Abstract:  Studies conducted on neurodegenerative diseases diversely report on changes in the cerebral microvasculature: Fundamental hallmarks of prevalent neurodegenerative diseases, such as Alzheimer’s disease (AD), dementia with Lewy bodies, Parkinson’s disease, Huntington’s disease, include region-specific neuronal loss and neuroinflammation eventually leading to brain atrophy. Numerous studies have also demonstrated that neurodegeneration and changes in the microvasculature are interconnected. For example, in AD, changes in vessel density have been reported to vary — increasing, remaining unchanged, or decreasing — in brain regions most affected by neurodegeneration. In human cases of Parkinson’s disease, reports have also been contradictory — some suggesting an increase and others suggesting a decrease in vascular density in substantia nigra pars compacta. In mouse models of AD, the vessel density in forebrain areas with neurodegeneration was reported to follow a characteristic pattern with increased density during the early stages of neurodegeneration, which later transformed into stages with lower densities (Thomsen et al., 2025). Considering the very limited effects of amyloid-removal strategies on cognitive decline (van Dyck et al., 2023), interest in the role of vascular pathology in AD pathogenesis is on the rise. Furthermore, relationships between vascular pathology and neurodegeneration are of major interest for conditions of vascular etiology such as cerebral small vessel disease and stroke, as well as the high co-occurrence of the vascular pathology and neurodegenerative diseases.