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Sliepen SH, Korioth J, Christoph T, Tzschentke TM, Diaz‐delCastillo M, Heegaard A, Rutten K. The nociceptin/orphanin FQ receptor system as a target to alleviate cancer-induced bone pain in rats: Model validation and pharmacological evaluation. Br J Pharmacol 2021; 178:1995-2007. [PMID: 31724155 PMCID: PMC8246843 DOI: 10.1111/bph.14899] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 08/13/2019] [Accepted: 09/27/2019] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND AND PURPOSE Cancer-induced bone pain remains inadequately controlled, and current standard of care analgesics is accompanied by several side effects. Nociceptin/orphanin FQ peptide (NOP) receptor agonists have demonstrated broad analgesic properties in rodent neuropathic and inflammatory pain models. Here, we investigate the analgesic potential of NOP receptor activation in a rodent cancer-induced bone pain model. EXPERIMENTAL APPROACH Model validation by intratibial inoculation in male Sprague Dawley rats was performed with varying MRMT-1/Luc2 cell quantities (0.5-1.5 × 106 ·ml-1 ) and a behavioural battery (>14 days post-surgery) including evoked and non-evoked readouts: paw pressure test, cold plate, von Frey, open field, and weight distribution. Anti-allodynic potential of the endogenous NOP receptor ligand nociceptin (i.t.) and NOP receptor agonist Ro65-6570 ( i.p.) was tested using von Frey filaments, followed by a combination experiment with Ro65-6570 and the NOP receptor antagonist J-113397 (i.p.). Plasma cytokine levels and NOP receptor gene expression in dorsal root ganglion (DRG, L4-L6) and bone marrow were examined. KEY RESULTS Inoculation with 1.5 × 106 ·ml-1 of MRMT-1/Luc2 cells resulted in a robust and progressive pain-related phenotype. Nociceptin and Ro65-6570 treatment inhibited cancer-induced mechanical allodynia. J-113397 selectively antagonized the effect of Ro65-6570. MRMT-1/Luc2-bearing animals demonstrated elevated plasma cytokine levels of IL-4, IL-5, IL-6 and IL-10 plus unaltered NOP-r gene expression in DRG and reduced expression in bone marrow. CONCLUSION AND IMPLICATIONS Nociceptin and Ro65-6570 selectively and dose-dependently reversed cancer-induced bone pain-like behaviour. The NOP receptor system may be a potential target for cancer-induced bone pain treatment. LINKED ARTICLES This article is part of a themed issue on The molecular pharmacology of bone and cancer-elated bone diseases. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.9/issuetoc.
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Affiliation(s)
- Sonny H.J. Sliepen
- Grünenthal InnovationGrünenthal GmbHAachenGermany
- Department of Drug Design and Pharmacology, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | | | | | | | - Marta Diaz‐delCastillo
- Department of Drug Design and Pharmacology, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Anne‐Marie Heegaard
- Department of Drug Design and Pharmacology, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Kris Rutten
- Grünenthal InnovationGrünenthal GmbHAachenGermany
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Axelsson M, Schønning V, Bockting C, Buysse A, Desmet M, Dewaele A, Giovazolias T, Hannon D, Kafetsios K, Meganck R, Ntani S, Rutten K, Triliva S, Van Beveren L, Vandamme J, Øverland S, Hensing G. Lived experiences: a focus group pilot study within the MentALLY project of mental healthcare among European users. BMC Health Serv Res 2020; 20:605. [PMID: 32611345 PMCID: PMC7329529 DOI: 10.1186/s12913-020-05454-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Accepted: 06/22/2020] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Mental healthcare is an important component in societies' response to mental health problems. Although the World Health Organization highlights availability, accessibility, acceptability and quality of healthcare as important cornerstones, many Europeans lack access to mental healthcare of high quality. Qualitative studies exploring mental healthcare from the perspective of people with lived experiences would add to previous research and knowledge by enabling in-depth understanding of mental healthcare users, which may be of significance for the development of mental healthcare. Therefore, the aim of the current study was to describe experiences of mental healthcare among adult Europeans with mental health problems. METHOD In total, 50 participants with experiences of various mental health problems were recruited for separate focus group interviews in each country. They had experiences from both the private and public sectors, and with in- and outpatient mental healthcare. The focus group interviews (N = 7) were audio recorded, transcribed verbatim and analysed through thematic analysis. The analysis yielded five themes and 13 subthemes. RESULTS The theme Seeking and trying to find help contained three subthemes describing personal thresholds for seeking professional help, not knowing where to get help, and the importance of receiving help promptly. The theme Awaiting assessment and treatment contained two subthemes including feelings of being prioritized or not and feelings of being abandoned during the often-lengthy referral process. The theme Treatment: a plan with individual parts contained three subthemes consisting of demands for tailored treatment plans in combination with medications and human resources and agreement on treatment. The theme Continuous and respectful care relationship contained two subthemes describing the importance of continuous care relationships characterised by empathy and respect. The theme Suggestions for improvements contained three subthemes highlighting an urge to facilitate care contacts and to increase awareness of mental health problems and a wish to be seen as an individual with potential. CONCLUSION Facilitating contacts with mental healthcare, a steady contact during the referral process, tailored treatment and empathy and respect are important aspects in efforts to improve mental healthcare. Recommendations included development of collaborative practices between stakeholders in order to increase general societal awareness of mental health problems.
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Affiliation(s)
- Malin Axelsson
- Department of Care Science, Faculty of Health and Society, Malmö University, Jan Waldenströms gata 25 – F416, SE-205 06 Malmö, Sweden
| | - Viktor Schønning
- Department of Public Health and Community Medicine, Institute of Medicine, The Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
- Department of Health Promotion, Division of Mental and Physical Health, Norwegian Institute of Public Health, Bergen, Norway
| | - Claudi Bockting
- Amsterdam UMC, Department of Psychiatry (AMC) and Institute for Advanced Studies, University of Amsterdam, Amsterdam, the Netherlands
| | - Ann Buysse
- Department of Experimental Clinical and Health Psychology, Faculty of Psychology and Educational Sciences, Ghent University, Ghent, Belgium
| | - Mattias Desmet
- Department of Psychoanalysis and Clinical Consulting, Faculty of Psychology and Educational Sciences, Ghent University, Ghent, Belgium
| | - Alexis Dewaele
- Department of Experimental Clinical and Health Psychology, Faculty of Psychology and Educational Sciences, Ghent University, Ghent, Belgium
| | | | - Dewi Hannon
- Department of Experimental Clinical and Health Psychology, Faculty of Psychology and Educational Sciences, Ghent University, Ghent, Belgium
| | | | - Reitske Meganck
- Department of Psychoanalysis and Clinical Consulting, Faculty of Psychology and Educational Sciences, Ghent University, Ghent, Belgium
| | - Spyridoula Ntani
- Department of Psychology, University of Crete, Rethymno, Crete Greece
| | - Kris Rutten
- Department of Educational Studies, Faculty of Psychology and Educational Sciences, Ghent University, Ghent, Belgium
| | - Sofia Triliva
- Department of Psychology, University of Crete, Rethymno, Crete Greece
| | - Laura Van Beveren
- Department of Educational Studies, Faculty of Psychology and Educational Sciences, Ghent University, Ghent, Belgium
| | - Joke Vandamme
- Department of Experimental Clinical and Health Psychology, Faculty of Psychology and Educational Sciences, Ghent University, Ghent, Belgium
| | - Simon Øverland
- Department of Health Promotion, Division of Mental and Physical Health, Norwegian Institute of Public Health, Bergen, Norway
- Division of Mental and Physical Health, Norwegian Institute of Public Health & Department of Psychosocial Science, University of Bergen, Bergen, Norway
| | - Gunnel Hensing
- Department of Public Health and Community Medicine, Institute of Medicine, The Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
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Van Beveren L, Rutten K, Hensing G, Spyridoula N, Schønning V, Axelsson M, Bockting C, Buysse A, De Neve I, Desmet M, Dewaele A, Giovazolias T, Hannon D, Kafetsios K, Meganck R, Øverland S, Triliva S, Vandamme J. A Critical Perspective on Mental Health News in Six European Countries: How Are "Mental Health/Illness" and "Mental Health Literacy" Rhetorically Constructed? Qual Health Res 2020; 30:1362-1378. [PMID: 32249686 PMCID: PMC7307005 DOI: 10.1177/1049732320912409] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
In this study, we aim to contribute to the field of critical health communication research by examining how notions of mental health and illness are discursively constructed in newspapers and magazines in six European countries and how these constructions relate to specific understandings of mental health literacy. Using the method of cluster-agon analysis, we identified four terminological clusters in our data, in which mental health/illness is conceptualized as "dangerous," "a matter of lifestyle," "a unique story and experience," and "socially situated." We furthermore found that we cannot unambiguously assume that biopsychiatric discourses or discourses aimed at empathy and understanding are either exclusively stigmatizing or exclusively empowering and normalizing. We consequently call for a critical conception of mental health literacy arguing that all mental health news socializes its audience in specific understandings of and attitudes toward mental health (knowledge) and that discourses on mental health/illness can work differently in varying contexts.
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Affiliation(s)
| | | | | | | | - Viktor Schønning
- University of Gothenburg, Gothenburg,
Sweden
- Norwegian Institute of Public Health,
Bergen, Norway
| | | | | | | | | | | | | | | | | | | | | | - Simon Øverland
- Norwegian Institute of Public Health,
Bergen, Norway
- University of Bergen, Bergen,
Norway
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Triliva S, Ntani S, Giovazolias T, Kafetsios K, Axelsson M, Bockting C, Buysse A, Desmet M, Dewaele A, Hannon D, Haukenes I, Hensing G, Meganck R, Rutten K, Schønning V, Van Beveren L, Vandamme J, Øverland S. Healthcare professionals' perspectives on mental health service provision: a pilot focus group study in six European countries. Int J Ment Health Syst 2020; 14:16. [PMID: 32165920 PMCID: PMC7060571 DOI: 10.1186/s13033-020-00350-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2019] [Accepted: 02/29/2020] [Indexed: 12/11/2022] Open
Abstract
Background The mental healthcare treatment gap (mhcGAP) in adult populations has been substantiated across Europe. This study formed part of MentALLY, a research project funded by the European Commission, which aimed to gather qualitative empirical evidence to support the provision of European mental healthcare that provides effective treatment to all adults who need it. Methods Seven focus groups were conducted with 49 health professionals (HPs), including psychologists, psychiatrists, social workers, general practitioners, and psychiatric nurses who worked in health services in Belgium, Cyprus, Greece, the Netherlands, Norway and Sweden. The focus group discussions centered on the barriers and facilitators to providing quality care to people with mild, medium, and severe mental health problems. Analyses included deductively and inductively driven coding procedures. Cross-country consensus was obtained by summarizing findings in the form of a fact sheet which was shared for triangulation by all the MentALLY partners. Results The results converged into two overarching themes: (1) Minding the treatment gap: the availability and accessibility of Mental Health Services (MHS). The mhcGAP gap identified is composed of different elements that constitute the barriers to care, including bridging divides in care provision, obstacles in facilitating access via referrals and creating a collaborative ‘chain of care’. (2) Making therapeutic practice relevant by providing a broad-spectrum of integrated and comprehensive services that value person-centered care comprised of authenticity, flexibility and congruence. Conclusions The mhcGAP is comprised of the following barriers: a lack of funding, insufficient capacity of human resources, inaccessibility to comprehensive services and a lack of availability of relevant treatments. The facilitators to the provision of MHC include using collaborative models of primary, secondary and prevention-oriented mental healthcare. Teamwork in providing care was considered to be a more effective and efficient use of resources. HPs believe that the use of e-mental health and emerging digital technologies can enhance care provision. Facilitating access to a relevant continuum of community-based care that is responsive coordinated and in line with people’s needs throughout their lives is an essential aspect of optimal care provision.
