GAD65/67-positive neurons expressed HIF-1α under hypoxic conditions. A) HIF-1α expression co-localized with GAD65/67-ir in neurons exposed to hypoxia when compared to normoxia (upper panel) or GAD65/67-negative neurons in hypoxia (bottom panel, open arrow). B) Quantification shows the percentage of HIF-1α-expressing GAD65/67-positive neurons after hypoxia in vitro (mean ± SD; from n = 6 cultures). C) In vivo immunostaining illustrates HIF-1α-positive (bottom panel, solid arrow) and HIF-1α-negative (bottom panel, open arrow) in GAD65/67-ir neurons in the ipsilateral region, whereas the contralateral region shows no HIF-1α staining in GAD65/67-ir neurons (see Figure 1 for region selection). Scale bars, 10 μm (A); 20 μm (B).