scholarly journals Evidence of anticipatory immune and hormonal responses to predation risk in an echinoderm

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jean-François Hamel ◽  
Sara Jobson ◽  
Guillaume Caulier ◽  
Annie Mercier
Keyword(s):  
Predation Risk ◽  
Stress Responses ◽  
Emotional States ◽  
Cognitive Ecology ◽  
Hormonal Responses ◽  
Alarm Signals ◽  
Adaptive Value ◽  
Main Components ◽  
Experimental Trials ◽  
Prolonged Stress

AbstractRecent efforts have been devoted to the link between responses to non-physical stressors and immune states in animals, mostly using human and other vertebrate models. Despite evolutionary relevance, comparatively limited work on the appraisal of predation risk and aspects of cognitive ecology and ecoimmunology has been carried out in non-chordate animals. The present study explored the capacity of holothuroid echinoderms to display an immune response to both reactive and anticipatory predatory stressors. Experimental trials and a mix of behavioural, cellular and hormonal markers were used, with a focus on coelomocytes (analogues of mammalian leukocytes), which are the main components of the echinoderm innate immunity. Findings suggest that holothuroids can not only appraise threatening cues (i.e. scent of a predator or alarm signals from injured conspecifics) but prepare themselves immunologically, presumably to cope more efficiently with potential future injuries. The responses share features with recently defined central emotional states and wane after prolonged stress in a manner akin to habituation, which are traits that have rarely been shown in non-vertebrates, and never in echinoderms. Because echinoderms sit alongside chordates in the deuterostome clade, such findings offer unique insights into the adaptive value and evolution of stress responses in animals.

scholarly journals Stress responses to conspecific visual cues of predation risk in zebrafish

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3739 ◽  
Author(s):  
Thiago Acosta Oliveira ◽  
Renan Idalencio ◽  
Fabiana Kalichak ◽  
João Gabriel dos Santos Rosa ◽  
Gessi Koakoski ◽  
...  
Keyword(s):  
Predation Risk ◽  
Stress Responses ◽  
Visual Cues ◽  
Behavioral Changes ◽  
Prey Fish ◽  
Alarm Signals ◽  
Defensive Responses ◽  
Defensive Behaviors ◽  
Antipredator Behaviors ◽  
Cortisol Increase

Chemical communication relating to predation risk is a trait common among fish species. Prey fish under threat of predation can signal risk to conspecific fish, which then exhibit defensive responses. Fish also assess predation risk by visual cues and change their behavior accordingly. Here, we explored whether these behavioral changes act as visual alarm signals to conspecific fish that are not initially under risk. We show that shoals of zebrafish (Danio rerio) visually exposed to a predator display antipredator behaviors. In addition, these defensive maneuvers trigger antipredator reactions in conspecifics and, concomitantly, stimulate the hypothalamus-pituitary-interrenal axis, leading to cortisol increase. Thus, we conclude that zebrafish defensive behaviors act as visual alarm cues that induce antipredator and stress response in conspecific fish.

Role of hypothalamic inputs in maintaining pituitary-adrenal responsiveness in repeated restraint

2003 ◽  
Vol 285 (5) ◽  
pp. E1110-E1117 ◽  
Author(s):  
D. Zelena ◽  
Z. Mergl ◽  
A. Földes ◽  
K. J. Kovács ◽  
Z. Tóth ◽  
...  
Keyword(s):  
Chronic Stress ◽  
Stress Responses ◽  
Mrna Level ◽  
Hormonal Changes ◽  
Mediobasal Hypothalamus ◽  
Hormonal Responses ◽  
Pomc Mrna ◽  
Paraventricular Nucleus Of Hypothalamus ◽  
Pituitary Adrenal Axis

The role of hypothalamic structures in the regulation of chronic stress responses was studied by lesioning the mediobasal hypothalamus or the paraventricular nucleus of hypothalamus (PVH). Rats were acutely (60 min) and/or repeatedly (for 7 days) restrained. In controls, a single restraint elevated the plasma adrenocorticotropin (ACTH), corticosterone, and prolactin levels. Repeated restraint produced all signs of chronic stress, including decreased body and thymus weights, increased adrenal weight, basal corticosterone levels, and proopiomelanocortin (POMC) mRNA expression in the anterior pituitary. Some adaptation to repeated restraint of the ACTH response, but not of other hormonal responses, was seen. Lesioning of the mediobasal hypothalamus abolished the hormonal response and POMC mRNA activation to acute and/or repeated restraint, suggesting that the hypothalamo-pituitary-adrenal axis activation during repeated restraint is centrally driven. PVH lesion inhibited the ACTH and corticosterone rise to the first restraint by ∼50%. In repeatedly restrained rats with PVH lesion, the ACTH response to the last restraint was reduced almost to basal control levels, and the elevation of POMC mRNA level was prevented. PVH seems to be important for the repeated restraint-induced ACTH and POMC mRNA stimulation, but it appears to partially mediate other restraint-induced hormonal changes.