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Affiliation(s)
- Sofia Triliva
- 1Department of Psychology, University of Crete, 74100 Rethymno, Crete, Greece
| | - Spyridoula Ntani
- 1Department of Psychology, University of Crete, 74100 Rethymno, Crete, Greece
| | | | | | - Malin Axelsson
- 2Department of Care Science, Faculty of Health and Society, Malmö University, Malmö, Sweden
| | - Claudi Bockting
- 3Department of Psychiatry, Amsterdam UMC, Location AMC, University of Amsterdam, Amsterdam, The Netherlands.,4Institute for Advanced Studies, University of Amsterdam, Amsterdam, The Netherlands
| | - Ann Buysse
- 5Department of Experimental Clinical and Health Psychology, Faculty of Psychology and Educational Sciences, Ghent University, Ghent, Belgium
| | - Mattias Desmet
- 6Department of Psychoanalysis and Clinical Consulting, Faculty of Psychology and Educational Sciences, Ghent University, Ghent, Belgium
| | - Alexis Dewaele
- 5Department of Experimental Clinical and Health Psychology, Faculty of Psychology and Educational Sciences, Ghent University, Ghent, Belgium
| | - Dewi Hannon
- 5Department of Experimental Clinical and Health Psychology, Faculty of Psychology and Educational Sciences, Ghent University, Ghent, Belgium
| | - Inger Haukenes
- 7Research Unit for General Practice, NORCE-Norwegian Research Centre, Bergen, Norway.,8Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway
| | - Gunnel Hensing
- 9Department of Public Health and Community Medicine, Institute of Medicine, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Reitske Meganck
- 6Department of Psychoanalysis and Clinical Consulting, Faculty of Psychology and Educational Sciences, Ghent University, Ghent, Belgium
| | - Kris Rutten
- 10Department of Educational Studies, Faculty of Psychology and Educational Sciences, Ghent University, Ghent, Belgium
| | - Viktor Schønning
- 9Department of Public Health and Community Medicine, Institute of Medicine, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden.,11Division of Mental and Physical Health, Norwegian Institute of Public Health & Department of Psychosocial Science, University of Bergen, Bergen, Norway
| | - Laura Van Beveren
- 10Department of Educational Studies, Faculty of Psychology and Educational Sciences, Ghent University, Ghent, Belgium
| | - Joke Vandamme
- 5Department of Experimental Clinical and Health Psychology, Faculty of Psychology and Educational Sciences, Ghent University, Ghent, Belgium
| | - Simon Øverland
- 11Division of Mental and Physical Health, Norwegian Institute of Public Health & Department of Psychosocial Science, University of Bergen, Bergen, Norway
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Sliepen SHJ, Diaz-Delcastillo M, Korioth J, Olsen RB, Appel CK, Christoph T, Heegaard AM, Rutten K. Cancer-induced Bone Pain Impairs Burrowing Behaviour in Mouse and Rat. In Vivo 2019; 33:1125-1132. [PMID: 31280201 DOI: 10.21873/invivo.11582] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 05/16/2019] [Accepted: 05/20/2019] [Indexed: 02/07/2023]
Abstract
BACKGROUND Cancer-induced bone pain remains a serious public health concern, with a need for translational behavioural tests in order to assess nociception in preclinical models of this condition. Burrowing is an innate, ethologically relevant rodent behaviour that has been proven sensitive to chronic pain conditions. Herein, we studied for the first time whether burrowing performance is altered in preclinical models of cancer-induced bone pain. MATERIALS AND METHODS Mice and rats were inoculated with syngeneic breast cancer cells. Bone degradation was radiographically evaluated and nociception was assessed in limb-use and burrowing tests. RESULTS Cancer-bearing rodents showed reduced relative bone density and limb-use scores, confirming disease development. Burrowing performance decreased over time in both rodent models. CONCLUSION Burrowing performance was reduced in both rodent models, indicating that the burrowing test is a relevant and reproducible behavioural test for assessing disease development in both mouse and rat models of cancer-induced bone pain.
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Affiliation(s)
- Sonny Hermanus Johannes Sliepen
- Grünenthal GmbH, Grünenthal Innovation, Aachen, Germany.,Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Marta Diaz-Delcastillo
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Rikke Brix Olsen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Camilla Kristine Appel
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Anne-Marie Heegaard
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Kris Rutten
- Grünenthal GmbH, Grünenthal Innovation, Aachen, Germany
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Abstract
Purpose
In Flanders, the subventions in the cultural sector are mainly divided and decided upon within the framework of the Arts Decree. Within this policy framework, art organizations may choose in their funding applications for “participation” as one of the five possible functions to describe their artistic and cultural practices. However, questions need to be raised about the different interpretations of the notion of participation within this policy framework. The growing trend of evidence-based policy-making implies that participation risks to become a “target” that needs to be achieved instrumentally, which paradoxically ignores the fact that participatory practices within culture and the arts are very often diverse, multi-layered and context-specific practices. Starting from this paradox, the purpose of this paper is to explore how the current policy framework is translated into different “participatory” art practices by art organizations and specifically how cultural practitioners themselves conceptualize it.
Design/methodology/approach
In this paper, the authors discuss the results of a qualitative research based on semi-structured interviews with cultural practitioners about how they grapple with the notion of participation within their organizations and practices.
Findings
The results clearly show that practitioners use micro-politics of resistance to deal with different, and often conflicting, conceptualizations of participation in relation to this cultural policy framework.
Research limitations/implications
The implications of the findings are vital for the discussion about cultural policy. These micro-politics of resistance do not only have an impact on the development of individual participatory art practices but also on the broader participatory arts landscape and on how the function of participation is perceived within the renewed policy framework.
Originality/value
The original contribution of this paper is to explore the perspective of practitioners in cultural organizations about the function of participation in the Arts Decree in Flanders and specifically how the notion of participation is operationalized in their practices in relation to this cultural policy framework.
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7
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Tzschentke TM, Rutten K. Mu-opioid peptide (MOP) and nociceptin/orphanin FQ peptide (NOP) receptor activation both contribute to the discriminative stimulus properties of cebranopadol in the rat. Neuropharmacology 2018; 129:100-108. [PMID: 29155273 DOI: 10.1016/j.neuropharm.2017.11.026] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 11/13/2017] [Accepted: 11/15/2017] [Indexed: 12/11/2022]
Abstract
The novel potent analgesic cebranopadol is an agonist at nociceptin/orphanin FQ peptide (NOP) and classical opioid receptors, with the highest in-vitro activity at NOP and mu-opioid peptide (MOP) receptors, and somewhat lower activity at kappa-opioid peptide (KOP) and delta-opioid peptide (DOP) receptors. We addressed the question of which of these pharmacological activities contribute to the stimulus properties of cebranopadol using a rat drug discrimination procedure. First, cebranopadol was tested in generalization tests against a morphine cue, including receptor-specific antagonism. Second, cebranopadol was established as a cue, and MOP, NOP, KOP and DOP receptor-selective agonists were tested in generalization tests. Third, cebranopadol in combination with receptor-selective antagonists was tested against the cebranopadol cue. Cebranopadol generalized to the morphine cue. Full generalization was only seen at clearly supra-analgesic doses. The effect of cebranopadol was reduced by naloxone, but was enhanced by the NOP receptor antagonist J-113397. In cebranopadol-trained rats, cebranopadol as well as morphine produced generalization. A NOP receptor agonist did not, while a DOP receptor agonist and a KOP receptor agonist weakly generalized to the cebranopadol cue. Conversely, generalization of cebranopadol was reduced by naloxone and J-113397, but not by a DOP or a KOP receptor antagonist. These results suggest a contribution of MOP receptor activity and a relative lack of contribution of DOP and KOP receptor activity to cebranopadol's stimulus properties. The findings regarding the contribution of NOP receptor activity were equivocal, but interestingly, the morphine-like stimulus property of cebranopadol appears to be reduced by its intrinsic NOP receptor activity.
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Affiliation(s)
- Thomas M Tzschentke
- Dept. Pharmacology, Grünenthal Innovation, Grünenthal GmbH, Aachen, Germany.
| | - Kris Rutten
- Dept. Pharmacology, Grünenthal Innovation, Grünenthal GmbH, Aachen, Germany
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Abstract
Purpose
In previous research on rhetoric and narrative in management research, cultural narratives have been studied as tools to reflect on rhetorical situations from the perspective of management. The purpose of this paper is to present a similar exploration of rhetoric while focusing on a modern example from popular culture: the television series Mad Men.
Design/methodology/approach
This paper first discusses rhetorical concepts from the work of Kenneth Burke and Richard Lanham as inspirational guides, thereafter, these concepts are used to analyze the case of Mad Men. Specifically, the main character Don Draper is analyzed as a homo rhetoricus in an attention economy.
Findings
Don Draper becomes a case study of what it means to introduce a rhetorical perspective in advertising and management. It is argued that Don Draper’s reflections in the series can be described as a “perspective on perspectives” or as a “toggling” between different rhetorical perspectives.
Originality/value
Previous research discussed the emergence of spinning and the appearance of the “spin doctor” as a major figure in society in general and fiction in particular. In this article, it is argued that the same is also true for advertising. Mad Men is introduced as a case study about the revival of rhetoric as a major skill and an important perspective in and for our personal, professional and social lives.
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Wodarski R, Delaney A, Ultenius C, Morland R, Andrews N, Baastrup C, Bryden LA, Caspani O, Christoph T, Gardiner NJ, Huang W, Kennedy JD, Koyama S, Li D, Ligocki M, Lindsten A, Machin I, Pekcec A, Robens A, Rotariu SM, Voß S, Segerdahl M, Stenfors C, Svensson CI, Treede RD, Uto K, Yamamoto K, Rutten K, Rice AS. Cross-centre replication of suppressed burrowing behaviour as an ethologically relevant pain outcome measure in the rat: a prospective multicentre study. Pain 2016; 157:2350-65. [PMID: 27643836 PMCID: PMC5028161 DOI: 10.1097/j.pain.0000000000000657] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Revised: 05/19/2016] [Accepted: 05/20/2016] [Indexed: 12/11/2022]
Abstract
Burrowing, an ethologically relevant rodent behaviour, has been proposed as a novel outcome measure to assess the global impact of pain in rats. In a prospective multicentre study using male rats (Wistar, Sprague-Dawley), replication of suppressed burrowing behaviour in the complete Freund adjuvant (CFA)-induced model of inflammatory pain (unilateral, 1 mg/mL in 100 µL) was evaluated in 11 studies across 8 centres. Following a standard protocol, data from participating centres were collected centrally and analysed with a restricted maximum likelihood-based mixed model for repeated measures. The total population (TP-all animals allocated to treatment; n = 249) and a selected population (SP-TP animals burrowing over 500 g at baseline; n = 200) were analysed separately, assessing the effect of excluding "poor" burrowers. Mean baseline burrowing across studies was 1113 g (95% confidence interval: 1041-1185 g) for TP and 1329 g (1271-1387 g) for SP. Burrowing was significantly suppressed in the majority of studies 24 hours (7 studies/population) and 48 hours (7 TP, 6 SP) after CFA injections. Across all centres, significantly suppressed burrowing peaked 24 hours after CFA injections, with a burrowing deficit of -374 g (-479 to -269 g) for TP and -498 g (-609 to -386 g) for SP. This unique multicentre approach first provided high-quality evidence evaluating suppressed burrowing as robust and reproducible, supporting its use as tool to infer the global effect of pain on rodents. Second, our approach provided important informative value for the use of multicentre studies in the future.
