| 1. |
- Backström, Tobias, et al.
(författare)
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Anaesthesia and handling stress effects on pigmentation and monoamines in Arctic charr
- 2017
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Ingår i: Environmental Biology of Fishes. - : Springer. - 0378-1909 .- 1573-5133. ; 100:5, s. 471-480
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Tidskriftsartikel (refereegranskat)abstract
- Stress responsiveness differs between individuals and is often categorized into different stress coping styles. Using these stress coping styles for selection in fish farming could be beneficial, since stress is one main factor affecting welfare. In Arctic charr (Salvelinus alpinus) carotenoid pigmentation is associated with stress responsiveness and stress coping styles. Thus this could be an important tool to use for selection of stress resilient charr. However, anaesthetics seem to affect carotenoid pigmentation, and it would be better if the method for selection could be implemented during normal maintenance, which usually includes anaesthetics. Therefore, this study investigated how the use of anaesthetics affected carotenoid pigmentation, i.e. number of spots, over time compared to no-anaesthetic treatment. Additionally, the stress indicators monoamines and glucocorticoids were investigated. The results indicate that the anaesthetic MS-222 affects number of spots on the right side. This anaesthetic also increased dopaminergic activity in the telencephalon. Both brain dopaminergic and serotonergic activity was associated with spottiness. Further, behaviour during anaesthetization was associated with spots on the left side, but not the right side. Repetition of the same treatment seemed to affect spot numbers on the right side. In conclusion, this study shows that inducing stress in charr affects the carotenoid spots. Thus, it is possible to use anaesthetics when evaluating spottiness although careful planning is needed.
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| 2. |
- Backström, Tobias, et al.
(författare)
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Arginine-vasotocin influence on aggressive behaviour and dominance in rainbow trout
- 2009
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Ingår i: Physiology and Behavior. - : Elsevier BV. - 0031-9384 .- 1873-507X. ; 96:3, s. 470-475
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Tidskriftsartikel (refereegranskat)abstract
- The mammalian neuropeptide arginine-vasopressin (AVP) and its non-mammalian homologue arginine-vasotocin (AVT) are involved in social behavior including aggression in vertebrates. Juvenile rainbow trout (Onchorhynchus mykiss) are highly territorial and we tested the effect of two different doses each of AVT and Manning compound, an AVP V1A receptor antagonist, on aggressive behavior and the outcome of staged fights for social dominance in size matched pairs. Each pair consisted of one fish receiving AVT or Manning compound through an intracerebroventricular (icv) injection and one fish receiving a similar icv injection of saline. In addition, plasma cortisol and brain serotonergic activity were monitored. Fish receiving AVT at a dose of 200 ng became subordinate whereas AVT at a dose of 20 ng had no effect on the outcome of fights for social dominance. Further, Manning compound had no effect on the outcome of fights for dominance but at a dose of 200 ng it had an effect on fight duration. Fish receiving 200 ng Manning compound and losing dyadic fights appeared to take longer to become subordinate. Neither AVT nor Manning compound had any effects on plasma cortisol levels or brainstem serotonergic activity. The apparent inhibiting effect of AVT on aggression could be centrally mediated.
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| 3. |
- Backström, Tobias, et al.
(författare)
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Central corticotropin releasing factor and social stress
- 2013
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Ingår i: Frontiers in Neuroscience. - : Frontiers Media SA. - 1662-4548 .- 1662-453X. ; 7
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Forskningsöversikt (refereegranskat)abstract
- Social interactions are a main source of stress in vertebrates. Social stressors, as well as other stressors, activate the hypothalamic-pituitary-adrenal (HPA) axis resulting in glucocorticoid release. One of the main components of the HPA axis is corticotropin releasing factor (CRF). The neuropeptide CRF is part of a peptide family including CRF, urocortin 1-3, urotensin 1-3, and sauvagine. The actions of the CRF family are mediated by at least two different receptors with different anatomical distribution and affinities for the peptides. The CRF peptides affect several behavioral and physiological responses to stress including aggression, feeding, and locomotor activity. This review will summarize recent research in vertebrates concerning how social stress interacts with components of the CRF system. Consideration will be taken to the different models used for social stress ranging from social isolation, dyadic interactions, to group dominance hierarchies. Further, the temporal effect of social stressor from acute, intermittent, to chronic will be considered. Finally, strains selected for specific behavior or physiology linked to social stress will also be discussed.
