Fig. 8: Repeated experience with geometric linearity across four days enriches the intrinsic sleep repertoire in sphere-reared rats.

a Incidence of p/replay and track-specific-exclusive p/replay for future tracks were above chance across groups and higher in cuboid-reared rats on Day 3 (left), and above chance and similar between groups on Day 4 (right). Yellow/black stars: p-values for statistical comparison with shuffle/chance. b Experience-dependent reduction in proportion of pyramidal cell-pair correlations across sleep frames in sphere-reared rats (left, cuboid-reared vs. sphere-reared Pearson’s correlations; Day1, p = 6.5 × 10⁻¹¹; Day4, p = 0.54, two-sided rank-sum tests) and in proportion of significantly correlated neuronal ensembles across sleep frames in sphere-reared rats (right, cuboid-reared vs. sphere-reared Pearson’s correlations; Day1, p = 0.025; Day4, p = 0.14, two-sided t-tests). c Experience on linear tracks increased the number of sleep-frame clusters exclusively in the sphere-reared rats (left, representative examples from same rats across days; right: cuboid-reared vs. sphere-reared Pearson’s correlations; Day1, p = 0.0051; Day4, p = 0.37, two-sided rank-sum tests). d Significant increase in cluster specificity for multiple individual tracks from Pre-Day2Run1 sleep to Pre-Day3Runs (p = 0.019) and Pre-Day4Runs (p = 8.6 × 10⁻⁵) sleep sessions in sphere-reared but not cuboid-reared rats (p = 0.18, p = 0.14, two-sided t-tests), resulting in similar cluster specificity in sphere- vs. cuboid-reared rats on Pre-Day4Runs sleep sessions (p = 0.10, two-sided t-test). e Concerted recovery of six individual neuronal parameters (Methods) after 4 days of experience with geometric linearity in sphere-reared rats. Quantification of recovery: proportion between-group difference in parameter values on Day4 (large gray dot) along normalized arbitrary scale bounded by the corresponding values on Day1-2 in the sphere- (‘zero’; red dot) and cuboid-reared (‘one’; blue square) rats. Small gray dots: contribution of each factor to the group average (large dot). f Role of early-life geometric experience in development of the hippocampal neuronal ensemble repertoire. Colored/gray squares: frame-pair clusters. Midline: 3 separate linear tracks with place cells recruited from color-matching clusters. In a, d data are mean ± SEM. In b, c shaded regions are 95% confidence intervals. N (rats/group x 2 directions/rat per track) on Day3 and 4: Cuboid-reared (P25-26 and P26-27, respectively)=6; Sphere-reared (P26 and P27, respectively)=8 (detailed in Methods). ***p < 0.005. **p < 0.01. *p < 0.05. ns = not significant. Source data provided as Source Data file.