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Affiliation(s)
- Rachel Wodarski
- Pain Research Group, Department of Surgery and Cancer, Imperial College, London, United Kingdom
- Eli Lilly and Company, Erl Wood Manor, Windlesham, United Kingdom
| | - Ada Delaney
- Department of Physiology and Pharmacology, Karolinska Institute, Stockholm, Sweden
| | - Camilla Ultenius
- Neuroscience CNSP iMED, AstraZeneca R&D Södertälje, Södertälje, Sweden
| | - Rosie Morland
- Pain Research Group, Department of Surgery and Cancer, Imperial College, London, United Kingdom
| | - Nick Andrews
- Department of Neurobiology, Boston Children's Hospital, MA, USA
| | - Catherine Baastrup
- Danish Pain Research Center, Aarhus University Hospital, Aarhus, Denmark
| | - Luke A. Bryden
- CNS Disease Division Research Germany, Boehringer Ingelheim Pharma GmbH and Co KG, Biberach an der Riss, Germany
| | - Ombretta Caspani
- Department of Neurophysiology, Centre for Biomedicine and Medical Technology Mannheim (CBTM), Heidelberg University, Mannheim, Germany
| | - Thomas Christoph
- Department of Pharmacology and Biomarker Development, Translational Science and Strategy, Grünenthal GmbH, Aachen, Germany
| | - Natalie J. Gardiner
- Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
| | - Wenlong Huang
- Pain Research Group, Department of Surgery and Cancer, Imperial College, London, United Kingdom
| | | | - Suguru Koyama
- Laboratory for Pharmacology, Pharmaceutical Research Center, Asahi Kasei Pharma Corporation, Shizuoka, Japan
| | - Dominic Li
- Eli Lilly and Company, Indianapolis, IN, USA
| | - Marcin Ligocki
- Eli Lilly and Company, Erl Wood Manor, Windlesham, United Kingdom
| | | | - Ian Machin
- Deal, Kent, United Kingdom. L. A. Bryden is now with the Department of Experimental Psychology, University of Oxford, Oxford, United Kingdom. W. Huang is now with the Institute of Medical Sciences, University of Aberdeen, United Kingdom. C. Stenfors is now with the R&D CNS Research, Orion Corporation, Orion Pharma, Espoo, Finland
| | - Anton Pekcec
- CNS Disease Division Research Germany, Boehringer Ingelheim Pharma GmbH and Co KG, Biberach an der Riss, Germany
| | - Angela Robens
- Department of Pharmacology and Biomarker Development, Translational Science and Strategy, Grünenthal GmbH, Aachen, Germany
| | - Sanziana M. Rotariu
- Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
| | - Sabrina Voß
- Department of Neurophysiology, Centre for Biomedicine and Medical Technology Mannheim (CBTM), Heidelberg University, Mannheim, Germany
| | - Marta Segerdahl
- Neuroscience CNSP iMED, AstraZeneca R&D Södertälje, Södertälje, Sweden
- H. Lundbeck A/S, Valby, Denmark
| | - Carina Stenfors
- Neuroscience CNSP iMED, AstraZeneca R&D Södertälje, Södertälje, Sweden
| | - Camilla I. Svensson
- Department of Physiology and Pharmacology, Karolinska Institute, Stockholm, Sweden
| | - Rolf-Detlef Treede
- Department of Neurophysiology, Centre for Biomedicine and Medical Technology Mannheim (CBTM), Heidelberg University, Mannheim, Germany
| | - Katsuhiro Uto
- Laboratory for Pharmacology, Pharmaceutical Research Center, Asahi Kasei Pharma Corporation, Shizuoka, Japan
| | - Kazumi Yamamoto
- Laboratory for Pharmacology, Pharmaceutical Research Center, Asahi Kasei Pharma Corporation, Shizuoka, Japan
| | - Kris Rutten
- Department of Pharmacology and Biomarker Development, Translational Science and Strategy, Grünenthal GmbH, Aachen, Germany
| | - Andrew S.C. Rice
- Pain Research Group, Department of Surgery and Cancer, Imperial College, London, United Kingdom
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Patel R, Rutten K, Valdor M, Schiene K, Wigge S, Schunk S, Damann N, Christoph T, Dickenson AH. Electrophysiological characterization of activation state-dependent Ca(v)2 channel antagonist TROX-1 in spinal nerve injured rats. Neuroscience 2015; 297:47-57. [PMID: 25839150 PMCID: PMC4436437 DOI: 10.1016/j.neuroscience.2015.03.057] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 03/13/2015] [Accepted: 03/24/2015] [Indexed: 11/27/2022]
Abstract
TROX-1 exhibits activation state-dependent inhibition of Cav2.2 in vitro. TROX-1 selectively attenuates neuronal responses to mechanical stimulation. Anti-nociceptive effect of TROX-1 dependent on pathophysiological state.
Prialt, a synthetic version of Cav2.2 antagonist ω-conotoxin MVIIA derived from Conus magus, is the first clinically approved voltage-gated calcium channel blocker for refractory chronic pain. However, due to the narrow therapeutic window and considerable side effects associated with systemic dosing, Prialt is only administered intrathecally. N-triazole oxindole (TROX-1) is a novel use-dependent and activation state-selective small-molecule inhibitor of Cav2.1, 2.2 and 2.3 calcium channels designed to overcome the limitations of Prialt. We have examined the neurophysiological and behavioral effects of blocking calcium channels with TROX-1. In vitro, TROX-1, in contrast to state-independent antagonist Prialt, preferentially inhibits Cav2.2 currents in rat dorsal root ganglia (DRG) neurons under depolarized conditions. In vivo electrophysiology was performed to record from deep dorsal horn lamina V/VI wide dynamic range neurons in non-sentient spinal nerve-ligated (SNL) and sham-operated rats. In SNL rats, spinal neurons exhibited reduced responses to innocuous and noxious punctate mechanical stimulation of the receptive field following subcutaneous administration of TROX-1, an effect that was absent in sham-operated animals. No effect was observed on neuronal responses evoked by dynamic brushing, heat or cold stimulation in SNL or sham rats. The wind-up response of spinal neurons following repeated electrical stimulation of the receptive field was also unaffected. Spinally applied TROX-1 dose dependently inhibited mechanically evoked neuronal responses in SNL but not sham-operated rats, consistent with behavioral observations. This study confirms the pathological state-dependent actions of TROX-1 through a likely spinal mechanism and reveals a modality selective change in calcium channel function following nerve injury.
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Affiliation(s)
- R Patel
- University College London, Gower Street, Department of Neuroscience, Physiology and Pharmacology, London WC1E 6BT, UK.
| | - K Rutten
- Grünenthal GmbH, Global Preclinical Research, 52078 Aachen, Germany
| | - M Valdor
- Grünenthal GmbH, Global Preclinical Research, 52078 Aachen, Germany
| | - K Schiene
- Grünenthal GmbH, Global Preclinical Research, 52078 Aachen, Germany
| | - S Wigge
- Grünenthal GmbH, Global Preclinical Research, 52078 Aachen, Germany
| | - S Schunk
- Grünenthal GmbH, Global Preclinical Research, 52078 Aachen, Germany
| | - N Damann
- Grünenthal GmbH, Global Preclinical Research, 52078 Aachen, Germany
| | - T Christoph
- Grünenthal GmbH, Global Preclinical Research, 52078 Aachen, Germany
| | - A H Dickenson
- University College London, Gower Street, Department of Neuroscience, Physiology and Pharmacology, London WC1E 6BT, UK
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Rutten K, Tzschentke TM, Koch T, Schiene K, Christoph T. Pharmacogenomic study of the role of the nociceptin/orphanin FQ receptor and opioid receptors in diabetic hyperalgesia. Eur J Pharmacol 2014; 741:264-71. [PMID: 25169429 DOI: 10.1016/j.ejphar.2014.08.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Revised: 07/10/2014] [Accepted: 08/05/2014] [Indexed: 01/03/2023]
Abstract
Targeting functionally independent receptors may provide synergistic analgesic effects in neuropathic pain. To examine the interdependency between different opioid receptors (µ-opioid peptide [MOP], δ-opioid peptide [DOP] and κ-opioid peptide [KOP]) and the nociceptin/orphanin FQ peptide (NOP) receptor in streptozotocin (STZ)-induced diabetic polyneuropathy, nocifensive activity was measured using a hot plate test in wild-type and NOP, MOP, DOP and KOP receptor knockout mice in response to the selective receptor agonists Ro65-6570, morphine, SNC-80 and U50488H, or vehicle. Nocifensive activity was similar in non-diabetic wild-type and knockout mice at baseline, before agonist or vehicle administration. STZ-induced diabetes significantly increased heat sensitivity in all mouse strains, but MOP, DOP and KOP receptor knockouts showed a smaller degree of hyperalgesia than wild-type mice and NOP receptor knockouts. For each agonist, a significant antihyperalgesic effect was observed in wild-type diabetic mice (all P<0.05 versus vehicle); the effect was markedly attenuated in diabetic mice lacking the cognate receptor compared with wild-type diabetic mice. Morphine was the only agonist that demonstrated near-full antihyperalgesic efficacy across all non-cognate receptor knockouts. Partial or near-complete reductions in efficacy were observed with Ro65-6570 in DOP and KOP receptor knockouts, with SNC-80 in NOP, MOP and KOP receptor knockouts, and with U50488H in NOP and DOP receptor knockouts. There was no evidence of NOP and MOP receptor interdependency in response to selective agonists for these receptors. These findings suggest that concurrent activation of NOP and MOP receptors, which showed functional independence, may yield an effective and favorable therapeutic analgesic profile.
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MESH Headings
- Analgesics, Opioid/pharmacology
- Analgesics, Opioid/therapeutic use
- Animals
- Diabetes Mellitus, Experimental/drug therapy
- Diabetes Mellitus, Experimental/genetics
- Diabetes Mellitus, Experimental/metabolism
- Hyperalgesia/drug therapy
- Hyperalgesia/genetics
- Hyperalgesia/metabolism
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Rats
- Rats, Sprague-Dawley
- Receptors, Opioid/physiology
- Receptors, Opioid, mu/agonists
- Receptors, Opioid, mu/physiology
- Nociceptin Receptor
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Affiliation(s)
- Kris Rutten
- Grünenthal GmbH, Global Preclinical Drug Development, Department of Pain Pharmacology, Zieglerstrasse 6, 52078 Aachen, Germany.
| | - Thomas M Tzschentke
- Grünenthal GmbH, Global Preclinical Drug Development, Department of Pain Pharmacology, Zieglerstrasse 6, 52078 Aachen, Germany
| | - Thomas Koch
- Grünenthal GmbH, Global Preclinical Drug Development, Department of Molecular Pharmacology, Aachen, Germany
| | - Klaus Schiene
- Grünenthal GmbH, Global Preclinical Drug Development, Department of Pain Pharmacology, Zieglerstrasse 6, 52078 Aachen, Germany
| | - Thomas Christoph
- Grünenthal GmbH, Global Preclinical Drug Development, Department of Pain Pharmacology, Zieglerstrasse 6, 52078 Aachen, Germany
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12
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Soetaert R, Rutten K. Rhetoric and narratives as equipment for living: spinning in Borgen. Journal of Organizational Change Management 2014. [DOI: 10.1108/jocm-09-2014-0168] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Purpose– The purpose of this paper is to present a theoretical background for studying rhetoric and narratives as equipment for living. Analyzing a case study on spinning and the spin doctor in recent narratives with a major focus on the Danish TV-seriesBorgen. Arguing that narratives can be equipment for teaching.Design/methodology/approach– Introducing rhetorical concepts as tools for an analysis of narratives (based on the work of Kenneth Burke).Findings– The authors argue for the importance of rhetoric and narrative as tools for meaning-making, illustrate how spinning has become a major topic in recent fiction (and the TV-seriesBorgenin particular), and focus on howBorgencan be equipment for living from different “terministic screens.”Originality/value– The authors analyze how a popular narrative asBorgencan be read as equipment for living, focussing on how the spin doctor has become a major character in fiction, and illustrate what the authors can learn from narratives about rhetoric and spinning.
