Figure 3.

Neuronal Discrimination in CA1, but Not in the DG, Reflects Behavioral Discrimination

(A) Views of the virtual environment pairs (similar pair, F versus N; distinct pair, F versus N^∗).

(B) Representative recording sessions in the F-N (top) and F-N^∗ (bottom) environments. Blue traces represent the position of the animal along the track, and black tick marks indicate animal licks. Green rectangles indicate the correct licking choice in the F and N (N or N^∗) laps, whereas red ones indicate the incorrect choice (i.e., the animal licking in the wrong reward zone) for the F and N (N or N^∗) laps.

(C) Quantification of behavioral performance in the N (N and N^∗) environments, measured as reward rate (STAR Methods). Blue lines refer to single sessions of DG-implanted animals, orange lines refer to single sessions of CA1-implanted animals, and circles with error bars represent mean ± SEM (N, 0.28 ± 0.03; N^∗, 0.37 ± 0.04; n = 42 sessions; Wilcoxon test, t = 204, p = 0.02).

(D) PoV correlations between all pairs of positions in the two tracks FN (left) or FN^∗ (right) across all imaging recording sessions in DG-implanted animals. The left panel shows the same data as Figure 1H, left panel, but with a different color map scale.

(E) Left: paired spatial decorrelation between different environments (FN and FN^∗) in the DG (FN, 0.33 ± 0.07; FN^∗, 0.37 ± 0.06; n = 8 sessions; Wilcoxon test, t = 13, p = 0.49). Right: spatial decorrelation, quantified as the difference between spatial correlations within the same and different environments (FN and FN^∗), in the DG (FN, 0.32 ± 0.06, n = 7; FN^∗, 0.29 ± 0.04, n = 3 mice; LMM, p = 0.99). FN decorrelation in the right panel represents the same data as Figure 1J, left. Symbols with error bars represent mean ± SEM of individual animals. Gray circles represent recording sessions.

(F) Same as (D) but for CA1-implanted animals. The left panel shows the same data as Figure 1H, right panel, but with a different color map scale.

(G) Same analysis and same symbols as in (E) but for CA1-implanted animals (left: FN, 0.12 ± 0.02; FN^∗, 0.26 ± 0.02; n = 19 sessions, Wilcoxon test, t = 1, p = 2 × 10⁻⁵); right: FN, 0.03 ± 0.05, n = 7 mice; FN^∗, 0.18 ± 0.05, n = 6 mice; LMM, p = 0.0004). FN decorrelation in the right panel represents the same data as Figure 1J, right.

(H) Correlation between behavioral performance (reward rate) and spatial decorrelation in the DG (left: n = 7 mice and 70 sessions; Pearson’s r = –0.03; LMM, p = 0.75) and CA1 (right: n = 7 mice and 69 sessions; Pearson’s r = 0.43; LMM, p = 0.0002).

(I) Correlation between behavioral performance (reward rate) and decoder performance in the DG (AUC; left: n = 7 mice and 41 sessions, Pearson’s r = –0.01; LMM, p = 0.95) and in CA1 (right: n = 7 mice and 61 sessions, Pearson’s r = 0.25; LMM, p = 0.04).

ns, not statistically significant. ^∗p < 0.05, ^∗∗p < 0.01, ^∗∗∗p < 0.001. See also Figure S2.