Effect of orexin-B-saporin-induced lesions of the lateral hypothalamus on performance on a progressive ratio schedule

It has been suggested that a sub-population of orexinergic neurones whose somata lie in the lateral hypothalamic area (LHA) play an important role in regulating the reinforcing value of both food and drugs. This experiment examined the effect of disruption of orexinergic mechanisms in the LHA on per...

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Main Authors: Olarte-Sánchez, Cristian, Valencia Torres, Lourdes, Body, Stephanie, Cassaday, Helen J., Bradshaw, Chris, Szabadi, Elemer
Format: Article
Published: Sage 2012
Online Access:https://eprints.nottingham.ac.uk/2255/
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author Olarte-Sánchez, Cristian
Valencia Torres, Lourdes
Body, Stephanie
Cassaday, Helen J.
Bradshaw, Chris
Szabadi, Elemer
author_facet Olarte-Sánchez, Cristian
Valencia Torres, Lourdes
Body, Stephanie
Cassaday, Helen J.
Bradshaw, Chris
Szabadi, Elemer
author_sort Olarte-Sánchez, Cristian
building Nottingham Research Data Repository
collection Online Access
description It has been suggested that a sub-population of orexinergic neurones whose somata lie in the lateral hypothalamic area (LHA) play an important role in regulating the reinforcing value of both food and drugs. This experiment examined the effect of disruption of orexinergic mechanisms in the LHA on performance on the progressive-ratio schedule of reinforcement, in which the response requirement increases progressively for successive reinforcers. The data were analysed using a mathematical model which yields a quantitative index of reinforcer value and dissociates effects of interventions on motor and motivational processes (Killeen, 1994). Rats were trained under a progressive-ratio schedule using food-pellet reinforcement. They received bilateral injections of conjugated orexin-B-saporin (OxSap) into the LHA or sham lesions. Training continued for a further 40 sessions after surgery. Equations were fitted to the response rate data from each rat, and the parameters of the model were derived for successive blocks of 10 sessions. The OxSap lesion reduced the number of orexin-containing neurones in the LHA by approximately 50% compared to the sham-lesioned group. The parameter expressing the incentive value of the reinforcer was not significantly altered by the lesion. However, the parameter related to the maximum response rate was significantly affected, suggesting that that motor capacity was diminished in the OxSap-lesioned group. The results indicate that OxSap lesions of the LHA disrupted food-reinforced responding on the progressive-ratio schedule. It is suggested that this disruption was brought about by a change in non-motivational (motor) processes.
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spelling nottingham-22552020-05-04T20:22:43Z https://eprints.nottingham.ac.uk/2255/ Effect of orexin-B-saporin-induced lesions of the lateral hypothalamus on performance on a progressive ratio schedule Olarte-Sánchez, Cristian Valencia Torres, Lourdes Body, Stephanie Cassaday, Helen J. Bradshaw, Chris Szabadi, Elemer It has been suggested that a sub-population of orexinergic neurones whose somata lie in the lateral hypothalamic area (LHA) play an important role in regulating the reinforcing value of both food and drugs. This experiment examined the effect of disruption of orexinergic mechanisms in the LHA on performance on the progressive-ratio schedule of reinforcement, in which the response requirement increases progressively for successive reinforcers. The data were analysed using a mathematical model which yields a quantitative index of reinforcer value and dissociates effects of interventions on motor and motivational processes (Killeen, 1994). Rats were trained under a progressive-ratio schedule using food-pellet reinforcement. They received bilateral injections of conjugated orexin-B-saporin (OxSap) into the LHA or sham lesions. Training continued for a further 40 sessions after surgery. Equations were fitted to the response rate data from each rat, and the parameters of the model were derived for successive blocks of 10 sessions. The OxSap lesion reduced the number of orexin-containing neurones in the LHA by approximately 50% compared to the sham-lesioned group. The parameter expressing the incentive value of the reinforcer was not significantly altered by the lesion. However, the parameter related to the maximum response rate was significantly affected, suggesting that that motor capacity was diminished in the OxSap-lesioned group. The results indicate that OxSap lesions of the LHA disrupted food-reinforced responding on the progressive-ratio schedule. It is suggested that this disruption was brought about by a change in non-motivational (motor) processes. Sage 2012 Article PeerReviewed Olarte-Sánchez, Cristian, Valencia Torres, Lourdes, Body, Stephanie, Cassaday, Helen J., Bradshaw, Chris and Szabadi, Elemer (2012) Effect of orexin-B-saporin-induced lesions of the lateral hypothalamus on performance on a progressive ratio schedule. Journal of Psychopharmacology, 26 (6). pp. 871-886. ISSN 0269-8811 http://jop.sagepub.com/content/26/6/871.abstract doi:10.1177/0269881111409607 doi:10.1177/0269881111409607
spellingShingle Olarte-Sánchez, Cristian
Valencia Torres, Lourdes
Body, Stephanie
Cassaday, Helen J.
Bradshaw, Chris
Szabadi, Elemer
Effect of orexin-B-saporin-induced lesions of the lateral hypothalamus on performance on a progressive ratio schedule
title Effect of orexin-B-saporin-induced lesions of the lateral hypothalamus on performance on a progressive ratio schedule
title_full Effect of orexin-B-saporin-induced lesions of the lateral hypothalamus on performance on a progressive ratio schedule
title_fullStr Effect of orexin-B-saporin-induced lesions of the lateral hypothalamus on performance on a progressive ratio schedule
title_full_unstemmed Effect of orexin-B-saporin-induced lesions of the lateral hypothalamus on performance on a progressive ratio schedule
title_short Effect of orexin-B-saporin-induced lesions of the lateral hypothalamus on performance on a progressive ratio schedule
title_sort effect of orexin-b-saporin-induced lesions of the lateral hypothalamus on performance on a progressive ratio schedule
url https://eprints.nottingham.ac.uk/2255/
https://eprints.nottingham.ac.uk/2255/
https://eprints.nottingham.ac.uk/2255/