Fig. 1: Experimental design and early-life emergence of place cells and theta sequences after sphere-rearing.

a Experimental design: rearing in cuboid (top) or spherical (bottom) cages (left panel), and the critical features of Euclidean geometry experienced in cuboid-cages (blue lines, a1-4, top) and their curved non-Euclidean analogs during deprivation from Euclidean geometry inside spheres (red lines, a1-4, bottom). b Experimental design (Day1): Sleep and navigational run sessions on a linear track. c Animal velocity during run (p = 0.79, two-sided rank-sum test). d Examples of simultaneously-recorded place cell sequences in cuboid- (left) and sphere-reared rats (right). e Place map stability (top, p = 0.21, two-sided rank-sum test) and primary place field length (bottom, p = 0.00025, two-sided rank-sum test) during Day1Run1 across experimental groups. f Decoded (heatmaps) and real (yellow lines) single-lap Day1Run1 trajectories (left). Decoding error (right) across groups (p = 0.97, two-sided rank-sum tests) and compared to shuffles (p = 0.00098 for each group, one-sided signed-rank tests). g Theta sequences (left, examples) compared across groups (p = 0.38, two-sided t-test) and against shuffles (cuboid: p = 0.00037, sphere: p = 0.0018, paired one-sided t-tests) using the quadrant ratio method (right). Data in c, e–g are represented as mean ± SEM. N = 10 (5 rats/group; 2 directions/rat). ***p < 0.005. ns = not significant. Source data are provided as a Source Data file. Cartoons in Fig. 1/Panels a, b adapted from U. Farooq, G. Dragoi, Emergence of preconfigured and plastic time-compressed sequences in early postnatal development. Science 363, 168–173 (2019). DOI: 10.1126/science.aav0502. Reprinted with permission from AAAS.