Hippocampal Long Axis Differentiation in Memory and Seizure Networks

The structure-function gradient along the hippocampal long axis is recognized but poorly understood. Rodent recordings mainly sample the dorsal hippocampus (posterior), while surgical recordings in epilepsy patients typically sample from the ventral hippocampus (anterior), because of greater known involvement in seizure networks. These divergent recording practices imply that the mechanisms of rodent spatial navigation may not directly apply to human episodic memory. In general, the role of the posterior hippocampus in human memory and seizure networks is under-appreciated. We survey the basic, translational, and clinical research accounting for long-axis differentiation and outline future research directions.