This structure is the chief source of mammalian theta rhythms.  The alveus portion of it forms a superficial layer between its CA region and the fimbria, and this structure is attached to the bottom of the amygdala. Antidepressants typically target this structure's dentate gyrus, which has a very high rate of neurogenesis. Damage to it results in anterograde amnesia, as this structure is necessary for the formation of new memories and general storage of long-term memories. For 10 points, name this part of the limbic system located in the medial
This structure is the chief source of mammalian theta rhythms.  The alveus portion of it forms a superficial layer between its CA region and the fimbria, and this structure is attached to the bottom of the amygdala. Antidepressants typically target this structure's dentate gyrus, which has a very high rate of neurogenesis. Damage to it results in anterograde amnesia, as this structure is necessary for the formation of new memories and general storage of long-term memories. For 10 points, name this part of the limbic system located in the medial temporal lobe, with a Greek name meaning "seahorse".
This structure is the chief source of mammalian theta rhythms.  
 hippocampus [prompt on “limbic system” until “alveus”; then do not accept it]