text: Our finding that about 40% of the MDglutamate signal is related to oxidative stress (as indicated by the factor of dependency and the assumption that 8-iso-PGF2a is a specific marker for oxidative stress) is intriguing, and may reflect another potentially important link between oxidative stress and excitotoxicity via the microglial antiporter system Xc 2 (Sato et al., 2002), releasing cytotoxic levels of glutamate into the interstitial compartment to replenish intracellular cystine to maintain the glutathione system when challenged by oxidative stress (Qin et al.