Suppression of microglia activation after hypoxia–ischemia results in age-dependent improvements in neurologic injury

We previously found increased microglial proliferation and pro-inflammatory cytokine release in infant mice compared to juvenile mice after hypoxia–ischemia (HI). The aim of the current study was to assess for differences in the effect of microglial suppression on HI-induced brain injury in infant and juvenile mice. HI was induced in neonatal (P9) and juvenile (P30) mice and minocycline or vehicle was administered at 2h and 24h post-HI. P9 minocycline-treated mice demonstrated early but transient improvements in neurologic injury, while P30 minocycline-treated mice demonstrated sustained improvements in cerebral atrophy and Morris Water Maze performance at 60days post-HI.