Extended Data Fig. 10: Coordination of remapping with behavior across hippocampal subpopulations.
From: A flexible hippocampal population code for experience relative to reward
a) Mean speed post-reward-switch on each trial across backward (left; n = 24 sessions) and forward (right; n = 22 sessions) reward switches included for calculating reward-relative population remapping in Fig. 8. Note abrupt deceleration on the first post-switch trial for forward switches. Speed is normalized to the max of each session. b) Same as (a) but for mean licking on each trial. Lick rate is normalized to the max of each session. c) Trial-by-trial correlation matrix of the spatially binned licking behavior (left) and running speed (right) from example animal m18, day 12, switch 6. Reward zone switch occurs at trial 30. d) Left column: Trial-by-trial correlation matrix of the spatially binned population vector (PV) activity of each neuronal subpopulation from the same example mouse and day shown in (c). Color scale applies to all rows. Middle column: Distance score for PV activity (gray) and licking (light purple) with sigmoidal fit (PV: black, licking: dark purple). Dots indicate the inflection point or “remap trial”, also listed in square brackets. Right column: Same as middle but comparing the distance score for PV (gray, repeated from middle) to speed (green). e) PV remap trials for non-RR remapping cells compared to the remap trials of licking and speed. A linear mixed effects model (LMM) was fit to the remap trials as described in Fig. 8, with mice as random effects. In (e–g), p-values are from two-sided coefficient t-tests, with Benjamini-Hochberg correction for multiple comparisons. LMM fixed effects: lick – PV: β = 1.667, p = 0.30; speed – PV: β = 4.190, p = 0.0012; forward switch direction compared to backward, PV: β = −1.089, p = 0.52; forward switch direction x [lick – PV]: β = −0.621, p = 0.70; forward switch direction x [speed – PV]: β = −4.372, p = 0.020; switch day: β = 0.112, p = 0.63. f) Same as (e) but for appearing cells (limited to sessions in which 2 clusters could be identified in the PV activity). LMM fixed effects: lick – PV: β = −9.308, p = 6e-6; speed – PV: β = −7.462, p = 2.7e-4; forward switch direction compared to backward, PV: β = −3.222, p = 0.33; forward switch direction x [lick – PV]: β = 1.197, p = 0.69; forward switch direction x [speed – PV]: β = −1.538, p = 0.69; switch day: β = 0.218, p = 0.69. g) PV remap trial distributions for each subpopulation, pooled across backward and forward switches. Mean ± SD remap trial: RR = 31.91 ± 2.37; non-RR: 32.86 ± 3.91; appear: 43.0 ± 7.22. Boxes, interquartile range; whiskers, 2.5th to 97.5th percentile; horizontal lines, median; notches, median confidence interval from 10,000 bootstraps. Note smallest variance of RR cells. An LMM with fixed effects of subpopulation (compared to RR), switch direction, the interaction of switch direction and subpopulation, and switch day, with mice as random effects, shows significant effects only of subpopulation for appearing cells: non-RR – RR: β = 0.819, p = 0.57; appear – RR: β = 10.888, p = 2.2e-14; forward switch direction compared to backward: β = −1.40, p = 0.43; forward switch direction x [non-RR – RR]: β = 0.087, p = 0.96; forward switch direction x [appear – RR]: β = −2.752, p = 0.43; switch day: β = 0.174, p = 0.56.
