Effects of astrocytes in cervical spinal cord posterior horn on allodynia in rat models of migraine / 中华神经科杂志

ABSTRACT

Objective To explore the effects of astrocytes in cervical spinal cord posterior horn on allodynia in rat models of migraine.Methods Fifty-four male SD rats were randomly divided into 9 groups (each group n =6) blank group,sham surgery group,new inflammatory soup 3 d group (IS 3 d group),new inflammatory soup 7 d group(IS 7 d group),saline group,fluorocitrate (FCA)prevention group,FCA prevention control group,FCA treatment group,FCA treatment control group.Following the IS stimulation in the rat dual matter,Von-Frey hair was used to monitor the pain threshold of periorbital skin.Immunofluorescence technique was used to observe the expression of specific marker of astrocyte,glial fibrilary acidic protein (GFAP),and neuron activation marker,C-fos.Results ①Von-Frey hair study showed the thresholds of IS 3 d group and IS 7 d group were significantly decreased compared with the control group(3 d5.3 ±0.3 vs 6.4 ±0.3,F =40.15;7 d3.0 ±0.3 vs 6.3 ±0.2,F =382.5,both P ＜0.01).The pain thresholds of FCA prevention group and FCA treatment group both began to significantly increase at the day 4 (FCA prevention5.5 ± 5.1 vs 5.1 ± 0.2,F =16.00 ;FCA treatment4.3 ± 0.2 vs 3.0 ± 0.2,F =138.0,both P ＜ 0.01).②GFAP immunofluorescence showed that the mean optical density (A) values of IS 3 d group and IS 7 d group were significantly increased compared with the control group(3 d24.5 ±4.4 vs 14.8 ± 2.5,F =32.54;7 d38.9 ± 7.1 vs 14.6 ± 1.8,F =63.56,both P ＜ 0.01).()C-fosimmunofluorescence showed that mean A value of IS 3 d group was significantly increased compared with the control group (20.4 ± 2.3 vs 8.4 ± 1.1,F =129.0,P ＜ 0.01).The difference was not significant between the IS 7 d group and the control group.Conclusions Activated astrocytes contribute to the facial allodynia induced by chronic dural inflammation.Its inhibitor FCA could both prevent and treat the allodynia behaviour.All of these suggest that astrocytes may not only contribute to the initiation of mechanical allodynia but also the maintenance.