Benjamin Goddard

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The aim of the present experiment was to investigate the effects of cocaine primes and exposure to foot shock stress on reinstatement of operant responding maintained by a cocaine-conditioned stimulus in rats never trained to actively self-administer cocaine. Following a baseline session of responding for a light-buzzer compound stimulus, rats underwent(More)
Methadone maintenance at appropriate doses can effectively reduce cocaine abuse in heroin-dependent individuals. In the present studies, we investigated the effect of high-dose methadone maintenance cocaine conditioned place preference (CPP) and cocaine intravenous self-administration. Rats implanted with methadone-filled osmotic mini-pumps (20 and 55(More)
To elucidate the effects of steady-state methadone exposure on responding to cocaine conditioned stimuli and on cocaine-induced alterations in central opioid, hypocretin/orexin, and D2 receptor systems, male Sprague-Dawley rats received intravenous infusions of 1 mg/kg/inf cocaine paired with an audiovisual stimulus over three days of conditioning. Then,(More)
The aim of this study was to explore the psychopharmacological characteristics of opioid-induced conditioned reinforcement using oxycodone, a potent mu-opioid receptor agonist with known abuse potential. In differed groups of rats, passive intravenous infusions of oxycodone (100 infusions/3 h×6 sessions in total; 0, 0.01, 0.05 and 0.1 mg/kg/inf) were paired(More)
Although it is well established that drug conditioned stimuli produce a variety of conditioned responses, it is not known whether such stimuli can also reinforce an arbitrary operant response and thus serve as conditioned reinforcers. Volunteers (n = 39) recruited from a residential treatment center for substance dependence were tested on a task in which(More)
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