Ectopic discharges trigger sympathetic sprouting in rat dorsal root ganglia following peripheral nerve injury.
Experimental backgrounds of ectopic discharges were made by i.p. administrating of 4-aninopyriding (4-AP), a K(+) channel blocker, or anisodamine, a muscarinic receptor blocker, in CCI rats, and the sympathetic sprouting in the dorsal root ganglia (DRG) as well as the heat-hyperalgesia was observed. It was demonstrated that the increased ectopic discharges induced by 4-AP promote sympathetic sprouting in the DRG and a greater number of sympathetic basket cells were developed, causing exacerbation of heat-hyperalgesia in CCI rats. On the contrary, the sympathetic sprouting in the DRG and heat-hyperalgesia are evidently diminished after anisodamine injection. Our results suggest that ectopic discharges may be an immediate factor in triggering sympathetic sprouting in DRG following peripheral nerve injury.
Dong
Chenghai
C
Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Peking Union Medical College, 100005, Beijing, China.
Xie
Zuolei
Z
Fan
Jiyun
J
Xie
Yikuan
Y