Preserved performance in a hippocampal-dependent spatial task despite complete place cell remapping

The spatially localized firing of hippocampal place cells is thought to underlie the navigational function of the, hippocampus. Performance on a spatial task learned using a particular place cell map should therefore deteriorate if the map is disrupted. To test this prediction, we trained rats on a hippocampal-dependent spatial task in a black box and tested them in a white box. Although the change from black to white induced remapping of most place cells, navigational performance remained essentially intact. Furthermore, place cell activity was also unrelated to specific aspects of the task such as tone onset, response, or goal location. Together, these results imply that the spatial information needed to solve this navigation task is represented outside the hippocampus and suggest that the place cells encode some other aspect, such as the spatial context. (C) 2003 Wiley-Liss, Inc.