Model of the hippocampal formation explains the coexistence of grid cells and place cells

TL;DR

This paper presents a computational model of the hippocampal formation that explains the coexistence of grid and place cells as a natural outcome of an internal dynamical model supporting spatial navigation and memory formation.

Contribution

It introduces a novel theoretical framework based on information theory that accounts for the simultaneous emergence of grid and place cell activities in the hippocampal-entorhinal circuit.

Findings

Explains grid and place cell activity as a computational by-product.

Shows how spatial representations emerge from circuit transformations.

Links spatial navigation to episodic memory formation.

Abstract

In this paper we explain the strikingly regular activity of the 'grid' cells in rodent dorsal medial entorhinal cortex (dMEC) and the spatially localized activity of the hippocampal place cells in CA3 and CA1 by assuming that the hippocampal region is constructed to support an internal dynamical model of the sensory information. The functioning of the different areas of the hippocampal-entorhinal loop and their interaction are derived from a set of information theoretical principles. We demonstrate through simple transformations of the stimulus representations that the double form of space representation (i.e. place field and regular grid tiling) can be seen as a computational 'by-product' of the circuit. In contrast to other theoretical or computational models we can also explain how place and grid activity may emerge at the respective areas simultaneously. In accord with recent views, our results point toward a close relation between the formation of episodic memory and spatial navigation.