The dentate gyrus is part of the hippocampal formation involved in neurogenesis and the formation of new episodic memories when we explore new environments. The dentate gyrus rests in the medial temporal lobe. It is made up of three layers: molecular (cell-free, dendrites of granule cells), granular (granule cells), and polymorphic (mossy cells). The dentate pyramidal basket cells are found between the granular and polymorphic layers. Inputs to the dentate gyrus including the entorhinal cortex, pre/parasubiculum, brainstem, septal nuclei, and hypothalamus. Neurons in the dentate gyrus project to the CA3 field of the hippocampus.