Extended Data Fig. 3: CA1- or amygdala-specific reduction of p-eIF2α facilitates consolidation of contextual fear memory.

a, Representative illustration of target area for p-eIF2α reduction in the dorsal hippocampus. Two independent experiments showed similar results. b, Immunohistochemistry for eGFP reporter demonstrates that deletion of WT Eif2a fTg is restricted to the CA1 region of the hippocampus. Two independent experiments showed similar results. c, d, Eif2a^A/AfTg⁺ mice were injected with AAV9.Camk2a0.4.Cre.SV40 (AAV9-Camk2a-Cre) or control AAV9.Camk2a0.4.eGFP.WPRE.rBG (AAV9-Camk2a-eGFP) targeting the CA1. Contextual memory was significantly enhanced in AAV9-Camk2a-Cre-injected mice as compared to AAV9-Camk2a-eGFP-injected mice tested 24 h (F _{1, 30} = 5.19; n = 7, 10) and 15 days (t _13.19 = 2.72; n = 10, 9) after training. e, Auditory fear memory remains unaffected (F _{1, 28} = 0.18; n = 8, 8). f, There was no difference in the time spent in the outer and inner zone in an open field test (F _{1, 36} = 3.63 × 10⁻⁹; n = 10, 10). Heat-map represents the group-average of path travelled in an open field arena, red = more time, blue = less time. g, Representative immunohistochemistry images demonstrating the amygdala-specific injections of the virus. Scale bars: 500 μm. Two independent experiments showed similar results. h, i, Contextual memory was significantly enhanced in Eif2a^A/AfTg⁺ mice injected with a virus expressing AAV9-Camk2a-Cre in the amygdala tested 24 h (F _{1, 32} = 11.92; n = 9, 9) and 15 days (t _12.2 = 3.42; n = 10, 9) after training. j, Auditory fear memory is also enhanced (F _{1, 32} = 12.01; n = 9, 9). k, There was no difference in the time spent in the outer versus inner zone in an open field test (F _{1, 36} = 8.3 × 10⁻⁹; n = 10, 10). Heat-map represents the group-average of path travelled in an open field arena. l, Experimental scheme in acute hippocampal slices: Schaffer collateral fibres were stimulated in two independent pathways with extracellular electrodes and fEPSPs were recorded in CA1 stratum radiatum. m, A single high-frequency train (1 × HFS for 1 s) elicited early LTP in slices from AAV9.Camk2a0.4.eGFP.WPRE.rBG (Camk2a-eGFP)-injected mice (E-LTP 30 min post-HFS, F _{1, 7} = 8.2; n = 8, 8). n, o, L-LTP induced by four tetanic trains at 100 Hz is similar in slices from Camk2a-eGFP- and Camk2a-Cre-injected mice (o; F _{1, 7} = 0.071; n = 7, 8). p, Paired-pulse facilitation (PPF) is defined as the ratio of the amplitude of the 2nd versus the 1st fEPSPs responses over increasing time intervals. The decay rates of PPF did not differ between Camk2a-eGFP- and Camk2a-Cre-injected mice, indicating intact short-term plasticity (F _{1, 48} = 0.041; n_mice = 8, 6, points represent group means). q, Diagram of experimental arrangement for recording intrinsic and firing properties in CA1 excitatory neurons. r, Resting membrane potential was significantly increased in Camk2a-Cre-injected mice (t _16.59 = 2.28; n = 8, 12). s, Input resistance is not affected in CAMK2α-eGFP and CAMK2α-Cre positive neurons (t _14.63 = 0.72; n = 8, 10). t, The number of action potential in response to incremental somatic depolarization (F/I gain relationship) is not different between CAMK2α-eGFP⁺ and CAMK2α-Cre⁺ excitatory neurons (t ₁₃ = 0.56; n = 8, 9). u, Examples of traces obtained in response to 100 pA current injection in CAMK2α-eGFP⁺ or the CAMK2α-Cre⁺ excitatory neurons. Data are presented as mean ± s.e.m. in c–f, h–k, m–p, r–t. p-values by two-way ANOVA in c, h, j, followed by Sidak’s multiple comparisons post hoc test; two-tailed unpaired t-test with Welch’s correction in d, i, r; two-way ANOVA (repeated measurements) in m followed by Sidak’s multiple comparisons post hoc test are indicated. Points represent individual mice unless stated otherwise.

Source data