Research Article
Dexmedetomidine Inhibits Voltage-Gated Sodium Channels via α2-Adrenoceptors in Trigeminal Ganglion Neurons
Figure 4
Effects of dexmedetomidine on INa via Gi/o protein-coupled α2-adrenoceptors in small-sized TG neurons. (a) Treatment with yohimbine (0.5 μM, 2 min) suppresses the inhibitory effects of dexmedetomidine on INa in small-sized TG neurons (). (b) Intracellular perfusion with GDPβ-S (2.5 mM, 8 min) blocks inhibition of INa by dexmedetomidine (). (c) Summary of inhibitory yohimbine and GDPβ-S effects on the dexmedetomidine-mediated inhibition of INa. Results are presented as mean ± SEM. n.s.: no significance. (d) Working hypothesis for the inhibition of INa by dexmedetomidine via Gi/o protein-coupled α2-adrenoceptors in small-sized TG neurons. Sensory TG neurons do not only express neuronal VGSCs and Gi/o protein-coupled α2-adrenoceptors. Stimulation of the α2-adrenoceptor by dexmedetomidine suppresses the activity of VGSCs by inhibitory GPCR pathways in dissociated small-sized TG neurons.
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