The topological anatomy of the hippocampus: a clue to its function.

The anatomy of the hippocampus and dentate gyrus is considered with respect to the topology of its afferents and efferents. The topological attributes of the hippocampal formation represent a four-dimensional array with the demensions being: the afferent input to laminated dendritic zones, the intrinsic tri-synaptic hippocampal system, the longitudinal and commissural association systems, and time. Within this four-dinmensional array, active foci can vary dynamically in space and time, depending upon the pattern of afferent activity. The features of hippocampal topology may relate to the role of the hippocampal formation in information storage and processing.