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Hadamitzky M, Lückemann L, Pacheco-López G, Schedlowski M. Pavlovian Conditioning of Immunological and Neuroendocrine Functions. Physiol Rev 2020; 100:357-405. [DOI: 10.1152/physrev.00033.2018] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The phenomenon of behaviorally conditioned immunological and neuroendocrine functions has been investigated for the past 100 yr. The observation that associative learning processes can modify peripheral immune functions was first reported and investigated by Ivan Petrovic Pavlov and his co-workers. Their work later fell into oblivion, also because so little was known about the immune system’s function and even less about the underlying mechanisms of how learning, a central nervous system activity, could affect peripheral immune responses. With the employment of a taste-avoidance paradigm in rats, this phenomenon was rediscovered 45 yr ago as one of the most fascinating examples of the reciprocal functional interaction between behavior, the brain, and peripheral immune functions, and it established psychoneuroimmunology as a new research field. Relying on growing knowledge about efferent and afferent communication pathways between the brain, neuroendocrine system, primary and secondary immune organs, and immunocompetent cells, experimental animal studies demonstrate that cellular and humoral immune and neuroendocrine functions can be modulated via associative learning protocols. These (from the classical perspective) learned immune responses are clinically relevant, since they affect the development and progression of immune-related diseases and, more importantly, are also inducible in humans. The increased knowledge about the neuropsychological machinery steering learning and memory processes together with recent insight into the mechanisms mediating placebo responses provide fascinating perspectives to exploit these learned immune and neuroendocrine responses as supportive therapies, the aim being to reduce the amount of medication required, diminishing unwanted drug side effects while maximizing the therapeutic effect for the patient’s benefit.
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Affiliation(s)
- Martin Hadamitzky
- Institute of Medical Psychology and Behavioral Immunobiology, University Hospital Essen, Essen, Germany; Health Sciences Department, Metropolitan Autonomous University (UAM), Campus Lerma, Mexico; and Department of Clinical Neuroscience, Osher Center for Integrative Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Laura Lückemann
- Institute of Medical Psychology and Behavioral Immunobiology, University Hospital Essen, Essen, Germany; Health Sciences Department, Metropolitan Autonomous University (UAM), Campus Lerma, Mexico; and Department of Clinical Neuroscience, Osher Center for Integrative Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Gustavo Pacheco-López
- Institute of Medical Psychology and Behavioral Immunobiology, University Hospital Essen, Essen, Germany; Health Sciences Department, Metropolitan Autonomous University (UAM), Campus Lerma, Mexico; and Department of Clinical Neuroscience, Osher Center for Integrative Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Manfred Schedlowski
- Institute of Medical Psychology and Behavioral Immunobiology, University Hospital Essen, Essen, Germany; Health Sciences Department, Metropolitan Autonomous University (UAM), Campus Lerma, Mexico; and Department of Clinical Neuroscience, Osher Center for Integrative Medicine, Karolinska Institutet, Stockholm, Sweden
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Tekampe J, van Middendorp H, Sweep FCGJ, Roerink SHPP, Hermus ARMM, Evers AWM. Conditioning cortisol in humans: design and pilot study of a randomized controlled trial. Pilot Feasibility Stud 2019; 5:9. [PMID: 30680223 PMCID: PMC6337859 DOI: 10.1186/s40814-018-0382-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 12/07/2018] [Indexed: 11/18/2022] Open
Abstract
