Data from: During hippocampal inactivation, grid cells maintain synchrony, even when the grid pattern is lost

The grid cell network in the medial entorhinal cortex (MEC) has been
subject to thorough testing and analysis, and many theories for their
formation have been suggested. To test some of these theories, we
re-analyzed data from Bonnevie et al., 2013, in which the hippocampus was
inactivated and grid cells were recorded in the rat MEC. We investigated
whether the firing associations of grid cells depend on hippocampal
inputs. Specifically, we examined temporal and spatial correlations in the
firing times of simultaneously recorded grid cells before and during
hippocampal inactivation. Our analysis revealed evidence of network
coherence in grid cells even in the absence of hippocampal input to the
MEC, both in regular grid cells and in those that became head-direction
cells after hippocampal inactivation. This favors models, which suggest
that phase relations between grid cells in the MEC are dependent on
intrinsic connectivity within the MEC.