Objective:This study was performed to figure out how dermal blood flow changed in skin territory following peripheral nerve injury,and to determine whether this change correlated to alteration of excitability/conductivity or axonal degeneration of the nerve distal to injury. Methods:Skin blood flow was monitored by time-lapse laser Doppler perfusion imaging (LDPI) in a rat model of sciatic nerve transection injury. Meanwhile,compound muscle action potentials (CMAPs) were recorded in gastrocnemius muscle by applying electrical stimuli to the nerve distal to injury,and the distal nerve was immunostained for neurofilament-200 and S-100 protein. Results:Sciatic nerve transection led to an immediate and robust increase of blood perfusion,which recovered to normal extent in 3 days post-injury,in the ipsilateral hind paw. In 24 h after injury,CMAP amplitude reduced more than 95% in gastrocnemius muscle upon stimulating the nerve distal to injury. However,the majority of axons were seen to degenerate in the distal nerve aftre 4 days. Conclusion:Blood perfusion increase in skin territory,resulted from the sciatic nerve transection,was gradually recovered to normal in 3 days post-injury. Although there seemed a correlation between dermal perfusion increase and axonal degeneration,the maintenance of axonal excitability in the distal nerve did not necessarily correlate to increase of skin blood perfusion.