Dexmedetomidine Attenuates Dynamic Allodynia in a Mouse Model of Trigeminal Neuropathic Pain
10.13471/j.cnki.j.sun.yat-sen.univ（med.sci）.2022.0605
- VernacularTitle:右美托咪定缓解三叉神经痛小鼠动态痛觉超敏反应
- Author:
Zhi-hui QI
1
;
Jing LI
1
;
Zhong-xing WANG
1
;
Rong HU
1
Author Information
1. Department of Anesthesiology， The First Affiliated Hospital of Sun Yat-sen University， Guangzhou 510080， China
- Publication Type:Journal Article
- Keywords:
dexmedetomidine;
medial prefrontal cortex;
c-Fos;
neuropathic pain
- From:
Journal of Sun Yat-sen University(Medical Sciences)
2022;43(6):898-904
- CountryChina
- Language:Chinese
-
Abstract:
ObjectiveTo investigate the analgesic effect and mechanism of dexmedetomidine （DEX） on dynamic allodynia （DA） in mice with trigeminal neuropathic pain. MethodsWe established the model of trigeminal neuropathic pain in male mice by a chronic constriction injury （CCI） of the infraorbital branch of the trigeminal nerve （ION）. Mice were randomly separated into the following groups： Sham， CCI-ION， CCI-ION+vehicle， CCI-ION+DEX， Sham+DEX （each group contained four to six mice）. For the measurement of DA， the ipsilateral and contralateral skin of the whisker pad within the infraorbital territory （V2） or the lower jaw within the mandibular nerve territory （V3） were stimulated by light-moving brush strokes. We used immunofluorescence staining to evaluate the possible mechanisms. ResultsCompare with the sham group， light-moving brush strokes induced obvious DA in ipsilateral and contralateral skin of V2 territory and V3 territory at 3 d or 7 d after CCI-ION surgery （P=0.004 8； P<0.000 1）， and the number of c-Fos （a marker for neuronal excitability） positive cells in bilateral mPFC increased significantly （P=0.044 1 ， P=0.044 4）. In addition， 15 μg/kg and 30 μg/kg DEX separately alleviated bilateral primary and secondary DA induced by light-moving mechanical facial stimuli in mice with trigeminal neuropathic pain （P<0.000 1）， and decreased the excitability of neurons in bilateral mPFC （P=0.012 5， P=0.048 8）. Furthermore， there was no significant difference in analgesic effect between the two concentrations of DEX （P>0.05）. ConclusionsDEX is a useful therapeutic approach for attenuating DA in trigeminal neuropathic pain disorders. This effect is associated with the inhibition of hyperexcitability of neurons in mPFC induced by light-moving mechanical facial stimuli after trigeminal neuropathic pain.
