Fig. 3: Aging fiber tracts are enriched in WAM and DAM2 signatures.

A Bar plot of activated microglia marker mRNAs Lgals3, Aif1, Trem2, Tyrobp, and Gpnmb, B complement pathway marker mRNAs C1qa, C1qb, and C1qc, and C activated astrocyte marker mRNAs Serpina3n, Gfap, Gpnmb, and Vim in fiber tracts of young, middle, and old mice. Each dot shows the average expression of the two technical replicates for each mouse relative to the mean of the young group, equivalent to n = 4 biological replicates per group. Data were summarized as mean ± standard error of the relative mean counts. p values are reported from an unpaired two-tailed t-test with Welch’s correction comparing middle vs. young and old vs. young. D Heatmap showing average expression in young, middle, and old groups of four mRNA sets (set 1–4) from ref. ¹⁸. Values in the color scale are signals normalized on a per mRNA basis. E Visualization of average expression of WAM (n = 29), DAM1 (n = 77), top DAM2 (n = 92), and SenNet (n = 17) mRNA sets in young (Y1MB, Y2FB), middle (M2MA, M1FB), and old (O2MB, O1FB) mice using SPATA (see Methods). The WAM mRNA set is from ref. ¹⁸, the DAM1 and DAM2 mRNA sets are from ref. ¹⁹, and the SenNet mRNA set is from ref. ²⁰ (Supp. Data 7). Values in the color scale are the expression scores of the mRNA sets. Source data are provided as a Source Data file.