Fig. 4.

Pretraining intrahippocampal infusion ofArc antisense ODNs impairs 48 hr retention test performance, without affecting task acquisition or short-term memory.A, The experimental timeline is shown.Arc antisense 3 ODN or scrambled 3 ODN were administered bilaterally 3 hr before training in the spatial water task (1 nmol in 1 μl; n = 6–7 rats per group). The two training sessions were separated by 30 min. A 90 sec probe test was given 48 hr later. B, Acquisition data from the pretraining and training sessions are shown. No differences were seen for either the pretraining or training sessions between the antisense and scramble ODN groups (p > 0.05, repeated-measures ANOVA).C, D, The platform-crossings (C) and annulus search time (D) retention test measures are shown. Scrambled ODN-treated rats demonstrated a spatial bias for the training location, whereas the Arcantisense ODN-treated rats did not [*p < 0.005, comparing training vs opposite measures within a group (2-tailed pairedt test)].