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13
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van Donkelaar EL, Prickaerts J, Akkerman S, Rutten K, Steinbusch HWM, Blokland A. No effect of acute tryptophan depletion on phosphodiesterase inhibition--related improvements of short-term object memory in male Wistar rats. Acta Psychiatr Scand 2013; 128:107-13. [PMID: 23772681 DOI: 10.1111/acps.12166] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/16/2013] [Indexed: 01/22/2023]
Abstract
OBJECTIVE To further explore the implication of the serotonin (5-HT) system in the improvement of rat short-term object recognition after administration of the type 2 phosphodiesterase inhibitor (PDE-I) BAY 60-7550 and the type 5 PDE-I vardenafil, the effect of PDE2 and PDE5 inhibition upon central amino acid levels, 5-HT, and related parameters were measured after applying acute tryptophan depletion (ATD). METHOD Wistar rats were orally administered saline or a protein-carbohydrate mixture with or without tryptophan (TRP). TRP-depleted animals additionally received an oral vehicle injection or the PDE inhibitors BAY 60-7550 or vardenafil at a dose known to improve object memory performance. RESULTS Although ATD significantly decreased TRP levels in the hippocampus 2 h after administration, 5-HT levels appeared only moderately affected, without any changes observed in the amount of 5-HIAA or 5-HT turnover rate. Moreover, no effects of PDE inhibition upon 5-HT or related parameters were observed. CONCLUSION Changes in 5-HT neurotransmitter activity might be excluded as a potential underlying mechanism of the previously reported ability of PDE inhibitors to improve short-term object memory in rats. It is suggested that a decrease in cerebral blood flow potentially underlies ATD-induced object memory deficits, most likely due to decrease in NO synthesis.
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Affiliation(s)
- E L van Donkelaar
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, The Netherlands.
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14
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Rutten K, Robens A, Read SJ, Christoph T. Pharmacological validation of a refined burrowing paradigm for prediction of analgesic efficacy in a rat model of sub-chronic knee joint inflammation. Eur J Pain 2013; 18:213-22. [PMID: 23852581 DOI: 10.1002/j.1532-2149.2013.00359.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/02/2013] [Indexed: 12/26/2022]
Abstract
BACKGROUND Burrowing is an evolutionarily conserved behaviour in rodents. This study validates a refined burrowing paradigm (requiring a reduced number of animals) in a rat model of sub-chronic knee joint inflammation and evaluates its sensitivity and specificity for analgesic drugs. METHODS Knee joint inflammation in rats was induced by intra-articular injection with complete Freund's adjuvant (CFA). Burrowing performance was assessed at baseline without study drugs, and in CFA-naive and CFA-injected animals following administration of the analgesic drugs naproxen, pregabalin and morphine, each at three doses, or corresponding vehicle (nine rats per dose group). The specificity of the model was evaluated by also testing the anxiogenic drug yohimbine, the stimulant drug dexamphetamine and the anxiolytic drug chlordiazepoxide in CFA-naive and CFA-injected animals. Percentage maximum possible effect (%MPE) was determined by relating the difference between post-CFA and baseline burrowing performance in each drug dose group to that in the vehicle group in each experiment. RESULTS Burrowing performance in the vehicle groups was decreased by 39.0-59.8% in CFA-injected animals compared with CFA-naive animals. CFA-induced reductions in burrowing performance were reversed by each of the three analgesic drugs tested. The highest %MPE was 75.2% with naproxen 50 mg/kg, 80.9% with pregabalin 10 mg/kg and 77.0% with morphine 1 mg/kg (all p < 0.05 vs. control). CFA-induced reductions in burrowing performance were not reversed by yohimbine, dexamphetamine or chlordiazepoxide. CONCLUSIONS This study provides pharmacological validation of a refined burrowing paradigm for analgesic efficacy that exhibits good predictive validity, with high sensitivity and specificity.
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Affiliation(s)
- K Rutten
- Department of Pharmacology Pain, Global Biomedical Sciences, Grünenthal GmbH, Aachen, Germany
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15
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Rutten K, Schiene K, Robens A, Leipelt A, Pasqualon T, Read SJ, Christoph T. Burrowing as a non-reflex behavioural readout for analgesic action in a rat model of sub-chronic knee joint inflammation. Eur J Pain 2013; 18:204-12. [PMID: 23853119 DOI: 10.1002/j.1532-2149.2013.00358.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/31/2013] [Indexed: 12/25/2022]
Abstract
BACKGROUND Innate responses against spontaneous pain are proposed to improve the predictive validity of preclinical analgesia models. Therefore, development and validation of novel readouts is necessary. To investigate whether innate rodent burrowing is a useful alternative behavioural readout for assessment of analgesic efficacy, a complete Freund's adjuvant (CFA)-induced model of sub-chronic inflammation was used to compare the effects of naproxen, ibuprofen and pregabalin in weight-bearing (WB), open-field (OF) and burrowing assays. METHODS Male Sprague Dawley rats were injected with 150 μL of CFA (2 mg/mL) into the knee (hind leg) 3 days before testing. Naproxen, ibuprofen and pregabalin were administered at different doses 30, 90 and 60 min, respectively, before testing. WB was determined using a rat incapacitance tester; horizontal distance moved and vertical rearings were recorded in an OF; and burrowing was measured by the weight of gravel remaining in a hollow tube after 60 min. RESULTS CFA-induced arthritis reduced WB, OF activity and burrowing. Naproxen, pregabalin and ibuprofen treatment normalized WB; however, horizontal OF activity was not improved by any treatment; rearing behaviour was moderately reinstated by ibuprofen (100 mg/kg). In burrowing, naproxen (100 mg/kg), ibuprofen (31.6 and 100 mg/kg) and pregabalin (10 mg/kg) reversed CFA-induced deficits. CONCLUSIONS Burrowing performance is an alternative non-reflex readout relying on innate rodent behaviour that is affected by nociceptive behaviour and can be pharmacologically manipulated. The burrowing assay appears to be more sensitive than OF assays and is as sensitive as WB assays at distinguishing between analgesic doses and doses that impair locomotion.
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Affiliation(s)
- K Rutten
- Department of Pharmacology Pain, Global Biomedical Sciences, Grünenthal GmbH, Aachen, Germany
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16
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Reneerkens OA, Rutten K, Bollen E, Hage T, Blokland A, Steinbusch HW, Prickaerts J. Inhibition of phoshodiesterase type 2 or type 10 reverses object memory deficits induced by scopolamine or MK-801. Behav Brain Res 2013; 236:16-22. [DOI: 10.1016/j.bbr.2012.08.019] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Revised: 08/10/2012] [Accepted: 08/14/2012] [Indexed: 12/31/2022]
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17
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Sierksma ASR, Rutten K, Sydlik S, Rostamian S, Steinbusch HWM, van den Hove DLA, Prickaerts J. Chronic phosphodiesterase type 2 inhibition improves memory in the APPswe/PS1dE9 mouse model of Alzheimer's disease. Neuropharmacology 2012; 64:124-36. [PMID: 22771768 DOI: 10.1016/j.neuropharm.2012.06.048] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Revised: 06/22/2012] [Accepted: 06/24/2012] [Indexed: 01/08/2023]
Abstract
Alzheimer's disease (AD) is characterized by progressive cognitive deficits and synaptic dysfunction. Over the last decade phosphodiesterase inhibitors (PDEIs) have received increasing attention as putative cognition enhancers and have been suggested as a novel treatment strategy for AD. Given their ability to prevent hydrolysis of cAMP and/or cGMP, they can stimulate the cAMP/protein kinase A (PKA)/cAMP element-binding protein (CREB) and cGMP/PKG/CREB pathway to enhance synaptic transmission by increasing CREB phosphorylation (pCREB) and brain-derived neurotrophic factor (BDNF) transcription. Based on previous research, we hypothesized that chronic PDE2I treatment would improve AD-related cognitive deficits, by decreasing amyloid-β (Aβ) plaque load, enhancing pCREB and BDNF levels and increasing synaptic density in the hippocampus of 8-month-old APPswe/PS1dE9 mice. Results indicated that chronic PDE2I treatment could indeed improve memory performance in APPswe/PS1dE9 mice, without affecting anxiety, depressive-like behavior or hypothalamus-pituitary-adrenal axis regulation. However, no treatment effects were observed on Aβ plaque load, pCREB or BDNF concentrations, or presynaptic density in the hippocampus, suggesting that other signaling pathways and/or effector molecules might be responsible for its cognition-enhancing effects. Presynaptic density in the stratum lucidum of the CA3 subregion was significantly higher in APPswe/PS1dE9 mice compared to WT controls, possibly reflecting a compensatory mechanism. In conclusion, PDEs in general, and PDE2 specifically, could be considered as promising therapeutic targets for cognition enhancement in AD, although the underlying mechanism of action remains to be elucidated. This article is part of a Special Issue entitled 'Cognitive Enhancers'.
