Figure 6. GFAP promoter-positive cells generate granule cells in the perinatal period.

Double-immunostaining for reporter gene expression and cell specific markers in the GC layer of CGE; CAG-EGFP mice (EGFP, A–D) or GCE;R26R mice (βgal, E–M) analyzed at P35 after two tamoxifen injections at P5. (A–C), apotome acquired 1 µm-thick Z-plane projections of tissue sections double immunostained for the EGFP reporter (A), Hu (B) and merged images (C) in the GC layer. (D), reconstructed image of the EGFP staining obtained from a 6 µm-thick Z-stack of 1 µm-thick slices from the same view as in A–C. (E–H), 1 µm-thick Z-plane projections of sections triple immunostained for βgal (E), NeuN (F), BrdU (G) and merged images (H). Panel (I) is a 2X magnification of (H). Many reporter-positive cells are NeuN-positive (small arrows) some of which also incorporate the mitotic marker BrdU (open arrows). (J–M), 1 µm-thick Z-plane projections of sections double immunostained for βgal (J) and GAD-67 (K); DAPI nuclear staining (L) and merged images (M). The images demonstrate that βgal staining is in small cells in the IGL with 5–6-µm diameter cell body (arrows), whereas reporter expression is absent in Purkinje cells (P) and large GAD-67 positive neurons of the IGL (likely Golgi cells, arrowhead). All images are Apotome acquired 1 µm-thick Z-stack projections. Scale bars, 10 µm for (A–D) and 20 µm for (E–H); scale bar in (J) 10 µm for (J–M).