Spacial Map Example (Figure 8)

Spacial Map Example

Assuming grid cells may be part of a generalized, path-integration-based map of the spatial environment, such as a map anchored to external landmarks (perhaps as in figs. 3a, d, and g), but persists in their absence (perhaps as in figs. 3b, e and h), then the ability to find one’s way depends on neural algorithms that integrate information about place, distance and direction (perhaps as in figs. 6a and b), but if the implementation of these operations in cortical microcircuits is poorly understood, then so too may any number of associated depictions and in order to provide an accurate reflection of the matter at hand, then perhaps (as in figs. 5a, 7 or 8 shown below) a directionally oriented, topographically organized neural map of the spatial environment contained by the dorsocaudal medial entorhinal cortex (dMEC) may prove beneficial.

“The ability to find one’s way depends on neural algorithms that integrate information about place, distance and direction, but the implementation of these operations in cortical microcircuits is poorly understood. Here we show that the dorsocaudal medial entorhinal cortex (dMEC) contains a directionally oriented, topographically organized neural map of the spatial environment. Its key unit is the `grid cell’, which is activated whenever the animal’s position coincides with any vertex of a regular grid of equilateral triangles spanning the surface of the environment. Grids of neighbouring cells share a common orientation and spacing, but their vertex locations (their phases) differ. The spacing and size of individual fields increase from dorsal to ventral dMEC. The map is anchored to external landmarks, but persists in their absence, suggesting that grid cells may be part of a generalized, path-integration-based map of the spatial environment.”
http://adsabs.harvard.edu/abs/2005Natur.436..801H
(Figure 8)