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Affiliation(s)
- Annerieke S R Sierksma
- Department of Psychiatry and Neuropsychology, Faculty of Health, Medicine and Life Science, School for Mental Health and Neuroscience (MHeNS), Maastricht University, Maastricht, The Netherlands
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18
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Reneerkens OA, Rutten K, Akkerman S, Blokland A, Shaffer CL, Menniti FS, Steinbusch HW, Prickaerts J. Phosphodiesterase type 5 (PDE5) inhibition improves object recognition memory: Indications for central and peripheral mechanisms. Neurobiol Learn Mem 2012; 97:370-9. [DOI: 10.1016/j.nlm.2012.02.008] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2011] [Revised: 02/16/2012] [Accepted: 02/27/2012] [Indexed: 01/10/2023]
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van Goethem NP, Rutten K, van der Staay FJ, Jans LAW, Akkerman S, Steinbusch HWM, Blokland A, van't Klooster J, Prickaerts J. Object recognition testing: rodent species, strains, housing conditions, and estrous cycle. Behav Brain Res 2012; 232:323-34. [PMID: 22481082 DOI: 10.1016/j.bbr.2012.03.023] [Citation(s) in RCA: 88] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2011] [Revised: 03/14/2012] [Accepted: 03/18/2012] [Indexed: 11/28/2022]
Abstract
The object recognition task (ORT) allows assessing learning and memory processes in rodents. In this study, two areas in which knowledge about the ORT could be extended were addressed; i.e. generality to species and strains, and intervening variables including housing and estrous cycle. Regarding generality to species and strains, the ORT performance of golden hamsters was assessed. The hamsters showed sufficient exploration times, object recognition performance, and a retention-interval dependent decline similar to rats and mice. Subsequently, we tested three mouse strains which have not been described before in the ORT; i.e. OF1, NMRI, and SJL mice. OF1 and NMRI strains performed equally well, whereas the SJL strain showed low exploration times and no memory retention. Therefore, the SJL strain is unsuited for ORT experiments using a 1h retention interval and a fixed (3 min) trial duration. Furthermore, the sensitivity to a pharmacological memory deficit model (scopolamine) was tested in three rat strains. Each strain showed a dose dependent relationship, but the least effective dose of scopolamine differed among the three strains, the effect being greater in the order of Wistar, Long-Evans, Hooded Lister rats. Finally, to investigate potential intervening variables in the ORT, the effects of housing conditions and estrous cycle were investigated with rats. Single housing resulted in absolute higher performance than social housing. Furthermore, females in pro-estrus/estrus showed better performance compared to females in met-estrus/di-estrus. Taken together, object recognition appears to be a common ability of rodent species, but different strains have different memory capacities and sensitivities to scopolamine, individual housing leads to higher performance, and performance of females is dependent on the estrous cycle phase. Thus, rodent species, strain, housing, and estrous cycle should be taken into consideration in ORT studies.
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Affiliation(s)
- Nick P van Goethem
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience-MHeNS, European Graduate School of Neuroscience-EURON, Maastricht University, Maastricht, The Netherlands
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Rutten K, Tzschentke T, Christoph T, De Vry J, Schröder W. S182 CRITICAL APPRAISAL OF THE CONDITIONED PLACE PREFERENCE PARADIGM AS READOUT FOR SPONTANEOUS PAIN IN STREPTOZOTOCIN-INDUCED DIABETIC RATS. ACTA ACUST UNITED AC 2012. [DOI: 10.1016/s1754-3207(11)70757-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
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van der Staay FJ, Rutten K, Erb C, Blokland A. Effects of the cognition impairer MK-801 on learning and memory in mice and rats. Behav Brain Res 2011; 220:215-29. [DOI: 10.1016/j.bbr.2011.01.052] [Citation(s) in RCA: 116] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2010] [Revised: 01/26/2011] [Accepted: 01/29/2011] [Indexed: 12/28/2022]
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Vanmierlo T, Rutten K, van Vark - van der Zee LC, Friedrichs S, Bloks VW, Blokland A, Ramaekers FC, Sijbrands E, Steinbusch H, Prickaerts J, Kuipers F, Lütjohann D, Mulder M. Cerebral accumulation of dietary derivable plant sterols does not interfere with memory and anxiety related behavior in Abcg5-/- mice. Plant Foods Hum Nutr 2011; 66:149-56. [PMID: 21431910 PMCID: PMC3134714 DOI: 10.1007/s11130-011-0219-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Plant sterols such as sitosterol and campesterol are frequently applied as functional food in the prevention of atherosclerosis. Recently, it became clear that plasma derived plant sterols accumulate in murine brains. We questioned whether plant sterols in the brain are associated with alterations in brain cholesterol homeostasis and subsequently with brain functions. ATP binding cassette (Abc)g5-/- mice, a phytosterolemia model, were compared to Abcg5+/+ mice for serum and brain plant sterol accumulation and behavioral and cognitive performance. Serum and brain plant sterol concentrations were respectively 35-70-fold and 5-12-fold increased in Abcg5-/- mice (P<0.001). Plant sterol accumulation resulted in decreased levels of desmosterol (P<0.01) and 24(S)-hydroxycholesterol (P<0.01) in the hippocampus, the brain region important for learning and memory functions, and increased lanosterol levels (P<0.01) in the cortex. However, Abcg5-/- and Abcg5+/+ displayed no differences in memory functions or in anxiety and mood related behavior. The swimming speed of the Abcg5-/- mice was slightly higher compared to Abcg5+/+ mice (P<0.001). In conclusion, plant sterols in the brains of Abcg5-/- mice did have consequences for brain cholesterol metabolism, but did not lead to an overt phenotype of memory or anxiety related behavior. Thus, our data provide no contra-indication for nutritional intake of plant sterol enriched nutrition.
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Affiliation(s)
- Tim Vanmierlo
- Department of Neuroscience, Maastricht University, Universiteitssingel 50, 6229 ER Maastricht, The Netherlands
- Institute of Clinical Chemistry and Clinical Pharmacology, University Clinics Bonn, Sigmund-Freud-Str. 25, 53105 Bonn, Germany
| | - Kris Rutten
- Department of Neuroscience, Maastricht University, Universiteitssingel 50, 6229 ER Maastricht, The Netherlands
| | - Leonie C. van Vark - van der Zee
- Department of Internal Medicine, Division of Pharmacology, Vascular and Metabolic Diseases, Erasmus Medical Center, ‘s-Gravendijkwal 230, 3015 CE Rotterdam, The Netherlands
| | - Silvia Friedrichs
- Institute of Clinical Chemistry and Clinical Pharmacology, University Clinics Bonn, Sigmund-Freud-Str. 25, 53105 Bonn, Germany
| | - Vincent W. Bloks
- Department of Pediatrics, University Medical Center Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands
| | - Arjan Blokland
- Department of Neuropsychology and Psychopharmacology, Maastricht University, Universiteitssingel 40, 6229 ER Maastricht, The Netherlands
| | - Frans C. Ramaekers
- Department of Molecular Cell Biology, Maastricht University, Universiteitssingel 50, 6229 ER Maastricht, The Netherlands
| | - Eric Sijbrands
- Department of Internal Medicine, Division of Pharmacology, Vascular and Metabolic Diseases, Erasmus Medical Center, ‘s-Gravendijkwal 230, 3015 CE Rotterdam, The Netherlands
| | - Harry Steinbusch
- Department of Neuroscience, Maastricht University, Universiteitssingel 50, 6229 ER Maastricht, The Netherlands
| | - Jos Prickaerts
- Department of Neuroscience, Maastricht University, Universiteitssingel 50, 6229 ER Maastricht, The Netherlands
| | - Folkert Kuipers
- Department of Pediatrics, University Medical Center Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands
| | - Dieter Lütjohann
- Institute of Clinical Chemistry and Clinical Pharmacology, University Clinics Bonn, Sigmund-Freud-Str. 25, 53105 Bonn, Germany
| | - Monique Mulder
- Department of Neuroscience, Maastricht University, Universiteitssingel 50, 6229 ER Maastricht, The Netherlands
- Department of Internal Medicine, Division of Pharmacology, Vascular and Metabolic Diseases, Erasmus Medical Center, ‘s-Gravendijkwal 230, 3015 CE Rotterdam, The Netherlands
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Rutten K, van der Kam EL, De Vry J, Tzschentke TM. Critical evaluation of the use of extinction paradigms for the assessment of opioid-induced conditioned place preference in rats. Pharmacology 2011; 87:286-96. [PMID: 21577043 DOI: 10.1159/000327680] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Accepted: 03/14/2011] [Indexed: 11/19/2022]
Abstract
The rewarding effects of drugs of abuse are often studied by means of the conditioned place preference (CPP) paradigm. CPP is one of the most widely used models in behavioral pharmacology, yet its theoretical underpinnings are not well understood, and there are very few studies on the methodological and theoretical aspects of this model. An important drawback of the classical CPP paradigm is that it often does not show dose-dependent results. The persistence of the conditioned response, i.e. the time required until the CPP effect is extinct, may be related to the strength of conditioning, which in turn may be related to the rewarding efficacy of a drug. Resistance to extinction may therefore be a useful additional measure to quantify the rewarding effect of drugs. In the present study we examined the persistence of drug-environment associations after conditioning with morphine (1, 3 and 10 mg/kg i.p.), oxycodone (0.3, 1 and 3 mg/kg i.p.) and heroin (0.05, 0.25 and 0.5 mg/kg i.p.) by repeated retesting in the CPP apparatus (15-min sessions, 5 days/week) until the rats reached extinction (i.e. less than 55% preference over 3 consecutive sessions). Following an unbiased CPP protocol, morphine, oxycodone and heroin induced CPP with minimal effective doses of 3, 1 and 0.25 mg/kg, respectively, and with similar effect sizes for each CPP-inducing dose. The number of sessions required for extinction was positively correlated with the dose of the drug (experiment 1: 18 and 45 sessions for 3 and 10 mg/kg morphine, and 19 and 27 sessions for 1 and 3 mg/kg oxycodone; experiment 2: 12 and 24 sessions for 3 and 10 mg/kg morphine, and 10 and 14 sessions for 0.25 and 0.5 mg/kg heroin). These findings suggest that the use of an extinction paradigm can extend the quantitative assessment of the rewarding effect of drugs - however, within certain limits only. The present paradigm appears to be less suited for comparing the rewarding efficacy of different drugs due to great test-retest variability. Finally, the additional potential gain of information using this paradigm has to be weighed against the considerably large amount of additional time and effort.
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Affiliation(s)
- Kris Rutten
- Department of Pharmacology, Global Preclinical Research and Development, Grünenthal GmbH, Aachen, Germany.
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Rutten K, De Vry J, Bruckmann W, Tzschentke TM. Pharmacological blockade or genetic knockout of the NOP receptor potentiates the rewarding effect of morphine in rats. Drug Alcohol Depend 2011; 114:253-6. [PMID: 21095077 DOI: 10.1016/j.drugalcdep.2010.10.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Revised: 09/27/2010] [Accepted: 10/14/2010] [Indexed: 11/18/2022]
Abstract
The Nociceptin/OrphaninFQ (NOP) system is believed to be involved in drug abuse and addiction. We have recently demonstrated that activation of the NOP receptor, by systemic administration of the NOP receptor agonist Ro65-6570, attenuated the rewarding effect of various opioids in conditioned place preference (CPP) in rats and this attenuating effect was reversed by the NOP receptor antagonist J-113397. The present study demonstrates that co-administration of J-113397 (4.64 mg/kg, i.p.) during conditioning, facilitates morphine-induced CPP. Moreover, we found that NOP receptor knockout rats (oprl1(-/-)) are more sensitive to the rewarding effect of morphine than wildtype control rats. Thus, pharmacological or genetic inactivation of the NOP system rendered rats more susceptible to the rewarding effect of morphine. These findings support the suggestion that the endogenous NOP system attenuates the rewarding effect of opioids and therefore offers a therapeutic target for the treatment of drug abuse and addiction.
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Affiliation(s)
- Kris Rutten
- Grünenthal GmbH, Global Preclinical Research and Development, Department of Pharmacology, Aachen, Germany.
