Defined neuronal cell types in the lateral entorhinal cortex supporting object and space coding
Final Report Abstract
The hippocampal formation is one of the most studied brain areas as it supports spatial coding and spatial memory, and is amongst the first to be affected in Alzheimer’s Disease accounting for cognitive deficits. The hippocampus proper receives input from the medial and lateral entorhinal cortex and is thought to associate object-place-context information. Based on anatomical information, however, it stands to reason that associations might occur already in the regions upstream of the hippocampus, i.e. in the medial and lateral entorhinal cortex (MEC and LEC) that are heavily connected bi-directionally. In vivo electrophysiological studies in freely moving rodents have provided ample evidence that the MEC comprises a plethora of spatially tuned cells, whilst the LEC harbours object cells. Thus, in a simplified fashion the MEC and LEC were thought to provide “where” and “what” information, respectively, to the hippocampus. However, there is increasing evidence that there may not be such a clear division of tasks. The goal of this grant was to perform studies in the LEC as this brain region has remained understudied. Indeed, we found that the LEC comprises object cells and spatially tuned cells, as well as a small population of cells that are both object- and spatially-tuned. We also studied fastspiking GABAergic interneurons that in most brain circuits are thought to provide input gain control. Whilst we do not contest this view, we propose that also this cell population may have yet other functions. These latter findings are of relevance much beyond this study and constituted the basis for a new grant in which we analyse what fast-spiking interneurons code for when animals are tested in a more complex environment.
Publications
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Distinct spatial maps and multiple object codes in the lateral entorhinal cortex. Neuron, 111(19), 3068-3083.e7.
Huang, Xu; Schlesiger, Magdalene Isabell; Barriuso-Ortega, Isabel; Leibold, Christian; MacLaren, Duncan Archibald Allan; Bieber, Nina & Monyer, Hannah
