Figure 5.

Amphetamine exposure in adolescence, but not in adulthood, leads to augmented salience attribution and requires dcc in dopamine neurons. Salience attribution was quantified by calculating the total locomotor activity across a 15-min test of conditioned locomotor activity (mean±SEM). (a) Mice exposed to amphetamine (AMPH) during adolescence (from PND 22±1 to PND 31±1) display augmented salience attribution when re-exposed to the previously drug-paired chamber in adulthood (PND 75±15), in comparison with their saline controls (n=5 per group; * indicates p=0.006). (b) Mice exposed to AMPH (n=7) or saline (n=9) during adulthood (from PND 75±15 to PND 845±1) show no differences in salience attribution when re-exposed to a previously drug-paired chamber approximately 6 weeks (∼PND 120±15) after treatment termination. (c) dcc^lox/loxDAT^Cre mice (n=8 per group) exposed to AMPH or saline during adolescence (from PND 22±1 to PND 31±1) show no differences in salience attribution when re-exposed to a previously drug-paired chamber in adulthood (PND 75±15).