Additional arteriovenous zonation characteristics of DRG endothelium. (A) Flow cytometry–based quantification of CD64⁺F4/80⁺ DRG or ScN macrophages, normalized to wet weight of tissue. n = 3 experiments pooled, three mice/exp. Student’s unpaired t test. ***P < 0.001. (B) qPCR of MACS-enriched CD31⁺ endothelial cells (ECs) from indicated organs, normalized to brain. n = 4 (brain), 5 (DRG), 2 (kidney, liver, lung). Illustration created with https://BioRender.com. (C) Expression of artery and vein signature genes across mouse DRG endothelial clusters (Avraham et al., 2020): artery (A), capillary (C), vein (V). Tukey’s multiple comparisons test. *P < 0.05, **P < 0.01, ***P < 0.001. (D) Enrichment of DRG vein or artery signature genes in BBB or peripheral endothelial cells (Munji et al., 2019). DRG artery genes are enriched in BBB, whereas DRG vein genes are enriched in peripheral endothelium. (E) Expression of DRG vein or artery signature genes in endothelial cells isolated from indicated organs (Kalucka et al., 2020). DRG artery genes are enriched in brain endothelial cells, and DRG vein genes are enriched in several peripheral endothelial types. (F) CLDN5-GFP expression in entire DRG section from Cldn5^GFP/+ mouse, visualizing cropped areas in Fig. 2 H. Scale bar, 100 μm. (G) Immunostaining of PLVAP in entire DRG section, visualizing cropped areas in Fig. 2 I. Scale bar, 100 μm. (H) Whole-mount imaging of native GFP expression in DRG from Cldn5^GFP/+ mice, confirming absence of CLDN5 expression in large veins (arrowheads) and venous capillaries. Scale bar, 200 μm. (I) CLDN5 and PLVAP immunostaining in indicated tissues. Outside of the DRG, PLVAP⁺CLDN5⁻ vessels are only present in epineurial blood vessels. ScN and SpN endoneurial vessels are PLVAP⁻CLDN5⁺. Scale bar, 100 μm. (J) Artery and vein signature gene expression in human DRG endothelial clusters (Avraham et al., 2022). Tukey’s multiple comparisons test. *P < 0.05, **P < 0.01, ***P < 0.001.