Fig. 7: Chemogenetic reactivation of the cellular networks activated at learning, as well as relearning, matures functional competence.

a Mice (n = 9) were trained in CFC at PN17 and tested 1 day (T1) and 7 days later (T2). ***P < 0.001 (one-way RM ANOVA followed by Tukey’s multiple comparisons test). b Densitometry of c-Fos western blot analysis obtained from dHC whole-protein extracts from mice trained in CFC at PN17 and euthanized 30 min, 24 h, or 48 h after training (naive PN17, n = 5; 30 min, n = 5; 24 h, n = 6; 48 h, n = 5; naive PN19, n = 3). To account for developmental differences, two groups of naive (N) rats were used (PN17 and PN19). **P < 0.01 versus PN17-N (one-way ANOVA followed by Dunnett’s multiple comparisons test). Actin was used as a loading control. Data are expressed as mean percentage ± s.e.m. of the PN17 naive group. c Mice (n = 5 per group) were trained in CFC at PN17 and injected with CNO 30 min before being tested 7 days after training (T1). Mice were tested again 7 days later (T2). **P < 0.01; ***P < 0.001 (two-way RM ANOVA followed by Bonferroni’s multiple comparisons test). d Mice (n = 6 per group) were trained at PN17 or remained in the home cage (control), and were tested 1 day (T1) and 7 days later (T2/Tr). At T2, mice received a single low-intensity shock (0.3 mA) in the training context (saving), and were tested 1 day later (T3). *P < 0.05; **P < 0.01; ***P < 0.001 (two-way RM ANOVA followed by Bonferroni’s multiple comparisons test). CFC memory retention is expressed as mean % freezing ± s.e.m. For detailed statistical information, see Supplementary Tables 14–17.