Natural stressors and disease risk: does the threat of predation increase amphibian susceptibility to ranavirus?

2012 ◽  
Vol 90 (7) ◽  
pp. 893-902 ◽  
Author(s):  
N.A. Haislip ◽  
J.T. Hoverman ◽  
D.L. Miller ◽  
M.J. Gray
Keyword(s):  
Predation Risk ◽  
Stress Responses ◽  
Species Interactions ◽  
Disease Risk ◽  
Natural Populations ◽  
Emerging Infectious Diseases ◽  
Host Susceptibility ◽  
Continuous Exposure ◽  
Amphibian Species ◽  
Predator Cues

Emerging infectious diseases have been identified as threats to biodiversity, yet our understanding of the factors contributing to host susceptibility to pathogens within natural populations remains limited. It has been proposed that species interactions within communities affect host susceptibility to pathogens, thereby contributing to disease emergence. In particular, predation risk is a common natural stressor that has been hypothesized to compromise immune function of prey through chronic stress responses possibly leading to increased susceptibility to pathogens. We examined whether predation risk experienced during the development of four larval anuran species increases susceptibility (mortality and infection) to ranaviruses, a group of viruses responsible for amphibian die-offs. Using controlled laboratory experiments, we exposed each species to a factorial combination of two virus treatments (no virus or virus) crossed with three predator-cue treatments (no predators, larval dragonflies, or adult water bugs). All four amphibian species reduced activity by 22%–48% following continuous exposure to predator cues. In addition, virus exposure significantly reduced survival by 17%–100% across all species. However, exposure to predator cues did not interact with the virus treatments to elevate mortality or viral load. Our results suggest that the expression of predator-induced plasticity in anuran larvae does not increase ranaviral disease risk.

scholarly journals Comparative vulnerability of Indosylvirana temporalis and Clinotarsus curtipes (Anura: Ranidae) tadpoles to water scorpions: importance of refugia and swimming speed in predator avoidance

2021 ◽  
Vol 20 (2) ◽  
pp. 159-164
Author(s):  
Santosh M. Mogali ◽  
Bhagyashri A. Shanbhag ◽  
Srinivas K. Saidapur
Keyword(s):  
Predation Risk ◽  
Swimming Speed ◽  
Predator Avoidance ◽  
Body Sizes ◽  
Experimental Trials

The comparative vulnerability of two co-existing tadpole species (Indosylvirana temporalis and Clinotarsus curtipes) to their common predator, water scorpions (Laccotrephes sp.; Hemiptera: Nepidae), and the importance of refugia in predator avoidance were studied in the laboratory. In a total of 60 experimental trials, 10 tadpoles each of I. temporalis and C. curtipes of comparable body sizes were exposed to water scorpions (starved for 48 h). Thirty trials included refugia while 30 did not. The results of this study showed that in both the absence and the presence of refugia C. curtipes tadpoles fell prey to water scorpions more frequently than I. temporalis tadpoles. A main difference between the two species is the speed of swimming; Vmax of C. curtipes (24.73 cm/s) tadpoles is lower than that of I. temporalis (30.78 cm/s) tadpoles. This is likely to be the reason why more C. curtipes tadpoles were preyed upon than were I. temporalis tadpoles. Predation risk of tadpoles of both species was affected significantly by the presence of refuge sites. The vulnerability of both tadpole species was lower where refuge sites were available. The present study clearly shows that I. temporalis tadpoles avoid predation by water scorpions more effectively than do C. curtipes tadpoles.

Hormones, stress and the welfare of animals

2018 ◽  
Vol 58 (3) ◽  
pp. 408 ◽  
Author(s):  
A. J. Tilbrook ◽  
C. R. Ralph
Keyword(s):  
Stress Responses ◽  
Sympathoadrenal System ◽  
Hormonal Responses ◽  
Positive Effects ◽  
Adrenal Axis ◽  
Pituitary Adrenal Axis

There are numerous endocrine (hormonal) responses during stress and these are often complex. This complexity makes the study of endocrine stress responses challenging and the challenges are intensified when attempts are made to use measures of hormones to assess the welfare of animals because so many endocrine systems are activated during stress and because there are countless stimuli that trigger these systems. Most research has concentrated on only a small number of these endocrine systems, particularly the hypothalamo–pituitary adrenal axis and the sympathoadrenal system, and there is a need to broaden the scope of endocrine systems that are studied. Furthermore, systematic approaches are required to establish when the actions of hormones associated with stress responses result in physiological and/or behavioural consequences that will have negative or positive effects on the welfare of animals.

