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Behavioral economic assessment of price and cocaine consumption following self-administration histories that produce escalation of either final ratios or intake.

Oleson EB, Roberts DC - Neuropsychopharmacology (2008)

Bottom Line: It was found that a history of LgA training produced an increase in cocaine consumption; whereas a history of PR training produced an increase in the maximal price (P(max)) expended for cocaine.Importantly, the concepts of consumption and price were found to be dissociable.That is, LgA training produced an increase in consumption but a decrease in P(max), whereas PR training produced an increase in P(max) without increasing consumption.

View Article: PubMed Central - PubMed

Affiliation: Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA.

ABSTRACT
Various self-administration procedures are being developed to model specific aspects of the addiction process. For example, 'increased cocaine intake over time' has been modeled by providing long access (LgA) to cocaine during daily self-administration sessions under a fixed-ratio (FR1) reinforcement schedule. In addition, 'increased time and energy devoted to acquire cocaine' has been modeled by providing access to cocaine during daily self-administration sessions under a progressive-ratio (PR) schedule. To investigate the distinctiveness of these models, the behavioral economics variables of consumption and price were applied to cocaine self-administration data. To assess changes in consumption and price, cocaine self-administration was tested across a descending series of doses (0.237-0.001 mg per injection) under an FR1 reinforcement schedule to measure drug intake in the high dose range and thresholds in the low range. Cocaine consumption remained relatively stable across doses until a threshold was reached, at which maximal responding was observed. It was found that a history of LgA training produced an increase in cocaine consumption; whereas a history of PR training produced an increase in the maximal price (P(max)) expended for cocaine. Importantly, the concepts of consumption and price were found to be dissociable. That is, LgA training produced an increase in consumption but a decrease in P(max), whereas PR training produced an increase in P(max) without increasing consumption. These results suggest that distinct aspects of the addiction process can be parsed using self-administration models, thereby facilitating the investigation of specific neurobiological adaptations that occur through the addiction process.

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Related in: MedlinePlus

Effect of self-administration procedures which produce an escalation of consumption or final ratio on Pmax. Data are expressed as the mean (±SEM) Pmax. The left pair of bars illustrates Pmax values determined from animals that had been tested with access to cocaine during daily 6h (LgA) or 2 hr (ShA) sessions for 14 days. The right pair of bars illustrates Pmax values from groups of animals that had been tested for 14 days on a PR schedule (PR) or an FR1 schedule matched for total drug intake (Match). Asterisks indicate significant differences between groups (p < 0.05).
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Figure 5: Effect of self-administration procedures which produce an escalation of consumption or final ratio on Pmax. Data are expressed as the mean (±SEM) Pmax. The left pair of bars illustrates Pmax values determined from animals that had been tested with access to cocaine during daily 6h (LgA) or 2 hr (ShA) sessions for 14 days. The right pair of bars illustrates Pmax values from groups of animals that had been tested for 14 days on a PR schedule (PR) or an FR1 schedule matched for total drug intake (Match). Asterisks indicate significant differences between groups (p < 0.05).

Mentions: The results of the behavioral economics variable Pmax determined from each experimental group are illustrated in figure 5. The left side of figure 5 shows Pmax values determined from the LgA and ShA groups. The LgA group is represented by black bars whereas the ShA group is represented by white bars. LgA trained animals showed a significantly reduced Pmax in comparison animals given ShA to cocaine (F(1,12) = 12.417, p < 0.01). The right side of figure 5 shows Pmax values determined from the PR group and the match group. The PR group is represented by black bars whereas the match group is represented by white bars. PR trained animals exhibited a significantly increased Pmax versus the match group (F(1,12) = 8.33, p = 0.014). Pmax values and final ratios were also compared within the same animal. A correlation was found between Pmax values established using the threshold procedure and final ratios established using a PR schedule (r = 0.705) as illustrated in the supplementary information (S3).


