Dr. Brian Bernier and colleagues in the Drew lab published a research paper in the Journal of Neuroscience entitled “Dentate gyrus contributes to retrieval as well as encoding: Evidence from context fear conditioning, recall, and extinction”. Despite abundant evidence that the hippocampal dentate gyrus (DG) plays a critical role in memory, it has remained unclear whether DG’s role relates to memory acquisition or retrieval. Using contextual fear conditioning and optogenetic inhibition, this research reveals that DG contributes to both of these processes. In addition, using computational simulations, specific mechanisms through which suppression of DG affects memory performance are identified. This research also reveals that the DG contributes to fear extinction learning, a process in which learned fear is attenuated through exposures to a fearful context in the absence of threat.