A concurrently available nondrug reinforcer prevents the acquisition or decreases the maintenance of cocaine-reinforced behavior

Abstract

Lever-pressing responses of 55 rats were reinforced with IV-delivered cocaine (0.2 mg/kg) or saline under conditions of continuous access for 15 24-h sessions. The rats also responded on tongue-operated drinking devices for deliveries of a 3% (w/v) glucose + 0.125% (w/v) saccharin (G+S) solution or water. The effects of removing these substances on behavior maintained by G+S, water, cocaine, or saline were compared in 11 groups. Terminating cocaine access produced a decrease in G+S drinking and an increase in food and water intake. In contrast, a group of rats that did not initially self-administer G+S showed increases in G+S drinking when cocaine was removed, and G+S-maintained responding persisted when cocaine was reinstated. Substitution of water for G+S produced a nearly two-fold increase in cocaine-reinforced behavior but no change in IV-delivered saline self-administration in a control group. A group that did not initially self-administer cocaine increased its infusion rate to over 400 infusions per day as soon as G+S was replaced with water. The effect of presenting cocaine to a group that responded for G+S alone was to decrease G+S intake, but there was only a transient decrease in water intake in the control group. Likewise, presentation of G+S to a group of rats self-administering cocaine resulted in a decrease in infusions, but saline infusions did not change in a control group. Generally, there was an increase in food and water intake during cocaine removal, but food and water intake did not vary systematically with the removal or presentation of G+S.(ABSTRACT TRUNCATED AT 250 WORDS)

Rapid Assessment of Choice between Cocaine and Food in Rhesus Monkeys: Effects of Environmental Manipulations and Treatment with d-Amphetamine and Flupenthixol

“…This agrees with previous findings that the presence of an alternative reinforcer can decrease cocaine self-administration to an extent that is dependent on the magnitude of the alternative reinforcer (Carroll et al, 1989;Nader and Woolverton, 1991;Higgins, 1997;Campbell and Carroll, 2000;Hart et al, 2000). A corollary to this principle, clearly demonstrated in the context of the present study, is that a decrease in the magnitude of an alternative reinforcer may increase cocaine self-administration.…”

Brief Social Defeat Stress: Long Lasting Effects on Cocaine Taking During a Binge and Zif268 mRNA Expression in the Amygdala and Prefrontal Cortex

“…The unit dose is a major variable for quantitatively and qualitatively predicting patterns of continuous cocaine self-administration behavior (Fitch and Roberts, 1993). During extended periods of access, lower doses of cocaine (o0.5 mg/kg/infusion) establish patterns of intake that follow a circadian pattern, and intake occurs primarily during the dark phase in the nocturnal rat over consecutive days (Carroll et al, 1989;Fitch and Roberts, 1993). Circadian control is abolished when higher doses of cocaine (40.5 mg/kg/infusion) are made available.…”

Reward comparison: the Achilles’ heel and hope for addiction

“…In general, it appears that all natural rewards can be protective. Drug self-administration is reduced by the availability of a sweet such as saccharin or a glucose + saccharin mixture [83][84][85]. Drug self-administration is reduced by the availability of a running wheel, particularly in females [86].…”

“…Environmental enrichment also is protective in rats when provided during adulthood alone [90]. Sweets and even chow are protective when presented in adulthood concurrent with the opportunity to self-administer drug [83][84][85]. Finally, the sweets need not be concurrently available to be protective in adult rats.…”