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Bavbek S, Ozyigit LP, Baiardini I, Braido F, Roizen G, Jerschow E. Placebo, Nocebo, and Patient-Reported Outcome Measures in Drug Allergy. THE JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY. IN PRACTICE 2023; 11:371-379. [PMID: 36521832 DOI: 10.1016/j.jaip.2022.11.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 11/24/2022] [Accepted: 11/30/2022] [Indexed: 12/14/2022]
Affiliation(s)
- Sevim Bavbek
- Division of Allergy and Clinical of Immunology, Department of Chest Diseases, Ankara University, School of Medicine, Ankara, Turkey.
| | - Leyla Pur Ozyigit
- Adult Allergy Service, Glenfield Hospital, University Hospitals of Leicester NHS Trust, Leicester, United Kingdom
| | - Ilaria Baiardini
- Istituti di Ricovero e Cura a Carattere Scientifico, Ospedale Policlinico San Martino, Genova, Italy; Università di Genova, (DIMI), Genova, Italy
| | - Fulvio Braido
- Istituti di Ricovero e Cura a Carattere Scientifico, Ospedale Policlinico San Martino, Genova, Italy; Università di Genova, (DIMI), Genova, Italy
| | - Gigia Roizen
- Department of Immunology, Clinica Alemana De Santiago, Santiago, Chile
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Duke-Novakovski T, Jimenez CP, Fujiyama M, Beazley SG. Plasma histamine concentrations in horses administered sodium penicillin, guaifenesin-xylazine-ketamine and isoflurane with morphine or butorphanol. Vet Anaesth Analg 2020; 48:17-25. [PMID: 33229232 DOI: 10.1016/j.vaa.2020.10.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 10/16/2020] [Accepted: 10/17/2020] [Indexed: 10/23/2022]
Abstract
OBJECTIVE Various drugs administered to horses undergoing surgical procedures can release histamine. Histamine concentrations were evaluated in horses prepared for surgery and administered butorphanol or morphine intraoperative infusions. STUDY DESIGN Prospective studies with one randomized. ANIMALS A total of 44 client-owned horses. METHODS In one study, anesthesia was induced with xylazine followed by ketamine-diazepam. Anesthesia was maintained with guaifenesin-xylazine-ketamine (GXK) during surgical preparation. For surgery, isoflurane was administered with intravenous (IV) morphine (group M: 0.15 mg kg-1 and 0.1 mg kg-1 hour-1; 15 horses) or butorphanol (group B: 0.05 mg kg-1 and 0.01 mg kg-1 hour-1; 15 horses). Histamine and morphine concentrations were measured using enzyme-linked immunoassay before opioid injection (time 0), and after 1, 2, 5, 30, 60 and 90 minutes. In a subsequent study, plasma histamine concentrations were measured in 14 horses before drug administration (baseline), 15 minutes after IV sodium penicillin and 15 minutes after starting GXK IV infusion. Statistical comparison was performed using anova for repeated measures. Pearson correlation compared morphine and histamine concentrations. Data are presented as mean ± standard deviation. Significance was assumed when p ≤ 0.05. RESULTS With histamine, differences occurred between baseline (3.2 ± 2.4 ng mL-1) and GXK (5.2 ± 7.1 ng mL-1) and between baseline and time 0 in group B (11.9 ± 13.4 ng mL-1) and group M (11.1 ± 12.4 ng mL-1). No differences occurred between baseline and after penicillin or between groups M and B. Morphine concentrations were higher at 1 minute following injection (8.1 ± 5.1 ng mL-1) than at 30 minutes (4.9 ± 3.1 ng mL-1) and 60 minutes (4.0 ± 2.5 ng mL-1). Histamine correlated with morphine at 2, 30 and 60 minutes. CONCLUSIONS AND CLINICAL RELEVANCE GXK increased histamine concentration, but concentrations were similar with morphine and butorphanol.