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| 4. |
- Backström, Tobias, et al.
(författare)
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CRF and urotensin I effects on aggression and anxiety-like behavior in rainbow trout
- 2011
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Ingår i: Journal of Experimental Biology. - : The Company of Biologists. - 0022-0949 .- 1477-9145. ; 214:6, s. 907-914
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Tidskriftsartikel (refereegranskat)abstract
- Corticotropin-releasing factor (CRF) is central in the stress response but also modulates several behaviors including anxiety-related behaviors and aggression. In this study, juvenile rainbow trout (Oncorhynchus mykiss) were tested for competitive ability, determined during dyadic fights for dominance, after intracerebroventricular (i.c.v.) administration of CRF, urotensin I (UI), the non-specific CRF antagonist alpha-helical RF9-41 (ahCRF) or the CRF receptor subtype 1-specific antagonist antalarmin, when paired with a mass-matched con-specific injected with saline. In addition, isolated fish received the same substances. Plasma cortisol and brain monoamines were monitored in all fish. Most fish receiving CRF showed a conspicuous behavior consisting of flaring the opercula, opening the mouth and violent shaking of the head from side to side. When this occurred, the fish immediately forfeited the fight. Similar behavior was observed in most fish receiving UI but no effect on outcome of dyadic fights was noted. This behavior seems similar to non-ambulatory motor activity seen in rats and could be anxiety related. Furthermore, fish receiving CRF at a dose of 1000. ng became subordinate, whereas all other treatments had no effects on the outcome of dyadic fights. In addition, isolated fish receiving ahCRF had lower brain stem concentrations of 5-hydroxyindoleacetic acid, serotonin, 3,4-dihydroxyphenylacetic acid and dopamine. In conclusion, CRF seems to attenuate competitive ability, and both CRF and UI seem to induce anxiety-like behavior.
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| 5. |
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| 6. |
- Backström, Tobias, et al.
(författare)
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Dominance and stress signalling of carotenoid pigmentation in Arctic charr (Salvelinus alpinus): Lateralization effects?
- 2015
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Ingår i: Physiology and Behavior. - : Elsevier BV. - 0031-9384 .- 1873-507X. ; 138, s. 52-57
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Tidskriftsartikel (refereegranskat)abstract
- Social conflicts are usually solved by agonistic interactions where animals use cues to signal dominance or subordinance. Pigmentation change is a common cue used for signalling. In our study, the involvement of carotenoid-based pigmentation in signalling was investigated in juvenile Arctic charr (Salvelinus alpinus). Size-matched pairs were analysed for pigmentation both before and after being tested for competitive ability. We found that dominant individuals had fewer carotenoid-based spots on the right and left sides as well as lower plasma cortisol levels compared to subordinate individuals. Further, the number of spots on both sides was positively associated with plasma cortisol levels. These results indicate that carotenoid-based pigmentation in Arctic charr signals dominance and stress coping style. Further, it also appears as if carotenoid-based pigmentation is lateralized in Arctic charr, and that the right side signals aggression and dominance whereas the left side signals stress responsiveness. (C) 2014 Elsevier Inc. All rights reserved.
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| 7. |
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| 8. |
- Backström, Tomas, 1957-, et al.
(författare)
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Group creativity and work process structure
- 2015
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Ingår i: The XXVI ISPIM Innovation Conference ISPIM'15.
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Konferensbidrag (refereegranskat)abstract
- Creativity in work life typically includes several people, thus there is a need to understand how people interact and support each other in creative group processes. Is there, for example, a need for a structure of the work process of a creative group? This paper is about the possibility to enable self-organisation and if an attempt to do so can increase group creativity. In the experiment of this study half of the groups were given a work process structured to enable self-organisation. The degree of self-organisation was measured with a questionnaire and the idea flow was observed and analysed. Ideas were significantly more often observed and used by other group members in the more self-organised groups, and the two best solutions of the task were find among them. A work process structured according to the six delta model seems to increase self-organization as well as creativity of a group.
