FIGURE 1.

Glutamate induces reversible oxidative DNA damage in cerebral cortical neurons. A and B, cortical cultures were exposed to 20 μm glutamate for 10 min, then, after 6 or 24 h the cells were harvested and comet assays were performed in the presence of no enzyme, FPG, or T4 endonuclease. Panel A shows representative images of nuclear DNA. First row of panel A is the control group, without glutamate treatment, pre-treated with FPG or T4 endo. The second and third rows of panel A are 6 and 24 h after glutamate treatment, respectively. Panel B shows the results of quantitative measurements of DNA damage (Olive Tail Moment). C, cellular ATP levels at the indicated time points after a 10-min exposure to 20 μm glutamate; values for glutamate-treated neurons were normalized to the value for untreated control cultures. Values for treated cultures are expressed as a percentage of the value for untreated control cultures (100%) (mean ± S.D.; *, p < 0.05; **, p < 0.01; ***, p < 0.001).