Cocaine makes actions insensitive to outcomes but not extinction: implications for altered orbitofrontal-amygdalar function.
Addiction is characterized by persistent drug-seeking despite adverse consequences or outcomes. Such persistent behavior may result from drug-induced brain changes that increase the control of behavior by associations between antecedent cues and responses. However, it is equally plausible that brain changes cause a decrease in the control of behavior by the value of likely outcomes. To test whether drug exposure can cause persistent behavior, and to distinguish between these two accounts of such behavior, we tested cocaine-experienced rats in a Pavlovian 'reinforcer devaluation' task, which provides independent assessments of the control of behavior by antecedent cues and outcome representations. We found that cocaine exposure caused persistent responding in this setting a month after the last drug treatment, and that this deficit resulted from an inability to use representations of outcome value to guide behavior rather than from changes in stimulus-response learning or response inhibition.
Schoenbaum
Geoffrey
G
Department of Anatomy and Neurobiology, University of Maryland School of Medicine, 20 Penn Street, HSF-2 S251, Baltimore, MD 21201, USA. schoenbg@schoenbaumlab.org
Setlow
Barry
B
D000679:Amygdala / Q000187:drug effects* / Q000502:physiology; D000818:Animals; D003042:Cocaine / Q000494:pharmacology*; D003213:Conditioning, Psychological / Q000187:drug effects* / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D005108:Extinction, Psychological / Q000187:drug effects* / Q000502:physiology; D005625:Frontal Lobe / Q000187:drug effects* / Q000502:physiology; D008297:Male; D051381:Rats; D020318:Rats, Long-Evans
D003042:Cocaine