Fig. 4: MEC tuning to eye position.
From: Mouse entorhinal cortex encodes a diverse repertoire of self-motion signals
a VR and Neuropixels probe setup. b Histology showing Neuropixels probe placement (red) in MEC. c Top: Photograph of eye. Red, pupil positions from one session. Green, positions within the inner 98% of the distribution. H/V, horizontal/vertical eye axes. Bottom: Example eye position traces. Red ticks, landmark occurrences. d Horizontal eye position over 50 trials. Red lines, landmarks. e As in (d) but for vertical eye position. f Horizontal eye positions in one session. Boxplots: distributions in individual mice (n = 8), averaged across sessions. Box, interquartile range; vertical line, median; whiskers extend from the 1st to 99th percentiles. Mean ± sem across mice; units = % of eye width from mean position: 1st percentile = −3.50 ± 0.61, 25th percentile = −0.97 ± 0.27, median = −0.11 ± 0.032, 75th percentile = 0.83 ± 0.26, 99th percentile = 5.28 ± 0.87. g As in (f) but for vertical eye position. 1st percentile = −2.74 ± 0.64, 25th percentile = −0.35 ± 0.11, median = −0.035 ± 0.11, 75th percentile = 0.28 ± 0.11, 99th percentile = 1.60 ± 0.21. h, as in (f) but for horizonal eye velocity. Units = % of eye width from mean position/sec: 1st percentile = −6.19 ± 0.74, 25th percentile = −0.58 ± 0.091, median = −0.11 ± 0.029, 75th percentile = 0.36 ± 0.12, 99th percentile = 6.87 ± 0.66. i As in (f) but for vertical eye velocity. 1st percentile = −2.83 ± 0.55, 25th percentile = −0.29 ± 0.025, median = 0.013 ± 0.010, 75th percentile = 0.31 ± 0.031, 99th percentile = 3.15 ± 0.68. j Top: Proportion of cells jointly encoding variables. Bottom: Percentage of cells significantly encoding each variable with cell count at top. k Tuning to multiple variables (n = 2861 cells). “Other”, combinations observed in <10 cells. Few cells encoded eye position, eye velocity, or body speed alone (horizontal eye position, 0.3%, vertical eye position, 0.1%, horizontal eye velocity, 0.2%, vertical eye velocity, 0.2%, body speed 5%). 23% of MEC cells encoded body position non-conjunctively. N.S., no significant tuning.
