APP and Alzheimer disease: When we looked at the ratio of dark astrocytes over all astrocytes in direct contact with a blood vessel, this dark state presented equivalent ratios in APP-PS1 mice and C57BL/6J controls (Control 6.309 ± 3.415% of dark astrocytes vs AD 12.28 ± 4.489% of dark astrocytes, p = 0.3332).