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Lei M, Tan Y, Tu H, Tan W. Neuronal basis and diverse mechanisms of pathogen avoidance in Caenorhabditis elegans. Front Immunol 2024; 15:1353747. [PMID: 38751431 PMCID: PMC11094273 DOI: 10.3389/fimmu.2024.1353747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Accepted: 04/22/2024] [Indexed: 05/18/2024] Open
Abstract
Pathogen avoidance behaviour has been observed across animal taxa as a vital host-microbe interaction mechanism. The nematode Caenorhabditis elegans has evolved multiple diverse mechanisms for pathogen avoidance under natural selection pressure. We summarise the current knowledge of the stimuli that trigger pathogen avoidance, including alterations in aerotaxis, intestinal bloating, and metabolites. We then survey the neural circuits involved in pathogen avoidance, transgenerational epigenetic inheritance of pathogen avoidance, signalling crosstalk between pathogen avoidance and innate immunity, and C. elegans avoidance of non-Pseudomonas bacteria. In this review, we highlight the latest advances in understanding host-microbe interactions and the gut-brain axis.
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Affiliation(s)
- Ming Lei
- Academy of Medical Engineering and Translational Medicine (AMT), Tianjin University, Tianjin, China
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, Hunan University, Changsha, Hunan, China
- The Key Laboratory of Zhejiang Province for Aptamers and Theranostics, Zhejiang Cancer Hospital, Hangzhou Institute of Medicine (HIM), Chinese Academy of Sciences, Hangzhou, Zhejiang, China
| | - Yanheng Tan
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, Hunan University, Changsha, Hunan, China
| | - Haijun Tu
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, Hunan University, Changsha, Hunan, China
| | - Weihong Tan
- Academy of Medical Engineering and Translational Medicine (AMT), Tianjin University, Tianjin, China
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, Hunan University, Changsha, Hunan, China
- The Key Laboratory of Zhejiang Province for Aptamers and Theranostics, Zhejiang Cancer Hospital, Hangzhou Institute of Medicine (HIM), Chinese Academy of Sciences, Hangzhou, Zhejiang, China
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Tortora F, Hadipour AL, Battaglia S, Falzone A, Avenanti A, Vicario CM. The Role of Serotonin in Fear Learning and Memory: A Systematic Review of Human Studies. Brain Sci 2023; 13:1197. [PMID: 37626553 PMCID: PMC10452575 DOI: 10.3390/brainsci13081197] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Revised: 08/07/2023] [Accepted: 08/08/2023] [Indexed: 08/27/2023] Open
Abstract
Fear is characterized by distinct behavioral and physiological responses that are essential for the survival of the human species. Fear conditioning (FC) serves as a valuable model for studying the acquisition, extinction, and expression of fear. The serotonin (5-hydroxytryptamine, 5-HT) system is known to play a significant role in emotional and motivational aspects of human behavior, including fear learning and expression. Accumulating evidence from both animal and human studies suggests that brain regions involved in FC, such as the amygdala, hippocampus, and prefrontal cortex, possess a high density of 5-HT receptors, implicating the crucial involvement of serotonin in aversive learning. Additionally, studies exploring serotonin gene polymorphisms have indicated their potential influence on FC. Therefore, the objective of this work was to review the existing evidence linking 5-HT with fear learning and memory in humans. Through a comprehensive screening of the PubMed and Web of Science databases, 29 relevant studies were included in the final review. These studies investigated the relationship between serotonin and fear learning using drug manipulations or by studying 5-HT-related gene polymorphisms. The results suggest that elevated levels of 5-HT enhance aversive learning, indicating that the modulation of serotonin 5-HT2A receptors regulates the expression of fear responses in humans. Understanding the role of this neurochemical messenger in associative aversive learning can provide insights into psychiatric disorders such as anxiety and post-traumatic stress disorder (PTSD), among others.
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Affiliation(s)
- Francesco Tortora
- Dipartimento di Scienze Cognitive, Psicologiche, Pedagogiche e Degli Studi Culturali, Università Degli Studi di Messina, Via Concezione 6, 98121 Messina, Italy; (F.T.); (A.F.)
| | - Abed L. Hadipour
- Dipartimento di Scienze Cognitive, Psicologiche, Pedagogiche e Degli Studi Culturali, Università Degli Studi di Messina, Via Concezione 6, 98121 Messina, Italy; (F.T.); (A.F.)
| | - Simone Battaglia
- Centro Studi e Ricerche in Neuroscienze Cognitive, Dipartimento di Psicologia “Renzo Canestrari”, Campus di Cesena, Alma Mater Studiorum Università di Bologna, Viale Rasi e Spinelli 176, 47521 Cesena, Italy;
| | - Alessandra Falzone
- Dipartimento di Scienze Cognitive, Psicologiche, Pedagogiche e Degli Studi Culturali, Università Degli Studi di Messina, Via Concezione 6, 98121 Messina, Italy; (F.T.); (A.F.)
| | - Alessio Avenanti
- Centro Studi e Ricerche in Neuroscienze Cognitive, Dipartimento di Psicologia “Renzo Canestrari”, Campus di Cesena, Alma Mater Studiorum Università di Bologna, Viale Rasi e Spinelli 176, 47521 Cesena, Italy;
- Centro de Investigación en Neuropsicología y Neurociencias Cognitivas, Universidad Católica Del Maule, Talca 3460000, Chile
| | - Carmelo M. Vicario
- Dipartimento di Scienze Cognitive, Psicologiche, Pedagogiche e Degli Studi Culturali, Università Degli Studi di Messina, Via Concezione 6, 98121 Messina, Italy; (F.T.); (A.F.)
