The hippocampus

The hippocampus is one of the most thoroughly investigated structures in the brain. Ever since the 1957 report of the case study H.M., who famously lost the ability to form new, declarative memories after surgical removal of the hippocampus and nearby temporal lobe structures to treat intractable epilepsy, the hippocampus has been at the forefront of research into the neurobiological bases of memory. This research led to the discovery in the hippocampus of long-term potentiation, the pre-eminent model of the cellular basis of memory. Furthermore, the discovery of place cells, head direction cells, and grid cells in the rodent hippocampal formation established a firm foundation for the notion that the hippocampus plays a critical role in memory formation by providing the brain with a spatiotemporal framework within which the various sensory, emotional, and cognitive components of an experience are bound together. This framework allows the experience to be stored in such a way that it can be later retrieved as a conscious recollection of that experience. A Primer on the hippocampus: James Knierim first reviews the basic anatomy of the hippocampus, providing a historical overview of early conceptions of hippocampal circuitry and describing modern findings on hippocampal physiology and function.