Fig. 5: Maturation of memory competence is selective for the type of learning domain.
From: Early life experiences selectively mature learning and memory abilities
a, b Rats were trained (Tr1) in IA at PN17 in context A and retrained (Tr2) at PN18 in the same context (n = 8) (a) or in a different context, context B (n = 7) (b). Rats were tested 1 day later in context A (T1) and 2 h later in context B (T2). Five days later, they were again tested in context A (T3), and 2 h later in context B (T4). c Rats were trained in nOL following three schedules (n = 8 rats per schedule): (i) one training trial (Tr) at PN17; (ii) two training trials (Tr1 and Tr2) in the same context with the same object locations spaced by 1 day (nOLA + nOLA), or (iii) two training trials spaced by 1 day, but with the second trial presenting a different pair of objects in a different location (nOLA + nOLB). All rats were tested 2 h after the last training (Test). d Rats (n = 8) were trained in IA at PN17, and then trained in nOL at PN18. Rats were tested in nOL 2 h after nOL training (nOL test, T), and in IA 7 days after IA training (IA T1) then 1 day (IA T2) following the reminder shock (RS). e Rats (n = 7 per group) were trained in nOL at PN17, bilaterally injected in the dHC with BDNF immediately after training (black arrow), and tested in nOL 2 h afterward (nOL test, T). Then, the rats were trained in IA at PN18, and tested 1 day (IA T1) and 7 days later (IA T2), then again 1 day (IA T3) following the RS. *P < 0.05, **P < 0.01, ***P < 0.001 (one-way RM ANOVA followed by Tukey’s multiple comparisons test). ###P < 0.001 significance for one-sample t tests comparing each group to chance performance (50%). IA memory retention is expressed as mean latency ± s.e.m. (in seconds, s). nOL memory retention is expressed as % time spent exploring the moved object ± s.e.m. For detailed statistical information, see Supplementary Tables 8–11.