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Riegel M, Wierzba M, Wypych M, Ritchey M, Jednoróg K, Grabowska A, Vuilleumier P, Marchewka A. Distinct medial-tempora lobe mechanisms of encoding and amygdala-mediated memory reinstatement for disgust and fear. Neuroimage 2022; 251:118889. [PMID: 35065268 DOI: 10.1016/j.neuroimage.2022.118889] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 12/22/2021] [Accepted: 01/06/2022] [Indexed: 11/29/2022] Open
Abstract
Current models of episodic memory posit that retrieval involves the reenactment of encoding processes. Recent evidence has shown that this reinstatement process - indexed by subsequent encoding-retrieval similarity of brain activity patterns - is related to the activity in the hippocampus during encoding. However, we tend to re-experience emotional events in memory more richly than dull events. The role of amygdala - a critical hub of emotion processing - in reinstatement of emotional events was poorly understood. To investigate it, we leveraged a previously overlooked divergence in the role of amygdala in memory modulation by distinct emotions - disgust and fear. Here we used a novel paradigm in which participants encoded complex events (word pairs) and their memory was tested after 3 weeks, both phases during fMRI scanning. Using representational similarity analysis and univariate analyses, we show that the strength of amygdala activation during encoding was correlated with memory reinstatement of individual event representations in emotion-specific regions. Critically, amygdala modulated reinstatement more for disgust than fear. This was in line with other differences observed at the level of memory performance and neural mechanisms of encoding. Specifically, amygdala and perirhinal cortex were more involved during encoding of disgust-related events, whereas hippocampus and parahippocampal gyrus during encoding of fear-related events. Together, these findings shed a new light on the role of the amygdala and medial temporal lobe regions in encoding and reinstatement of specific emotional memories.
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Affiliation(s)
- Monika Riegel
- Laboratory of Brain Imaging, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Warsaw 02-093, Poland; Department of Psychology, Columbia University, New York 10027, United States of America; Centre interfacultaire de gérontologie et d'études des vulnerabilities, University of Geneva, CH-Geneva 1211, Switzerland.
| | - Małgorzata Wierzba
- Laboratory of Brain Imaging, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Warsaw 02-093, Poland
| | - Marek Wypych
- Laboratory of Brain Imaging, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Warsaw 02-093, Poland
| | - Maureen Ritchey
- Department of Psychology and Neuroscience, Boston College, Chestnut Hill, MA 02467, United States of America
| | - Katarzyna Jednoróg
- Laboratory of Brain Imaging, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Warsaw 02-093, Poland
| | - Anna Grabowska
- SWPS University of Social Sciences and Humanities, Warsaw 03-815, Poland
| | - Patrik Vuilleumier
- Department of Neuroscience, University Medical Center, Geneva CH-1211, Switzerland; Swiss Center for Affective Sciences, University of Geneva, Campus Biotech, CH-Geneva 1211, Switzerland; Geneva Neuroscience Center, University of Geneva, Geneva CH-1211, Switzerland
| | - Artur Marchewka
- Laboratory of Brain Imaging, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Warsaw 02-093, Poland
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Szymkow A, Frankowska N, Galasinska K. Testing the Disgust-Based Mechanism of Homonegative Attitudes in the Context of the COVID-19 Pandemic. Front Psychol 2021; 12:647881. [PMID: 34079494 PMCID: PMC8165159 DOI: 10.3389/fpsyg.2021.647881] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 04/21/2021] [Indexed: 11/13/2022] Open
Abstract
Negative attitudes and stigmatization can originate from the perception of a disease-related threat. Following the spread of the COVID-19 pandemic, it is often suggested that incidents of discriminatory behavior are the result of defense mechanisms aimed at avoiding pathogens. According to the behavioral immune system theory, people are motivated to distance themselves from individuals who show signs of infection, or who are only heuristically associated with a disease, primarily because of the disgust they evoke. In this paper we focus on negative attitudes toward gay men and lesbians who are among social groups that have been persistently framed as "unclean." In our correlational study (N = 500 heterosexual participants; Polish sample data collected during the first COVID-19 lockdown in Poland, in March/April 2020) we tested moderation models derived from the behavioral immune system theory. Specifically, we investigated whether perceived vulnerability to disease and perceived threat of contracting COVID-19 moderate the relation between disgust and homonegativity. We found that sexual disgust (but not pathogen nor moral disgust) predicted homonegative attitudes. This effect was stronger for participants expressing higher levels of perceived vulnerability to disease but was not dependent on the perception of the COVID-19 threat. The results reaffirm previous evidence indicating a pivotal role of disgust in disease-avoidance mechanisms. They also point to functional flexibility of the behavioral immune system by demonstrating the moderating role of perceived vulnerability to disease in shaping homonegative attitudes. Finally, they show that the threat of COVID-19 does not strengthen the relationship between disgust and homonegativity.
