Contribution of the Retrosplenial Cortex to Path Integration and Spatial Codes

In the proposed model, we suppose the retrosplenial cortex (RSC) conveys path integration (PI) information to the hippocampal system. Our model shows the potential of the PI field in reproducing diverse neuronal activities involved in the spatial representation of animals. We explain the absence of places cells in the RSC because of the difficulty of neurons to access the whole PI field. The simulated activity with only local connections fits with the recorded activities in the RSC. Moreover, we emphasize the importance of the entorhinal cortex (EC) as a hub to merge the different afferent cortical activities in order to build an efficient hash code for complex pattern recognition and novelty detection at the level of the hippocampus. The grid cells could be a by-product of this compression mechanism in the EC.