Regional Differences in Susceptibility to Hypoxic-Ischemic Injury in the Preterm Brain: Exploring the Spectrum from White Matter Loss to Selective Grey Matter Injury in a Rat Model

Figure 2

Astrogliosis and microgliosis in relation to severity of white matter injury in hypoxic-ischemic (HI) neonatal rats. Seventy-two hours following HI at postnatal day 6 (P6), numerous reactive astrocytes (a–d) and activated microglia (e–h) are present throughout the brains of neonatal rats with significant white matter injury. Representative photomicrographs depict GFAP-positive astrocytes and mild (a), moderate (b), and severe (c) astrogliosis following HI. Histogram in (d) displays the region-specific pattern and degree of reactive astrocytosis as a function of MBP loss. Lower panels depict CD68-positive microglia and mild (e), moderate (f), and severe (g) microgliosis following HI. Histogram in (h) shows the region-specific pattern and degree of microglial activation as a function of white matter injury severity. Magnification 40x.