Fig. 4.

Expression of GABAergic markers in GCs born in the adult rat. A1) Confocal images at 7 dpi showing a GFP⁺ granule cell expressing GAD₆₇ (arrow) and A2) a granule cell that does not express GAD₆₇ (arrowhead). A ${\text{GAD}}_{67}^{+}$ interneuron can be observed beside the GFP⁺ granule cell. B and C) Images depicting newborn GCs at 10 and 15 dpi, respectively, which express (arrows) and do not express ${\text{GAD}}_{67}^{+}$ (arrowheads). D) At 30 dpi, no GFP⁺ granule cell expressed ${\text{GAD}}_{67}^{+}$. E) Three-dimensional reconstructions through the Z-axis of GFP⁺ cells (fifty optical slices at 0.5 μm intervals) were used to verify the co-localization of GFP, GAD₆₇ and Prox1. DAPI, blue; GAD₆₇ Red; Overlay with Prox1, in light blue, and orthogonal projections are shown on the right panel. F) Confocal images depicting the coexistence of GAD₆₇ and GABA in a GFP⁺ granule cell at 10 dpi. G) At 30 dpi, no GFP⁺ granule cell expressed GABA. Calibrations in the rightmost panels apply for all panels in the corresponding row. ML, molecular layer; GCL, granule cell layer; H, hilus. H) Mean number of GFP⁺ GCs per rat (black bars) and number of GFP⁺ GCs expressing GAD₆₇/GABA at the different postinjection times (n=5/bar). I) Electrophysiological recordings of a developing GFP⁺ granule cell at 14 dpi and of an adult granule cell.