BRGs were selected based on (i) the highest absolute Braak label correlation (|r|), (ii) highest absolute FC between R1 and R6 (|FCR1–R6|), and (iii) smallest BH-corrected P-values of the FC (PFC). The top 10% (2001) ranked genes for each one of the three criteria resulted in genes with |r| > 0.66, |FCR1–R6| > 1.33, and PFC < 0.00304 (Fig. 2a). The overlap of the three sets of top 10% ranked genes resulted in 960 BRGs, with 348 negatively and 612 positively correlated genes showing a decreasing (r < 0) or increasing (r > 0) expression pattern across regions R1–R6, respectively (Fig. 2b, c, Supplementary Fig. 3, and Supplementary Data 1). Negatively correlated BRGs were significantly enriched for gene ontology (GO) terms like anatomical structure morphogenesis and blood vessel morphogenesis (Supplementary Data 2), while positively correlated BRGs were significantly enriched for functions like anterograde trans-synaptic signaling and nervous system development (BH-corrected P < 0.05, DAVID; Supplementary Data 3).
