Brain adaptation to hypoxia and hyperoxia in mice

Scheme summarizing the observations in this study. In normoxia (21%O2), protective mechanisms are balanced with oxidative stress, with little or no damage to brain as evident for low apoptosis of neurons. In hypoxia (10%O2), the factors associated with increased oxidative stress grow to an extent larger than those that elicit protection, thereby inferring brain damage. In hyperoxia (30%O2), the amount of pro-oxidant factors is low, but anti-oxidant factors are also low. Consequently the balance is shifted towards pro-oxidant, thereby inferring damage.166