Although both Alzheimer's disease (AD) and normal aging contribute to age-related hippocampal dysfunction, they are likely governed by separate molecular mechanisms. In principle, gene expression profiling can offer molecular clues about underlying mechanisms, but in practice techniques like microarray present unique analytic challenges when applied to disorders of the brain. Imaging-guided microarray is an approach designed to address these analytic challenges. Here, we will first review findings applying variants of functional magnetic resonance imaging (fMRI) to AD and normal aging, establishing the spatiotemporal profiles that dissociate one from the other. Then, we will review preliminary findings applying imaging-guided microarray to AD and normal aging, in an attempt to isolate molecular profiles that dissociate the two main causes of age-related hippocampal dysfunction.