl staining. Brain-derived expression of NF (BNDF) and neurotrophin-3 (NT-3) was detected by immunofluorescence, and the number of positive cells was counted. Expression of Trk B and Trk protein C receptor was measured by western blotting. In the NF/Trk group, the expression of NF/Trk pathway components remarkably increased. In addition, the morphology of motor neurons in the anterior gray column was improved. Expression of BNDF and NT-3 was significantly increased in motor neurons of the anterior gray column in NF/Trk rats compared with those of sham-operated and model rats (P<0.05). NFs promote motor recovery following acute SCI in rats and may have valuable clinical applications.