Robert G K Munn, Caitlin S Mallory, Kiah Hardcastle, Dane M Chetkovich, Lisa M Giocomo. Entorhinal velocity signals reflect environmental geometry. bioRxiv 671222; doi: https://doi.org/10.1101/671222

Summary
The entorhinal cortex contains neural signals for representing self-location, including grid cells that fire in periodic locations and velocity signals that encode an animal’s speed and head direction. Recent work revealed that the size and shape of the environment influences grid patterns. Whether entorhinal velocity signals are equally influenced or provide a universal metric for self-motion across environments remains unknown. Here, we report that changes to the size and shape of the environment result in re-scaling in entorhinal speed codes. Moreover, head direction cells re-organize in an experience-dependent manner to align with the axis of environmental change. A knockout mouse model allows a dissociation of the coordination between cell types, with grid and speed, but not head direction, cells responding in concert to environmental change. These results align with predictions of grid cell attractor models and point to inherent flexibility in the coding features of multiple functionally-defined entorhinal cell types.

Robert G K Munn, Caitlin S Mallory, Kiah Hardcastle, Dane M Chetkovich, Lisa M Giocomo. Entorhinal velocity signals reflect environmental geometry. bioRxiv 671222; doi: https://doi.org/10.1101/671222