Antisense knockdown of Arc/Arg3.1 protein in the LA impairs auditory fear memory reconsolidation. a, Western blot analysis of Arc/Arg3.1 protein from LA homogenates from rats given intra-LA infusion of antisense and scrambled ODNs (200 pmol; 1 μl) on opposite sides of the brain, reactivated, and killed 2 h later (n = 7). *p < 0.05 relative to the scrambled ODN-infused side. b, Schematic of the behavioral protocol. c, Postshock freezing scores in Arc/Arg3.1 ODN (n = 4) and scrambled ODN (n = 5) groups immediately after the conditioning trials. d, Freezing scores in each group during the memory reactivation trial. e, PR-STM assessed at 3 h after memory reactivation in each group. f, PR-LTM assessed 24 h after reactivation in each group. g, PR-LTM depicted as a percentage of PR-STM for each rat in each group. *p < 0.01 relative to the scrambled group. h, Histological verification of cannula placements for rats infused with Arc/Arg3.1 antisense (white circles) or scrambled (black circles) ODNs. Panels adapted from Paxinos and Watson (1998).