The effect of μ-opioid receptor activation on GABAergic neurons in the spinal dorsal horn

• 발행기관: 대한생리학회-대한약리학회
• 저자명: Yoo Rim Kim Hyun Geun Shim Chang-Eop Kim Sang Jeong Kim
• 간행물 정보: 『The Korean Journal of Physiology & Pharmacology』제22권 제4호, 419~425쪽, 전체 7쪽
• 주제분류: 의약학 > 의학일반
• 파일형태: PDF
• 발행일자: 2018.07.31

영문 초록

The superficial dorsal horn of the spinal cord plays an important role in pain transmission and opioid activity. Several studies have demonstrated that opioids modulate pain transmission, and the activation of μ-opioid receptors (MORs) by opioids contributes to analgesic effects in the spinal cord. However, the effect of the activation of MORs on GABAergic interneurons and the contribution to the analgesic effect are much less clear. In this study, using transgenic mice, which allow the identification of GABAergic interneurons, we investigated how the activation of MORs affects the excitability of GABAergic interneurons and synaptic transmission between primary nociceptive afferent and GABAergic interneurons. We found that a selective μ-opioid agonist, [D-Ala2, NMe-Phe4, Gly-ol]-enkephanlin (DAMGO), induced an outward current mediated by K+ channels in GABAergic interneurons. In addition, DAMGO reduced the amplitude of evoked excitatory postsynaptic currents (EPSCs) of GABAergic interneurons which receive monosynaptic inputs from primary nociceptive C fibers. Taken together, we found that DAMGO reduced the excitability of GABAergic interneurons and synaptic transmission between primary nociceptive C fibers and GABAergic interneurons. These results suggest one possibility that suppression of GABAergic interneurons by DMAGO may reduce the inhibition on secondary GABAergic interneurons, which increase the inhibition of the secondary GABAergic interneurons to excitatory neurons in the spinal dorsal horn. In this circumstance, the sum of excitation of the entire spinal network will control the pain transmission.

목차

INTRODUCTION

METHODS

RESULTS

DISCUSSION

ACKNOWLEDGEMENTS

CONFLICTS OF INTEREST

REFERENCES

키워드

DAMGO GABAergic interneurons Opioid Pain Substantia gelatinosa