Behavioral economic assessment of price and cocaine consumption following self-administration histories that produce escalation of either final ratios or intake.

Oleson EB, Roberts DC - Neuropsychopharmacology (2008)

Effect of self-administration procedures which produce an escalation of consumption or final ratio on Pmax. Data are expressed as the mean (±SEM) Pmax. The left pair of bars illustrates Pmax values determined from animals that had been tested with access to cocaine during daily 6h (LgA) or 2 hr (ShA) sessions for 14 days. The right pair of bars illustrates Pmax values from groups of animals that had been tested for 14 days on a PR schedule (PR) or an FR1 schedule matched for total drug intake (Match). Asterisks indicate significant differences between groups (p < 0.05).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2626138&req=5

Figure 5: Effect of self-administration procedures which produce an escalation of consumption or final ratio on Pmax. Data are expressed as the mean (±SEM) Pmax. The left pair of bars illustrates Pmax values determined from animals that had been tested with access to cocaine during daily 6h (LgA) or 2 hr (ShA) sessions for 14 days. The right pair of bars illustrates Pmax values from groups of animals that had been tested for 14 days on a PR schedule (PR) or an FR1 schedule matched for total drug intake (Match). Asterisks indicate significant differences between groups (p < 0.05).
Mentions: The results of the behavioral economics variable Pmax determined from each experimental group are illustrated in figure 5. The left side of figure 5 shows Pmax values determined from the LgA and ShA groups. The LgA group is represented by black bars whereas the ShA group is represented by white bars. LgA trained animals showed a significantly reduced Pmax in comparison animals given ShA to cocaine (F(1,12) = 12.417, p < 0.01). The right side of figure 5 shows Pmax values determined from the PR group and the match group. The PR group is represented by black bars whereas the match group is represented by white bars. PR trained animals exhibited a significantly increased Pmax versus the match group (F(1,12) = 8.33, p = 0.014). Pmax values and final ratios were also compared within the same animal. A correlation was found between Pmax values established using the threshold procedure and final ratios established using a PR schedule (r = 0.705) as illustrated in the supplementary information (S3).

Bottom Line: It was found that a history of LgA training produced an increase in cocaine consumption; whereas a history of PR training produced an increase in the maximal price (P(max)) expended for cocaine.Importantly, the concepts of consumption and price were found to be dissociable.That is, LgA training produced an increase in consumption but a decrease in P(max), whereas PR training produced an increase in P(max) without increasing consumption.

View Article: PubMed Central - PubMed

Affiliation: Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA.

ABSTRACT
Various self-administration procedures are being developed to model specific aspects of the addiction process. For example, 'increased cocaine intake over time' has been modeled by providing long access (LgA) to cocaine during daily self-administration sessions under a fixed-ratio (FR1) reinforcement schedule. In addition, 'increased time and energy devoted to acquire cocaine' has been modeled by providing access to cocaine during daily self-administration sessions under a progressive-ratio (PR) schedule. To investigate the distinctiveness of these models, the behavioral economics variables of consumption and price were applied to cocaine self-administration data. To assess changes in consumption and price, cocaine self-administration was tested across a descending series of doses (0.237-0.001 mg per injection) under an FR1 reinforcement schedule to measure drug intake in the high dose range and thresholds in the low range. Cocaine consumption remained relatively stable across doses until a threshold was reached, at which maximal responding was observed. It was found that a history of LgA training produced an increase in cocaine consumption; whereas a history of PR training produced an increase in the maximal price (P(max)) expended for cocaine. Importantly, the concepts of consumption and price were found to be dissociable. That is, LgA training produced an increase in consumption but a decrease in P(max), whereas PR training produced an increase in P(max) without increasing consumption. These results suggest that distinct aspects of the addiction process can be parsed using self-administration models, thereby facilitating the investigation of specific neurobiological adaptations that occur through the addiction process.

Show MeSH
Related in: MedlinePlus