Females are at higher risk for certain opioid addictive behaviors, but the influence of ovarian hormones is unknown. In our rat model of heroin self-administration, females exhibited higher relapse rates that correlated with rates of heroin seeking on the first extinction session. We administered estradiol alone, or in combination with…

Stimuli conditioned with a substance can generate drug-approach behaviors due to their acquired motivational properties. According to implicit theories of addiction, these stimuli can decrease cognitive control automatically. The present study (n = 49) examined whether reward-associated stimuli can interfere with cognitive processes in the absence…

Drugs of abuse cause changes in the prefrontal cortex (PFC) and associated regions that impair inhibitory control over drug-seeking. Breaking the contingencies between drug-associated cues and the delivery of the reward during extinction learning reduces rates of relapse. Here we used vagus nerve stimulation (VNS) to induce targeted synaptic…

Conditioned stimuli (CS) can modulate reward-seeking behavior. This modulatory effect can be maladaptive and has been implicated in excessive reward seeking and relapse to drug addiction. We previously demonstrated that exposure to an appetitive CS causes an increase in the activation of extracellular signal-regulated kinase (ERK) and cyclic-AMP…

An important aspect of goal-directed action selection is differentiating between actions that are more or less likely to be reinforced. With repeated performance or psychostimulant exposure, however, actions can assume stimulus-elicited--or "habitual"--qualities that are resistant to change. We show that selective knockdown of prelimbic…