Extended Data Fig. 2. Neural activity in dMT, but not MAP-Kinase cascade or protein synthesis, is necessary for memory maintenance following reactivation.

(a) Freezing to tones during habituation (Hab.; first two blocks of day 1), conditioning (Cond.; last three blocks of day 1), test 1 (day 7), and test 2 (drug-free test; day 14) performed 7 days after dMT infusion of saline (SAL, white circles, n= 10) or muscimol (MUS, green circles, n= 14), in rats never given bar-press training. Infusion of MUS into the dMT impaired fear retrieval during test 1 (t= −4.35, P< 0.001), and also one week later during test 2 (t= −2.14, P= 0.04). (b) Freezing to tones during habituation (Hab.; first three blocks of day 1), conditioning (Cond.; last three blocks of day 1) and drug-free test (day 8) performed 24 h after dMT infusion of saline (SAL, n= 5) or muscimol (MUS, n= 7). Rats were infused in their home cage without fear reactivation. MUS infused this way had no effect on fear retrieval the following day (t= −0.88, P= 0.39). (c) Intra-dMT infusion of MAP-Kinase inhibitor U0126 (1 μg/0.5μl/side, n= 11) immediately after a two-tone test on day 7 did not alter freezing levels during a drug-free test performed the following day, compared to a vehicle control (VEH, n= 9, t= 0.37, P= 0.71). (d) Intra-dMT infusion of the protein synthesis inhibitor anisomycin (ANISO, 62.5μg/0.5μl/side, n= 7) immediately after a two-tone test on day 7 did not alter freezing levels during a drug-free test performed the following day, compared to vehicle control (VEH, n= 5, t=1.33, P=0.21). One-way ANOVA repeated measures was used on day 1. Unpaired t-test between SAL and MUS groups were used on days 7, 8, and 14. Data are shown as mean ± SEM in blocks of two trials; *P< 0.05.