Multilayered imaging and stereological analysis unveils cerebellar neurodegenerative disease associated vascular remodeling

Previous studies have extensively examined the remodeling of vascular networks in cerebral neurodegenerative diseases; however, the comprehensive understanding of cerebellar vascular remodeling in the context of cerebellar neurodegenerative disease (CBND) remains limited. The present study aims to elucidate CBND - associated vascular remodeling through multilayered imaging and stereological analysis, utilizing PCKO ^Tomato Vessel ^Green mice as a valuable model. We developed PCKO ^Tomato Vessel ^Green mice, in which the dynamin - related protein 1 gene (Drp1) was selectively knocked out (KO) from Purkinje cells (PCs), which express TdTomato, while blood vessels express ZsGreen. Cerebellar tissues underwent tissue transparency treatment, imaging with Amira, and processing with Imaris. After performing boundary segmentation and classification of blood vessels, a comprehensive analysis was conducted to statistically calculate 14 parameters, including vascular radius, vascular volume, vascular chord length, vascular curved length, vascular tortuosity, vascular θ value, vascular φ value, and vascular nodes. Additionally, six parameters associated with volume fraction (VF) were also calculated. The results demonstrated that in CBND mice at the advanced stage, vascular alterations were exclusively observed in capillaries, but not in larger vessels. Specifically, more than 50% of capillaries were lost, while the main vessels remained intact. However, all vessels retained their vascular topological characteristics. The significant reductions in PC-to-vessel VF, PC-to-capillary VF, and PC-to-non-capillary VF, along with the significant increase in capillary-to-cerebellum VF, may play a central role in neurovascular remodeling in CBND. Structural remodeling of capillaries and the vascular VF could serve as diagnostic indicators for the early stages of clinical diseases. These findings could have important implications for clinical medicine.