Astrogenesis in the murine dentate gyrus is a life-long and dynamic process (2022)
Figure 5

Figure 5: Dynamics of adult astrogenesis under antineurogenic conditions.

A Experimental scheme of adult and aging BrdU birth-dating paradigm used in B-D. 8 week-, 14 month-, and 21 month-old hGFAPeGFP animals were administered with BrdU via drinking water for 12 days, generated (BrdU+) cells were analysed at day 12.

B Representative confocal images of BrdU-incorporating cells (magenta) assigned to distinct cell types of 8 week-, 14 month-, and 21 month-old hGFAPeGFP mice: rNSCs [identified by their SOX2+ (green) cell bodies residing in the SGZ with a GFAP+ radial process (cyan)]; IPCs/neuroblasts [SOX2+ (green) nuclei located to the SGZ, DCX+ cells (white) in the SGZ and GZ, respectively], and astrocytes [SOX2+ cells (green) in the hilus, GZ, and ML].

C Quantification of total numbers of generated cell types (BrdU+; rNSCs, IPCs + neuroblasts, astrocytes) per area in the DGs of 8 week-, 14 month-, and 21 month-old hGFAPeGFP animals. rNSCs: *** p = 0.00076, ** p = 0.0014; IPCs/neuroblasts **** p < 0.0001; astrocytes: *** p = 0.0008; * p = 0.0403; one-way ANOVA with Tukey's post hoc test.

D Quantification of the percentages of generated cell types out of all generated cells (rNSCs, IPCs + neuroblasts, astrocytes) in the DG of 8 week-, 14 month-, and 21 month-old animals. rNSCs: not significant; IPCs/neuroblasts **** p < 0.0001, *** p = 0.0001; astrocytes: ** p < 0.0019, **** p < 0.0001; one-way ANOVA with Tukey's post hoc test.

E Representative images of proliferating cells (MCM2+; magenta): rNSCs [SOX2+ cell nuclei (cyan) residing in the SGZ with a NESTIN+ radial process (white)]; IPCs [SOX2+ nuclei (cyan) located to the SGZ], and astrocytes [SOX2+ cells (cyan) in the hilus, GZ, and ML; arrowheads].

F Quantification of total numbers of proliferating (MCM2+) cell types per area in the DGs of 8 week-, 14 month-, and 21 month-old animals. rNSCs: not significant; IPCs **** p < 0.0001; astrocytes: * p = 0.0216; * p = 0.0266; one-way ANOVA with Tukey's post hoc test.

G Confocal images of 8 week- and 14 month-old NestinCreERT2; GFP animals, which received tamoxifen for five days (10 times, every 12 h) and were killed 12 days after the last tamoxifen shot. The majority of recombined cells were rNSCs [SOX2+ cell nuclei (cyan) residing in the SGZ with a NESTIN+ radial process (white)] and IPCs/neuroblasts [SOX2+ (cyan) nuclei located to the SGZ, DCX+ cells (magenta) in the SGZ and GZ, respectively], and only very few astrocytes [SOX2+ cells (cyan) in the hilus, GZ, and ML] were generated by initially recombined rNSCs.

H Quantification of total numbers of recombined (GFP+) rNSCs, IPCs/neuroblasts, astrocytes per area in the DGs of 8 week- and 14 month-old animals. rNSCs: * p = 0.0460; IPCs/neuroblasts: **** < 0.0001; astrocytes: not significant; unpaired t-test.

Data information: All data are represented as mean ± SEM; number of experimental animals (indicated by red dots): (C,D) n = 5 in 8 week-old mice, n = 6 in 14 month-old mice, n = 5 in 21 month-old mice; (F) n = 4 in 8 week-old mice, n = 6 in 14 month- and 21 month-old mice; (H) n = 3 in 8 week-old mice, n = 5 in 14 month-old mice; values are indicated in Table EV3; dotted lines border SGZ and GZ; scale bars = 50 µm.