Figure 2.

Characteristics of conditioned hyperactivity in WT mice. WT mice (n=10 per group) were sensitized to AMPH, as previously described, in order to produce conditioned hyperactivity (observed following saline injection). In order to demonstrate the context dependency of the condition hyperactivity mice were tested in the paired test chamber or a home cage-like environment as shown in (a). AMPH-sensitized mice are hyperactive (as compared with saline pre-exposed) only in the paired test chamber (^**p<0.01, Bonferroni). In order to test that the decline in conditioned hyperactivity was extinction, mice were re-exposed to the paired test chamber in a second extinction session 10 days after the first test as shown in (b). AMPH-sensitized mice display similar conditioned hyperactivity in both tests (^***p<0.001, Bonferroni). Results are presented as means±SEM.