Axel Montagne, PhD, UK Dementia Research Institute, University of Edinburgh, Edinburgh, UK, discusses his work on the role of blood-brain barrier (BBB) dysfunction in cognitive impairment and neurodegenerative disease. Recent research using molecular approaches and animal model imaging has highlighted the importance of endothelial cells, pericytes, and their crosstalk, in BBB function. Pericytes begin to degenerate and detach from the vasculature with age. This process is accelerated in disease, making the BBB leaky and leading to neuronal death and cognitive decline. The complex interaction between pericytes and endothelial cells is also thought to contribute to dementia, with platelet-derived growth factor β (PDGF-β)/PDGFR-β signaling playing a key role. Compromised endothelium-pericyte crosstalk has been shown to alter cerebral blood flow, neuroinflammation, and transcytosis. Questions remain regarding the causes of pericyte dysfunction and how this leads to a destabilized endothelium. This interview took place at the ESOC 2022 congress in Lyon, France.