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Affiliation(s)
- Aleksandra Szymkow
- Center for Research on Biological Basis of Social Behavior, SWPS University of Social Sciences and Humanities, Warsaw, Poland
| | - Natalia Frankowska
- Center for Research on Biological Basis of Social Behavior, SWPS University of Social Sciences and Humanities, Warsaw, Poland
| | - Katarzyna Galasinska
- Center for Research on Biological Basis of Social Behavior, SWPS University of Social Sciences and Humanities, Warsaw, Poland
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Hoffman C, Aballay A. Role of neurons in the control of immune defense. Curr Opin Immunol 2019; 60:30-36. [PMID: 31117013 DOI: 10.1016/j.coi.2019.04.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 04/11/2019] [Accepted: 04/12/2019] [Indexed: 11/28/2022]
Abstract
Studies in recent years have strengthened the notion that neural mechanisms are involved in the control of immune responses. From initial studies that highlighted the vagus nerve control of inflammatory responses in vertebrates, many advances have been made, including the dissection of specific neural circuits that are involved in controlling immunity. Part of this has been facilitated by the use of a tractable model animal, Caenorhabditis elegans, in which individual neurons involved in sensing pathogens and controlling the immune response have been identified. Importantly, some of the underlying mechanisms involved in the neural control of immune pathways appear to be present in evolutionarily diverse species. This review focuses on some major developments in vertebrates and C. elegans, and how these discoveries may lead to advances in understanding neural-immune connections that govern inflammatory responses.
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Affiliation(s)
- Casandra Hoffman
- Molecular Microbiology and Immunology, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, 6351 Richard Jones Hall, Mail Code: L220, Portland, OR 97239, United States
| | - Alejandro Aballay
- Molecular Microbiology and Immunology, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, 6351 Richard Jones Hall, Mail Code: L220, Portland, OR 97239, United States.
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Harmon-Jones E, Harmon-Jones C, Summerell E. On the Importance of Both Dimensional and Discrete Models of Emotion. Behav Sci (Basel) 2017; 7:E66. [PMID: 28961185 PMCID: PMC5746675 DOI: 10.3390/bs7040066] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 08/30/2017] [Accepted: 09/27/2017] [Indexed: 11/16/2022] Open
Abstract
We review research on the structure and functions of emotions that has benefitted from a serious consideration of both discrete and dimensional perspectives on emotion. To illustrate this point, we review research that demonstrates: (1) how affective valence within discrete emotions differs as a function of individuals and situations, and how these differences relate to various functions; (2) that anger (and other emotional states) should be considered as a discrete emotion but there are dimensions around and within anger; (3) that similarities exist between approach-related positive and negative discrete emotions and they have unique motivational functions; (4) that discrete emotions and broad dimensions of emotions both have unique functions; and (5) evidence that a "new" discrete emotion with discrete functions exists within a broader emotion family. We hope that this consideration of both discrete and dimensional perspectives on emotion will assist in understanding the functions of emotions.
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Affiliation(s)
- Eddie Harmon-Jones
- School of Psychology, The University of New South Wales, Sydney 2052, Australia.
| | - Cindy Harmon-Jones
- School of Psychology, The University of New South Wales, Sydney 2052, Australia.
| | - Elizabeth Summerell
- School of Psychology, The University of New South Wales, Sydney 2052, Australia.
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Dong Y, Han Y, Wang Z, Qin Z, Yang C, Cao J, Chen Y. Role of serotonin on the intestinal mucosal immune response to stress-induced diarrhea in weaning mice. BMC Gastroenterol 2017; 17:82. [PMID: 28633646 PMCID: PMC5479009 DOI: 10.1186/s12876-017-0634-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Accepted: 06/08/2017] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND During weaning, babies and young animal often experience diarrhea from food intolerance and/or decreasing levels of maternal antibodies, and diarrhea tends to be particularly severe during the early-weaned period, which often exhibits an underdeveloped immune system, a disturbed gut environment and results in nutrient malabsorption and dehydration. It was deduced that neuroendocrine might have close relation with diarrhea, especially 5-HT. METHODS To explore the role of serotonin (5-HT) in weaning mice subjected to stress-induced diarrhea, 21-day-old weaned mice were divided into the following groups: control group, stress-induced diarrhea group (restrained by binding the hind limbs and intragastric administration of folium sennae with 0.4 g/mL, 15 mL/kg body weight) and para-chlorophenylalanine (PCPA) + stress-induced diarrhea group (30 mg/mL, 300 mg/kg body weight PCPA intraperitoneal injection before stress-induced diarrhea treatment). RESULTS Based on results from enzyme-linked immunosorbent assays, histological staining, lymphocyte proliferation assays and flow cytometry analysis, we found that the mice experienced increases in several stress markers, which coincided with severe diarrhea and an increase in 5-HT levels. However, pre-treatment with PCPA resulted in a decrease in the stress indicators and the severity of diarrhea, which correlated with decreased 5-HT levels. Interestingly, stress-induced diarrhea caused changes in various aspects of the immune system, including the amount of intraepithelium lymphocytes, CD4+/CD8+ T lymphocyte populations, B and T lymphocyte proliferation, and the secretion of sIgA and cytokines in the small intestine and ileum. However, these immune system changes could be reversed upon treatment with PCPA. CONCLUSIONS We observed a distinct correlation between 5-HT levels and the occurrence of stress-induced diarrhea in weaning mice, which may result in the deregulation of the mucosal immune system.
