Fig. 4.

Effect of chronic delivery of AT-201 and J-113397 on extinction responding in Context B. A Timeline of Exp. 2–3. B AT-201: Number of active and inactive lever presses and number of active lever presses during the seven 6-h extinction sessions in context B. Vehicle (n = 18, 8 males, 10 females), 3.8 mg/kg/day (n = 17, 8 males, 9 females), and 12 mg/kg/day AT-201 (n = 17, 7 males, 10 females). C J-113397: Number of active and inactive lever presses and number of active lever presses during the seven 6-h extinction sessions in context B. Vehicle (n = 18, 8 males, 10 females), 12.6 mg/kg/day (n = 17, 7 males, 10 females), and 40 mg/kg/day J-113397 (n = 19, 8 males, 11 females). During the 6-h extinction sessions, active lever presses led to contingent presentations of the tone-light clue previously paired with heroin, but not heroin. All data are mean ± SEM