From Grid Cells to Place Cells: A Radial Basis Function Network Model

Grid cells in dorsocaudal region of medial entorhinal cortex, introduced by Hafting et al. recently in 2005, show an activity pattern correlated with animal's position. These cells increase firing frequency at multiple regions in the environment, arranged in regular triangular grids. Each cell has some properties including spacing, orientation, and phase shift of the nodes of its grid. Grid cells are known to be the principal cortical inputs to place cells of the hippocampus, previously defined to play an important role in memory for places. In this article we have proposed an artificial neural network model based on radial basis function, which allows for the single confined place fields of hippocampal pyramidal cells to be emerged from the activities of grid cells. Place fields could be formed considering a modest number of grid cells (for example, 25) with diverse orientation and spacing which is consistent with physiological experiments.