A role for hilar cells in pattern separation in the dentate gyrus: A computational approach
- 27 October 2008
- journal article
- research article
- Published by Wiley in Hippocampus
- Vol. 19 (4), 321-337
- https://doi.org/10.1002/hipo.20516
Abstract
We present a simple computational model of the dentate gyrus to evaluate the hypothesis that pattern separation, defined as the ability to transform a set of similar input patterns into a less‐similar set of output patterns, is dynamically regulated by hilar neurons. Prior models of the dentate gyrus have generally fallen into two categories: simplified models that have focused on a single granule cell layer and its ability to perform pattern separation, and large‐scale and biophysically realistic models of dentate gyrus, which include hilar cells, but which have not specifically addressed pattern separation. The present model begins to bridge this gap. The model includes two of the major subtypes of hilar cells: excitatory hilar mossy cells and inhibitory hilar interneurons that receive input from and project to the perforant path terminal zone (HIPP cells). In the model, mossy cells and HIPP cells provide a mechanism for dynamic regulation of pattern separation, allowing the system to upregulate and downregulate pattern separation in response to environmental and task demands. Specifically, pattern separation in the model can be strongly decreased by decreasing mossy cell function and/or by increasing HIPP cell function; pattern separation can be increased by the opposite manipulations. We propose that hilar cells may similarly mediate dynamic regulation of pattern separation in the dentate gyrus in vivo, not only because of their connectivity within the dentate gyrus, but also because of their modulation by brainstem inputs and by the axons that “backproject” from area CA3 pyramidal cells.This publication has 93 references indexed in Scilit:
- The CA3 “backprojection” to the dentate gyrusProgress in Brain Research, 2007
- Extrinsic afferent systems to the dentate gyrusProgress in brain research, 2007
- The dentate gyrus: fundamental neuroanatomical organization (dentate gyrus for dummies)Progress in Brain Research, 2007
- Interneurons of the dentate gyrus: an overview of cell types, terminal fields and neurochemical identityPublished by Elsevier BV ,2007
- A computational theory of hippocampal function, and empirical tests of the theoryProgress in Neurobiology, 2006
- Dissociating hippocampal subregions: A double dissociation between dentate gyrus and CA1Hippocampus, 2001
- Hippocampal conjunctive encoding, storage, and recall: Avoiding a trade‐offHippocampus, 1994
- Computational analysis of the role of the hippocampus in memoryHippocampus, 1994
- Computational constraints suggest the need for two distinct input systems to the hippocampal CA3 networkHippocampus, 1992
- Hippocampal synaptic enhancement and information storage within a distributed memory systemTrends in Neurosciences, 1987