Effect of alpha-tocopherol and free radicals on anoxic damage in the rat hippocampal slice

The effect of alpha-tocopherol on irreversible transmission loss subsequent to anoxia was examined using the hippocampal slice preparation. A population spike was recorded from the dentate granule cell layer after stimulation of the perforant path. The amplitude of the population spike was compared before and after anoxia. Control slices recovered to 22 +/- 7% of their preanoxic amplitude after 7 min of anoxia. Slices treated with alpha-tocopherol showed significantly greater recovery after anoxia (P less than 0.001). The population spike recovered to 64 +/- 15% of its preanoxic amplitude. As alpha-tocopherol is a free radical scavenger, our results provide evidence that free radicals are partly responsible for irreversible anoxic damage. alpha-Tocopherol is not toxic and may prove efficacious in protecting the brain against anoxic damage.