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Rutten K, Wallace TL, Works M, Prickaerts J, Blokland A, Novak TJ, Santarelli L, Misner DL. Enhanced long-term depression and impaired reversal learning in phosphodiesterase 4B-knockout (PDE4B-/-) mice. Neuropharmacology 2011; 61:138-47. [PMID: 21458469 DOI: 10.1016/j.neuropharm.2011.03.020] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2011] [Revised: 03/22/2011] [Accepted: 03/24/2011] [Indexed: 12/19/2022]
Abstract
3'-5'-Cyclic adenosine monophosphate (cAMP) is known to be an important regulator of synaptic plasticity. The effects of cAMP are mediated through downstream effectors such as protein kinase A (PKA), Ca(2+) and cAMP-response element binding protein (CREB). The phosphodiesterase 4 (PDE4) family of enzymes, which is comprised of four genes and at least 25 protein isoforms, mediates the hydrolysis of cAMP, yet little is presently known about the contribution of specific PDE4 isoforms to synaptic plasticity and cognitive behavior. The purpose of the present studies was to determine the contribution of the PDE4B gene in mediating synaptic plasticity and cognitive behavior. Electrophysiological recordings from hippocampal slice preparations of mice deficient in the PDE4B gene (PDE4B(-/-)) showed that knockout animals displayed markedly enhanced basal postsynaptic responses to stimulation and long-term depression as compared to wild-type littermates. Interestingly, no genotypic differences were noted in long-term potentiation experiments following several different induction protocols. On the behavioral level PDE4B(-/-) mice displayed impaired reversal learning in the Morris water maze compared to wild-type littermates, but no differences in acquisition and retention of spatial memory and fear conditioning. Taken together, these results suggest that the PDE4B gene may play a role in synaptic activity and long-term depression and is involved in spatial reversal memory. Our findings support the view that various PDE4 isoforms are non-redundant and have distinct neurological roles.
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Affiliation(s)
- Kris Rutten
- CNS Discovery Research, Roche Palo Alto, Palo Alto, CA, USA.
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Rutten K, Van Der Kam EL, De Vry J, Bruckmann W, Tzschentke TM. The mGluR5 antagonist 2-methyl-6-(phenylethynyl)-pyridine (MPEP) potentiates conditioned place preference induced by various addictive and non-addictive drugs in rats. Addict Biol 2011; 16:108-15. [PMID: 20579001 DOI: 10.1111/j.1369-1600.2010.00235.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
We have recently reported that the metabotropic glutamate receptor 5 antagonist 2-methyl-6-(phenylethynyl)-pyridine (MPEP) potentiates acquisition of conditioned place preference (CPP) induced by heroin and ketamine. The present study investigated to what extent this effect of MPEP can be generalized to other classes of drugs, such as the stimulants nicotine and cocaine, and to drugs that produce CPP in the rat despite a lack of abuse potential in humans, such as buspirone and clonidine. Adult male Sprague Dawley rats were subjected to a standard unbiased CPP protocol (six conditioning sessions lasting 20 minutes for nicotine and 40 minutes for the other compounds). Rats were conditioned with either nicotine (0.05-0.2 mg/kg, subcutaneously), cocaine [1-10 mg/kg, intraperitoneally (i.p.)], buspirone (0.3-3 mg/kg, i.p.) or clonidine (0.2-0.6 mg/kg, i.p.) in combination with MPEP (0 or 10 mg/kg, i.p.). For nicotine and cocaine, the minimal effective dose to induce CPP was lowered by pre-treatment with MPEP. While buspirone and clonidine did not induce CPP when given alone (i.e. combined with MPEP vehicle), both compounds induced CPP after pre-treatment with MPEP. It is concluded that MPEP consistently potentiates acquisition of drug-induced reward, independent of the mechanism of action of the co-administered drug. We suggest that the proposed anti-abuse effect of MPEP may be due to a substitution-like effect.
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Affiliation(s)
- Kris Rutten
- Department of Pharmacology, Aachen, Germany.
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Rutten K, De Vry J, Bruckmann W, Tzschentke TM. Effects of the NOP receptor agonist Ro65-6570 on the acquisition of opiate- and psychostimulant-induced conditioned place preference in rats. Eur J Pharmacol 2010; 645:119-26. [PMID: 20674566 DOI: 10.1016/j.ejphar.2010.07.036] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2010] [Revised: 06/11/2010] [Accepted: 07/15/2010] [Indexed: 12/14/2022]
Abstract
Activation of the Nociceptin/Orphanin FQ (NOP) receptor may have anti-abuse effects. The present study examined the consequence of NOP receptor activation on the rewarding effect of opiates and psychostimulants in the conditioned place preference task in rats. First, the motivational effect of the NOP receptor agonists Ro64-6198 (0.316-3.16 mg/kg i.p.) and Ro65-6570 (1-10mg/kg i.p.) when administered alone, was assessed. Ro65-6570 was selected for further drug combination studies since, unlike Ro64-6198, it was devoid of an intrinsic motivational effect. Next, the minimal effective dose to induce reward for the opiates heroin (0.1-3.16 mg/kg i.p.), morphine (1-10mg/kg i.p.), hydrocodone (0.316-10mg/kg i.p.), tilidine (1-31.6 mg/kg i.p.), hydromorphone (0.1-10mg/kg i.p.), and oxycodone (0.0316-10mg/kg i.p.), as well as for the psychostimulants cocaine (3.16-31.6 mg/kg i.p.) and dexamphetamine (0.316-3.16 mg/kg i.p.) in combination with Ro 65-6570 (0 or 3.16 mg/kg i.p.) was determined. All drugs produced conditioned place preference, and for opiates and cocaine, but not for dexamphetamine, the minimal effective dose was higher when combined with Ro65-6570 (3.16 mg/kg i.p.). Attenuation of the rewarding effect of tilidine (3.16 mg/kg i.p.) and oxycodone (1mg/kg i.p.) by Ro65-6570 (3.16 mg/kg i.p.) could be reversed by pre-treatment with the NOP receptor antagonist J-113397 (4.64 mg/kg i.p.), suggesting that the attenuating effect of Ro65-6570 on opiates is due to activation of the NOP receptor. Taken together, the present study suggests that activation of NOP receptors effectively attenuates the rewarding effect of opiates, but may be less effective in reducing psychostimulant-induced reward.
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Affiliation(s)
- Kris Rutten
- Grünenthal GmbH, Global Preclinical Research and Development, Department of Pharmacology, Zieglerstrasse 6, 52078 Aachen, Germany.
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Vanmierlo T, Bloks VW, van Vark-van der Zee LC, Rutten K, Kerksiek A, Friedrichs S, Sijbrands E, Steinbusch HW, Kuipers F, Lütjohann D, Mulder M. Alterations in brain cholesterol metabolism in the APPSLxPS1mut mouse, a model for Alzheimer's disease. J Alzheimers Dis 2010; 19:117-27. [PMID: 20061631 DOI: 10.3233/jad-2010-1209] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Disturbances in cerebral cholesterol metabolism have been implicated in the pathogenesis of Alzheimer's disease (AD). Here, we provide evidence that alterations in brain cholesterol homeostasis also can be a consequence of disease progression. We found that APPSLxPS1mut mice, at the age of 9 months when AD-like pathology starts to develop, display increased levels of the cholesterol precursor desmosterol and of the cholesterol metabolite 27-hydroxy(OH)cholesterol in their cerebellum in comparison with wild-type controls. At the age of 21 months, when APPSLxPS1mut brain contains abundant amyloid deposits, desmosterol levels had further increased (> 200% in comparison with wild-type mice) in all brain regions examined. 24(S)-OHcholesterol levels were increased in hippocampus and cerebellum of the APPSLxPS1mut mice, while 27-OHcholesterol levels were increased in cerebellum exclusively. Brain cholesterol levels remained unaffected. In line with the fact that desmosterol and 24(S)-OHcholesterol are Liver X Receptor (LXR) activators, the LXR-target genes Abca1 and Apoc1 were upregulated predominantly in hippocampus of APPSLxPS1mut mice at both ages evaluated. The reduced expression of the enzyme that converts desmosterol into cholesterol, the Selective AD indicator 1 gene (Seladin-1/Dhcr24), in both cortex and cerebellum may underlie the increased desmosterol levels in 21 month-old APPSLxPS1mut mice.
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Affiliation(s)
- Tim Vanmierlo
- Department of Neuroscience, Maastricht University, Maastricht, The Netherlands
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Tzschentke T, Kam E, Rutten K, Robens A, Vry J. 363 DISSOCIATION OF ANALGESIC, ANTI‐AVERSIVE AND REWARDING EFFECTS OF DIFFERENT CLASSES OF ANALGESICS IN THE RAT. Eur J Pain 2009. [DOI: 10.1016/s1090-3801(09)60366-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- T. Tzschentke
- Grünenthal GmbH, Preclinical Drug Development, Department of Pharmacology, Aachen, Germany
| | - E. Kam
- Grünenthal GmbH, Preclinical Drug Development, Department of Pharmacology, Aachen, Germany
| | - K. Rutten
- Grünenthal GmbH, Preclinical Drug Development, Department of Pharmacology, Aachen, Germany
| | - A. Robens
- Grünenthal GmbH, Preclinical Drug Development, Department of Pharmacology, Aachen, Germany
| | - J. Vry
- Grünenthal GmbH, Preclinical Drug Development, Department of Pharmacology, Aachen, Germany
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Vanmierlo T, Rutten K, Dederen J, Bloks VW, van Vark-van der Zee LC, Kuipers F, Kiliaan A, Blokland A, Sijbrands EJG, Steinbusch H, Prickaerts J, Lütjohann D, Mulder M. Liver X receptor activation restores memory in aged AD mice without reducing amyloid. Neurobiol Aging 2009; 32:1262-72. [PMID: 19674815 DOI: 10.1016/j.neurobiolaging.2009.07.005] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2008] [Revised: 06/03/2009] [Accepted: 07/10/2009] [Indexed: 11/19/2022]
Abstract
Alterations in cerebral cholesterol metabolism are thought to play a role in the progression of Alzheimer's disease (AD). Liver X receptors (LXRs) are key regulators of cholesterol metabolism. The synthetic LXR activator, T0901317 has been reported to improve memory functions in animal models for AD and to reduce amyloid-β (Aβ) deposition in the brain. Here we provide evidence that long-term administration of T0901317 to aged, 21-month-old APPSLxPS1mut mice restores impaired memory. Cerebral cholesterol turnover was enhanced as indicated by the increased levels of brain cholesterol precursors and the upregulation of LXR-target genes Abca1, Abcg1, and Apoe. Unexpectedly, the improved memory functions in the APPSLxPS1mut mice after T0901317 treatment were not accompanied by a decrease in Aβ plaque load in the cortex or hippocampus DG, CA1 or CA3. T0901317 administration also enhanced cerebral cholesterol turnover in aged C57BL/6NCrl mice, but did not further improve their memory functions. In conclusion, long-term activation of the LXR-pathway restored memory functions in aged APPSLxPS1mut mice with advanced Aβ deposition. However the beneficial effects of T0901317 on memory in the APPSLxPS1mut mice were independent of the Aβ plaque load in the hippocampus, but were associated with enhanced brain cholesterol turnover.
