| Objective: To observe dopamine 1 acceptor (DA1R) and five hydroxy tryptamine 1A acceptor (5-HT1AR) expression in the section far-end spinal cord neuron and the caspase-3 change in skeletal muscle after spinal cord transaction of adult rats, to explore neuronal activeness in spinal cord and the denervated skeletal muscle change.Methods: 45 SD rats were randomly divided into three groups:Sham,Control,Experimental group (spinal cord injury1d, 1w, 2w, 4w group). Spinal cord transaction model was established in rat. Spinal cord neurons and skeletal muscle morphology were respectively observed by HE staining and Nissl staining. The expression of dopamine 1 receptor (DA1R), serotonin 1A receptor (5-HT1AR) and caspase-3 were tested with immunhistochemistry. The differences between groups were compared.Results: Pathological changes were distinct in denervated skeletal muscle after 4 weeks, meanwhile Caspase-3 expression was higher than that in control group. Dopamine receptor 1-positive cells were mainly distributed in spinal cord gray matterⅦ-Ⅷcell layer, and serotonin 1A receptor (5-HT1AR ) positive cells in spinal cord gray matterⅢ-Ⅳcell layer and the ventral horn. After spinal cord transaction 7d, 2w, 4w, the number of positive cells was statistically significant compared with the control group. Conclution: Function of neuron activity in the end section of spinal cord injury and partially denervated muscle degeneration were observed. Short term (4w) gray matter nerve cells can secrets DA1R and 5-HT1AR, maintain the function of neuronal activity and activate of central pattern generator leading to rhythmic movement, meanwhile higher receptor may have an important role in keeping delaying skeletal muscle morphological changes and muscle wet weight. Therefore, repair or application of exogenous DA and 5-HT media as soon as possible after spinal cord injury is conducive to long-term recovery of neurological function.. |
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