Quantitative assessment of the recovery of nerve function, especially sensory and autonomic nerve function, remains a challenge in the field of nerve regeneration research. We previously found that neural control of vasomotor activity could be potentially harnessed to evaluate nerve function. In the present study, five different models of left sciatic nerve injury in rats were established: nerve crush injury, nerve transection/suturing, nerve defect/autografting, nerve defect/conduit repair, and nerve defect/non-regeneration. Laser Doppler perfusion imaging was used to analyze blood perfusion of the hind feet. The toe pinch test and walking track analysis were used to assess sensory and motor functions of the rat hind limb, respectively. Transmission electron microscopy was used to observe the density of unmyelinated axons in the injured sciatic nerve. Our results showed that axonotmesis-evoked vasodilatation in the foot 6 months after nerve injury/repair recovered to normal levels in the nerve crush injury group and partially in the other three repair groups; whereas the nerve defect/non-regeneration group exhibited no recovery in vasodilatation. Furthermore, the recovery index of axonotmesis-evoked vasodilatation was positively correlated with toe pinch reflex scores and the density of unmyelinated nerve fibers in the regenerated nerve. As C-fiber afferents are predominantly responsible for dilatation of the superficial vasculature in the glabrous skin in rats, the present findings indicate that axonotmesis-evoked vasodilatation can be used as a novel way to assess C-afferent function recovery after peripheral nerve injury.
[1]Jiangnan Univ, Peoples Hosp Wuxi City 3, Affiliated Hosp, Dept Orthoped, Wuxi, Jiangsu, Peoples R China;
[2]Jiangnan Univ, Wuxi Sch Med, Wuxi, Jiangsu, Peoples R China;
[3]Nantong Univ, Minist Educ, Key Lab Neuroregenerat, Nantong, Jiangsu, Peoples R China;
[4]Nantong Univ, Coinnovat Ctr Neuroregenerat Jiangsu Prov, Nantong, Jiangsu, Peoples R China;
[5]Nantong Hosp Tradit Chinese Med, Dept Orthoped, Nantong, Jiangsu, Peoples R China;
[6]Fudan Univ, Zhongshan Hosp, Dept Emergency Med, Shanghai, Peoples R China;
[7]New York State Inst Basic Res Dev Disabil, Dept Neurochem, Inge Grundke Iqbal Res Floor, Staten Isl, NY 10314 USA
(8.0+极速模式)