Dissociating the roles of dorsal and ventral CA1 for the temporal processing of spatial locations, visual objects, and odors

The differential contributions of the dorsal and ventral hippocampus for learning and memory have long been of interest. The present experiments were designed to evaluate the contributions of dorsal CA1 and ventral CA1 for temporal processing. Animals were run on three temporal ordering paradigms: one with visual objects, one with olfactory stimuli, and one with spatial locations. Animals with lesions to dorsal CA1 showed deficits for the temporal ordering of visual objects relative to control animals, and deficits for the temporal ordering of spatial locations relative to control and ventral CA1 lesioned animals. Animals with lesions to ventral CA1 showed deficits for the temporal ordering of olfactory information relative to control and dorsal CA1 lesioned animals, and a mild deficit for the temporal ordering of visual objects relative to control animals, but not as severe as those shown by the dorsal CA1 lesioned animals. These data suggest that dorsal CA1 and ventral CA2 contribute to temporal ordering processes, and that dorsal CA1 and ventral CA1 are dissociable for temporal ordering based upon the nature of the information that is processed.