The role of neuronal and glial activation in spinal cord in the mechanism of neuropathic pain following three different peripheral nerve injuries in rats
- VernacularTitle:脊髓神经元和胶质细胞激活在三种神经病理性疼痛大鼠模型脊髓水平致痛机制中的作用
- Author:
Xiao-Gao JIN
;
Ai-Lin LUO
;
Jin-Tao WANG
;
Guangxiong ZHANG
;
Li WAN
;
Ke AN
;
Ying XU
;
Yuke TIAN
- Publication Type:Journal Article
- Keywords:
Neuralgia;
Neuron;
Astrocytes;
Microglia
- From:
Chinese Journal of Anesthesiology
1994;0(01):-
- CountryChina
- Language:Chinese
-
Abstract:
Objective To determine if there is any difference in neuronal and glial(astrocytic and microglial)activation in the spinal cord in three rat models of neuropathic pain.Methods Twenty-four SD rats weighing 150-200 g were randomly divided into 4 groups(n=6 each):Ⅰ control group;Ⅱ chronic constrictive injury group(CCI);Ⅲ spinal nerve ligation group(SNL)and Ⅳ spared nerve injury(SNI).No operation was performed in control group.In CCI group left sciatic nerve was exposed and loosely ligated with catgut.In SNL group the L_5 spinal nerve was exposed and ligated with silk suture and cut.In SNI group tibial nerve and common fibular nerve were ligated and cut.Pain threshold was measured using plantar tactile stimulator(Ugo,Basile Co. Italy)every other day from 3 days before until 15 days after operation.50% paw withdrawal threshold was measured using up-and-down sequential mechanical stimulation of different intensity(0.45,0.70,1.20,2.00, 3.63,5.50,8.50,15.10 g)applied to the plantar surface of the injured paw.On the 15~(th) day after operation after pain threshold was measured the animals were anesthetized with intraperitoneal 10% chloral hydrate 400 mg? kg~(-1).The L_(5,6) segment of the spinal cord was isolated.Neuronal,astrocytic and microglial activation was determined by immuno-histochemistry with antibodies of c-Fos(a proto-oncogene protein),GFAP(an astrocyte marker)and OX-42(a microglial marker).Results The 50% paw withdrawal threshold reached the lowest level on the 7~(th) day after operation.The lowest level was maintained until the 15~(th) day after operation in group CCI,SNL and SNI.The 50 % paw withdrawal threshold was(14.1+1.5)g in control group,(2.5+0.5)g in CCI group, (1.5?0.6)g in group SNL and(0.8?0.4)g in group SNI.The number of c-Fos positive neurons in laminae Ⅳ-Ⅵ of dorsal horn was significantly greater in group CCI,SNL and SNI than in control group,but there was no significant difference among the 3 peripheral nerve injury groups.The activation of astrocytes and microglias in laminae Ⅰ-Ⅳ of dorsal horn was significantly increased in group CCI,SNL and SNI than in control group but there was no significant difference among the 3 peripheral nerve injury groups.Condusion There is no significant difference in activation of neurons and astrocytes and microglias in the ipsilateral dorsal horn among the 3 pain models.
