Some theories of memory propose that the hippocampus integrates the individual items and events of experience within a contextual or spatial framework. The hippocampus receives cortical input from two major pathways: the medial entorhinal cortex (MEC) and the lateral entorhinal cortex (LEC). During exploration in an open field, the firing fields of MEC grid cells form a periodically repeating, triangular array. In contrast, LEC neurons show little spatial selectivity, and it has been proposed that the LEC may provide non-spatial input to the hippocampus. Here, we recorded MEC and LEC neurons while rats explored an open field that contained discrete objects. LEC cells fired selectively at locations relative to the objects, whereas MEC cells were weakly influenced by the objects. These results provide the first direct demonstration of a double dissociation between LEC and MEC inputs to the hippocampus under conditions of exploration typically used to study hippocampal place cells.
Keywords: hippocampus, objects, navigation, memory, medial entorhinal cortex, grid cells
Citation: Deshmukh SS and Knierim JJ (2011) Representation of non-spatial and spatial information in the lateral entorhinal cortex. Front. Behav. Neurosci. 5:69. doi: 10.3389/fnbeh.2011.00069
Received: 22 August 2011; Accepted: 03 October 2011;
Published online: 28 October 2011.
Edited by:Donald A. Wilson, New York University School of Medicine, USA
Reviewed by:Rebecca D. Burwell, Brown University, USA
Copyright: © 2011 Deshmukh and Knierim. This is an open-access article subject to a non-exclusive license between the authors and Frontiers Media SA, which permits use, distribution and reproduction in other forums, provided the original authors and source are credited and other Frontiers conditions are complied with.
*Correspondence: James J. Knierim, Krieger Mind/Brain Institute, Johns Hopkins University, 338 Krieger Hall, 3400 North Charles Street, Baltimore, MD 21218, USA. e-mail: firstname.lastname@example.org