Sign- and goal-tracking score does not correlate with addiction-like behavior following prolonged cocaine self-administration

• Published in: Psychopharmacology Vol. 238; no. 8; pp. 2335 - 2346
• Main Authors: Pohořalá, Veronika, Enkel, Thomas, Bartsch, Dusan, Spanagel, Rainer, Bernardi, Rick E.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-08-2021; Springer; Springer Nature B.V
• Subjects: Addictions; Analysis; Animal behavior; Animals; Attention - drug effects; Attention - physiology; Behavior, Addictive - psychology; Biomedical and Life Sciences; Biomedicine; Classical conditioning; Cocaine; Cocaine - administration & dosage; Conditioned stimulus; Conditioning, Classical - drug effects; Conditioning, Classical - physiology; Dopamine Uptake Inhibitors - administration & dosage; Dosage and administration; Drug abuse; Drug self-administration; Drug-Seeking Behavior - drug effects; Drug-Seeking Behavior - physiology; Evaluation; Goals; Intermediates; Intravenous administration; Male; Methods; Motivation; Motivation - drug effects; Motivation - physiology; Neurosciences; Original Investigation; Pharmacology/Toxicology; Phenotypes; Phenotyping; Physiological aspects; Psychiatry; Psychological aspects; Punishment; Rats; Rats, Sprague-Dawley; Reinforcement; Reward; Reward (Psychology); Self Administration; Unconditioned stimulus; Germany; Goal trackers; Self-administration; Pavlovian conditioned approach; 3-CRIT; Addiction; Rats; Cocaine; Sign trackers
• ISSN: 0033-3158; 1432-2072
• DOI: 10.1007/s00213-021-05858-z

Rationale
In classical conditioning, sign-tracking reflects behavior directed toward a conditioned stimulus (CS) in expectation of a reward (unconditioned stimulus, US); in contrast, goal-tracking describes behavior directed toward the location of delivery of a US. As cues previously paired with drugs of abuse promote drug-seeking and drug-taking behavior in both animals and humans and thus contribute to the severity of substance abuse, sign-tracking may represent a maladaptive cue-focused behavior that may increase addiction vulnerability as compared to goal-tracking. Recent studies do, in fact, support this possibility. Previous work in this area has focused primarily on paradigms using relatively limited exposure to drug rather than extended drug intake.
Objectives
Here, we used the DSM-IV–based 3-criteria (3-CRIT) model and examined whether a relationship exists between sign- or goal-tracking phenotypes and the prevalence of criteria associated with addiction-like behavior following extended cocaine self-administration as measured in this model.
Methods
Forty-six male Sprague Dawley rats underwent a Pavlovian conditioned approach (PCA) procedure and were characterized along a continuum as goal-trackers (GTs), intermediates (INTs), or sign-trackers (STs). The animals were subsequently trained to intravenous self-administer cocaine during 45 self-administration (SA) sessions and characterized for the 3 criteria outlined in the model: persistence of drug-seeking, motivation for cocaine-taking, and resistance to punishment.
Results
We performed correlational analyses on the traits measured, finding no relationships between PCA score and addiction-like characteristics measured using the 3-CRIT model of addiction. However, STs showed significantly greater resistance to punishment than GTs.
Conclusions
Phenotyping along a continuum of PCA scores may not be a valid predictor for identifying vulnerability to the addiction-like behaviors examined using the 3-CRIT model. However, PCA phenotype may predict a single feature of the 3-CRIT model, resistance to punishment, among those rats classified as either STs or GTs.