Background Conditioning of physiological responses can be achieved by repeatedly pairing a previously neutral conditioned stimulus with the administration of a pharmacologically salient unconditioned stimulus. This type of conditioning has been effective for specific immune and endocrine responses, but results with regard to conditioning of cortisol, a key stress-regulatory parameter, are currently unclear. This paper describes a pharmacological conditioning design, optimized for the examination of effects of cortisol conditioning under both basal conditions and in response to stress. Methods A double-blind randomized controlled conditioning paradigm aimed at conditioning of cortisol is conducted in 48 healthy female volunteers. During the acquisition phase, a gustatory stimulus (conditioned stimulus) is paired with hydrocortisone (100 mg, capsulated, unconditioned stimulus) three times before being administered together with placebo during three evocation sessions. To investigate possible effects of cortisol conditioning in response to stress, participants are exposed to the Trier Social Stress Test during the third evocation session. Primary outcome measure of this study is the mean area under the curve of salivary cortisol during the first two evocation sessions. As secondary outcomes, self-reported affect and stress as well as alpha-amylase are investigated. A pilot study was conducted to ensure that this design is feasible to be used in a larger study. Discussion This study design provides an innovative opportunity to examine the conditioning of cortisol under basal conditions and in response to stress. Also, the possible effect of cortisol conditioning on secondary outcomes of self-reported affect and alpha-amylase can be investigated. If cortisol could successfully be conditioned, this would be of conceptual relevance, showing that hypothalamic pituitary adrenal (HPA) axis regulation can be influenced by associative learning processes. Eventually, this could also have important clinical implications for understanding and treating stress-related disorders in which HPA axis dysregulation might play a role. Trial registration Nederlands Trial Register, NTR4651. Registered on 29 July 2014 Electronic supplementary material The online version of this article (10.1186/s40814-018-0382-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- J Tekampe
- 1Health, Medical and Neuropsychology Unit, Faculty of Social and Behavioural Sciences, Institute of Psychology, Leiden University, P.O. Box 9555, 2300 RB, Leiden, The Netherlands.,2Department of Medical Psychology, Radboud university medical center, Nijmegen, The Netherlands
| | - H van Middendorp
- 1Health, Medical and Neuropsychology Unit, Faculty of Social and Behavioural Sciences, Institute of Psychology, Leiden University, P.O. Box 9555, 2300 RB, Leiden, The Netherlands.,2Department of Medical Psychology, Radboud university medical center, Nijmegen, The Netherlands
| | - F C G J Sweep
- 3Department of Laboratory Medicine, Radboud university medical center, Nijmegen, The Netherlands
| | - S H P P Roerink
- 4Division of Endocrinology, Department of Internal Medicine, Radboud university medical center, Nijmegen, The Netherlands
| | - A R M M Hermus
- 4Division of Endocrinology, Department of Internal Medicine, Radboud university medical center, Nijmegen, The Netherlands
| | - A W M Evers
- 1Health, Medical and Neuropsychology Unit, Faculty of Social and Behavioural Sciences, Institute of Psychology, Leiden University, P.O. Box 9555, 2300 RB, Leiden, The Netherlands.,2Department of Medical Psychology, Radboud university medical center, Nijmegen, The Netherlands.,5Department of Psychiatry, Leiden University Medical Center, Leiden, The Netherlands
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Skvortsova A, Veldhuijzen DS, Kloosterman IEM, Meijer OC, van Middendorp H, Pacheco-Lopez G, Evers AWM. Conditioned hormonal responses: A systematic review in animals and humans. Front Neuroendocrinol 2019; 52:206-218. [PMID: 30590067 DOI: 10.1016/j.yfrne.2018.12.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 11/21/2018] [Accepted: 12/21/2018] [Indexed: 12/09/2022]
Abstract
In contrast to classical conditioning of physiological responses such as immune responses and drug effects, only a limited number of studies investigated classical conditioning of endocrine responses. The present paper is the first systematic review that integrates evidence from animal and human trials regarding the possibility to condition the endocrine responses. Twenty-six animal and eight human studies were included in the review. We demonstrated that there is accumulating evidence that classical conditioning processes are able to influence specific endocrine responses, such as cortocosterone/cortisol and insulin, while more limited evidence exists for other hormones. Animal and human studies were generally consistent in their findings; however, the limited number of human studies makes it difficult to generalize and translate the results of animal research to humans. Next to methodological recommendations for future studies, we suggest several ways how classically conditioned endocrine responses can be used in clinical practice.
