Study of nerve grafting to the change of GDNF and GFRα1 on neurons after brachial plexus nerve injury in young rats

Abstract

Objective To investigate the difference of the glial cell line-derived neurotrophic factor and its receptor content of proximal neurons after nerve grafting was used to reconstruct C5 root in young rats.Methods Model of C5 resection was set up in 12 18-day-old SD rats.Experimental animals were divided in to two groups, one group for C5 resection, another for nerve grafting to reconstruct the C5 defection.At 4 weeks postoperatively, the immunohistochemical staining was performed and the number of GDNF and GFRa1 immunohistochemical positive neurons were calculated respectively.Results The number of GDNF positive neurons in spinal cord and dorsal root ganglion of C5 repairing group was 786.3 ± 176.84 and 2997.0 ±357.99, and that of C5 resection group was 335.0 ± 49.50 and 1632.0 ± 305.55.On the other hand, the number of GFRa1 positive neurons in spinal cord and dorsal root ganglion of C5 repairing group was 787.5 ±178.55 and 3111.0 ± 445.72, that of the other group was 397.3 ± 41.78 and 1588.3 ± 229.00.The statistical analysis result showed GDNF and GFR immunohistochemical positive neurons in spinal cord and dorsal root ganglion of C5 repairing group was statistically more than that of C5 resection group(P < 0.01 ).Conclusion The neuronal protective effect of nerve grafting after reconstructing brachial plexus nerve injury in young rats may be attributed to the increase of GDNF and its receptor GFRa1 content of proximal neuron. Key words: Brachial plexus; Nerve grafting; Neuron; Glial cell line-derived neurotrophic factor; Obstetric brachial plexus palsy