Cohort	Young Age	Old Age	Other Ages Used	Figures
Cohort 1	3 months	20 months	–	Figure 1A (Y‐maze)
Cohort 2	2 months	22 months	–	Figure 1A (Y‐maze), 1B (Barnes maze)
Cohort 3	3 months	20 months	–	Figure 1C,D (Y‐maze)
Cohort 4	6.5 months	22.5 months	–	Figure 1E,F (Grip strength)
Cohort 5	3 months	24 months	6, 12, 18 months	Figure 2A,B (DCX)
Cohort 6	2 months	24 months	–	Figure 2C,D (Ki67), Supplementary Figure 1B,1C (BrdU)
Cohort 7	3 months	24 months	12, 18 months	Figure 2E,F (Synapses); Figure 3 (Microglia); Figure 4D–G (GFAP); Figure 5 (T cells); Supplementary Figure 1A, 1D–F (Gene expression); Supplementary Figure 2 (Microglia/Inflammation); Supplementary Figure 3 (Gene expression)
Cohort 8	3 months	22.5 months	–	Figure 4A–C (GFAP), 4H–J (Western blots)
Cohort 9	4 months	22 months	–	Figure 6 (LPS)