Document Detail

Effects of cocaine self-administration on food-reinforced responding using a discrete trial procedure in rats.
MedLine Citation:
PMID:  14694351     Owner:  NLM     Status:  MEDLINE    
Cocaine addiction has been characterized by a shift from controlled to uncontrolled and compulsive drug use. Using novel self-administration procedures, we attempted to model this transitional phase and characterize the behavioral changes that underlie it. We chose to use food-reinforced responding across the light/dark cycle as an indicator of the degree to which cocaine was disrupting ongoing behavior as a potential measure of dysregulation. Four groups of rats (n=5-6) were given 24-h access to cocaine (1.5 mg/kg/inj) available in 2, 3, 4, or 5 discrete trials/h. All rats were given continuous access to a second lever that resulted in the delivery of a 45 mg food pellet under a fixed ratio 1 schedule. The results showed that under low access conditions (eg 2 discrete trials/h), both food- and cocaine-reinforced responding were diurnally regulated and occurred coincidentally. As access to cocaine was increased, there was a progressive disruption in the diurnal control over both food- and cocaine-maintained responding. High access conditions also produced transient decreases in the total levels of food-reinforced responding. These findings suggest that high access to cocaine under the discrete trial cocaine self-administration procedure produces a transient disruption in the diurnal control over behavior maintained by food and that the level of control (or loss of) may be a useful marker of dysregulation.
W J Lynch; D C S Roberts
Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology     Volume:  29     ISSN:  0893-133X     ISO Abbreviation:  Neuropsychopharmacology     Publication Date:  2004 Apr 
Date Detail:
Created Date:  2004-03-22     Completed Date:  2004-05-17     Revised Date:  2011-05-18    
Medline Journal Info:
Nlm Unique ID:  8904907     Medline TA:  Neuropsychopharmacology     Country:  United States    
Other Details:
Languages:  eng     Pagination:  669-75     Citation Subset:  IM    
Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Winston-Salem, NC, USA.
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MeSH Terms
Analysis of Variance
Behavior, Addictive / chemically induced,  psychology*
Behavior, Animal / drug effects
Cocaine / administration & dosage*,  toxicity
Conditioning, Operant
Dopamine Uptake Inhibitors / administration & dosage*,  toxicity
Rats, Sprague-Dawley
Reinforcement (Psychology)*
Reinforcement Schedule*
Time Factors
Grant Support
Reg. No./Substance:
0/Dopamine Uptake Inhibitors; 50-36-2/Cocaine

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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