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A local measure of symmetry and orientation for individual spikes of grid cells

Fig 8

Quantifying temporal disruptions of grid patterns.

a) Generated spike locations with 2000 spikes (left). Each spike k is color-coded with its grid score . The first 1000 spikes are drawn from a spatially uniform distribution (top right) and the last 1000 spikes are drawn from a perfect grid (bottom right), at a constant rate of 1 spike per second. b) scores in a as a function of spike time. Note that the score of many spikes is 0. c) The scores from b, filtered with a 100 second time window (dotted lines indicate window size). d) Two experimentally recorded spike maps, color coded with scores. The recordings are 52 minutes in total and contain 13 trials in light (with an illuminated cue card) and 13 trials in darkness, each of 2 minutes duration. e) The scores as a function of time, filtered with a 1 minute window. From top to bottom: First cell from d; second cell from d; mean over both cells. Shadings indicate light trials. Pearson’s correlation coefficients, r, between lighting condition and filtered grid scores are shown for each scenario. f) Spike maps for cell 1 and cell 2, separated into spikes fired during light trials and spikes fired during dark trials. g) Temporal evolution of grid scores after changes in lighting condition. Each 2 minute trial was separated into 12 × 10 second blocks. Each point shows the mean score of all spikes in a time block in light trials (light blue) and dark trials (dark blue), averaged over 73 grid cells. Grid scores are calculated in reference to all spikes during light trials (see text for details). Experimental data recorded and made publicly available by Pérez-Escobar et al. [21].

doi: https://doi.org/10.1371/journal.pcbi.1006804.g008