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Affiliation(s)
- Tanya Duke-Novakovski
- Department of Small Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Sakatoon, SK, Canada
| | - Carolina Palacios Jimenez
- Department of Small Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Sakatoon, SK, Canada
| | - Masako Fujiyama
- Department of Small Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Sakatoon, SK, Canada
| | - Shannon G Beazley
- Department of Small Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Sakatoon, SK, Canada
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Meeuwis SH, van Middendorp H, van Laarhoven AIM, van Leijenhorst C, Pacheco-Lopez G, Lavrijsen APM, Veldhuijzen DS, Evers AWM. Placebo and nocebo effects for itch and itch-related immune outcomes: A systematic review of animal and human studies. Neurosci Biobehav Rev 2020; 113:325-337. [PMID: 32240668 DOI: 10.1016/j.neubiorev.2020.03.025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 03/24/2020] [Indexed: 12/19/2022]
Abstract
Placebo and nocebo effects can influence somatic symptoms such as pain. For itch and other dermatological symptoms these effects have been far less investigated. This review systematically integrates evidence from both animal (mainly rodents) and human trials on placebo and nocebo effects in itch, itch-related symptoms and conditions of the skin and mucous membranes, and related immune outcomes (e.g., histamine). Thirty-one animal studies, and fifty-five human studies (k = 21 healthy participants, k = 34 patients) were included. Overall, studies consistently show that placebo and nocebo effects can be induced by various methods (e.g., suggestions, conditioning and social cues), despite high heterogeneity across studies. Effects of suggestions were found consistently across subjective and behavioral parameters (e.g., itch and scratching in humans), whereas conditioning was likely to impact physiological parameters under certain conditions (e.g., conditioning of histamine levels in stressed rodents). Brain areas responsible for itch processing were associated with nocebo effects. Future research may investigate how variations in methods impact placebo and nocebo effects, and whether all symptoms and conditions can be influenced equally.
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Affiliation(s)
- Stefanie H Meeuwis
- Health, Medical and Neuropsychology Unit, Institute of Psychology, Faculty of Social and Behavioral Sciences, Leiden University, P.O. Box 9555, 2300RB, Leiden, the Netherlands; Leiden Institute for Brain and Cognition, P.O. Box 9600, 2300RC, Leiden University Medical Center, Leiden, the Netherlands.
| | - Henriët van Middendorp
- Health, Medical and Neuropsychology Unit, Institute of Psychology, Faculty of Social and Behavioral Sciences, Leiden University, P.O. Box 9555, 2300RB, Leiden, the Netherlands; Leiden Institute for Brain and Cognition, P.O. Box 9600, 2300RC, Leiden University Medical Center, Leiden, the Netherlands
| | - Antoinette I M van Laarhoven
- Health, Medical and Neuropsychology Unit, Institute of Psychology, Faculty of Social and Behavioral Sciences, Leiden University, P.O. Box 9555, 2300RB, Leiden, the Netherlands; Leiden Institute for Brain and Cognition, P.O. Box 9600, 2300RC, Leiden University Medical Center, Leiden, the Netherlands; Department of Psychiatry, Leiden University Medical Center, P.O. Box 9600, 2300RC, Leiden, the Netherlands
| | - Cora van Leijenhorst
- Health, Medical and Neuropsychology Unit, Institute of Psychology, Faculty of Social and Behavioral Sciences, Leiden University, P.O. Box 9555, 2300RB, Leiden, the Netherlands
| | - Gustavo Pacheco-Lopez
- Health, Medical and Neuropsychology Unit, Institute of Psychology, Faculty of Social and Behavioral Sciences, Leiden University, P.O. Box 9555, 2300RB, Leiden, the Netherlands; Metropolitan Autonomous University (UAM), Campus Lerma, Health Sciences Department, Lerma, 52005, Edo Mex, Mexico
| | - Adriana P M Lavrijsen
- Department of Dermatology, Leiden University Medical Center, P.O. Box 9600, 2300RC, Leiden, the Netherlands
| | - Dieuwke S Veldhuijzen
- Health, Medical and Neuropsychology Unit, Institute of Psychology, Faculty of Social and Behavioral Sciences, Leiden University, P.O. Box 9555, 2300RB, Leiden, the Netherlands; Leiden Institute for Brain and Cognition, P.O. Box 9600, 2300RC, Leiden University Medical Center, Leiden, the Netherlands
| | - Andrea W M Evers
- Health, Medical and Neuropsychology Unit, Institute of Psychology, Faculty of Social and Behavioral Sciences, Leiden University, P.O. Box 9555, 2300RB, Leiden, the Netherlands; Leiden Institute for Brain and Cognition, P.O. Box 9600, 2300RC, Leiden University Medical Center, Leiden, the Netherlands; Department of Psychiatry, Leiden University Medical Center, P.O. Box 9600, 2300RC, Leiden, the Netherlands
