Figure 4

Brain CD45 immunoreactivity is reduced in MCP-1^-/- mice after LPS treatment. MCP-1^-/- and MCP-1^+/+ mice were injected i.p. with LPS or saline, and brains were removed 6 hours later. Brain sections (30 μm) were stained with anti-CD45 as described in Methods. Fields of view were randomly generated using StereoInvestigator for 2–3 sections per mouse and photographed at 20× magnification using a Nikon Eclipse 80 i microscope. Arrow shows example of morphologically identified leukocytes. Immunoreactive density was measured on at least 7 pictures from both the hippocampus (A) or cortex (B) per mouse and analyzed by Image J. Values for the hippocampus (C) and cortex (D) are represented as mean ± SEM, n = 5 mice per group. ** represents significant difference between LPS-treated MCP-1^+/+ mice and LPS-treated MCP-1^-/- mice, p < 0.001; # represents significant difference between saline-treated MCP-1^+/+ mice and LPS-treated MCP-1^+/+ mice, p < 0.001; and ≠ represents significant difference between saline-treated MCP-1^-/- mice and LPS-treated MCP-1^-/- mice, p < 0.01. Scale bar = 50 μm.