Fig. 4: Enhanced functional connectivity and CS+ predictability in the CR ensemble with an emergent hub of US-responsive neurons after fear conditioning.

a Functional connectivity in an example neuronal circuit, estimated by the CRF model. Top 50% edge potentials were visualized. b Higher functional connectivity within the CR ensemble (CRE) compared with the others (Non-CRE) during the day[D]4-early (D4E). c Higher decoding performance for CS+ in CRE compared with Non-CRE during D4E. d Enhanced functional connectivity within the CRE in an example circuit after fear conditioning (cf., a; n = 67 CRE neurons marked by red ellipses [left, spatial maps] or black dots [right, functional connectivity scores]). e Changes in functional connectivity and cellular decoding performance (for CS+ and CS−) in CRE, CRE-noRSE (CRE excluding those overlapping with RS ensemble), or Non-CRE, evaluated by calculating D4E-D3E differences (N = 7 mice, 2000 times bootstrap resampling). f, g dmPFC neuronal responses to the US on D3. Neural activities (mean over seven trials) were aligned at the US onset ordered by the magnitude of response for 1.5 sec from the US onset. As neural activity, z-normalized ΔF/F is shown. Green dotted lines, US onset; yellow bar, 1-sec US presentation. f (top) All neurons. (middle) US-responsive neurons (USR). (bottom) Mean ± s.e.m. of respective categories. g US responses of CRE or Non-CRE. h US-responsive neurons on D3 were predominantly involved in the CRE or CRE-noRSE on D4. i–k Comparison of functional connectivity scores (i–j) and CS+-decoding performances (k) between USR and others (NonUSR) at D4E (i, k), or between D3E and D4E (j), either within the CRE or Non-CRE. N = 7 mice in Fig. 4 (except for a, d). Two-tailed, paired permutation test (b, p = 0.016; c, p = 0.016), bootstrap resampling-based analysis (e: p < 0.001, < 0.001, 0.013, 0.006, 0.411 and 0.270, left to right), Fisher’s exact test (h: top, p = 0.001; bottom, p = 0.008), Wilcoxon rank-sum test (i: CRE, p = 0.020; Non-CRE, p = 0.999; k: CRE, p = 0.001; non-CRE, p = 0.350), and Wilcoxon signed-rank test (d: p < 0.0001; j: CRE, p = 0.003; Non-CRE, p = 0.554) were used. *p < 0.05; **p < 0.01; ***p < 0.001; ****p < 0.0001; n.s., not significant. Red bars, median; boxes in d, e, i–k indicate 25th–75th percentiles. See Methods and Source Data for details.