Connectivity of the Hippocampus

More than 100 years after the first explorations of the hippocampal region by Ramon y Cajal1 numerous detailed anatomical studies on various aspects of the region have been published. An increasingly complex picture of the intrinsic wiring has emerged over the years. During the last decade in particular, we have seen an ever-increasing number of potentially relevant connections being added to our already vast knowledge database such that by now the complexity and mere volume of the database are almost beyond comprehension. Several comprehensive reviews have been published to which the reader is referred for many of the connections not covered in this chapter or for more details on the connections described here. Recently, we published an interactive database of all known connections of principle cells in the region of the rat (Van Strien et al., 2009). All these reviews have at least two common features: they contain much valuable information, summarized such that the original publications can be recovered, and they require persistent ambition to read through them in order to obtain the relevant information one might be looking for when studying a particular experimental question.

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