Histological analysis of regional LPS induced changes of cell number, micro- and astroglial activation. A, cell number detection by Hoechst 33342 staining and detection of microglial (ED1), neuronal (NeuN), and astroglial (GFAP) immunoreactivity in the cortex, 24 h after intraperitoneal application of LPS (LPS) or vehicle (Con). Results are given as percentage of immunopositive area. The inset shows a 100× magnification of ED1 positive microglial cells located along a cerebral blood vessel. (mean ± SEM; n = 5 animals/group; Student's t test; *p ≤ 0.05, **p ≤ 0.01). B, Quantitative analysis of Hoechst 33342 staining, ED1, NeuN, and GFAP immunostaining in the cortex (Cx), cerebellum (Cb), thalamus (THL), and hippocampus (HC).