A model of predictive learning in the rat hippocampal principal cells during spatial activity

We propose a model of predictive learning in the rat hippocampus which is based on the synaptic potentiation of hippocampal pyramidal cells during temporally asymmetric pairing of EPSPs and backpropagating action potentials. The proposal is that potentiation of the synapses that mossy fibre projections of the dentate gyrus make with pyramidal cells in the CA3 region of the hippocampus causes a gradual shift backward in time of the postsynaptic activity of the CA3 cells, the firing of which initially corresponded to the rat being in a particular location. Thus these "place cells" now fire before the rat reaches this location, causing an apparent backward shift in space of the place field of the cell. The model offers both an explanation of this phenomenon which has been observed experimentally, and a possible basis for further understanding of the role of the hippocampus.