Figure 1: Hypoxia inducible factor 1 alpha (HIF-1α) immunohistochemistry in striatum 24 hours following 2-hour exposure period. Immunohistochemistry on paraffin-embedded serial coronal sections (6 μm thickness), sections/animal, animals/group. For each magnification level, images were captured with the same exposure time for both groups; representative images are shown. (a) Control group brain (20x) reveals light immunoreactivity in neuronal cytoplasm and absent immunoreactivity in neuronal nuclei. (b) Xenon group brain (20x) reveals more immunoreactivity in neuronal cytoplasm compared to (a), and immunoreactivity in neuronal nuclei is present. (c) Control group brain (40x). (d) Xenon group brain (40x) reveals strong and diffuse nuclear immunoreactivity (arrowheads) with cytoplasmatic immunoreactivity. Scale bar represents 20 μm.