Whether speed and head direction signals provide invariant self-motion signals across environments or change their coding in response to metric changes to the environment

Munn, Robert GK, Caitlin S. Mallory, Kiah Hardcastle, Dane M. Chetkovich, and Lisa M. Giocomo. Entorhinal velocity signals reflect environmental geometry. Nat Neurosci (2020) doi:10.1038/s41593-019-0562-5

Abstract
“The entorhinal cortex contains neurons that represent self-location, including grid cells that fire in periodic locations and velocity signals that encode running speed and head direction. Although the size and shape of the environment influence 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 speed cells rescale after changes to the size and shape of the environment. Moreover, head direction cells reorganize in an experience-dependent manner to align with the axis of environmental change. A knockout mouse model allows dissociation of the coordination between cell types, with grid and speed cells, but not head direction cells, responding in concert to environmental change. These results point to malleability in the coding features of multiple entorhinal cell types and have implications for which cell types contribute to the velocity signal used by computational models of grid cells.”

Munn, Robert GK, Caitlin S. Mallory, Kiah Hardcastle, Dane M. Chetkovich, and Lisa M. Giocomo. Entorhinal velocity signals reflect environmental geometry. Nat Neurosci (2020) doi:10.1038/s41593-019-0562-5