Fig. 1.

The preservation of NSPC populations is associated with GR expression and age-related changes in the amplitude of circadian CORT oscillations. a Representative example of Nestin-GFP⁺/GFAP⁺/GR⁺ NSPC with characteristic vertical process and triangular cell-body in the SGZ of the DG. a’ The boxed area in A is magnified and channels split and Z-stacked, showing the expression of individual markers. Arrowhead: cell soma. a” The dashed black line shows a transversal cell section. b Histogram of the transversal section in (a”), showing fluorescent intensity signals for DNA (blue), GFP (green), GFAP (black) and GR (red). Representative examples of c–d Type-2a/GR⁺, e–f Type-2b/GR⁺, g–h Type-1/GR⁻, i–j Type-2a/GR⁻, and k–l Type-2b/GR⁻ NSPC. In all cases cells with intensity value ≥1500 across the nucleus were considered GR⁺ (Fig. S2D). NSPC in the DG of m 3, n 6, o 10, p 14, or q 18-month-old mice. The boxed areas are shown magnified in the panels below each image. Arrows: Nestin-GFP⁺/GR⁻ Type-1 NSPC; arrowheads: Nestin-GFP⁺/GR⁺ Type-1 NSPC. Scale bars represent 40 μm (m–q”); 20 μm (a, c, e, g, i, and k); 15 μm (a’, c’, e’, g’, i’, and k’) and 10 μm (a”, c”, e”, g”, i”, and k”). r Best-fit curves and 95% confidence intervals of Type-1 GR⁺ (solid circles) GR⁻ (open circles); s Type-2a GR⁺ (solid triangles) and GR⁻ (open triangles) or (t) Type-2b GR⁺ (solid diamonds) and GR⁻ (open diamonds) cell numbers. Data points indicated by the different shapes are mean ± SEM (n = 5 mice, *p < 0.05, **p < 0.01, ***p < 0.001, one-way ANOVA) and NSPC population half-lives (t_1/2) are indicated in the figures. GR⁻ populations fitted exponential decay curves (p < 0.05, F-test, calculated t_1/2 = 1.02 (Type-1), 3.0 (Type-2a), and 0.9 months (Type-2b) NSPC, respectively). GR⁺ populations fitted linear decay curves (p < 0.05, F-test, calculated t_1/2 = 28 (Type-1), 36 (Type-2a) and 27 months (Type-2b) NSPC, respectively). Best curve fit comparisons are shown in Figure S2F-K. u Time-windows of blood collection. v AM and PM plasma [CORT] at different ages in mice. Bars are mean ± SEM and red circles individual data points (animals) (n = 5 mice, *p < 0.05, **p < 0.01, ***p < 0.001, vs. 3-month-old, one-way ANOVA). Calculated circadian CORT amplitude (black line) vs. w GR⁺ or x GR⁻ Type-1 (red lines), -2a (green lines) and -2b (blue lines) NSPC numbers at different ages in mice