Hippocampectomized rats can use a constellation of landmarks to recognize a place

The hippocampus, one of the most studied regions of the mammalian forebrain, plays some well-established roles in topographic navigation. For two decades, one widely accepted explanation for the observed impairment of hippocampectomized rats in spatial navigation has been an inability to form place representations. In this report, we present a direct experimental evidence that animals with hippocampal lesions can learn to recognize places using the constellation of distinct landmarks. The extrahippocampal implementation of all three basic constituents of topographic orientation - guidance, vector navigation, and place recognition - shows that the hippocampus, and its place cells, serve a much more specialized cognitive function than previously thought. We propose that this function includes multi-place and multi-vector topographic integration. (C) 2000 Elsevier Science B.V.