Abstract
Firing fields of grid cells in medial entorhinal cortex show compression or expansion after manipulations of the location of environmental barriers. This compression or expansion could be selective for individual grid cell modules with particular properties of spatial scaling. We present a model for differences in the response of modules to barrier location that arise from different mechanisms for the influence of visual features on the computation of location that drives grid cell firing patterns. These differences could arise from differences in the position of visual features within the visual field. When location was computed from the movement of visual features on the ground plane (optic flow) in the ventral visual field, this resulted in grid cell spatial firing that was not sensitive to barrier location in modules modeled with small spacing between grid cell firing fields. In contrast, when location was computed from static visual features on walls of barriers, i.e. in the more dorsal visual field, this resulted in grid cell spatial firing that compressed or expanded based on the barrier locations in modules modeled with large spacing between grid cell firing fields. This indicates that different grid cell modules might have differential properties for computing location based on visual cues, or the spatial radius of sensitivity to visual cues might differ between modules.
Highlights
How do we navigate from one location to another and how do we represent space to accomplish this task? Researchers have collected data from the entorhinal cortex in rodents to answer these questions, finding grid cells that fire whenever a rodent traverses through an array of locations falling on the vertices of tightly packed equilateral triangles
The generation of action potentials by grid cells in the rat medial entorhinal cortex depends upon the location of the rat as it forages in an open field environment [1,2,3]
This study demonstrated that separate populations, or modules, of grid cells in medial entorhinal cortex shared orientation and spacing, and demonstrated up to five modules with different spacing [9]
Summary
The generation of action potentials by grid cells in the rat medial entorhinal cortex depends upon the location of the rat as it forages in an open field environment [1,2,3]. When an environment was altered from a square with sides of 100 cm to a rectangle with sides of 70 cm and 100 cm, the grid cell firing fields showed compression of their spacing primarily in the dimension of the compression of the barriers [8]. This did not require regular physical contact with the walls of the environment (e.g. with the whiskers), suggesting sensitivity to the visual cues of the barriers
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