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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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Abstract
OBJECTIVE Allergic rhinitis symptoms can be reduced by behaviorally conditioning antihistamine. It is unclear whether these findings extend to histamine-induced itch or work when participants are informed about the conditioning procedure (open-label conditioning). The current study aims to investigate the efficacy of (open-label) antipruritic behavioral conditioning for histamine-induced itch. METHODS Healthy participants (n = 92; 84% female) were randomized to I) an open-label conditioned, II) closed-label conditioned, III) conditioned-not-evoked control, or IV) nonconditioned control group. A two-phase conditioning paradigm was used. During acquisition, a conditioned stimulus (CS; distinctively tasting beverage) was repeatedly paired with the H1-antihistamine levocetirizine (groups I-III). During evocation, the CS was paired with placebo (I, II), or instead of the CS, water was paired with placebo (III). The nonconditioned control group (IV) received CS with placebo in both phases. Itch after histamine iontophoresis and physiological data (i.e., spirometry, heart rate, skin conductance) were assessed. Combined conditioned and combined control groups were first compared, and analyses were repeated for separate groups. RESULTS Marginally lower itch was reported in the combined conditioned compared with the control groups (F(1,88) = 2.10, p = .076, ηpartial = 0.02); no differences between separate groups were found. No effects on physiological data were found, except for heart rate, which reduced significantly and consistently for control groups, and less consistently for conditioned groups (group by time interaction: F(7,80) = 2.35, p = .031, ηpartial = 0.17). CONCLUSION Limited support was found for the efficacy of antipruritic behavioral conditioning, regardless of whether participants were informed about the conditioning procedure. The application of open-label conditioning in patient populations should be further researched. TRIAL REGISTRATION www.trialregister.nl; ID NTR5544.
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Lückemann L, Unteroberdörster M, Kirchhof J, Schedlowski M, Hadamitzky M. Applications and limitations of behaviorally conditioned immunopharmacological responses. Neurobiol Learn Mem 2017; 142:91-98. [PMID: 28216206 DOI: 10.1016/j.nlm.2017.02.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Revised: 02/10/2017] [Accepted: 02/15/2017] [Indexed: 12/17/2022]
Abstract
The importance of placebo responses for the treatment of various medical conditions has increasingly been recognized, whereas knowledge and systematic application in clinical settings are still sparse. One possible application for placebo responses in pharmacotherapy is given by learning paradigms, such as behaviorally conditioned immunosuppression, aiming at drug dose reduction while maintaining therapeutic efficacy of drug treatment. In an established learning paradigm of conditioned taste aversion/avoidance (CTA) in both, rats and humans, respectively, a novel-tasting drinking solution (conditioned stimulus, CS) is paired with an injection of the immunosuppressive drug cyclosporine A (CsA) as unconditioned stimulus (US). The conditioned response, evoked by re-presenting the CS alone at a later time, is reflected by avoidance behavior of consuming the solution (conditioned taste aversion; CTA) and a diminished interleukin (IL)-2 and interferon (IFN)-γ cytokine production as well as mRNA expression of rat splenic T cells or human peripheral T lymphocytes, closely mimicking the immunosuppressive effects of CsA. However, due to unreinforced CS-re-exposure conditioned responses progressively decreases over time (extinction), reflecting a considerable challenge for potential clinical applications of this learned immunosuppression. The present article discusses and critically reviews actual approaches, applications but also limitations of learning paradigms in immune pharmacotherapy.
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Affiliation(s)
- Laura Lückemann
- Institute of Medical Psychology and Behavioral Immunobiology, University Hospital Essen, University of Duisburg-Essen, 45122 Essen, Germany
| | - Meike Unteroberdörster
- Department of Neurosurgery, University Hospital Essen, University of Duisburg-Essen, 45122 Essen, Germany
| | - Julia Kirchhof
- Institute of Medical Psychology and Behavioral Immunobiology, University Hospital Essen, University of Duisburg-Essen, 45122 Essen, Germany
| | - Manfred Schedlowski
- Institute of Medical Psychology and Behavioral Immunobiology, University Hospital Essen, University of Duisburg-Essen, 45122 Essen, Germany
| | - Martin Hadamitzky
- Institute of Medical Psychology and Behavioral Immunobiology, University Hospital Essen, University of Duisburg-Essen, 45122 Essen, Germany.
