Kir2.1 Channel Regulation of Glycinergic Transmission Selectively Contributes to Dynamic Mechanical Allodynia in a Mouse Model of Spared Nerve Injury.
10.1007/s12264-018-0285-8
- Author:
Yiqian SHI
1
;
Yangyang CHEN
1
;
Yun WANG
2
Author Information
1. Department of Neurology, Institutes of Brain Science and State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, 200032, China.
2. Department of Neurology, Institutes of Brain Science and State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, 200032, China. yunwang@fudan.edu.cn.
- Publication Type:Journal Article
- Keywords:
Dynamic allodynia;
Glycinergic transmission;
Kir2.1 channel;
ML133;
Spared nerve injury
- MeSH:
Animals;
Bicuculline;
pharmacology;
Disease Models, Animal;
Glycine;
metabolism;
Hyperalgesia;
drug therapy;
etiology;
metabolism;
Imidazoles;
pharmacology;
Inhibitory Postsynaptic Potentials;
drug effects;
physiology;
Male;
Mice, Inbred C57BL;
Neurons;
drug effects;
metabolism;
Neurotransmitter Agents;
pharmacology;
Peripheral Nerve Injuries;
drug therapy;
metabolism;
Phenanthrolines;
pharmacology;
Potassium Channels, Inwardly Rectifying;
antagonists & inhibitors;
metabolism;
Receptors, GABA-A;
metabolism;
Receptors, Glycine;
metabolism;
Strychnine;
pharmacology;
Synaptic Transmission;
drug effects;
physiology;
Tissue Culture Techniques;
Touch
- From:
Neuroscience Bulletin
2019;35(2):301-314
- CountryChina
- Language:English
-
Abstract:
Neuropathic pain is a chronic debilitating symptom characterized by spontaneous pain and mechanical allodynia. It occurs in distinct forms, including brush-evoked dynamic and filament-evoked punctate mechanical allodynia. Potassium channel 2.1 (Kir2.1), which exhibits strong inward rectification, is and regulates the activity of lamina I projection neurons. However, the relationship between Kir2.1 channels and mechanical allodynia is still unclear. In this study, we first found that pretreatment with ML133, a selective Kir2.1 inhibitor, by intrathecal administration, preferentially inhibited dynamic, but not punctate, allodynia in mice with spared nerve injury (SNI). Intrathecal injection of low doses of strychnine, a glycine receptor inhibitor, selectively induced dynamic, but not punctate allodynia, not only in naïve but also in ML133-pretreated mice. In contrast, bicuculline, a GABA receptor antagonist, induced only punctate, but not dynamic, allodynia. These results indicated the involvement of glycinergic transmission in the development of dynamic allodynia. We further found that SNI significantly suppressed the frequency, but not the amplitude, of the glycinergic spontaneous inhibitory postsynaptic currents (gly-sIPSCs) in neurons on the lamina II-III border of the spinal dorsal horn, and pretreatment with ML133 prevented the SNI-induced gly-sIPSC reduction. Furthermore, 5 days after SNI, ML133, either by intrathecal administration or acute bath perfusion, and strychnine sensitively reversed the SNI-induced dynamic, but not punctate, allodynia and the gly-sIPSC reduction in lamina IIi neurons, respectively. In conclusion, our results suggest that blockade of Kir2.1 channels in the spinal dorsal horn selectively inhibits dynamic, but not punctate, mechanical allodynia by enhancing glycinergic inhibitory transmission.
