TY - JOUR
T1 - Sensitivity to reinforcer delay predicts ethanol's suppressant effects, but itself is unaffected by ethanol
AU - Moschak, Travis M.
AU - Mitchell, Suzanne H.
N1 - Funding Information:
TMM was supported by NIAAA grant T32 AA007468 and F31 AA020741 , SHM was supported by Portland Alcohol Research Center grant P60 AA10760 . The funding sources had no further role in study design, data collection, analysis, interpretation, manuscript preparation or the decision to submit the paper for publication.
PY - 2013/9/1
Y1 - 2013/9/1
N2 - Background: Relative preference for smaller, sooner rewards over larger, later rewards ("delay discounting") is increased by acute ethanol. Additionally, drug-naïve levels of delay discounting can predict subsequent ethanol consumption. However, it is unknown whether these phenomena are driven by a difference in sensitivity to the reinforcer delay or a difference in sensitivity to the reinforcer magnitude, because typical delay discounting tasks manipulate both parameters simultaneously. Methods: To disambiguate these factors, two tasks were developed in which animals chose between levers with either different delay contingencies (adjusting delay task) or different magnitude contingencies (adjusting magnitude task). When task performance was stable, rats received ethanol (0, 0.6, and 0.9. g/kg, i.p.). Results: Ethanol did not affect sensitivity to delay or sensitivity to magnitude. However, responding was suppressed at the highest dose of ethanol (0.9. g/kg). Less suppression was found in animals exhibiting high levels of drug-naïve sensitivity to delay. Conclusion: Thus, this study suggests that ethanol's effect on standard delay discounting tasks is not due to an alteration in sensitivity to delay or magnitude. Additionally, these data show that animals with high sensitivity to delay are resistant to the behaviorally suppressant effects of ethanol, which suggests that low tolerance for delayed rewards and low sensitivity to the behaviorally suppressant effects of ethanol may partly be driven by the same underlying mechanism.
AB - Background: Relative preference for smaller, sooner rewards over larger, later rewards ("delay discounting") is increased by acute ethanol. Additionally, drug-naïve levels of delay discounting can predict subsequent ethanol consumption. However, it is unknown whether these phenomena are driven by a difference in sensitivity to the reinforcer delay or a difference in sensitivity to the reinforcer magnitude, because typical delay discounting tasks manipulate both parameters simultaneously. Methods: To disambiguate these factors, two tasks were developed in which animals chose between levers with either different delay contingencies (adjusting delay task) or different magnitude contingencies (adjusting magnitude task). When task performance was stable, rats received ethanol (0, 0.6, and 0.9. g/kg, i.p.). Results: Ethanol did not affect sensitivity to delay or sensitivity to magnitude. However, responding was suppressed at the highest dose of ethanol (0.9. g/kg). Less suppression was found in animals exhibiting high levels of drug-naïve sensitivity to delay. Conclusion: Thus, this study suggests that ethanol's effect on standard delay discounting tasks is not due to an alteration in sensitivity to delay or magnitude. Additionally, these data show that animals with high sensitivity to delay are resistant to the behaviorally suppressant effects of ethanol, which suggests that low tolerance for delayed rewards and low sensitivity to the behaviorally suppressant effects of ethanol may partly be driven by the same underlying mechanism.
KW - Delay discounting
KW - Ethanol
KW - Impulsivity
KW - Intertemporal choice
KW - Low level of response to alcohol
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U2 - 10.1016/j.drugalcdep.2013.07.009
DO - 10.1016/j.drugalcdep.2013.07.009
M3 - Article
C2 - 23910798
AN - SCOPUS:84881666849
SN - 0376-8716
VL - 132
SP - 22
EP - 28
JO - Drug and Alcohol Dependence
JF - Drug and Alcohol Dependence
IS - 1-2
ER -