Evaluating the differential roles of the dorsal dentate gyrus, dorsal CA3, and dorsal CA1 during a temporal ordering for spatial locations task

It has been demonstrated that the dorsal CA1 subregion of the hippocampus mediates temporal processing of information, that dorsal CA3 participates in the spatiotemporal processing of memory, and the dorsal dentate gyrus (DG) mediates spatial pattern separation. A temporal ordering of spatial locations task was developed to test the role of the dorsal DG, CA3, and CA1 for the temporal processing of spatial information with either high or low levels of spatial interference. The results indicate that animals with DG lesions showed difficulty performing the task at high levels of spatial interference, but were able to perform the task well when there was low spatial interference. Animals with lesions to CA3 did not show a preference for either spatial location presented during the study phase during the preference test, suggesting impaired spatiotemporal processing. Animals with lesions to CA1 showed a preference for a later presented spatial location over the earlier, the opposite preference to that shown by control animals. (C) 2008 Wiley-Liss, Inc.