Figure 1.

Glucocorticoid receptor agonist administration into the insular cortex enhances memory consolidation of inhibitory avoidance training. (A) Step-through latencies (mean ± SEM) in seconds on the 48 h inhibitory avoidance retention test of rats given bilateral infusions of the glucocorticoid receptor agonist RU 28362 (3 or 10 ng in 0.5 μl) into the IC immediately after training. ^*p < 0.05 as compared with the vehicle-treated group (n = 11–12 per group). (B) Step-through latencies (mean ± SEM) in seconds on the 48 h inhibitory avoidance retention test of rats given the glucocorticoid receptor agonist RU 28362 (3 or 10 ng in 0.5 μl) into the IC 3 h after training (n = 6–7 per group). (C) Location of injection needle tips within the IC of all rats included in the immediate infusions groups (black circles) and 15 rats with infusion needle tips in the somatosensory cortex as a control for site specificity (open circles). Adapted from Paxinos and Watson (2007). (D) Representative photomicrograph illustrating placement of cannulae and needle tips within the insular cortex. (E) Step-through latencies (mean ± SEM) in seconds on the 48 h inhibitory avoidance retention test of rats given bilateral infusions of the glucocorticoid receptor agonist RU 28362 (3 or 10 ng in 0.5 μl) into the somatosensory cortex, approximately 1 mm above the IC, immediately after training (n = 4–6 per group).