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Affiliation(s)
- Yulan Dong
- Laboratory of Veterinary Anatomy, College of Animal Medicine, China Agricultural University, Haidian, Beijing, 100193 People’s Republic of China
| | - Yanan Han
- Laboratory of Veterinary Anatomy, College of Animal Medicine, China Agricultural University, Haidian, Beijing, 100193 People’s Republic of China
| | - Zixu Wang
- Laboratory of Veterinary Anatomy, College of Animal Medicine, China Agricultural University, Haidian, Beijing, 100193 People’s Republic of China
| | - Zhuoming Qin
- Institute of Poultry, Shandong Academy of Agricultural Sciences, Jinan, 250100 China
| | - Chenyu Yang
- Laboratory of Veterinary Anatomy, College of Animal Medicine, China Agricultural University, Haidian, Beijing, 100193 People’s Republic of China
| | - Jing Cao
- Laboratory of Veterinary Anatomy, College of Animal Medicine, China Agricultural University, Haidian, Beijing, 100193 People’s Republic of China
| | - Yaoxing Chen
- Laboratory of Veterinary Anatomy, College of Animal Medicine, China Agricultural University, Haidian, Beijing, 100193 People’s Republic of China
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Asymmetric Arginine Dimethylation Modulates Mitochondrial Energy Metabolism and Homeostasis in Caenorhabditis elegans. Mol Cell Biol 2017; 37:MCB.00504-16. [PMID: 27994012 DOI: 10.1128/mcb.00504-16] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Accepted: 12/11/2016] [Indexed: 01/25/2023] Open
Abstract
Protein arginine methyltransferase 1 (PRMT-1) catalyzes asymmetric arginine dimethylation on cellular proteins and modulates various aspects of biological processes, such as signal transduction, DNA repair, and transcriptional regulation. We have previously reported that the null mutant of prmt-1 in Caenorhabditis elegans exhibits a slightly shortened life span, but the physiological significance of PRMT-1 remains largely unclear. Here we explored the role of PRMT-1 in mitochondrial function as hinted by a two-dimensional Western blot-based proteomic study. Subcellular fractionation followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis showed that PRMT-1 is almost entirely responsible for asymmetric arginine dimethylation on mitochondrial proteins. Importantly, isolated mitochondria from prmt-1 mutants represent compromised ATP synthesis in vitro, and whole-worm respiration in prmt-1 mutants is decreased in vivo Transgenic rescue experiments demonstrate that PRMT-1-dependent asymmetric arginine dimethylation is required to prevent mitochondrial reactive oxygen species (ROS) production, which consequently causes the activation of the mitochondrial unfolded-protein response. Furthermore, the loss of enzymatic activity of prmt-1 induces food avoidance behavior due to mitochondrial dysfunction, but treatment with the antioxidant N-acetylcysteine significantly ameliorates this phenotype. These findings add a new layer of complexity to the posttranslational regulation of mitochondrial function and provide clues for understanding the physiological roles of PRMT-1 in multicellular organisms.
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Daschner A. An Evolutionary-Based Framework for Analyzing Mold and Dampness-Associated Symptoms in DMHS. Front Immunol 2017; 7:672. [PMID: 28119688 PMCID: PMC5220099 DOI: 10.3389/fimmu.2016.00672] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 12/20/2016] [Indexed: 01/20/2023] Open
Abstract
Among potential environmental harmful factors, fungi deserve special consideration. Their intrinsic ability to actively germinate or infect host tissues might determine a prominent trigger in host defense mechanisms. With the appearance of fungi in evolutionary history, other organisms had to evolve strategies to recognize and cope with them. Existing controversies around dampness and mold hypersensitivity syndrome (DMHS) can be due to the great variability of clinical symptoms but also of possible eliciting factors associated with mold and dampness. An hypothesis is presented, where an evolutionary analysis of the different response patterns seen in DMHS is able to explain the existing variability of disease patterns. Classical interpretation of immune responses and symptoms are addressed within the field of pathophysiology. The presented evolutionary analysis seeks for the ultimate causes of the vast array of symptoms in DMHS. Symptoms can be interpreted as induced by direct (toxic) actions of spores, mycotoxins, or other fungal metabolites, or on the other side by the host-initiated response, which aims to counterbalance and fight off potentially deleterious effects or fungal infection. Further, individual susceptibility of immune reactions can confer an exaggerated response, and magnified symptoms are then explained in terms of immunopathology. IgE-mediated allergy fits well in this scenario, where individuals with an atopic predisposition suffer from an exaggerated response to mold exposure, but studies addressing why such responses have evolved and if they could be advantageous are scarce. Human history is plenty of plagues and diseases connected with mold exposure, which could explain vulnerability to mold allergy. Likewise, multiorgan symptoms in DMHS are analyzed for its possible adaptive role not only in the defense of an active infection, but also as evolved mechanisms for avoidance of potentially harmful environments in an evolutionary past or present setting.
