Patterns of brain injury due to hypoxia/ischemia (H/I) are age dependent: the preterm brain more vulnerable to white matter (WM) injury and the term infant more vulnerable to cortical neuronal injury and seizures. Animal models indicate that excitotoxicity due to overexpression of Ca2+ permeable AMPA receptors (AMPARs) may underlay this age-dependent regional vulnerability. Our previous studies in developing human brain suggest that Ca2+ permeable AMPARs are overexpressed on WM oligodendrocytes during the window of enhanced susceptibility to H/I (Follett et al., J Neurosci; 2004), and on cortical neurons when H/I causes cortical infarctions and seizures (Talos et al., SFN Abs; 2003). We hypothesized that AMPAR expression may regulate H/I injury patterns during earlier fetal development, specifically on critical transient cell types such as radial glia and subplate neurons. We evaluated whether Ca2+ permeable AMPARs were expressed on these cells at midgestation. Western blot analysis and immunocytochemistry...