Figure 3.

Postreactivation administration of clonidine does not impair short-term fear memories. (a) Schematic of the experimental design. Rats received a single systemic injection of clonidine (100 μg/kg) or its vehicle immediately after a reactivation session and were tested 4 h later for postreactivation short-term memory (PR-STM) and 1 day later for postreactivation long-term memory (PR-LTM). (b) Clonidine-treated rats (n=12) showed a similar conditioned response (freezing) to the vehicle group (n=9) when tested 4 h after reactivation, but reduced freezing behavior 1 day after injection. Bars represent mean±SEM freezing to the tone. Markers represent the mean±SEM freezing before the onset of the tone. Statistical significance: ^***p<0.001.