Basic Research On The Correlative Cortex Plasticity In BPA With Or Without Contralateral C7 Transfer

Objective The value of this study is to investigate mRNA and protein expression of GAP-43 in BPI with or without C7 nerve transfer and its relation with the possible mechanism of the cortex plasticity following contralateral C7 root transfer.Methods 126 adult female SD rats were randomly divided into 2 groups:BPI (brachial plexus injury)group and BPI with contralateral C7 transfer group,while control stage(control).each group has 8 different time stages(1d,3d,7d,2w,1m,3m,6m,10m)and control stage with 7 in each,and left was experimental side,the contralateral hemispheres defined as hemispheres contralateral to the injured side and the ipsilateral hemisphere was the hemispheres ipsilateral to the injured side,electromyography electrophysiology testing was used to confirm the success of contralateral C7 transfer model group,drawing from the Bilateral forelimb corresponding areas of cerebral cortex,followed by immunofluorescent staining to preliminary qualitative and positioning(n=18).GAP-43 protein and mRNA levels of 9 stages were measured using western blotting and SYBR Green I quantitative real-time PCR respectively.A correlation analysis was made between mRNA and protein expression of GAP-43 in rats to reveal the mechanism of brain plasticity in BAI with or without contralateral C7 transfer.Results Expression of GAP-43 mRNA in rats was up-regulated significantly,peaked in 1d,3d,1w stages,compared to the control group(P＜0.05),then gradually reduced in the bilateral forelimb corresponding areas of cerebral cortex in BPA group.while expression of GAP-43 mRNA in rats was up-regulated significantly,peaked in 1d,3d,1w stages,compared to the control group(P＜0.05),then gradually reduced in the bilateral forelimb corresponding areas of cerebral cortex in BPA with contralateral C7 transfer group,howerer,the expression of GAP-43 mRNA was increased again at 6m after contralateral C7 transfer with the restoration of limb function(P＜0.05).Western Blotting analysis revealed that the changes of protein levels were similar to that of mRNA levels. Conclusions These results indicate that the gene expression of GAP-43 at different stages is consistent with the clinical phenomenon on the corresponding cerebral cortex of rats in BPI with or without C7 nerve transfer,which is closely related with brain and synaptic plasticity,and may be involved in the functional reorganization of the corresponding cerebral cortex.