Fig. 3From: The potential neuroprotective role of a histone deacetylase inhibitor, sodium butyrate, after neonatal hypoxia-ischemiaSodium butyrate promotes the polarization of microglia from M1- to M2-like phenotype after neonatal hypoxia-ischemia. Seven-day-old rats (PND7) were subjected to hypoxia-ischemia followed by 6 days of recovery. SB or vehicle was administered directly after the onset of HI and for 5 consecutive days. Sections from ipsilateral hemispheres were stained for ED1 immunoreactivity (red), for arginase-1 (Arg-1), marker specific for M2 phenotype (green), and for IL-1β, marker for M1 phenotype (green). Nuclei were labeled with the Hoechst dye (blue). Six days after HI, the majority of ED1-positive cells expressed IL-1β, with only a few cells co-stained with ED1/Arg-1. The administration of SB after HI led to a marked decrease in the amount of cells presenting the M1 (ED1/IL-1β positive) phenotype of microglia with concomitant enhancement of cells stained with ED1/Arg-1 specific for M2 type. a Photomicrographs are representative of observations made from 5 animals per experimental group. Scale bar 100 μm. b Graphs show the percent of the ED1(+)/Arg-1(+) and ED1(+)/IL-1β (+) cells versus total pool of ED1-positive cells quantified in the frontal cortex (1.44 mm2 area). The values represent means ± SD of five animals per each experimental group. Student’s t test indicates significant differences in the number of ED1(+)/Arg-1(+) and ED1(+)/IL-1β (+) cells between the investigated groups: ***p < 0.001. IPSI ipsilateralBack to article page