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Affiliation(s)
- Aleksandrina Skvortsova
- Health, Medical and Neuropsychology Unit, Faculty of Social and Behavioural Sciences, Leiden University, 2333 AK Leiden, the Netherlands; Leiden Institute for Brain and Cognition, 2300 RC Leiden, the Netherlands.
| | - Dieuwke S Veldhuijzen
- Health, Medical and Neuropsychology Unit, Faculty of Social and Behavioural Sciences, Leiden University, 2333 AK Leiden, the Netherlands; Leiden Institute for Brain and Cognition, 2300 RC Leiden, the Netherlands
| | - Iris E M Kloosterman
- Health, Medical and Neuropsychology Unit, Faculty of Social and Behavioural Sciences, Leiden University, 2333 AK Leiden, the Netherlands
| | - Onno C Meijer
- Department of Medicine, Division of Endocrinology, Leiden University Medical Center, 2333 ZA Leiden, the Netherlands
| | - Henriët van Middendorp
- Health, Medical and Neuropsychology Unit, Faculty of Social and Behavioural Sciences, Leiden University, 2333 AK Leiden, the Netherlands; Leiden Institute for Brain and Cognition, 2300 RC Leiden, the Netherlands
| | - Gustavo Pacheco-Lopez
- Health, Medical and Neuropsychology Unit, Faculty of Social and Behavioural Sciences, Leiden University, 2333 AK Leiden, the Netherlands; Department of Health Sciences, Campus Lerma, Metropolitan Autonomous University (UAM), 52006 Lerma, Edo Mex, Mexico
| | - Andrea W M Evers
- Health, Medical and Neuropsychology Unit, Faculty of Social and Behavioural Sciences, Leiden University, 2333 AK Leiden, the Netherlands; Leiden Institute for Brain and Cognition, 2300 RC Leiden, the Netherlands; Department of Psychiatry, Leiden University Medical Center, 2333 ZA Leiden, the Netherlands
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Tekampe J, van Middendorp H, Sweep FC, Roerink SH, Hermus AR, Evers AW. Human Pharmacological Conditioning of the Immune and Endocrine System: Challenges and Opportunities. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2018; 138:61-80. [DOI: 10.1016/bs.irn.2018.01.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Petrakova L, Boy K, Kügler M, Benson S, Engler H, Möller L, Schedlowski M. Plasma cortisol response cannot be classically conditioned in a taste-endocrine paradigm in humans. Psychopharmacology (Berl) 2017; 234:3249-3257. [PMID: 28804807 DOI: 10.1007/s00213-017-4718-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 08/02/2017] [Indexed: 11/25/2022]
Abstract
RATIONALE Peripheral immune responses can be modified by associative learning procedures. Less is known, however, whether and to what extent neuroendocrine parameters can be classically conditioned. OBJECTIVES In this randomized double-blind study, we modified an established paradigm to behaviorally condition endocrine responses in humans. METHODS Thirty-one healthy male participants received a distinctively flavored green drink as the conditioned stimulus (CS) and intravenous injections of corticotropin-releasing hormone (CRH) (CRH group, N = 17) or NaCl (placebo group, N = 14) as the unconditioned stimulus (US) during two subsequent acquisition trials. Plasma levels of cortisol and noradrenaline, heart rate, and psychological parameters were analyzed before and 15, 30, 60, 120, and 180 min after injection. The two acquisition trials were followed by two evocation trials, during which participants underwent the same procedure but now receiving NaCl injections. RESULTS CRH administration induced pronounced increases in cortisol and noradrenaline plasma concentrations, heart rate, and anxiety levels. However, re-exposure to the CS during evocations trials did not provoke conditioned increases in neuroendocrine parameters. Median split of the CRH group based on the cortisol baseline level into "cort-high" and "cort-low" subgroups showed that the "cort-high" subgroup displayed a significantly increased cortisol production on evocation days compared to the "cort-low" subgroup and the placebo group. CONCLUSION This taste-endocrine paradigm employing CRH injection as the US in healthy male volunteers failed to induce a behaviorally conditioned cortisol release as a learned endocrine response. Future studies should clarify a possible role of higher baseline cortisol levels in perhaps facilitating a conditioned cortisol response.
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Affiliation(s)
- Liubov Petrakova
- Institute of Medical Psychology and Behavioral Immunobiology, University Hospital Essen, University of Duisburg-Essen, 45147, Essen, Germany
| | - Karoline Boy
- Institute of Medical Psychology and Behavioral Immunobiology, University Hospital Essen, University of Duisburg-Essen, 45147, Essen, Germany
| | - Marisa Kügler
- Institute of Medical Psychology and Behavioral Immunobiology, University Hospital Essen, University of Duisburg-Essen, 45147, Essen, Germany
| | - Sven Benson
- Institute of Medical Psychology and Behavioral Immunobiology, University Hospital Essen, University of Duisburg-Essen, 45147, Essen, Germany
| | - Harald Engler
- Institute of Medical Psychology and Behavioral Immunobiology, University Hospital Essen, University of Duisburg-Essen, 45147, Essen, Germany
| | - Lars Möller
- Clinic for Endocrinology, University Hospital Essen, Essen, Germany
| | - Manfred Schedlowski
- Institute of Medical Psychology and Behavioral Immunobiology, University Hospital Essen, University of Duisburg-Essen, 45147, Essen, Germany.