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Affiliation(s)
- Alvaro Daschner
- Instituto de Investigación Sanitaria, Hospital Universitario de la Princesa, Servicio de Alergia , Madrid , Spain
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Blake KR, Yih J, Zhao K, Sung B, Harmon-Jones C. Skin-transmitted pathogens and the heebie jeebies: evidence for a subclass of disgust stimuli that evoke a qualitatively unique emotional response. Cogn Emot 2016; 31:1153-1168. [PMID: 27380127 DOI: 10.1080/02699931.2016.1202199] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Skin-transmitted pathogens have threatened humans since ancient times. We investigated whether skin-transmitted pathogens were a subclass of disgust stimuli that evoked an emotional response that was related to, but distinct from, disgust and fear. We labelled this response "the heebie jeebies". In Study 1, coding of 76 participants' experiences of disgust, fear, and the heebie jeebies showed that the heebie jeebies was elicited by unique stimuli which produced skin-crawling sensations and an urge to protect the skin. In Experiment 2,350 participants' responses to skin-transmitted pathogen, fear-inducing, and disgust-inducing vignettes showed that the vignettes elicited sensations and urges which loaded onto heebie jeebies, fear, and disgust factors, respectively. Experiment 3 largely replicated findings from Experiment 2 using video stimuli (178 participants). Results are consistent with the notion that skin-transmitted pathogens are a subclass of disgust stimuli which motivate behaviours that are functionally consistent with disgust yet qualitatively distinct.
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Affiliation(s)
- Khandis R Blake
- a School of Psychology , University of New South Wales , Sydney , NSW , Australia
| | - Jennifer Yih
- b Psychological Sciences , Vanderbilt University , Nashville , TN , USA
| | - Kun Zhao
- c School of Psychological Sciences , The University of Melbourne , Melbourne , VIC , Australia
| | - Billy Sung
- d School of Psychology , University of Queensland , Brisbane , QLD , Australia
| | - Cindy Harmon-Jones
- a School of Psychology , University of New South Wales , Sydney , NSW , Australia
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Curtis VA. Infection-avoidance behaviour in humans and other animals. Trends Immunol 2014; 35:457-64. [PMID: 25256957 DOI: 10.1016/j.it.2014.08.006] [Citation(s) in RCA: 156] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 08/25/2014] [Accepted: 08/25/2014] [Indexed: 12/19/2022]
Abstract
Compared with living free, the parasitic way of life has many attractions. Parasites create problems for all animals. Potential hosts can respond by learning to live with parasites (tolerance), actively fighting them (resistance), or they can avoid becoming infected in the first place (avoidance). I propose here a new classification of avoidance behaviour according to the epidemiology of infection risk, where animals must avoid (i) conspecifics, (ii) parasites and their vectors, (iii) parasite-rich environments, and (iv) niche infestation. I further explore how the disgust adaptive system, which coordinates avoidance behaviour, may form a continuum with the immune system through the sharing of signalling pathways, sites of action, and evolutionary history.
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Affiliation(s)
- Valerie A Curtis
- The Hygiene Centre, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 4HT, UK
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12
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Meisel JD, Kim DH. Behavioral avoidance of pathogenic bacteria by Caenorhabditis elegans. Trends Immunol 2014; 35:465-70. [PMID: 25240986 DOI: 10.1016/j.it.2014.08.008] [Citation(s) in RCA: 100] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Revised: 08/25/2014] [Accepted: 08/25/2014] [Indexed: 12/25/2022]
Abstract
The simple animal host Caenorhabditis elegans utilizes its nervous system to respond to diverse microbial cues, and can engage in a protective behavioral avoidance response to environmental pathogens. This behavior bears hallmarks of an immune response, with sensors and recognition systems that trigger a protective response following a learning experience. Neuronal circuits required for aversive learning have been defined, revealing conserved signaling modules with dual roles in immunity and neuronal responses to pathogenic bacteria. Identification of natural polymorphisms that modulate avoidance behavior has enabled an improved understanding of host-microbe interactions at the molecular level. We review here these findings and discuss how the microbial cues and host responses defined in C. elegans may provide insight into evolutionarily diverse host-microbe interactions.
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Affiliation(s)
- Joshua D Meisel
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Dennis H Kim
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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Vicario CM. Aberrant disgust response and immune reactivity in cocaine-dependent men might uncover deranged serotoninergic activity. Front Mol Neurosci 2014; 7:7. [PMID: 24574960 PMCID: PMC3920097 DOI: 10.3389/fnmol.2014.00007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Accepted: 01/20/2014] [Indexed: 11/13/2022] Open
Affiliation(s)
- Carmelo M Vicario
- School of Psychology, The University of Queensland Brisbane, QLD, Australia ; School of Psychology, The University of Bangor Bangor, UK
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14
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Toronchuk JA, Ellis GFR. Affective neuronal selection: the nature of the primordial emotion systems. Front Psychol 2013; 3:589. [PMID: 23316177 PMCID: PMC3540967 DOI: 10.3389/fpsyg.2012.00589] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Accepted: 12/12/2012] [Indexed: 11/13/2022] Open
Abstract
Based on studies in affective neuroscience and evolutionary psychiatry, a tentative new proposal is made here as to the nature and identification of primordial emotional systems. Our model stresses phylogenetic origins of emotional systems, which we believe is necessary for a full understanding of the functions of emotions and additionally suggests that emotional organizing systems play a role in sculpting the brain during ontogeny. Nascent emotional systems thus affect cognitive development. A second proposal concerns two additions to the affective systems identified by Panksepp. We suggest there is substantial evidence for a primary emotional organizing program dealing with power, rank, dominance, and subordination which instantiates competitive and territorial behavior and is an evolutionary contributor to self-esteem in humans. A program underlying disgust reactions which originally functioned in ancient vertebrates to protect against infection and toxins is also suggested.
