Comparison of naltrexone- and placebo-exposed offspring to cue-induced drug-seeking.

<p>Cue-induced drug seeking (cues present but no drug infusions;1 h) after an abstinence period of 6 weeks with comparison between offspring groups (placebo, naltrexone). A: Cumulative response record for cue-induce drug-seeking divided into 10 minute time bins. Data are expressed as number of active lever presses and represent mean ± SEM (two-way ANOVA, * <i>p</i><0.05, naltrexone (n = 9) versus placebo (n = 7) for each time bin). B: Total active and inactive lever presses during the drug-seeking session (represented by white bars, placebo: n = 9, naltrexone: n = 7) as compared to lever presses during 7 days of stable responding under a fixed-ratio 1 (represented by black bars, placebo: n = 12, naltrexone: n = 9). Data expressed as number of lever presses and represent mean ± SEM (one-way ANOVA: * <i>p</i><0.05, ** <i>p</i><0.01, *** <i>p</i><0.001, naltrexone versus placebo).