Extended Data Fig. 6.: Tracking Single-cell and population dynamics across training reveals stability of task encoding accompanies learning.
From: Neural dynamics underlying associative learning in the dorsal and ventral hippocampus
a, c. Activity during CS+ trials for neurons registered across specific session pairs. For each time bin, activity z-scores for each neuron were averaged across all trials within a session, and neurons were sorted by peak firing rate latency during the indicated session. b, d. Quantification of cells with increased responsiveness to different task epochs. Individual cells show high remapping of responsiveness to CS+ task epochs across Early and Late sessions, but increased stability from Late to Reacquisition. Proportion of cells responsive across two sessions was compared to the expected distribution of overlap based on the proportion of responsive cells in each individual session (n = 241 cells from 11 vCA1 mice and 337 cells from 4 dCA1 mice for Early vs Late and n = 253 cells from 10 vCA1 mice and 377 cells from 5 dCA1 mice for Late vs Reacquisition. Level of significance for 10,000 shufflings). e-h. Same as in a-d, but for CS- trials (n = 241 cells from 11 vCA1 mice and 337 cells from 4 dCA1 mice for Early vs Late and n = 253 cells from 10 vCA1 mice and 377 cells from 5 dCA1 mice for Late vs Reacquisition. i, j. Comparison of weights assigned to individual cells during decoding analysis; higher weight indicates greater importance for encoding2. As activity is correlated with assigned weight, we plotted weights values after regressing out the components explained by the activity. We find an increased correlation of weight values after learning (Late and Reacquisition) compared to initial training (Early/Late), supporting a stabilization of task representations accompanies learning. (n = 241 cells from 11 vCA1 mice and 337 cells from 4 dCA1 mice for Early vs Late and n = 253 cells from 10 vCA1 mice and 377 cells from 5 dCA1 mice for Late vs Reacquisition, linear least- squares regression.). k, l. Confusion matrices for across-session decoding. * p < 0.05, ** p < 0.01, *** p < 0.001. See Supplementary Table 1 for all statistical analysis details.