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Affiliation(s)
- Judith A Toronchuk
- Department of Psychology, Trinity Western University Langley, BC, Canada ; Department of Biology, Trinity Western University Langley, BC, Canada
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Disgust elevates core body temperature and up-regulates certain oral immune markers. Brain Behav Immun 2012; 26:1160-8. [PMID: 22841694 DOI: 10.1016/j.bbi.2012.07.010] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Revised: 07/17/2012] [Accepted: 07/17/2012] [Indexed: 11/23/2022] Open
Abstract
Recent findings suggest that disgust can activate particular aspects of the immune system. In this study we examine whether disgust can also elevate core body temperature (BT), a further feature of an immune response to disease. In addition, we also examined whether food based disgust--a core eliciting stimulus--may be a more potent immune stimulus than non-food based disgust. Healthy males were randomly assigned to view one of four sets of images--food disgust, non-food disgust, food control and negative emotion control. Measures of BT, salivary immune and related markers, and self-report data, were collected before, and at two time points after image viewing. Disgust elevated BT relative to the negative emotion control condition, as did food images. Different mechanisms appeared to account for these effects on BT, with higher initial levels of Tumor Necrosis Factor alpha (TNF-a) and disgust, predictive of BT increases in the disgust conditions. Disgust also increased TNF-a, and albumin levels, relative to the control conditions. Type of disgust exerted little effect. These findings further support the idea that disgust impacts upon immune function, and that disgust serves primarily a disease avoidance function.
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Abstract
The new synthesis about disgust is that it is a system that evolved to motivate infectious disease avoidance. There are vital practical and intellectual reasons why we need to understand disgust better. Practically, disgust can be harnessed to combat the behavioural causes of infectious and chronic disease such as diarrhoeal disease, pandemic flu and smoking. Disgust is also a source of much human suffering; it plays an underappreciated role in anxieties and phobias such as obsessive compulsive disorder, social phobia and post-traumatic stress syndromes; it is a hidden cost of many occupations such as caring for the sick and dealing with wastes, and self-directed disgust afflicts the lives of many, such as the obese and fistula patients. Disgust is used and abused in society, being both a force for social cohesion and a cause of prejudice and stigmatization of out-groups. This paper argues that a better understanding of disgust, using the new synthesis, offers practical lessons that can enhance human flourishing. Disgust also provides a model system for the study of emotion, one of the most important issues facing the brain and behavioural sciences today.
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Affiliation(s)
- Valerie Curtis
- Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK.
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A natural history of hygiene. CANADIAN JOURNAL OF INFECTIOUS DISEASES & MEDICAL MICROBIOLOGY 2011; 18:11-4. [PMID: 18923689 DOI: 10.1155/2007/749190] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2006] [Accepted: 11/13/2006] [Indexed: 11/18/2022]
Abstract
In unpacking the Pandora's box of hygiene, the author looks into its ancient evolutionary history and its more recent human history. Within the box, she finds animal behaviour, dirt, disgust and many diseases, as well as illumination concerning how hygiene can be improved. It is suggested that hygiene is the set of behaviours that animals, including humans, use to avoid harmful agents. The author argues that hygiene has an ancient evolutionary history, and that most animals exhibit such behaviours because they are adaptive. In humans, responses to most infectious threats are accompanied by sensations of disgust. In historical times, religions, social codes and the sciences have all provided rationales for hygiene behaviour. However, the author argues that disgust and hygiene behaviour came first, and that the rationales came later. The implications for the modern-day practice of hygiene are profound. The natural history of hygiene needs to be better understood if we are to promote safe hygiene and, hence, win our evolutionary war against the agents of infectious disease.
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Curtis V, de Barra M, Aunger R. Disgust as an adaptive system for disease avoidance behaviour. Philos Trans R Soc Lond B Biol Sci 2011; 366:389-401. [PMID: 21199843 PMCID: PMC3013466 DOI: 10.1098/rstb.2010.0117] [Citation(s) in RCA: 357] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Disgust is an evolved psychological system for protecting organisms from infection through disease avoidant behaviour. This ‘behavioural immune system’, present in a diverse array of species, exhibits universal features that orchestrate hygienic behaviour in response to cues of risk of contact with pathogens. However, disgust is also a dynamic adaptive system. Individuals show variation in pathogen avoidance associated with psychological traits like having a neurotic personality, as well as a consequence of being in certain physiological states such as pregnancy or infancy. Three specialized learning mechanisms modify the disgust response: the Garcia effect, evaluative conditioning and the law of contagion. Hygiene behaviour is influenced at the group level through social learning heuristics such as ‘copy the frequent’. Finally, group hygiene is extended symbolically to cultural rules about purity and pollution, which create social separations and are enforced as manners. Cooperative hygiene endeavours such as sanitation also reduce pathogen prevalence. Our model allows us to integrate perspectives from psychology, ecology and cultural evolution with those of epidemiology and anthropology. Understanding the nature of disease avoidance psychology at all levels of human organization can inform the design of programmes to improve public health.
