Poster Presentation

Dopamine D2-Cx43 signal pathways in mirror image pain

Professor Bai Zhantao
Yanan University

Abstract

Dopamine, a kind of catecholamine neurotransmitter, is indispensable to pain responses. Multiple evidences demonstrated that dopamine D2 receptor (DRD2), gap junction and glia may participate in regulation of pain in different molecular and cellular pathways. However, whether promising interaction between these pain targets existed or not, remains need to be elucidated. Here, we showed that DRD2 blocker and gap junction inhibitor synergistically inhibited rat spontaneous pain behaviors, bilateral mechanical and unilateral thermal pain hypersensitivity. Live cell imaging demonstrated that the gap junctional hemi-channels of cultured astrocytes and microglia could be opened by Dopamine, and Dopamine-induced opening were reduced by DRD2 blocker. Furthermore, suppression of DRD2 significantly decreased the bilateral co-expression of Cx43 and GFAP protein in spinal cord and dorsal root ganglion. These results support the points that glia DRD2-Cx43 intracellular signaling pathways may directly mediate pain spreading from the injured side to contralateral side by asymmetric temporal differences, thus providing a novel understand to pain control and therapy by combined interference of membrane receptor-ion channels.