Project Summary The proposed study will investigate brain imaging markers of a small brainstem nucleus called the locus coeruleus, which is important for cognitive function and is the first brain region to show Alzheimer’s disease- related changes in older adults who go on develop dementia. The study will examine brain imaging locus coeruleus markers in older adults who go on to have a healthy aging experience over time and in those who go on to develop Alzheimer’s disease, cerebrovascular disease and cognitive decline. By comparing the trajectory of changes in brain imaging markers of the locus coeruleus, we can better understand the potential value of these imaging markers for tracking disease progression from a very early stage.