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Affiliation(s)
- Valerie Curtis
- The Hygiene Centre, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK.
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Neuberg SL, Kenrick DT, Schaller M. Human threat management systems: self-protection and disease avoidance. Neurosci Biobehav Rev 2011; 35:1042-51. [PMID: 20833199 PMCID: PMC3024471 DOI: 10.1016/j.neubiorev.2010.08.011] [Citation(s) in RCA: 252] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2010] [Revised: 08/18/2010] [Accepted: 08/18/2010] [Indexed: 10/19/2022]
Abstract
Humans likely evolved precautionary systems designed to minimize the threats to reproductive fitness posed by highly interdependent ultrasociality. A review of research on the self-protection and disease avoidance systems reveals that each system is functionally distinct and domain-specific: each is attuned to different cues; engages different emotions, inferences, and behavioral inclinations; and is rooted in somewhat different neurobiological substrates. These systems share important features, however. Each system is functionally coherent, in that perceptual, affective, cognitive, and behavioral processes work in concert to reduce fitness costs of potential threats. Each system is biased in a risk-averse manner, erring toward precautionary responses even when available cues only heuristically imply threat. And each system is functionally flexible, being highly sensitive to specific ecological and dispositional cues that signal greater vulnerability to the relevant threat. These features characterize a general template useful for understanding not only the self-protection and disease avoidance systems, but also a broader set of evolved, domain-specific precautionary systems.
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Affiliation(s)
- Steven L Neuberg
- Department of Psychology, Arizona State University, Tempe, AZ 85287-1104, United States.
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Ellis TB. Disgusting bodies, disgusting religion: the biology of Tantra. JOURNAL OF THE AMERICAN ACADEMY OF RELIGION. AMERICAN ACADEMY OF RELIGION 2011; 79:879-927. [PMID: 22180926 DOI: 10.1093/jaarel/lfr077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Hard-core Tantric practice is disgusting, a point several scholars make. Scholarly interpretations of Tantric disgustingness, however, tend to follow the lead of Mary Douglas in suggesting that what disgusts is ultimately a reflection of social–historical concerns with borders and boundaries. Such interpretations fail to take seriously the Tantric consumption of feces, menstrual blood, urine, semen, and phlegm. Likewise, they fail to take seriously the particular sexual act involved, that is, intercourse with a menstruating, riding-astride, out-of-caste, mother-substitute. Consulting contemporary disgust research, I suggest that hard-core Tantra is literally disgusting because it is literally maladaptive. Disgust was naturally selected to deter the ingestion of bio-toxic pathogens as well as the practice of suboptimal sexual intercourse. Disgust maintains the species' viability. Tantra confounds disgust and thus disgusts. Tantra engages antibiological behaviors in its characteristically religious war against the body. As a disgusting religion, Tantra may be a perfected religion.
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Stevenson RJ, Hodgson D, Oaten MJ, Barouei J, Case TI. The effect of disgust on oral immune function. Psychophysiology 2010; 48:900-7. [PMID: 21166686 DOI: 10.1111/j.1469-8986.2010.01165.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Disgust motivates avoidance of pathogen sources, but whether its role in disease avoidance extends into activating the immune system is unexplored. This was tested here by comparing oral immune markers before and after a disgust induction, relative to neutral and negative induction control groups. The disgust group, but not controls, revealed an oral inflammatory response, with increased salivary tumor necrotizing factor alpha and albumin, as well as a down-regulation of immunoglobulin A (SIgA) secretion. It has been hypothesized that disgust evolved in animals to clear toxins from the oral cavity by gaping and increased salivary flow. Our data suggest down-regulated SIgA secretion may be a vestige of this response so as to conserve protein, while the inflammatory reaction may reflect an adaptive response to disease threat, selectively triggered by disgust. The broader implications of these data for a discrete neuro-gut-immune axis are examined.
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Meissner K, Muth ER, Herbert BM. Bradygastric activity of the stomach predicts disgust sensitivity and perceived disgust intensity. Biol Psychol 2010; 86:9-16. [PMID: 20888886 DOI: 10.1016/j.biopsycho.2010.09.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2009] [Revised: 09/15/2010] [Accepted: 09/23/2010] [Indexed: 11/17/2022]
Abstract
The aim of this study was to investigate gastric and non-gastric autonomic responses to disgusting pictures and to assess the relationship between autonomic changes, disgust sensitivity, and perceived disgust intensity. Healthy participants viewed pictures with affectively neutral or disgusting content of either a high or moderate arousal level. Electrogastrogram, electrocardiogram, and electrodermal activity were recorded, and participants' disgust sensitivity and disgust intensity were assessed. No main effect of condition on gastric myoelectrical activity was found. However, stepwise regression analyses indicated that the percentage of bradygastria predicted disgust ratings in case of the highly arousing disgust pictures. When moderately arousing pictures were shown, disgust ratings were predicted by disgust sensitivity, which in turn was predicted by the percentage of bradygastria. Heart periods and respiratory sinus arrhythmia increased to a similar extent during both the highly arousing and moderately arousing picture blocks, while a tendency for larger skin conductance responses during the highly arousing picture block was shown. The results suggest that feelings of disgust may be specifically related to increased bradygastria, which may represent a prodromal sign of vomiting.
