The consequences of different "lapses" on relapse to heroin seeking in rats.

Abstract

Although human studies have shown that a lapse, the first violation of abstinence, often induces resumption of drug taking, or relapse, it is not known what aspect of a lapse is critical to relapse or whether this phenomenon can be studied in other species. Rats were trained to self-administer heroin accompanied by a discrete light stimulus. After extinction, different groups experienced different "lapses." Twenty-four hours later, all groups received a test for relapse. It was found that a lapse during which heroin was self-administered, or was presented in close temporal contiguity with lever pressing, induced subsequent heroin seeking. Simple exposure to heroin, or to heroin-related stimuli, during the lapse had little effect on responding in the test for relapse.

Methadone Maintenance Reduces Heroin- and Cocaine-Induced Relapse without Affecting Stress-Induced Relapse in a Rodent Model of Poly-Drug Use

“…In the same animals, however, methadone was not effective in reducing the reinstatement of drug seeking induced by foot-shock stress. These results suggest that at sufficiently high doses, methadone maintenance has the potential to reduce both heroin and cocaine seeking, possibly by reducing the incentive value of drug-related cues, and if drugs are used, by reducing the impact of their use on subsequent drugseeking behavior (Leri and Stewart, 2002;Marlatt, 2002). For drug-seeking activated by stressful experiences, however, methadone appears to be ineffective, even at a relatively high dose.…”

“…Nevertheless, the present results suggest the interesting possibility that methadone maintenance may not reduce, and may even enhance, the direct stimulatory and/ or motivational properties of cocaine (Foltin et al, 1995;Preston et al, 1996) while, at the same time, it may reduce the priming effects of cocaine exposure on cocaine-seeking behavior, which may in turn reduce further cocaine use (Borg et al, 1999). In order to test this hypothesis, we are currently investigating the effects of methadone maintenance on the intravenous self-administration of cocaine, exploring how different doses of methadone modulate the self-administration of different doses of cocaine, and whether methadone prevents increases in drug-seeking behavior caused by 'lapses' to cocaine use (Leri and Stewart, 2002). Taken together, with our current results, it is hoped that these studies in animals will shed light on the clinical issue of whether appropriate methadone doses may reduce both opiate and cocaine abuse.…”

A qualitative and quantitative review of cocaine-induced craving: The phenomenon of priming

“…For example, the role played by contingent compared to non-contingent cocaine administration may be important (Leri & Stewart, 2002), but has not been systematically evaluated in clinical studies. A recent investigation of priming effects utilized self-administration using patient-controlled analgesia (PCA) pumps.…”

Effect of yohimbine stress on reacquisition of oxycodone seeking in rats

“…One of these processes involves relearning that drug-associated stimuli are once again predictors of drugs and their effects (Bouton 2000). In rats, it is possible to study this process of "reacquisition" of drug seeking by various reconditioning procedures (Garcin et al 1977; Thompson and Ostlund 1965;Leri and Stewart 2002). In reconditioning of conditioned place preference (CPP), for example, rats receive conditioning followed by a test of preference, a period of extinction followed by another test of preference, a single session of reconditioning where the drug is repaired with the drug-paired compartment (and vehicle is repaired with the vehicle-paired compartment), and a final test of preference (i.e., test of reacquisition) administered 24 h later (Leri and Rizos 2005).…”