The mRNA expressions of M1/M2 polarization markers of microglia were measured using RT-PCR analysis in the penumbra region at 3 days after stroke induction. A. RT-PCR analysis of various M1 (IL-23, IL-12, and iNOS)/M2 (Fizz1, Ym1, and arginase-1) polarization markers of microglia. B. Summarized RT-PCR assays in HPI-201-induced TH experiments. Stroke increased M1 polarization cytokines and decreased M2 polarization cytokines, while HPI-201 significantly recovered M1/M2 polarization. * P<0.05 versus sham group; # P<0.05 versus stroke group; n=3–4 per group. C. Summarized RT-PCR assays in physical cooling (PC) induced TH experiments. While stroke increased the level of IL-23, IL-12, and iNOS, cooling significantly reduced IL-12 expression and showed trend of reducing IL-23 and iNOS in microglia cells. PC also increased the M2 marker YM-1.