Figure 5.

Antisense knockdown of Arc/Arg3.1 protein in the LA impairs memory consolidation of auditory fear conditioning. a, Schematic of the behavioral protocol. Rats were infused (1 μl/side) with one of two doses of scrambled ODN (200 pmol, n = 7 or 2 nmol, n = 6), or one of two doses of Arc/Arg3.1 antisense ODN (200 pmol, n = 8 or 2 nmol, n = 7) 6 h before fear conditioning consisting of 1 tone-shock pairing. b, Postshock freezing scores in each group immediately after the conditioning trial. c, Auditory fear memory assessed at 3 h after fear conditioning in each group. The black bars represent the scrambled ODN-infused groups, whereas the gray bars represent the antisense-infused groups. d, Auditory fear memory assessed at 24 h after fear conditioning in each group. *p < 0.05 relative to the scrambled ODN-infused groups. Also depicted are the memory retest scores for rats in the 2 nmol of Arc/Arg3.1 antisense group that were reconditioned drug-free ∼1 week later. e, Data depicting LTM as a percentage of STM for each rat in each group. *p < 0.05 relative to the scrambled ODN-infused groups. f, Histological verification of cannula placements for rats infused with 200 pmol of scrambled ODN (black circles), 200 pmol of Arc/Arg3.1 antisense ODN (white circles), 2 nmol of scrambled ODN (black squares) or 2 nmol of Arc/Arg3.1 antisense ODN (white squares). Panels were adapted from Paxinos and Watson (1997).