Figure 6.

Minocycline abrogated IgG-based neuroprotection from excitotoxic injury. A, Injury from NMDA: minocycline (mino) pretreatment (gray) significantly removed the neuroprotective effect of 2.0 and 20 μg/ml IgG (p < 0.002; α = 1.00) and had no impact from control on the severity of excitotoxic injury from NMDA when used alone. For comparison, respective injury levels without minocycline (white) from Figure 1 are shown. [Respective relative injury levels over the full dose range were (n = 23/group) 1.12 ± 0.10, 1.10 ± 0.10, 1.1.01 ± 0.06, 1.02 ± 0.06, 1.00 ± 0.06 and 1.01 ± 0.10 versus control (1.00 ± 0.03; n = 13)]. B, Injury from OGD: minocycline (mino) pretreatment (gray) had no impact on injury severity from OGD and significantly removed the neuroprotective effects otherwise seen from 0.2, 2.0, and 20 μg/ml IgG (p < 0.001; α = 1.00). [Respective relative injury levels over the full dose range were (n = 15/group) 1.05 ± 0.04, 1.03 ± 0.04, 1.04 ± 0.07, 1.08 ± 0.07, 0.98 ± 0.06 and 1.09 ± 0.04 vs control (1.00 ± 0.03; n = 12/group)]. Data represent mean ± SEM and significance (*p < 0.05).