FIGURE 2.

LPS induces NPY and Y₁ receptor expression. A, confocal microscopy photomicrographs show NPY and Y₁R localization (in red) on microglial cells (green) under basal conditions (control) and after 100 ng/ml LPS challenge for 24 h (LPS). Microglial cells stimulated with LPS exhibited an activated phenotype and expressed higher levels of both NPY and Y₁R. Cell morphology was visualized with CD11b labeling (in green), and nuclear morphology is shown with Hoechst 33342 staining (in blue). Scale bar, 10 μm. B, Western blotting analysis of LPS stimulatory effect on NPY (4 kDa) and Y₁R (44 kDa). After LPS challenge, an increase in NPY and Y₁R protein levels was observed. A representative blot is shown below each graph. Data are expressed as mean ± S.E. (error bars) (n = 6 for NPY and n = 4 for Y₁R) and as a percentage of control (*, p < 0.05; using Student's t test for comparison with control).