Cerebral microhemorrhages (CMHs) occur due to ruptures in cerebral microvessels that cause deposits of blood in the brain. Hypertension (HTN) is a major risk factor for CMHs, which have been associated with cognitive decline and ischemic strokes. Despite the clinical significance of CMHs, our understanding of CMH formation remains limited. To address this gap, our group has employed a perfusion-based vascular label with tissue clearing to enable three-dimensional visualization of CMHs with the surrounding microvasculature in HTN mice. Vessel diameters surrounding a CMH were approximately 4.22±0.81 µm. Vessel density in CMH positive tissue regions was approximately 0.083±0.017 µm-1.
Cerebral microbleeds (CMB) are deposits of blood that accumulate within the brain. An increase in CMBs is associated with an increased risk of cognitive impairment and stroke. The types of vessels associated with CMB formation remains unclear. We recently demonstrated the combined use of exogenous labels, vessel painting, and optical clearing to achieve three-dimensional views of blood vessels and CMBs. Here, we aimed to characterize brain vasculature by quantifying key vasculature-related metrics. An automated algorithm was developed to segment blood vessels within fluorescence images. An open-source neuron tracing software, neuTube, was then used to quantify blood vessel diameters.