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Affiliation(s)
- Tim Vanmierlo
- Department of Neuroscience, Maastricht University, Maastricht, The Netherlands
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Rutten K, Van Donkelaar EL, Ferrington L, Blokland A, Bollen E, Steinbusch HW, Kelly PA, Prickaerts JH. Phosphodiesterase inhibitors enhance object memory independent of cerebral blood flow and glucose utilization in rats. Neuropsychopharmacology 2009; 34:1914-25. [PMID: 19262466 DOI: 10.1038/npp.2009.24] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Phosphodiesterase (PDE) inhibitors prevent the breakdown of the second messengers, cyclic AMP (cAMP) and cyclic GMP (cGMP), and are currently studied as possible targets for cognitive enhancement. Earlier studies indicated beneficial effects of PDE inhibitors in object recognition. In this study we tested the effects of three PDE inhibitors on spatial memory as assessed in a place and object recognition task. Furthermore, as both cAMP and cGMP are known vasodilators, the effects of PDE inhibition on cognitive functions could be explained by enhancement of cerebrovascular function. We examined this possibility by measuring the effects of PDE5 and PDE4 inhibitor treatment on local cerebral blood flow and glucose utilization in rats using [14C]-iodoantipyrine and [14C]-2-deoxyglucose quantitative autoradiography, respectively. In the spatial location task, PDE5 inhibition (cGMP) with vardenafil enhanced only early phase consolidation, PDE4 inhibition (cAMP) with rolipram enhanced only late phase consolidation, and PDE2 inhibition (cAMP and cGMP) with Bay 60-7550 enhanced both consolidation processes. Furthermore, PDE5 inhibition had no cerebrovascular effects in hippocampal or rhinal areas. PDE4 inhibition increased rhinal, but not hippocampal blood flow, whereas it decreased glucose utilization in both areas. In general, PDE5 inhibition decreased the ratio between blood flow and glucose utilization, indicative of general oligaemia; whereas PDE4 inhibition increased this ratio, indicative of general hyperemia. Both oligaemic and hyperemic conditions are detrimental for brain function and do not explain memory enhancement. These results underscore the specific effects of cAMP and cGMP on memory consolidation (object and spatial memory) and provide evidence that the underlying mechanisms of PDE inhibition on cognition are independent of cerebrovascular effects.
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Affiliation(s)
- Kris Rutten
- Department of Neuroscience, Faculty of Health, Medicine and Life Sciences, School of Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands.
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Rutten K, Misner DL, Works M, Blokland A, Novak TJ, Santarelli L, Wallace TL. Enhanced long-term potentiation and impaired learning in phosphodiesterase 4D-knockout (PDE4D) mice. Eur J Neurosci 2008; 28:625-32. [PMID: 18702734 DOI: 10.1111/j.1460-9568.2008.06349.x] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Elevation of intracellular cyclic adenosine monophosphate (cAMP) concentrations and subsequent regulation of downstream target gene expression through phosphorylation of cAMP-responsive element binding protein (CREB) is hypothesized to underlie the mechanism(s) of long-term memory (LTM) formation. The phosphodiesterase 4 (PDE4) enzyme family is believed to play a key role in LTM by regulating cAMP levels. Thus far, four PDE4 isoforms have been identified (PDE4A, B, C and D); however, the requisite involvement of each of these isoforms in mediating LTM has yet to be elucidated. In the present study, genetic knockout mice were used to investigate the involvement of the PDE4D isoform in both in vitro and in vivo models of learning and memory. Hippocampal synaptic transmission measured electrophysiologically in CA1 slice preparations was similar between wild-type and PDE4D (-/-) mice yet, relative to wild-type controls, knockout mice displayed enhanced early long-term potentiation (LTP) following multiple induction protocols. Interestingly, the PDE4D (-/-) animals exhibited significant behavioral deficits in associative learning using a conditioned fear paradigm as compared with control littermates. The impairment in fear conditioning observed in the PDE4D (-/-) mice could not be attributed to differences in acquisition of the task, alterations in locomotor activity or effects on shock sensitivity. Overall, the in vitro and in vivo alterations in synaptic plasticity observed in the PDE4D (-/-) mice may be explained by adaptive responses occurring throughout development, and suggest that the PDE4D isoform may be an important mediator of LTM formation.
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Affiliation(s)
- Kris Rutten
- Neuroscience Department, Roche Palo Alto, 3431 Hillview Avenue, Palo Alto, CA 94304, USA
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van Donkelaar EL, Rutten K, Blokland A, Akkerman S, Steinbusch HWM, Prickaerts J. Phosphodiesterase 2 and 5 inhibition attenuates the object memory deficit induced by acute tryptophan depletion. Eur J Pharmacol 2008; 600:98-104. [PMID: 18957291 DOI: 10.1016/j.ejphar.2008.10.027] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2008] [Revised: 09/26/2008] [Accepted: 10/13/2008] [Indexed: 11/17/2022]
Abstract
The underlying mechanism of short-term memory improvement after inhibition of specific phosphodiesterases (PDEs) is still poorly understood. The present study aimed to reveal the ability of PDE5 and PDE2 inhibitors, that increase cyclic guanosine monophosphate (cGMP) and both cyclic adenosine monophosphate (cAMP) and cGMP, respectively, to reverse an object recognition deficit induced by acute tryptophan depletion. Acute tryptophan depletion is a pharmacological challenge tool to lower central serotonin (5-hydroxytryptamine; 5-HT) levels by depleting the availability of its dietary precursor tryptophan. Short-term object memory was tested in male Wistar rats by exposing them to the object recognition task. First, the effects of acute tryptophan depletion upon object recognition 2 h after administration of the nutritional mixture were established. Subsequently, acute tryptophan depletion was combined with the PDE5 inhibitor vardenafil (1, 3 and 10 mg/kg) or with the PDE2 inhibitor BAY 60-7550 (0.3, 1 and 3 mg/kg), 30 min prior to testing. Acute tryptophan depletion significantly lowered plasma tryptophan levels and impaired object recognition performance. Vardenafil (3 and 10 mg/kg) and BAY 60-7550 (3 mg/kg) were able to attenuate the acute tryptophan depletion induced object recognition impairment. Thus, both PDE5 and PDE2 inhibition improved short-term object recognition performance after an acute tryptophan depletion induced deficit. The underlying mechanisms, however, remain poorly understood and further studies are needed to determine whether the present findings can be explained by a direct effect of enhanced cAMP and cGMP levels upon 5-HT activity, or even other neurotransmitter systems, and possibly an interaction with synthesis of nitric oxide or effects upon cerebral blood flow function.
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Affiliation(s)
- Eva L van Donkelaar
- Department of Neuroscience, Faculty of Health, Medicine and Life Sciences, School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands.
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van der Staay FJ, Rutten K, Bärfacker L, DeVry J, Erb C, Heckroth H, Karthaus D, Tersteegen A, van Kampen M, Blokland A, Prickaerts J, Reymann KG, Schröder UH, Hendrix M. The novel selective PDE9 inhibitor BAY 73-6691 improves learning and memory in rodents. Neuropharmacology 2008; 55:908-18. [DOI: 10.1016/j.neuropharm.2008.07.005] [Citation(s) in RCA: 115] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2007] [Revised: 07/01/2008] [Accepted: 07/04/2008] [Indexed: 02/05/2023]
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Rutten K, Prickaerts J, Schaenzle G, Rosenbrock H, Blokland A. Sub-chronic rolipram treatment leads to a persistent improvement in long-term object memory in rats. Neurobiol Learn Mem 2008; 90:569-75. [DOI: 10.1016/j.nlm.2008.04.016] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2008] [Revised: 04/25/2008] [Accepted: 04/28/2008] [Indexed: 10/21/2022]
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Vanmierlo T, Rutten K, Portelius E, Blokland A, Prickaerts J, Kuipers F, Blennow K, Steinbusch H, Lütjohann D, Mulder M. Plant sterols in the brain, good or bad? Chem Phys Lipids 2008. [DOI: 10.1016/j.chemphyslip.2008.05.165] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Rosenbrock H, Rutten K, Prickaerts J, Schaenzle G, Dorner-Ciossek C, Blokland A. P2‐459: Long‐lasting improvement in long‐term object memory after subchronic rolipram treatment. Alzheimers Dement 2008. [DOI: 10.1016/j.jalz.2008.05.1538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
| | - Kris Rutten
- Maastricht UniversityDept. of NeuroscienceMaastrichtNetherlands
| | - Jos Prickaerts
- Maastricht UniversityDept. of NeuroscienceMaastrichtNetherlands
| | | | | | - Arjan Blokland
- Maastricht UniversityDept. Neuropsychology and PsychopharmacologyMaastrichtNetherlands
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Rutten K, Basile JL, Prickaerts J, Blokland A, Vivian JA. Selective PDE inhibitors rolipram and sildenafil improve object retrieval performance in adult cynomolgus macaques. Psychopharmacology (Berl) 2008; 196:643-8. [PMID: 18034336 PMCID: PMC2244695 DOI: 10.1007/s00213-007-0999-1] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2007] [Accepted: 10/23/2007] [Indexed: 11/29/2022]
Abstract
RATIONALE Selective phosphodiesterase (PDE) inhibitors improve the formation of hippocampus-dependent memories in several rodent models of cognition. However, studies evaluating the effects of PDE inhibition on prefrontal cortex-dependent cognition and in monkeys are rare. OBJECTIVES The present study investigates the effect of the PDE4 inhibitor rolipram and the PDE5 inhibitor sildenafil on object retrieval performance. Object retrieval is a prefrontal cortical-mediated task, which is likely to capture attention and response inhibition. MATERIALS AND METHODS The ability to retrieve a food reward from a clear box with an open side positioned in various orientations was assessed in adult male cynomolgus monkeys (Macaca fascicularis). RESULTS Rolipram (0.003-0.03 mg/kg, intramuscular [i.m.]) and sildenafil (0.3-3 mg/kg, i.m.) dose-dependently increased correct first reaches during difficult trials, reaching significance at 0.01 and 1 mg/kg, respectively. For both drugs, correct reaches were increased approximately 20%; that is, performance was improved from approximately 50 to approximately 70% correct. CONCLUSIONS Both rolipram and sildenafil improved object retrieval performance, thus demonstrating the cognition-enhancing effects of PDE inhibition on a prefrontal task of executive function in monkeys.
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Affiliation(s)
- K. Rutten
- Department of Neuroscience, School for Mental Health and Neuroscience, Maastricht University, Universiteitssingel 50, P.O. Box 616, 6200 MD Maastricht, The Netherlands ,Department of Neuroscience, Roche Pharmaceuticals Palo Alto, Palo Alto, CA USA
| | - J. L. Basile
- Department of Neuroscience, Roche Pharmaceuticals Palo Alto, Palo Alto, CA USA
| | - J. Prickaerts
- Department of Neuroscience, School for Mental Health and Neuroscience, Maastricht University, Universiteitssingel 50, P.O. Box 616, 6200 MD Maastricht, The Netherlands ,Department of Neuropsychology and Psychopharmacology, Maastricht University, Maastricht, The Netherlands
| | - A. Blokland
- Department of Neuropsychology and Psychopharmacology, Maastricht University, Maastricht, The Netherlands
| | - J. A. Vivian
- Department of Neuroscience, Roche Pharmaceuticals Palo Alto, Palo Alto, CA USA
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Rutten K, Reneerkens OAH, Hamers H, Sik A, McGregor IS, Prickaerts J, Blokland A. Automated scoring of novel object recognition in rats. J Neurosci Methods 2008; 171:72-7. [PMID: 18372047 DOI: 10.1016/j.jneumeth.2008.02.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2007] [Revised: 02/12/2008] [Accepted: 02/13/2008] [Indexed: 10/22/2022]
Abstract
The object recognition task (ORT) has become increasingly popular as a memory test in neuroscience research. Scoring of ORT performance is still mostly done by hand, which can be liable to subjective scoring. To our knowledge, no suited software is available yet since the direction of the nose of the animal cannot be tracked reliably. We have developed a software paradigm that reliably tracks the nose of the rats and have conducted a series of experiments to evaluate the reliability of this newly developed program. We used Wistar rats, which showed good object memory after 1h interval. Subsequently, we used scopolamine (SCOP) to impair the memory performance of the rats. The object exploration was scored by two observers and the automated system. Both observers and the automated system found an impairing drug effect of scopolamine on ORT performance. When using large objects the correlation between the discrimination index d2 of observers was: 0.60 (SCOP) and 0.79 (SAL). However, the correlation between observers and the automated system was quite low: 0.41 (SCOP) and 0.40 (SAL). Reducing the size of the objects increased the reliability between observers and the automated system substantially (0.82-0.87). We conclude that the use of small objects in combination with our program enables reliable automated scoring in the ORT, thus increasing the objectivity and validity of this task.
