Neuroprotective effects of insulin against H2O2-induced oxidative stress in primary hippocampal cell culture […] Results shows that 12 and 24 hour after exposure to 50, 100 and 150 uM H2O2, significant neuronal damage and cell death was evident both in morphological and MTT analysis, while 0.5 uM insulin was not effective enough to prevent these damages, when primary hippocampal neurons were pretreated with 1 M insulin, neuronal damage induced by 50 and 100 uM H2O2 was prevented while this dose of insulin was not able to prevent neuronal damage induced by 150 uM H2O2.;The present study also indicates that insulin fails to stimulate glucose oxidation and glycogen syn- thase activity in neurons. On the other hand, insulin does promote the survival and differentiation of fetal chick neurons in culture. This trophic effect was observed at low concentrations of insulin (10 ng/ml) and was dependent on the continuous presence of insulin in the medium. The number of neurons surviving in the presence of insulin was fewer than the number in serum, suggesting that only a specific population of neurons is supported by insulin;Neuronal necrosis inhibition by insulin through protein kinase C activation.