Updated project metadata. The islet amyloid polypeptide (IAPP), a pancreas-produced peptide, has beneficial functions in its monomeric form. However, IAPP aggregates, related to type 2 diabetes mellitus (T2DM), are toxic not only for the pancreas, but also for the brain. In the latter, IAPP is often found in vessels, where it is highly toxic for pericytes, cells that have contractile properties and regulate capillary blood flow. The aim of this study is to assess whether IAPP oligomers alter the morphology and contractility of pericytes using an in vitro brain vasculature model and evaluate the association between IAPP and capillary contraction in human brain tissue.