a, CaN CpG island analyzed and primer location. CaN is hypermethylated in CS animals at 1d and 7d (no retrieval test; 1h: F_{(3, 18)} = 0.27, 1d: F_{(3, 19)} = 5.73, 7d: F_{(3, 25)} = 33.52). * post hoc P ≤ 0.05. CaN’s hypermethylation is significantly greater at 1 and 7d (F_{(2, 20)} = 13.96, # P ≤ 0.01). See Supplementary Table 1 for N’s. b, Amplicon analyzed by BSP (transcription start site – TSS) at 7d. Charts depict number of alleles with 0, 1, 2 or 3 methylated CpGs in the amplicon. c, Single allele cytosine methylation for the 59 CpGs located in the amplicon at 7d (N = 4 per group). Error bars indicate s.e.m.

a, Intra-ACC infusions of 5-aza (N’s = 14, 13; F_{(1, 26)} = 11.48), zeb (N’s = 7, 7; F_{(1, 13)} = 21.07) or RG108 (N’s = 10, 10; F_{(1, 19)} = 5.17) 30d after training disrupted remote fear memory. * P ≤ 0.05. b, DNMTi interfered with CS-induced CaN methylation (N’s = 6, 6; F_(1,11) = 8.96) and normalized CaN transcript levels (t₈ = 8.34, * P ≤ 0.001). c, Intra-ACC infusions of DNMTi 1d after training had no effect on fear memory (N’s = 7, 8; F_(1,14) = 0.81, P > 0.05). Same animals also expressed normal fear memory 30 days later (F_(1,12) = 0.26, P > 0.05). Experiment was repeated in absence of a test at 2d to confirm lack of damage to ACC. Again, infusions had no effect on fear memory (N’s = 7, 8; F_(1,14) = 0.81, P > 0.05). Error bars indicate s.e.m.

a, 30d after training, CaN is still hypermethylated (F_{(3, 19)} = 4.77).* P ≤ 0.05. b, CaN transcript is decreased in CS at 30d (t₅ = −8.36, * P ≤ 0.001; F_{(2, 15)} = 12.72). c, 2h after retrieval test, CaN protein levels are decreased in CS as well (F_{(3, 30)} = 24.31, * P ≤ 0.001; # P ≤ 0.05). See Supplementary Table 2 for N’s.