Figure 5.

Conditional knockout of VGAT in the HDB reduces the survival of adult-born neurons in GCL and GL. (A) Schematic showing injection of Cre-mVenus or mVenus control virus into the HDB of Vgat^f/f mice. The timeline shows the experimental design with viral injection into HDB of Vgat^f/f mice followed 2 weeks later by I. P. injections of EdU and 6 weeks later by quantification of EdU incorporation into OB and Ki67 expression in the subventricular zone (SVZ). (B) Dual-color fluorescent in situ hybridization (FISH) confirms that VGAT is knocked out in Cre-expressing cells after viral injection of Cre into the HDB of Vgat^f/f mice (top) whereas Vgat is expressed in cells infected with the control mVenus virus injected into the HDB of Vgat^f/f mice (bottom). (C) Quantification of Vgat+ cell density in the HDB of cre-injected (magenta) and control-injected (black) Vgat^f/f mice. N = 9 mice, 18 sections. Nested t-test, ***p < 0.001. (D) Coronal section from a Vgat^f/f mouse HDB injected with Cre-mVenus (green) and stained for Ki67 (magenta) to label proliferating progenitor cells in the SVZ. The inset shows Ki67+ cells in the SVZ. (E) Quantification of Ki67+ cells in the SVZ of Vgat^f/f mice HDB-injected with Cre-mVenus or mVenus control viruses (black). Points represent values from individual mice. N = 23 mice, 37 sections. Nested t-test. (F) OB sections from Vgat^f/f mice injected into the HDB with Cre-mVenus showing EdU incorporation (magenta). White arrows mark EdU+ cells in the GCL. Yellow arrows mark EdU+ cells in the GL. ONL: olfactory nerve layer. (G) Same as (F), but in Vgat^f/f mice injected with mVenus virus (control). (H) Quantification of EdU+ cell density in GCL of 40 μm OB sections from Vgat^f/f mice HDB-injected with Cre (magenta) or mVenus (black; I). Same as (H) but quantified in the GL. Points represent values from individual mice. N = 21 total mice, 69 sections. Error bars are SE. Nested t-test, *p < 0.05.