Experiment study of the miR-124 and miR-138 expression in rat primary motor cortex during the trans-hemispheric functional reorganization after the contralateral C7 nerve transfer

Objective To investigate the role of miR-124 and miR-138 in regulating the brain trans-hemispheric functional reorganization after the contralateral C7 transfer. Methods According to the model establishment and surgical treatment, 126 male SD rats were divided randomly into three groups: operation group, simple avulsion group and sham group. In the operation group, the right total brachial plexus avulsion model was made and the left C7 nerve root was cut as a donor to repair the right median nerve through ulnar nerve bridging. In the simple avulsion group, only the right total brachial plexus avulsion model was made and the left brachial plexus was only exposed. The sham group only exposed the bilateral brachial plexus. RT-PCR was used to detect the expression of miR-124 and miR-138 in bilateral brain motor cortex of rats at different time points after operation, and the correlation was analyzed. Results The expression level of miR-124 and miR-138 in the operation group and simple avulsion group showed dynamic changes with time, while in the sham group they showed no significant difference between different time points. The expression level of miR-124 and miR-138 in the operation group were greater than those in the simple avulsion group, and those in the simple avulsion group was higher than those in the sham operation group (P 0.05). The expression levels of miR-124 and miR-138 in the left hemisphere of the simple avulsion group were significantly higher than those in the right hemisphere (P<0.05). Conclusion The miR-124 and miR-138 may be invovled in the regulation of brain function remodeling after the contralateral C7 nerve transfer. Key words: Brachial plexus; Animal experimentation; Contralateral C7 nerve transfer; miRNA