Figure 5.

Inhibition of hippocampal protein synthesis blocks reversal learning and hinders reinstatement of the original spatial memory. Animals with infusion cannulae implanted in the CA1 region of the dorsal hippocampus were trained during 5 d in the spatial version of the MWM, and 24 h after the last training session were submitted to eight consecutive reversal learning trials. (A) Mean escape latency (±SEM) to find the escape platform during reversal training. Immediately following the last reversal trial, animals received intra-CA1 infusions of anisomycin (160 μg/side; ANI) or vehicle; the black arrow indicates the moment of infusion. Memory retention was evaluated in a probe test carried out either at 2, 24, or 120 h after reversal learning. (B) Spatial preference during a 60-sec probe test for rats given intra-CA1 anisomycin (160 μg/side; ANI) or vehicle (VEH) immediately after reversal learning. Data are expressed as mean (±SEM) percentage of time swimming in the original (ORI) and opposite/reversal (REV) quadrant. **P < 0.01 and *P < 0.05 vs. VEH; n = 11–19 per group.