Fig. 3. Expression of GIRK2 in P0 cerebella. A, C, E, G, GIRK2 immunoreactivity is seen throughout the EGL in all genotypes that were examined (posterior is down). However, immunoreactivity is much lower in wv/wvcerebella (A,E), as compared with nonwv/wv cerebella (C, G), in which there is more intense immunoreactivity in the EGL and in what are likely Purkinje cells and their axons (arrowheads). This Purkinje cell staining appears to be transitory because only a few cells in the Purkinje cell plate are immunopositive, whereas many migrating Purkinje cells (arrows) and their axons are intensely immunoreactive. There are no noticeable differences in immunoreactivity because of the NR1 null mutation (compare C with G). B, D, F, H, High magnification of anterior EGL demarcated in A, C, E, and G, demonstrating GIRK2 immunoreactivity throughout the anterior EGL (bracketed bar), which is void of cell death in the P0wv/wv cerebellum. Scale bars: A, C, E, G, 100 μm; B, D, F, H, 20 μm.