Figure 3.

Inactivating one hippocampus after training (filled circles) disrupted place avoidance measured by the number of entrances (A) and the maximum time between entrances (B). Asymptotic performance was reached by day 3 (ne3→TTX), but the level of performance was worse than in Experiment 1 (open circles). Significantly worse performance according to the Newman-Keul's test is marked by a single asterisk. The posttraining inactivations caused a milder impairment compared with the inactivation given just before training in Experiment 1 (indicated by the broken horizontal lines). After training on day 5, the rats were injected with saline (ne5→SAL). The next day, performance was already improved relative to the previous day (double asterisk). The improvement was to the level of the intact asymptote and this was maintained on the next day following another posttraining saline injection. Representative performance during the last posttraining TTX (Left Inset) and the first posttraining saline (Right Inset) sessions are shown. The rat entered the shock sector for the first and last times at 54 s and 1,193 s during the posttraining TTX session, but only in the first half of the posttraining saline session (136 s to 582 s, first and last entrance times, respectively).