Figure 5.

Potential arrangements of self-motion and environmental inputs to grid cells and place cells.

The neural representations of self-location expressed by place and grid cells reflect both environmental and self-motion information. Grid cell activity (as well as head direction cell activity, not shown) is strongly influenced by self-motion cues which are proposed to originate from conjunctive shifter cells or velocity controlled oscillators. Place cells are strongly influenced by environmental information, including that relating to environmental boundaries (boundary vector cells), and to local cues (potentially from lateral entorhinal cortex) as well as non-spatial ‘contextual’ inputs that may ‘gate’ spatial inputs [14]. Regions containing grid cells and place cells are reciprocally connected, which may allow both representations to reflect an optimal combination of self-motion and environmental information [72]. Alternatively, self-motion and environmental information may respectively reach place cells and grid cells directly (dashed lines).