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Packard AEB, Egan AE, Ulrich-Lai YM. HPA Axis Interactions with Behavioral Systems. Compr Physiol 2016; 6:1897-1934. [PMID: 27783863 DOI: 10.1002/cphy.c150042] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Perhaps the most salient behaviors that individuals engage in involve the avoidance of aversive experiences and the pursuit of pleasurable experiences. Engagement in these behaviors is regulated to a significant extent by an individual's hormonal milieu. For example, glucocorticoid hormones are produced by the hypothalamic-pituitary-adrenocortical (HPA) axis, and influence most aspects of behavior. In turn, many behaviors can influence HPA axis activity. These bidirectional interactions not only coordinate an individual's physiological and behavioral states to each other, but can also tune them to environmental conditions thereby optimizing survival. The present review details the influence of the HPA axis on many types of behavior, including appetitively-motivated behaviors (e.g., food intake and drug use), aversively-motivated behaviors (e.g., anxiety-related and depressive-like) and cognitive behaviors (e.g., learning and memory). Conversely, the manuscript also describes how engaging in various behaviors influences HPA axis activity. Our current understanding of the neuronal and/or hormonal mechanisms that underlie these interactions is also summarized. © 2016 American Physiological Society. Compr Physiol 6:1897-1934, 2016.
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Affiliation(s)
- Amy E B Packard
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, Ohio, USA
| | - Ann E Egan
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, Ohio, USA
| | - Yvonne M Ulrich-Lai
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, Ohio, USA
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Schedlowski M, Enck P, Rief W, Bingel U. Neuro-Bio-Behavioral Mechanisms of Placebo and Nocebo Responses: Implications for Clinical Trials and Clinical Practice. Pharmacol Rev 2016; 67:697-730. [PMID: 26126649 DOI: 10.1124/pr.114.009423] [Citation(s) in RCA: 197] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The placebo effect has often been considered a nuisance in basic and particularly clinical research. This view has gradually changed in recent years due to deeper insight into the neuro-bio-behavioral mechanisms steering both the placebo and nocebo responses, the evil twin of placebo. For the neuroscientist, placebo and nocebo responses have evolved as indispensable tools to understand brain mechanisms that link cognitive and emotional factors with symptom perception as well as peripheral physiologic systems and end organ functioning. For the clinical investigator, better understanding of the mechanisms driving placebo and nocebo responses allow the control of these responses and thereby help to more precisely define the efficacy of a specific pharmacological intervention. Finally, in the clinical context, the systematic exploitation of these mechanisms will help to maximize placebo responses and minimize nocebo responses for the patient's benefit. In this review, we summarize and critically examine the neuro-bio-behavioral mechanisms underlying placebo and nocebo responses that are currently known in terms of different diseases and physiologic systems. We subsequently elaborate on the consequences of this knowledge for pharmacological treatments of patients and the implications for pharmacological research, the training of healthcare professionals, and for the health care system and future research strategies on placebo and nocebo responses.
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Affiliation(s)
- Manfred Schedlowski
- Institute of Medical Psychology and Behavioral Immunobiology (M.S.) and Department of Neurology (U.B.), University Clinic Essen, Essen, Germany; Department of Internal Medicine VI, Psychosomatic Medicine, University Hospital Tübingen, Tübingen, Germany (P.E.); and Department of Psychology, University of Marburg, Marburg, Germany (W.R.)
| | - Paul Enck
- Institute of Medical Psychology and Behavioral Immunobiology (M.S.) and Department of Neurology (U.B.), University Clinic Essen, Essen, Germany; Department of Internal Medicine VI, Psychosomatic Medicine, University Hospital Tübingen, Tübingen, Germany (P.E.); and Department of Psychology, University of Marburg, Marburg, Germany (W.R.)
