The extent to which the cerebrovasculature is affected in various brain disorders is still not well understood. To address this, we established a transcriptomic repository of major vascular cell types and microglia to compare the global transcriptomic response in mouse models of three human brain disorders linked to neuroinflammation and associated vascular reactivity: Alzheimer's disease (AD), traumatic brain injury (TBI), and cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). Single-cell analysis of >250,000 cells at different disease stages led to identification of two previously unknown vascular cell subtypes, expanded the endothelial zonation spectrum and allowed for a detailed analysis of the cellular and molecular responses. Surprisingly, most vascular cell types lacked major transcriptomic changes across the three conditions, while microglia exhibited significant, disease-specific transcriptional changes. Notably, microglial responses converged between late-stage TBI and AD, offering insights into the predisposition for neurodegeneration following TBI.