I am interested in identifying why learning becomes progressively more difficult with normal aging. With this broad goal in mind, I am studying the cellular properties of principle neurons of the hippocampus as an animal ages and after an animal has learned a task that involve the hippocampus. Thus far, we have identified that hippocampal pyramidal neurons (the principle output neurons of the hippocampus) become more excitable (that is, they are able to fire more action potentials) following successful learning.