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Affiliation(s)
- Karin Meissner
- Institute of Medical Psychology, Ludwig-Maximilians, University Munich, Germany.
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Prokop P, Fančovičová J. The association between disgust, danger and fear of macroparasites and human behaviour. Acta Ethol 2010. [DOI: 10.1007/s10211-010-0075-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Stevenson RJ, Case TI, Hodgson D, Porzig-Drummond R, Barouei J, Oaten MJ. A scale for measuring hygiene behavior: development, reliability and validity. Am J Infect Control 2009; 37:557-64. [PMID: 19362392 DOI: 10.1016/j.ajic.2009.01.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2008] [Revised: 01/12/2009] [Accepted: 01/13/2009] [Indexed: 10/20/2022]
Abstract
BACKGROUND There is currently no general self-report measure for assessing hygiene behavior. This article details the development and testing of such a measure. METHODS In studies 1 to 4, a total of 855 participants were used for scale and subscale development and for reliability and validity testing. The latter involved establishing the relationships between self-reported hygiene behavior and existing measures, hand hygiene behavior, illness rates, and a physiological marker of immune function. In study 5, a total of 507 participants were used to assess the psychometric properties of the final revised version of the scale. RESULTS The final 23-item scale comprised 5 subscales: general, household, food-related, handwashing technique, and personal hygiene. Studies 1 to 4 confirmed the scale's reliability and validity, and study 5 confirmed the scale's 5-factor structure. CONCLUSIONS The scale is potentially suitable for multiple uses, in various settings, and for experimental and correlational approaches.
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Stevenson RJ, Case TI, Oaten MJ. Frequency and recency of infection and their relationship with disgust and contamination sensitivity. EVOL HUM BEHAV 2009. [DOI: 10.1016/j.evolhumbehav.2009.02.005] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Disgust Sensitivity and Psychopathological Symptoms: Distinctions from Harm Avoidance. JOURNAL OF PSYCHOPATHOLOGY AND BEHAVIORAL ASSESSMENT 2008. [DOI: 10.1007/s10862-008-9096-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Charlton BG. A book of ideas collected from Medical Hypotheses: Death can be cured by Roger Dobson. Med Hypotheses 2008; 70:905-9. [PMID: 18280670 DOI: 10.1016/j.mehy.2008.01.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
A new collection of ideas from Medical Hypotheses by Roger Dobson is entitled Death can be cured and 99 other Medical Hypotheses. It consists of humorous summaries of Medical Hypotheses articles from the past 30 years. The book's humour derives mainly from the subject matter, although sometimes also from the 'unconventional' approach of the authors with respect to matters such as evidence, argument or inference. Medical Hypotheses has generated such a lot of apparently- or actually-bizarre ideas because it aims to be open to potentially revolutionary science. The journal's official stance is that more harm is done by a failure to publish one idea that might have been true, than by publishing a dozen ideas that turn out to be false. Bizarre ideas tend to catch attention, and may stimulate a valuable response--even when a paper is mostly-wrong. A paper may be flawed but still contain the germ of an idea that can be elaborated and developed. The journal review process is susceptible to both false positives and false negatives. False positives occur when we publish an idea that is wrong; false negatives occur when we fail to publish an important idea that is right, and a potential scientific breakthrough never happens. False positives are more obvious, since the paper will be ignored, refuted, or fail to be replicated--and often attracts criticism and controversy. Editors may therefore take the more cautious path of avoiding false positives more assiduously than false negatives; however, this policy progressively favours less-ambitious science. Consequently, in Medical Hypotheses the 'set point' of risk is nearer to the false positive end of the spectrum than for most journals - and the publication of many apparently-bizarre papers is a natural consequence of this policy.
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Hasshoff M, Böhnisch C, Tonn D, Hasert B, Schulenburg H. The role ofCaenorhabditis elegansinsulin‐like signaling in the behavioral avoidance of pathogenicBacillus thuringiensis. FASEB J 2007; 21:1801-12. [PMID: 17314144 DOI: 10.1096/fj.06-6551com] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Pathogens cause damage, and their elimination requires activation of the costly immune response. A highly economic defense strategy should thus be the behavioral avoidance of pathogens, as manifested in humans by all aspects of hygiene or revulsion at pathogen-rich material. Despite its potential importance, behavioral defenses have as yet received only little attention in biomedical research--in stark contrast to the physiological immune system. In the present study, the genetics of such behavioral defenses are elucidated in a simple model organism, the nematode Caenorhabditis elegans. We show for the first time that mutations in the insulin-like receptor (ILR) pathway lead to two distinct behavioral responses against pathogenic strains of the gram-positive bacterium Bacillus thuringiensis (BT), including the physical evasion of pathogens and their reduced oral uptake. Since this pathway also contributes to nematode stress resistance, the results surprisingly reveal a genetic link between physiological and behavioral defenses. Considering that many signaling pathways have conserved their functions across evolution, including the ILR pathway, this signaling cascade may represent an interesting candidate regulator for behavioral defenses in more complex organisms, including humans.
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Affiliation(s)
- Martin Hasshoff
- Institute for Animal Evolution and Ecology, Westfälische Wilhelms-University, Münster, Germany
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