Hypothesis: Deferoxamine pretreatment and abrupt withdrawal increases the vulnerability of neurons to hemoglobin. Model: Primary cortical cell cultures (murine); cultures were pretreated with deferoxamine alone, deferoxamine plus hemoglobin, or vehicle alone for 24 hours. After wash, cultures were then treated with hemoglobin alone, hemoglobin plus antioxidants, or hemoglobin plus deferoxamine or apoferritin. Outcome measures: Lactate dehydrogenase (LDH) release, culture nonheme iron, cell expression of ferritin, heme oxygenase-1 and glutathione peroxidase-4.