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Affiliation(s)
- K Rutten
- Department of Neuroscience, School of Mental Health and Neuroscience, Maastricht University, PO Box 616, 6200 MD, Maastricht, The Netherlands.
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Rutten K, Lieben C, Smits L, Blokland A. The PDE4 inhibitor rolipram reverses object memory impairment induced by acute tryptophan depletion in the rat. Psychopharmacology (Berl) 2007; 192:275-82. [PMID: 17265077 PMCID: PMC1915617 DOI: 10.1007/s00213-006-0697-4] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2006] [Accepted: 12/28/2006] [Indexed: 10/27/2022]
Abstract
RATIONALE The selective type IV phosphodiesterase inhibitor, rolipram, has been shown to improve long-term memory and can reverse the cholinergic deficit caused by scopolamine. However, the underlying mechanisms of action of rolipram remain obscure. OBJECTIVES The present study investigates the effect of rolipram in a serotonergic-deficit model of acute tryptophan depletion (ATD). In addition, the levels of plasma tryptophan (TRP) were compared to object recognition performance. MATERIALS AND METHODS The experiments were conducted using male Wistar rats. The time-dependent effect of ATD treatment (a gelatin-based protein mixture) on plasma TRP levels (0, 1, 3, and 6 h after injection) and object recognition task (ORT) performance (0.5, 1, 3, and 6 h after ATD treatment) was examined. The effect of rolipram (0, 0.01, 0.03, and 0.1 mg/kg, i.p.) was tested in the condition in which ATD induced a clear memory deficit. RESULTS ATD significantly lowered the plasma TRP ratio (TRP/Sigmalarge neutral amino acid) with a maximum of 48%, approximately 1 h after administration. Furthermore, ATD impairs ORT performance when administered 3 h before testing. Rolipram (0.1 mg/kg) reversed the memory deficit induced by ATD in a dose-dependent manner. CONCLUSIONS On the basis of previous studies and the ability to reverse a serotonergic deficit, we suggest that rolipram may act through elevation of cyclic adenosine monophosphate levels and subsequent increase in neurotransmitter release.
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Affiliation(s)
- K Rutten
- Department of Psychiatry and Neuropsychology, Brain and Behavior Institute, Maastricht University, Universiteitssingel 50, 6200 MD, Maastricht, The Netherlands.
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Rutten K, Prickaerts J, Hendrix M, van der Staay FJ, Sik A, Blokland A. Time-dependent involvement of cAMP and cGMP in consolidation of object memory: studies using selective phosphodiesterase type 2, 4 and 5 inhibitors. Eur J Pharmacol 2007; 558:107-12. [PMID: 17207788 DOI: 10.1016/j.ejphar.2006.11.041] [Citation(s) in RCA: 133] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2006] [Revised: 11/16/2006] [Accepted: 11/21/2006] [Indexed: 11/21/2022]
Abstract
The present study investigated the time-dependent memory enhancing properties of three selective phosphodiesterase inhibitors (PDE-I) vardenafil (PDE5-I), rolipram (PDE4-I) and BAY 60-7550 (PDE2-I) in the object recognition task. In particular, the time-dependent involvement of cAMP and cGMP in memory consolidation was assessed by altering the time points of drug administration. Vardenafil (1 mg/kg, p.o.), rolipram (0.03 mg/kg, i.p.), and BAY 60-7550 (3 mg/kg, p.o.) were tested in rats with a 24 h delay between the learning and the test trial. The PDE-Is were administered at different time points, i.e. directly after, 1 h, 3 h and 6 h after the first trial. Using a 24 h interval, vardenafil only showed an effect on object memory when injected directly after trial 1, rolipram only showed an improvement when injected 3 h after trial 1 and BAY 60-7550 improved memory when injected either directly after or 3 h after trial 1. No treatment effects were found when the compounds were administered 1 h or 6 h after the first trial. Our results extend our previous data that different types of PDE-Is affect different stages of memory consolidation. Moreover, the present study provides further support that selective PDE-Is can influence memory consolidation in a time-dependent manner, assumingly by elevating central cAMP and cGMP levels.
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Affiliation(s)
- Kris Rutten
- Department of Psychiatry and Neuropsychology, Brain and Behavior Institute, EURON, Maastricht University, 6200 MD Maastricht, The Netherlands.
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Blokland A, Rutten K, Prickaerts J. Analysis of spatial orientation strategies of male and female Wistar rats in a Morris water escape task. Behav Brain Res 2006; 171:216-24. [PMID: 16647766 DOI: 10.1016/j.bbr.2006.03.033] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2005] [Revised: 03/22/2006] [Accepted: 03/27/2006] [Indexed: 11/17/2022]
Abstract
In the present study we investigated spatial navigation in male and female Wistar rats in the Morris water escape task. Rats were subjected to procedures which required the use of a place (PLACE), cue (CUE) and egocentric (EGO) response to learn the task efficiently. In a first experiment rats were successively tested in the PLACE, CUE and EGO condition and in a second experiment the order of tasks was reversed. The first experiment showed that female rats swam longer distances and took more time to find the platform in the PLACE task. Further, the female rats spent less time near the previous platform position than the male rats during probe trial. No sex difference was found in the CUE and EGO task. In the second experiment, the female rats took longer to find the platform than the male rats in the EGO task. In the CUE and PLACE task no differences between the sexes was found during acquisition. However, the male rats spent more time near the previous platform position than the female rats during the probe trial of the PLACE task. On basis of present data it is concluded that the use of a PLACE-based strategy is better in male Wistar rats. CUE learning is not sex-dependent. The ability to use EGO strategies appears not to be different between male and female Wistar rats, but appears dependent on pre-exposure to the task.
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Affiliation(s)
- Arjan Blokland
- Faculty of Psychology, Maastricht University, The Netherlands.
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Rutten K, Vente JD, Sik A, Ittersum MMV, Prickaerts J, Blokland A. The selective PDE5 inhibitor, sildenafil, improves object memory in Swiss mice and increases cGMP levels in hippocampal slices. Behav Brain Res 2006; 164:11-6. [PMID: 16076505 DOI: 10.1016/j.bbr.2005.04.021] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2005] [Revised: 04/27/2005] [Accepted: 04/29/2005] [Indexed: 11/20/2022]
Abstract
Previous studies have shown memory enhancing effects of phosphodiesterase type 5 (PDE5) inhibitors in rats. However, differences in nitric oxide (NO)-mediated cyclic GMP (cGMP) signaling in the hippocampus have been described between rats and mice. In the present study we investigated the memory enhancing effects of the PDE5 inhibitor, sildenafil on memory performance in Swiss mice using the object recognition task. Sildenafil (0.3, 1 and 3 mg/kg) was administered orally directly after the first trial. The memory for the objects was retested 24 h later when mice show no memory for the familiar object. Sildenafil improved the object discrimination performance of Swiss mice at a dose of 1 mg/kg. Hippocampal slices of Swiss mice incubated with sildenafil (10 microM) increased cGMP levels in varicosities in the CA3 region of the hippocampus and a number of short, thin fibers. Addition of DEA/NO, an NO donor (10 microM), in the presence of sildenafil (10 microM) strongly increased cGMP immunoreactivity of varicosities in the CA3 region. Double immunostaining of cGMP with the presynaptic marker synaptophysin did not reveal any co-localization of these markers under any circumstance. Taken together, inhibition of PDE5 improves object recognition memory in mice. Furthermore, a postsynaptic role of cGMP could be involved in this respect.
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Affiliation(s)
- K Rutten
- Department of Psychiatry and Neuropsychology, Brain and Behavior Institute, Maastricht University, The Netherlands.
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Hoff EI, Blokland A, Rutten K, Steinbusch HWM, van Oostenbrugge RJ. Dissociable effects in reaction time performance after unilateral cerebral infarction: A comparison between the left and right frontal cortices in rats. Brain Res 2006; 1069:182-9. [PMID: 16412996 DOI: 10.1016/j.brainres.2005.11.070] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2005] [Revised: 11/14/2005] [Accepted: 11/16/2005] [Indexed: 10/25/2022]
Abstract
Reaction time performance reflects the speed of information processing, both in humans and lower vertebrates like the rat. The present study compared reaction time performance in rats following unilateral infarction to the frontal cortex. The objective was to model cognitive impairment as it is seen in humans after stroke. Rats were trained in a reaction time paradigm, after which unilateral cortical infarction was induced photochemically. Reaction time performance was differentially affected after unilateral infarction to either the left or right frontal cortex, whereas sham operation did not result in a significant alteration in reactivity. An overall increase in reaction time of about 10% was present at 4 weeks after frontal infarction. In addition, a lateralized reaction time deficit occurred very early after right frontal infarction as an increase of 10-15% in trials directed towards the contralesional side. Additional analyses showed that these reaction time deficits can be explained differently: the former as a gradual and general decrease in the speed of information processing, whereas the latter shows specific impairment to initiate a contralateral motor response. The former matches well with the mental slowing observed in stroke patients, whereas the latter resembles a neglect phenomenon. We conclude that measuring reaction time performance after frontal cortical infarction in rats could offer a useful tool to model particular human cognitive impairments following cerebral infarction.
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Affiliation(s)
- Erik I Hoff
- Department of Psychiatry and Neuropsychology, Division Cellular Neuroscience, Maastricht Brain and Behaviour Institute, Maastricht, The Netherlands.
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Rutten K, Prickaerts J, Blokland A. Rolipram reverses scopolamine-induced and time-dependent memory deficits in object recognition by different mechanisms of action. Neurobiol Learn Mem 2005; 85:132-8. [PMID: 16242977 DOI: 10.1016/j.nlm.2005.09.002] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2005] [Revised: 09/01/2005] [Accepted: 09/08/2005] [Indexed: 11/24/2022]
Abstract
In this study, the effect of the selective phosphodiesterase type 4 (PDE4) inhibitor rolipram on memory performance was investigated using the object recognition task. First, three doses of rolipram (0.01, 0.03 or 0.1 mg/kg) were tested with a 24h delay between the learning (T1) and the test (T2) trial. Doses of rolipram were injected at different time points (30 min before T1, immediately after T1 or 3 h after T1). In a second experiment, the effects of rolipram (0.03, 0.1 or 0.3 mg/kg) were tested in combination with scopolamine (0.1 mg/kg) applying a 1 h delay between trials. Both substances were administered 30 min before T1. Using a 24h interval, rolipram showed an improvement in long-term memory performance when injected 3 h after T1 at a dose of 0.03 mg/kg. Further, rolipram reversed the scopolamine-induced short-term memory deficit at a dose of 0.1 mg/kg. Although the improved memory performance in both conditions is likely to be explained by elevated cAMP levels, two separate working mechanisms might explain these effects.
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Affiliation(s)
- K Rutten
- Department of Psychiatry and Neuropsychology, Brain and Behaviour Institute, Maastricht University, PO Box 616, 6200 MD Maastricht, The Netherlands.
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