Figure 4. Shock-evoked responses of place cells.

(A) Left column: frequency distribution of shock-responsive place cell percentages in each rat. Middle column: population-averaged Af/s rates (from all rats combined) for shock-responsive versus non shock-responsive place cells. Right column: spatial distribution of place field peak locations during the training session, prior to grid electrification; x-axis shows distance traveled between the start (left) and end (right) of the short path in the current running direction (LR or RL). (B) Heatmaps (LR and RL tuning curves combined) are plotted for shock-responsive place cells in the drug-free (top) versus scopolamine (bottom) conditions during pre- (left) and post- (right) training sessions (rows are co-sorted on peaks from the pre-training session, columns are sorted so that the rat’s running direction goes from left to right for both LR and RL tuning curves); P matrices show pre- vs. post-extinction population vector correlations for shocks given drug-free (top) or on scopolamine (bottom); line graphs show that signed p-values (y-axis, log scale) fall below .01 at center track positions where drug-free shocks induced more remapping than shocks on scopolamine. (C) Same as (B) but for shock non-responsive place cells. ****p<0.0001.