Figure 6. Arterial structure is preserved, but capillary density is progressively reduced in the white matter of TgNotch3^R169C mice.

(A) Masson’s trichrome staining showing intact pial artery (upper panels) and small artery (lower panels) of 20-month-old TgNotch3^R169C mice. (B) Labeling for smooth muscle myosin heavy chain revealing a continuous rim of smooth muscle cells in pial and small artery of 20-month-old TgNotch3^R169C mice. (C) Double labeling for Notch3^ECD (5E1, red) and collagen IV (green) of capillaries in the cortex and the corpus callosum of 12-month-old TgNotch3^R169C mice showed robust aggregation of Notch3^ECD in both capillaries. (D) Mean total capillary length (mm of CD31⁺ structures per mm²) in the cortex of 12- and 20-month-old TgNotch3^R169C mice and the corpus callosum of 6-, 12-, and 20-month-old TgNotch3^R169C mice compared with age-matched TgNotch3^WT mice showed progressive age-related reduction in capillary density in the white matter of mutant mice (n = 4–5 mice per group). Scale bars: 25 μm.