| | - Winfried Rief
- Institute of Medical Psychology and Behavioral Immunobiology (M.S.) and Department of Neurology (U.B.), University Clinic Essen, Essen, Germany; Department of Internal Medicine VI, Psychosomatic Medicine, University Hospital Tübingen, Tübingen, Germany (P.E.); and Department of Psychology, University of Marburg, Marburg, Germany (W.R.)
| | - Ulrike Bingel
- Institute of Medical Psychology and Behavioral Immunobiology (M.S.) and Department of Neurology (U.B.), University Clinic Essen, Essen, Germany; Department of Internal Medicine VI, Psychosomatic Medicine, University Hospital Tübingen, Tübingen, Germany (P.E.); and Department of Psychology, University of Marburg, Marburg, Germany (W.R.)
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Wendt L, Albring A, Schedlowski M. Learned placebo responses in neuroendocrine and immune functions. Handb Exp Pharmacol 2014; 225:159-181. [PMID: 25304532 DOI: 10.1007/978-3-662-44519-8_10] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The phenomenon of learned placebo responses in neuroendocrine and immune functions is a fascinating example of communication between the brain and both the endocrine and peripheral immune systems. In this chapter, we will give a short overview of afferent and efferent communication pathways, as well as the central mechanisms, which steer the behavioral conditioned immune response. Subsequently, we will focus on data that provides evidence for learned immune responses in experimental animals and learned neuroendocrine and immune placebo responses in humans. Finally, we will take a critical look at these learning protocols, to determine whether or not they can be considered a viable additional treatment option to pharmacological regimens in clinical routine. This is fundamental, since there are still a number of issues, which need to be solved, such as the potential reproducibility, predictability, and extinction of the learned neuroendocrine and immune responses. Together, these findings not only provide an excellent basis to increase our understanding of human biology but may also have far reaching clinical implications. They pave the way for the ultimate aim of employing associative learning protocols as supportive treatment strategies in pharmacological regimens. As a result, medication levels may be reduced, as well as their unwanted side effects, providing a maximized therapeutic outcome to the benefit of the patient.
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Affiliation(s)
- Laura Wendt
- Institute of Medical Psychology and Immunobiology, University Hospital Essen, University of Duisburg-Essen, Hufelandstrasse 55, D-45122, Essen, Germany
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Davis KW, Cepeda-Benito A, Harraid JH, Wellman PJ. Plasma corticosterone in the rat in response to nicotine and saline injections in a context previously paired or unpaired with nicotine. Psychopharmacology (Berl) 2005; 180:466-72. [PMID: 15723229 DOI: 10.1007/s00213-005-2185-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2004] [Accepted: 01/06/2005] [Indexed: 10/25/2022]
Abstract
RATIONALE Following repeated injections with nicotine paired with a distinctive environment, some studies have reported that the distinctive context becomes a conditioned stimulus (CS) capable of eliciting conditioned corticosterone (CORT) release. Conversely, other studies have found that exposure to the CS results in conditioned attenuation of nicotine-induced CORT release. OBJECTIVE The present study was designed to examine whether these sets of separate findings could be replicated in animals exposed to the same experimental procedures within the same study. METHODS CORT assessments were conducted in a distinctive context after independent groups of animals were injected with either saline or nicotine (1 mg/kg, salt) after five or ten nicotine injections either explicitly paired or unpaired with a distinctive context. The design also included groups of nicotine-naïve rats exposed to the experimental procedures and assessed for CORT levels following either nicotine or saline injections during their first, and after their fifth and tenth context exposures. RESULTS CORT levels were higher after nicotine than after saline, and higher in the paired than in the unpaired condition. Exposure to the context without nicotine produced conditioned CORT release and exposure to the context did not attenuate nicotine-induced CORT release. CONCLUSIONS The results supported the notion that a CS associated with nicotine effects elicit a conditioned response (CR) in the form of CORT release. Future research will be needed to examine whether conditioned CORT release can explain the context-dependent attenuations of nicotine-induced CORT.
