Rat cortical neurons (11 DIV) were challenged with either 60 μM H₂O₂ or 50 μM glutamate for 24 h in the absence or presence of ABS-75 (1 μM) or MK801 (1 μM). Glutamate- and H₂O₂-induced injuries were assessed by (A) MAP-2 staining and (B) LDH activity. The results showed reduced neuronal damage in fullerene ABS-75– and MK801-treated cultures. P < 0.01, control versus ABS-75 and MK801, and ABS-75 versus MK801. P < 0.01, control versus ABS-75, and control versus MK801 (H₂O₂-induced injury). ANOVA followed by post-hoc test, mean ± SD. (C) Fullerene ABS-75 and MK801 effects on memory function were assessed on a plus maze apparatus. On the first day (acquisition trial), animals were placed at the edge of an open arm and the latency to the first entry in the central area was recorded. On the second day (retention trial), all animals were returned to the arena and the latency to the first transfer onto the central area was recorded. Drugs were administered i.p. 30 min before the retention trial. All animals moved to the central area in the acquisition trial. In the retention trial, only animals treated with 0.15 mg/kg MK801 had similar results to those of vehicle mice in the acquisition trial. Animals treated with PBS, 2% DMSO, or ABS-75 arrived at the central area faster in the retention trial than in the acquisition trial, indicating that, unlike MK801, fullerene ABS-75 does not impair memory function. P < 0.05, Kruskal-Wallis test followed by Dunn’s multiple comparisons test. n = 10 animals per group. Median (line through each box) ± SD (error bars) are shown. Original magnification, ×130.