Neurobiological Mechanisms of Fever

1998 ◽  
Vol 4 (2) ◽  
pp. 113-121 ◽  
Author(s):  
Anna K. Sundgren-Andersson ◽  
Silvia Gatti ◽  
Tamas Bartfai
Keyword(s):  
Body Temperature ◽  
Acetylcholinesterase Inhibitors ◽  
Sickness Behavior ◽  
The Body ◽  
Phase Reaction ◽  
Emotional States ◽  
Ovulatory Cycle ◽  
Neuronal Mechanisms ◽  
Cerebral Ischemic ◽  
Main Components

Increased body temperature (fever or hyperthermia) is a physiological response to many different stimuli. In fact, fever (a 1-4°C elevation of the body temperature) is not only a clinical symptom common to many infectious diseases but also a side effect of immunostimulating or antiviral therapies. Hyperthermic reactions, on the other hand, can be observed after treatment with antipsychotic drugs, 5-hydroxytryptamine-receptor agonists, and acetylcholinesterase inhibitors and as a reaction to anesthesia. Moreover, hyperthermic reactions can be related to particularly stressful emotional states, to the menstrual ovulatory cycle, and to pregnancy. Transient hyperthermia or fever is also a common consequence of cerebral ischemic events, and it is present during stress as well as intense physical exercise. This review focuses on fever, one of the main components of the systemic acute-phase reaction to external proinflammatory stimuli. Special emphasis is given to neuronal mechanisms of fever induction, in which the hypothalamus plays a crucial role in both control of the febrile response as well as other centrally mediated neurological signs of inflammation, such as increased sleep, activation of the hypothalamic-pituitary-adrenal axis, anorexia, and sickness behavior. This review pays particular attention to the role of proinflammatory cytokines as endogenous pyrogens. NEUROSCIENTIST 4:113-121, 1998

scholarly journals Host manipulation as a parasite transmission strategy when manipulation is exploited by non-host predators

2008 ◽  
Vol 4 (6) ◽  
pp. 663-666 ◽  
Author(s):  
Otto Seppälä ◽  
Jukka Jokela
Keyword(s):  
Predation Risk ◽  
Transmission Probability ◽  
Parasite Transmission ◽  
Host Manipulation ◽  
Predator Species ◽  
Transmission Strategy ◽  
Adaptive Value ◽  
Parasite Populations ◽  
Manipulation Strategy ◽  
Increased Susceptibility

Trophically transmitted parasites often alter their intermediate host's phenotype, thereby predisposing hosts to increased predation. This is generally considered to be a parasite strategy evolved to enhance transmission to the next host. However, the adaptive value of host manipulation is not clear, as it may be associated with costs, such as increased susceptibility to predator species that are unsuitable next hosts for the parasites. Thus, it has been proposed that, to be adaptive, manipulation should be specific by predisposing hosts more strongly to predation by target hosts (next host in the life cycle) than to non-hosts. Here we formally evaluate this prediction, and show that manipulation does not have to be specific to be adaptive. However, when manipulation is nonspecific, it needs to effectively increase the overall predation risk of infected hosts if it is to increase the parasite transmission probability. Thus, when initial predation risk is low, even highly nonspecific manipulation strategies can be adaptive. However, when initial predation risk is high, manipulation needs to be more specific to increase parasite transmission success. Therefore, nonspecific host manipulation may evolve in nature, but the adaptive value of a certain manipulation strategy can vary among different parasite populations depending on the variation in initial predation risk.

scholarly journals Psychological portrait of the co-dependent teenager

2020 ◽  
pp. 198-207
Author(s):  
Marina V. Shamardina ◽  
Olga А. Dorovskikh ◽  
Apollinaria A. Kozhevnikova
Keyword(s):  
Alcohol Dependence ◽  
Family Environment ◽  
Alcohol Addiction ◽  
Personality Characteristics ◽  
Emotional States ◽  
Parental Alcoholism ◽  
Dependent Behavior ◽  
Preventive Work ◽  
Main Components ◽  
The Relationship

The article considers personality characteristics of codependent adolescents. The aim of the study was to determine the components of the psychological portrait of a teenager with co-dependent behavior from among families where parents have alcohol addiction issues. The authors of the work studied the influence of a specific family environment on the personality of a teenager in the context of parental alcoholism. According to the results of the study, the personality characteristics of a teenager with one or two parents with alcohol dependence were identified. The dependent behavior of one of the parents forms certain emotional states in the adolescent, which leads not only to the appearance of negative personality characteristics, but also changes the behavior of the adolescent as a whole. The article also presents a psychological portrait of a co-dependent adolescent, lists its main components, shows the characteristic trends that show dependence, shows the relationship between infantility and conformism in co-dependent adolescents. The authors propose a book therapy method that can be used in preventive work with the emotional states of co-dependent adolescents.

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