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Affiliation(s)
- Kristina W Davis
- Dept. of Psychology, Texas A&M University, 4235 TAMU, College Station, TX 77843-4235, USA
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Moreira PSA, Pulman KGT, Pottinger TG. Extinction of a conditioned response in rainbow trout selected for high or low responsiveness to stress. Horm Behav 2004; 46:450-7. [PMID: 15465531 DOI: 10.1016/j.yhbeh.2004.05.003] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2003] [Revised: 02/17/2004] [Accepted: 05/11/2004] [Indexed: 10/26/2022]
Abstract
Two lines of rainbow trout (Oncorhynchus mykiss) that exhibit divergent endocrine responsiveness to stressors also display disparate behavioral traits. To investigate whether the high-responding (HR) and low-responding (LR) fish also differ in cognitive function, the rate of extinction of a conditioned response was compared between the two lines. Groups of HR and LR fish were exposed to a paired conditioned stimulus (CS; water off) and unconditioned stimulus (US; confinement stressor). After exposure to 18 CS-US pairings, at least 70% of individuals of both lines acquired a conditioned response (CR) manifested as an elevation of blood cortisol levels on presentation of the CS only. Post-conditioning, the fish were tested by presentation of the CS at weekly intervals, for 4 weeks, with no further reinforcement, and the extinction of the CR in the two lines was compared. The decline in mean plasma cortisol levels after exposure to the CS over successive tests suggested that the CR was retained for a shorter period among the HR (<14 days) than LR fish (<21 days). The frequency of individuals within each line whose plasma cortisol levels indicated a stress response when exposed to the CS was significantly greater among the LR than HR fish at 14 and 21 days with no HR fish falling into this category at 21 days. At 28 days post-conditioning, there were no HR fish and only three LR fish were categorized as "stressed". These results suggest that there are differences in cognitive function between the two lines. Possible mechanisms underlying these differences are discussed.
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Affiliation(s)
- P S A Moreira
- NERC Centre for Ecology and Hydrology Lancaster, Lancaster Environment Centre, Bailrigg, Lancaster LA1 4AP, UK.
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Abstract
This review of negative reinforcement models of drug dependence is part of a series that takes the position that a complete understanding of current concepts of dependence will facilitate the development of reliable and valid measures of the emergence of tobacco dependence. Other reviews within the series consider models that emphasize positive reinforcement and social learning/cognitive models. This review summarizes negative reinforcement in general and then presents four current negative reinforcement models that emphasize withdrawal, classical conditioning, self-medication and opponent-processes. For each model, the paper outlines central aspects of dependence, conceptualization of dependence development and influences that the model might have on current and future measures of dependence. Understanding how drug dependence develops will be an important part of future successful tobacco dependence measurement, prevention and treatment strategies.
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Affiliation(s)
- Thomas Eissenberg
- Department of Psychology and Institute for Drug and Alcohol Studies, Virginia Commonwealth University, VA, USA.
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Hucklebridge F. Behavioral conditioning of the immune system. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2003; 52:325-51. [PMID: 12498110 DOI: 10.1016/s0074-7742(02)52015-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Frank Hucklebridge
- Department of Biomedical Sciences, University of Westminster, London W1M 8JS, United Kingdom
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Exton MS, von Auer AK, Buske-Kirschbaum A, Stockhorst U, Göbel U, Schedlowski M. Pavlovian conditioning of immune function: animal investigation and the challenge of human application. Behav Brain Res 2000; 110:129-41. [PMID: 10802310 DOI: 10.1016/s0166-4328(99)00191-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
Pavlovian conditioning of immune functions provided early impetus to the rapidly expanding knowledge of bi-directional communication among the immune, endocrine, and central nervous systems. Since these early investigations, the phenomenology of this response has been well characterized. However the neural mechanisms and biological relevance of conditioned immunomodulation remain unclear. To this end, we present here data from our laboratories that have: (1) revealed some of the neural mechanisms and biological relevance of an animal model of conditioned immunomodulation; (2) demonstrated the conditionability and potential mechanisms of conditioned immune responses in healthy humans, and (3) investigated conditioned immunomodulation in a clinical sample. Together, these data demonstrate that animal models provide a basis for investigating mechanisms whereby conditioned changes in immune function may modulate health status in a clinical realm.
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Affiliation(s)
- M S Exton
- Institute for Medical Psychology, University of Essen, Hufelandstrasse 55, 45122, Essen, Germany.
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