Our long-standing interest in the mechanisms of neonatal stroke has recently become focused on the role of oxidative stress, as well as the influence of age on brain injury. My projects utilize in vivo models of hypoxia-ischemia in neonatal, and recently adult, mice of various transgenic strains. Of particular interest is the endogenous regulator of hydrogen peroxide, glutathione peroxidase (GPX). I have recently found that transgenic over-expressers of GPX have reduced brain injury after hypoxia-ischemia. Further studies on this important enzyme are underway. Another area of interest is the genetic variation in susceptibility to brain injury from hypoxia-ischemia. I have previously shown that some strains of mice are particularly resistant to injury. Microarray analysis of RNA from resistant and susceptible strains is being done to try to find the genes involved in hypoxic-ischemic injury.