Abstract
Objective To explore the changes of glutamic acid and NMDA receptor expression in motor cortex following contralateral C7 transfer. Methods Total root avulsion of the left brachial plexus and transfer of the right C7 nerve root to the left median nerve via ulnar nerve graft was established in a rat model. Recovery of median nerve function was monitored with electrophysiologic examination at various postoperative intervals. Representation of the injured forepaw was mapped using intracortical microstimulation (ICMS). According to the ICMS results, brain samples were harvested for determination of glutamic acid and NMDA receptors (NR1、 NR2A、NR2B)in motor cortex by immuno-histochemical assay. Results After the surgery recovery of flexor digitorum profundus was indicated by decrease in compound muscle action potential (CAMP) latency and increase in CMAP amplitude over time. At 4 months, median nerve representation region of the affected forelimb appeared in the ipsilateral motor cortex in 3 rats and upregulation of NR1 was observed in both hemispheres of all rats from the operative groups. The NR1 expression showed significant change in the normal and operative groups. Meanwhile, NR1 expression in the right cortex was significantly higher than that in the left cortex. At 7 months, both hemispheres of cortex activated the injured forepaw in 4 rats. There was a significant increase in NB2A expression in the right motor cortex in the operative groups and NR2A expression in rats following contralateral C7 transfer was significantly higher than that in the rats from the other operative groups. At 10 months, the contralateral motor cortex exclusively controlled the injured forepaw and the expression of NR2A was still up-regulated. NR2A expression in rats following contralateral C7 transfer was still significantly higher than that in the rats from the other operative groups. Conclusion Transhemispheric functional reorganization of the motor cortex is confirmed in rats following contralateral C7 transfer. NR1 plays an important role in the primary cortical plasticity and NR2A is needed to continue this reorganization in later stage. Key words: Brachial plexus; Nerve transfer; Glutamic acid; Functional reorganization; NMDA receptors
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
