Fig. 1.

Distribution of grid field parameters and generation of grid cell activity. (A) Data from Hafting et al., 2005 (left and middle) and Stensola et al., 2012 (right) were used to constrain the grid field properties. (B) The grid field properties were normalized along the dorso-ventral axis of the medial entorhinal cortex using a generalized logisitic function such that the grid field properties were represented approximately equally. (C) The gradient of grid field parameters in the medial entorhinal cortex (left) and the mapping between medial entorhinal cortex and dentate gyrus (center) determine where the grid field information is communicated to within the dentate gyrus. The final distribution of grid field parameters results in a gradient in the dentate gyrus (right). (D) An example grid field is shown with notation describing the field area, distance, and orientation properties. (E) Left: The movement of a virtual rat in white is overlaid on a grid field with a triangle and circle denoting the start and end points of the movement, respectively. Right: The firing rate (red) is determined using a grid field and the movement of the rat through the field. A non-homogeneous Poisson process is used to generate spiking activity (black) using the firing rate.