Fig. 4: dHPC→NAc place fields are modulated by local cues and reward zone.

a Heat maps of dHPC^- (left) and dHPC^→NAc (right) place cells’ average calcium events, ordered by place field location. White dashed lines: texture boundaries; yellow rectangle: reward zone. b Example place fields with edges near belt texture boundaries. Triangles mark start (no fill) and end (fill) points. Dashed black lines: texture boundaries. c, d Place field edges accumulate near texture boundary areas. Histograms of dHPC^- (green) and dHPC^→NAc (red) neurons’ place field start c and end d. Dotted line and shade: average and 95^th CI of 1000× randomly shuffled place fields. Both dHPC^- and dHPC^→NAc place field start and end positions are significantly overrepresented at the 99.9^th percentile (dotted black lines) compared to a randomly shuffled distribution (mean represented by horizontal black line). Start (χ²(1, 5332) = 5.136, P = 0.0234) and end positions (χ²(1, 5332) = 3.869, P = 0.0492) of dHPC^→NAc place fields are also significantly overrepresented compared to the dHPC^- population; chi-squared test, n = 6 mice, 5372 neurons. e, f Place cells are overrepresented near reward zone in high success trials. e Histograms (bars) and kernel density estimations (KDEs; lines) of place field centers for dHPC^- (left) and dHPC^→NAc (right) neurons, split into high success trials (green/red) and low success trials (gray). Reward zone (Rew.; yellow, 30 cm) and anticipation zone (Ant.; bright yellow, 30 cm) are indicated as rectangles. f Proportion of place fields in reward and anticipation zone (i.e., near reward zone) is significantly higher in high-success trials (colored bars) compared to low-success trials (gray bars) in NAc-projecting neurons (red) but not in dHPC^- neurons (green). 2-way mixed ANOVA, F_success(1,1) = 54.918, P < 0.001, F_projection(1,1) = 0.958, P = 0.338, F_interaction(1,1) = 2.969, P = 0.098. Two-tailed post-hoc Welch’s t-tests with Bonferroni correction: t_dHPC-(3.561) = 3.698, P = 0.0512; t_dHPC→NAc(3.479) = 8.671, P = 0.0036; t_{low_success}(13.629) = 0.093, P = 1; t_{high_success}(3.952) = 2.075, P = 0.215, n = 16 imaging sessions. Dashed line: even distribution of reward and anticipation zone. g A linear classifier shows significantly increased decoding accuracy of reward anticipation zone based on dHPC^→NAc neural activity compared to that of sample size-matched dHPC^- neurons. Wilcoxon’s t-test, W(9) = 5.0, n = 10 imaging sessions, P (two-tailed) = 0.020. Box-and-whisker plots in f, g show quartiles represented by the box and outlier-corrected minima and maxima by the whiskers. *P < 0.05, **P < 0.01, ***P < 0.001. Source data are provided as a Source Data file.