Fig. 3

Upregulation of H1R, H2R, and H3R expression in primary cultured astrocytes by histamine. Primary astrocytes were stimulated with histamine at 0.1 μg/ml for 24 h. a–c Immunofluorescence analysis of GFAP and histamine receptor expression. The cells were stained for the astrocyte marker GFAP (red) and for H1R, H2R, and H3R (green). Upregulated GFAP and HR expression on activated astrocytes was observed using confocal microscopy. The blue staining represents DAPI. Scale bar = 25 μm. d The expression levels of the histamine H1, H2, and H3 receptor subtypes were detected via Western blotting using specific antibodies. Each blot is representative of three experiments. e The expression levels of the histamine H1, H2, and H3 receptor subtypes were examined by quantitative RT-PCR. *p < 0.05, **p < 0.01 versus the control group. The data are presented as the mean ± s.e.m. of three independent experiments