Extended Data Fig. 2: Preprocessing of imaging data and ALM preparatory activity.
From: A combinatorial neural code for long-term motor memory
a. Mean two-photon fluorescence images from the same field of view (FOV) across 3 imaging sessions (Day 1, 17, and 60). b. Left, cranial windows from two example mice. Each black box indicates one imaging FOV (600 × 600 µm). Right, all imaging FOVs (n = 50 from 8 mice). Imaging FOVs cover ALM, defined as the area where photoinhibition during the delay epoch impairs behavior performance (dotted red line41) and exhibiting enriched choice selectivity (gray71). c. Spatial footprints of individual neurons from the same FOV across 3 imaging sessions, which are the output of Suite2p (Methods). d. Identified co-registered neurons (green) across 3 imaging sessions, which are computed by CellReg (Methods). e. The number of neurons from the expert-early session (n = 1,690 ± 758, mean ± SD), expert-late session (n = 1,704 ± 777), and matched neurons in both expert-early and expert-late sessions (n = 855 ± 402). 12.80 ± 8.90 (mean ± SD) days between imaging sessions. Data from Fig. 2. f. Fraction of match neurons across individual mice. Dots, individual FOVs. Error bars, mean ± SD. g. Distribution of centroid distance (left) and spatial footprint correlation (right) from nearest neighboring neuronal pairs (green) and other neighboring neuronal pairs within 10 µm (red). Centroid distance and spatial footprint correlation are parameters used to define co-registered neurons across imaging sessions used by CellReg package. Data from the same FOV in a, c, d. h. Density map between centroid distance and spatial footprint correlation from all co-registered neurons (n = 42,739 from 8 mice). Data from Fig. 2. i. Distribution of registration score from all co-registered neurons (n = 42,739 from 8 mice). j. dF/F0 activity (left), deconvolved activity (middle), and heatmap of single trial deconvolved activity (right) from two example neurons. Thick lines represent the mean; thin lines represent single trials. k. Single trial deconvolved activity (top) and peristimulus time histograms (PSTH, bottom) for correct and error trials are shown for three example ALM neurons. Trial types are based on instructed lick direction (blue, lick right; red, lick left). Correct trials, solid lines. Error trials, dotted lines. mean ± s.e.m. l. Top, comparison of individual neuron trial-type selectivity between correct and error trials. Neurons with significant trial-type selectivity (P < 0.001, two-tailed t-test). Selectivity is the difference in deconvolved activity between instructed lick right and lick left trials during the early sample epoch (left), late delay epoch (middle), and response epoch (right). On error trials, when mice licked in the opposite direction to the instruction provided by object location (Fig. 2a), a majority of ALM neurons switched their trial type preference to predict the licking direction during the delay and response epochs, as indicated by the negative correlations (R, Pearson’s correlation). Bottom, histogram of selectivity angle between correct and error trials. A negative angle indicates neuron switching selectivity on error trials. Bin size: 2°.
