Can molecular mechanisms involved in neural development help us to understand, prevent and perhaps reverse the course of brain ageing and neurodegenerative disorders? Brain development and function require complex cellular and molecular processes controlled by a number of different signaling mechanisms. One such signaling mechanism, the Notch pathway, has been recognized as an important player in the regulation of cellfate decisions during early neural development. However, the action of this evolutionary conserved and widely used cell-cell interaction mechanism is not confined to the developing nervous system. In addition, recent studies have shown that elucidating the mechanism of Notch signaling and its role in the brain is important for our understanding of neurological disorders such as Alzheimer's disease and cerebral arteriopathy CADASIL.