Dexmedetomidine (DEX) polarises microglial responses. Gene expression profile of inflammatory cytokines and mediators in the cell lysate of cultured BV2 microglia. (a) Pro-inflammatory cytokines were upregulated after lipopolysaccharide (LPS) treatment for 1 h. DEX significantly reduced expression, whilst yohimbine (Yoh) reversed the suppression of interleukin (IL)-6 (*P<0.05, **P<0.01, ****P<0.0001; one-way analysis of variance (anova) with Tukey's test; n=6 wells in each group). (b) Expression of M2 response-associated genes (IL-4, arginase-1, and CD206) were assessed. Whilst all were decreased after LPS treatment for 1 h, the level of IL-4, arginase-1, or CD206 was significantly enhanced by DEX. Yoh inhibited the DEX effect on all (*P<0.05, **P<0.01, ***P<0.001, ****P<0.0001; one-way anova with Tukey's test; n=6 wells in each group). Veh, vehicle; GAPDH, glyceraldehyde-3 phosphate dehydrogenase; TNF-α, tumour necrosis factor-α.