Effects of 8-OH-DPAT and WAY-100635 on performance on a time-constrained progressive-ratio schedule

Ho, M.-Y.; Body, S.; Kheramin, S.; Bradshaw, C. M.; Szabadi, E.

doi:10.1007/s00213-002-1375-9

Cited by 24 publications

(51 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Equation 1 was fitted to the overall response rate data from each rat under each treatment condition using an iterative least-squares method (SigmaPlot, Version 8.0), and the estimated values of the parameters β, δ and a were derived; goodness of fit was expressed as r 2 , the proportion of the data variance accounted for by the equation. In agreement with previous findings (Mobini et al 2000;Ho et al 2003;Zhang et al 2005aZhang et al , 2005bBezzina et al 2008aBezzina et al , 2008bRickard et al 2009), examination of the data revealed that in some rats very low response rates were generated under the highest ratios, which did not conform to Equation 1. Therefore the equation was fitted to each rat"s data after exclusion of these low rates using the following operational criterion (Mobini et al 2000).…”

Section: Discussionsupporting

confidence: 90%

“…Performance on the progressive-ratio schedule was similar to that seen in many previous studies (Bizo and Killeen 1997;Mobini et al 2000;Ho et al 2003;Kheramin et al 2005;Zhang et al 2005aZhang et al , 2005bBezzina et al 2008aBezzina et al , 2008bKilleen et al 2009;Rickard et al 2009). Overall response rate was bitonically related to ratio size; it increased rapidly to reach a peak, and then declined gradually as the response/reinforcer ratio was progressively increased.…”

Section: Discussionsupporting

confidence: 86%

“…However, doubts have been raised about the use of the breakpoint as an index of incentive value (Arnold and Roberts 1997;Mobini et al 2000;Ho et al 2003;Killeen et al 2009;Rickard et al 2009). This measure is sensitive not only to changes in reinforcer value but also to non-motivational variables such as the height of the operant lever (Aberman et al 1998;Skjoldager et al 1993) and the ratio step size (Stafford and Branch 1998).…”

Section: Introductionmentioning

confidence: 99%

“…Journal of Psychopharmacology,26,[857][858][859][860][861][862][863][864][865][866][867][868][869][870] -8 -Equation 1 was developed to describe performance on fixed-and variable-ratio schedules; however it also provides a good description of overall response rates on progressive-ratio schedules (Ho et al 2003;Kheramin et al 2005;Zhang et al 2005aZhang et al , 2005bBezzina et al 2008aBezzina et al , 2008bKilleen et al 2009;Rickard et al 2009). …”

Section: Introductionmentioning

confidence: 99%

“…Application of Equation 1 to progressive-ratio schedule performance has been used to detect the effects of brain lesions and centrally-acting drugs on motivational and motor-related processes (Mobini et al 2000;Ho et al 2003;Reilly 2003;Kheramin et al 2005;Zhang et al 2005aZhang et al , 2005bBezzina et al 2008aBezzina et al , 2008b.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

A clozapine-like effect of cyproheptadine on progressive ratio schedule performance

et al. 2011

View full text Add to dashboard Cite

Abstract. The atypical antipsychotic drug clozapine has multiple pharmacological actions, some of which, including 5-hydroxytryptamine (5-HT 2 ) and histamine (H 1 ) receptor antagonist effects, are shared by the non-selective 5-HT receptor antagonist cyproheptadine. Atypical antipsychotics have a characteristic profile of action on operant behaviour maintained by progressive-ratio schedules, as revealed by Killeen"s (1994) mathematical model of scheduled controlled behaviour. These drugs increase the values of a parameter that expresses the "incentive value" of the reinforcer (a) and a parameter that is inversely related to the "motor capacity" of the organism (δ). This experiment examined the effects of acute treatment with cyproheptadine and clozapine on performance on a progressive-ratio schedule of food reinforcement in rats; the effects of a conventional antipsychotic, haloperidol, and two drugs with food intake-enhancing effects, chlordiazepoxide and Δ 9 -tetrahydrocannabinol (THC), were also examined. Cyproheptadine (1, 5 mg kg -1 ) and clozapine (3.75, 7.5 mg kg -1 ) increased a and δ. Haloperidol (0.05, 0.1 mg kg -1 ) reduced a and increased δ.Chlordiazepoxide (3, 10 mg kg -1 ) increased a but reduced δ. THC (1, 3 mg kg -1 ) had no effect. Interpretation based on Killeen"s (1994) model suggests that cyproheptadine and clozapine enhanced the incentive value of the reinforcer and impaired motor performance. Motor impairment may be due to sedation (possibly reflecting H 1 receptor blockade). Enhancement of incentive value may reflect simultaneous blockade of H 1 and 5-HT 2 receptors, which has been proposed as the mechanism underlying the food intake-enhancing effect of cyproheptadine. In agreement with previous findings, haloperidol impaired motor performance and reduced the incentive value of the reinforcer. Chlordiazepoxide"s effect on a is consistent with its food intake-enhancing effect.

show abstract

Section: Discussionsupporting

confidence: 90%

Section: Discussionsupporting

confidence: 86%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

A clozapine-like effect of cyproheptadine on progressive ratio schedule performance

et al. 2011

View full text Add to dashboard Cite

show abstract

Theory of reinforcement schedules

Killeen

2023

J Exper Analysis Behavior

View full text Add to dashboard Cite

The three principles of reinforcement are (1) events such as incentives and reinforcers increase the activity of an organism; (2) that activity is bounded by competition from other responses; and (3) animals approach incentives and their signs, guided by their temporal and physical conditions, together called the “contingencies of reinforcement.” Mathematical models of each of these principles comprised mathematical principles of reinforcement (MPR; Killeen, 1994). Over the ensuing decades, MPR was extended to new experimental contexts. This article reviews the basic theory and its extensions to satiation, warm‐up, extinction, sign tracking, pausing, and sequential control in progressive‐ratio and multiple schedules. In the latter cases, a single equation balancing target and competing responses governs behavioral contrast and behavioral momentum. Momentum is intrinsic in the fundamental equations, as behavior unspools more slowly from highly aroused responses conditioned by higher rates of incitement than it does from responses from leaner contexts. Habits are responses that have accrued substantial behavioral momentum. Operant responses, being predictors of reinforcement, are approached by making them: The sight and feel of a paw on a lever is approached by placing paw on lever, as attempted for any sign of reinforcement. Behavior in concurrent schedules is governed by approach to momentarily richer patches (melioration). Applications of MPR in behavioral pharmacology and delay discounting are noted.

show abstract