O2-6-08. Mechanism of forelimb motor function restoration after cervical spinal cord hemisection in rats: Electorophysiological verification

• Published in: Clinical neurophysiology 2017-09, Vol.128 (9), p.e171-e172
• Main Authors: Takeuchi, Takumi, Takahashi, Masahito, Satomi, Kazuhiko, Hasegawa, Atsushi, Ohne, Hideaki, Sato, Shunsuke, Ichimura, Shoichi
• Format: Article
• Language: English
• ISSN: 1388-2457; 1872-8952
• DOI: 10.1016/j.clinph.2017.06.007

The objective of this study was to electrophysiologically assess corticospinal tracts of adult rats and recovery of motor function of their forelimbs after cervical cord hemisection. Of 39 adult rats used, compound muscle action potentials (CMAPs) of forelimbs of 15 rats were evaluated, before they received left C5 segmental hemisection of the spinal cord, by stimulating the pyramid of medulla oblongata on one side using an exciting microelectrode. All 15 rats exhibited contralateral electrical activity, but their CMAPs disappeared after hemisection. The remaining 24 rats received hemisection first, and CMAPs of 12 rats were assessed over time to study their recovery time. All of them exhibited electrical activity of forelimbs in four weeks after surgery. The remaining 12 rats received additional right C2 segmental hemisection, and variation of CMAPs between before and after surgery was examined. The right side of the 12 rats that received the additional hemisection exhibited no electrical activity in response to the stimulation of pyramids on both sides. These results suggest that changes in path between the resected and healthy sides, activation of ventral corticospinal tracts, and propriospinal neurons were involved in the recovery of motor function after cervical cord injury.