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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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Vits S, Cesko E, Enck P, Hillen U, Schadendorf D, Schedlowski M. Behavioural conditioning as the mediator of placebo responses in the immune system. Philos Trans R Soc Lond B Biol Sci 2011; 366:1799-807. [PMID: 21576137 DOI: 10.1098/rstb.2010.0392] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Current placebo research postulates that conditioning processes are one of the major mechanisms of the placebo response. Behaviourally conditioned changes in peripheral immune functions have been demonstrated in experimental animals, healthy subjects and patients. The physiological mechanisms responsible for this 'learned immune response' are not yet fully understood, but some relevant afferent and efferent pathways in the communication between the brain and the peripheral immune system have been identified. In addition, possible benefits and applicability in clinical settings have been demonstrated where behaviourally conditioned immunosuppression attenuated the exacerbation of autoimmune diseases, prolonged allograft survival and affected allergic responses. Here, we summarize data describing the mechanisms and the potential clinical benefit of behaviourally conditioned immune functions, with particular focus on learned placebo effects on allergic reactions.
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Affiliation(s)
- Sabine Vits
- Institute of Medical Psychology and Behavioral Immunobiology, University Clinic Essen, Essen, Germany.
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Schedlowski M, Pacheco-López G. The learned immune response: Pavlov and beyond. Brain Behav Immun 2010; 24:176-85. [PMID: 19698779 DOI: 10.1016/j.bbi.2009.08.007] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2009] [Revised: 08/10/2009] [Accepted: 08/14/2009] [Indexed: 01/26/2023] Open
Abstract
The ability to associate physiological changes with a specific flavor was most likely acquired during evolution as an adaptive strategy aimed at protecting the organism while preparing it for danger. The behaviorally conditioned or learned immune response is an exquisite example of the bidirectional communication between the central nervous system (CNS) and the peripheral immune system. How is it possible that specific immuno-modulating properties of a drug or substance (unconditioned stimulus) can be re-enlisted just by the mere re-exposure to a particular taste, odor or environment (conditioned stimulus)? To answer this key question, we review the neurobiological mechanism mediating this type of associative learning, as well as the pathways and mechanisms employed by the brain to harness the immune system during the execution of the conditioned immune response. Finally, we focus on the potential therapeutic relevance of such learned immune responses, and their re-conceptualization within the framework of "learned placebo effects".
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Affiliation(s)
- Manfred Schedlowski
- Institute of Medical Psychology and Behavioral Immunobiology, University of Duisburg-Essen, Medical Faculty, 45122 Essen, Germany.
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Riether C, Doenlen R, Pacheco-Lopez G, Niemi MB, Engler A, Engler H, Schedlowski M. Behavioural Conditioning of Immune Functions: How the Central Nervous System Controls Peripheral Immune Responses by Evoking Associative Learning Processes. Rev Neurosci 2008; 19:1-17. [DOI: 10.1515/revneuro.2008.19.1.1] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Abstract
PURPOSE OF REVIEW Classical conditioning is a form of associative learning, based on the pioneering work of I. P. Pavlov: due to its association with an unconditioned stimulus that induces an unconditioned response, an initially neutral stimulus will become a conditioned stimulus evoking a conditioned response in the absence of the unconditioned stimulus. One important area for the application of conditioning principles is the regulation of physiological systems in general, and endocrine responses and its concomitant changes specifically. Conditioned endocrine responses were predominantly addressed in animal studies so far, mainly examining conditioned insulin production (and blood-glucose change) and corticosterone release. RECENT FINDINGS There are very few studies on classical conditioning of endocrine responses in the annual period of this review. The advancement, however, is that some are conducted with humans. Recently, as a new avenue, hormones and neurotransmitters have been examined as mediators of basic conditioning processes. Moreover, there is an increasing interest in gender-specific conditioning responses which are influenced by gonadal hormones. SUMMARY Research on classical conditioning demonstrates that endocrine systems are adaptable to environmental signals. Likewise, the endocrine status of an organism (at least with regard to glucocorticoids and gonadal hormones) was shown to modify classically conditioned responses. Partly due to the high expenditure of conducting conditioning experiments, the quantity of studies is limited, but there is a need to extend this research to humans. In sum, the application of conditioning paradigms constitutes an important research tool for behavioral medicine as well as psychiatry to examine brain-behavior relationships.
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Affiliation(s)
- Ursula Stockhorst
- Institute of Medical Psychology, Heinrich-Heine-University Duesseldorf, Duesseldorf, Germany.
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