Fig. (6) MCP-1 concentration in the CSF: At 1 Week, MCP-1 concentration was comparable between NP-treated (n = 3) and sham animals (n = 6). By week 4, NP-treated animals (n = 5) tended to have higher levels of MCP-1 relative to sham (n = 4); however, this difference was non-significant (p = 0.355). Data are presented as mean ± standard error.