HYDROGEN-PEROXIDE IS SELECTIVELY TOXIC TO IMMATURE MURINE NEURONS IN-VITRO

Hydrogen peroxide (H2O2) accumulates during hypoxic-ischemic brain inj ury and may mediate neurotoxicity in the immature brain. To determine whether H2O2 causes maturation specific neurotoxicity, primary neurona l cultures were exposed to H2O2 (25, 50, 100 mu M) for 5 min or 24 h d uring in vitro development, and toxicity was assessed. Immature neuron s incurred marked and dose dependent injury after both brief and prolo nged H2O2 exposures, and marked dose dependent death following prolong ed H2O2 exposures. Mature neurons incurred marked injury following pro longed but not brief H2O2 exposures, and were relatively resistant to H2O2 induced death following both brief and prolonged exposures. Thus, H2O2 is selectively toxic to immature neurons in vitro, Neuronal vuln erability to H2O2 during in vivo development is unknown and warrants i nvestigation. (C) 1997 Elsevier Science Ireland Ltd.