The rodent hippocampus and spatial memory: from synapses to systems

Although its operations are not limited to the spatial domain, there is a near consensus that the hippocampus plays a critical role in memory for place. This review aims to explore this role, with a particular emphasis on the functions performed by distinct hippocampal subregions. The use of innovative lesioning techniques, localized pharmacological treatments, and molecular genetic interventions is offering increasingly precise brain-regional specificity and temporal control. Together with the electrophysiological recording of neuronal activity, these techniques are beginning to shed light on the functioning of specific components of the hippocampal circuitry in the different phases of memory - encoding, storage, consolidation, and retrieval. In view of these developments, we examine the involvement of the hippocampus in the encoding versus retrieval of spatial memory, before turning to the issue of long-term information storage and the role of 'cellular' and 'systems' consolidation processes in the formation of lasting memories.