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| 9. |
- Backström, Tobias, 1976-
(författare)
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Roles of Arginine-Vasotocin and Corticotropin-Releasing Hormone in Stress Responses and Agonistic Behaviour of Rainbow Trout
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The neuropeptides arginine-vasotocin (AVT) and corticotropin-releasing hormone (CRH) are involved in the hypothalamic-pituitary-interrenal (HPI) axis. During stress, the HPI axis is activated and cortisol is released into the blood. In addition to their role in the HPI axis, AVT and CRH also have behavioural effects. The roles of AVT and CRH in stress responses and agonistic behaviour were studied in this thesis, using two different models. In the first model, two strains of rainbow trout (Onchorhynchus mykiss) divergent in stress-induced release of cortisol were investigated. This was done by observing behaviour and stress responses under different conditions. These strains were found to have divergent stress coping strategies based on the observed behaviour and levels of plasma cortisol. This divergence in behaviour could be associated with the CRH system, since the mRNA levels of CRH differed between the strains during stress. However, no differences between strains were observed in AVT or its receptor expressions. In the second model, non-selected rainbow trout were paired and the effect of intracerebroventricular (icv) injections of an active substance (AVT, CRH or the CRH related peptide Urotensin-I (UI)) on fights for dominance was investigated. One fish of the pair received the active substance icv and the other received saline icv. Fish receiving AVT became subordinate in accordance with the suggestion that AVT attenuates aggression in territorial vertebrates. Fish receiving CRH became subordinate whereas UI showed no effect on fights for dominance. Further, both CRH and UI induced an anxiety-related behaviour similar to non-ambulatory motor activity in rats. In addition, CRH appeared to affect the dopaminergic and serotonergic systems. In this thesis, it is suggested that CRH is involved in the behavioural modulation of the stress coping strategies in teleost fish. Further, AVT and CRH seem to act inhibitory on aggressive behaviour.
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| 10. |
- Backström, Tomas, 1957-, et al.
(författare)
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Self-organisation and group creativity
- 2016
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Ingår i: The Journal of Creativity and Business Innovation. - 2351-6186. ; :2, s. 65-79
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Tidskriftsartikel (refereegranskat)abstract
- The team has become the basic organisational unit of development and innovation work and an understanding of creativity at the collective level is crucial for long-term sustainability. This article takes a process perspective and understands group creativity as emerging from the interaction among group members. It is about the possibility to enable the emergence of selforganisation, thereby increasing group creativity. This paper presents an experiment where four out of eight randomly formed groups of students were given a work order structured according to the group process model “GroPro”. In groups using the GroPro ideas were significantly more often promoted, observed and used by other group members, and used in the final solution. Further, the two best solutions and the more creative solutions of the task were found among the GroPro groups. A work process structured according to the GroPro model seems to increase self-organisation as well as the creativity of the group. Further, the group process is shown to be more important for group creativity than the individual creativity of the group members. Our results encourage more focus on the group process by both academia and practitioners.
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| 11. |
- Backström, Tobias, et al.
(författare)
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Short-term stress: effects on cortisol levels and carotenoid spots in Arctic char (Salvelinus alpinus)
- 2016
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Ingår i: Canadian Journal of Zoology. - : Canadian Science Publishing. - 0008-4301 .- 1480-3283. ; 94, s. 707-712
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Tidskriftsartikel (refereegranskat)abstract
- Earlier studies have shown that the carotenoid pigmentation in Arctic char (Salvelinus alpinus (L., 1758)) is connected to stress responsiveness. These studies also suggested that the pigmentation is dynamic and can change quickly. Therefore, we wanted to investigate the effect of a short-term stressor on the number of carotenoid spots before and after certain time intervals after the stressor. Individuals were exposed to a net-restraint stressor for 1 min and then assigned a recovery time of either 0, 1, 2, 8, or 24 h. Photographs were taken before the stressor and after the recovery time to count carotenoid spots and to look at the relative changes over time. Behaviour during the stressor and cortisol levels after the assigned recovery time were evaluated. We found that the change in spottiness, measured as the ratio of spots after and before the stressor, changed with recovery time on the right side but not on the left side. Furthermore, left-side spots were correlated with struggling activity. Thus, carotenoid pigmentation seems to be lateralized, with more static spots on the left side connected to stress responsiveness, whereas spots on the right side seem to be more dynamic.
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| 12. |
- Backström, Tobias, et al.
(författare)
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Social stress effects on pigmentation and monoamines in Arctic charr
- 2015
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Ingår i: Behavioural Brain Research. - : Elsevier BV. - 0166-4328 .- 1872-7549. ; 291, s. 103-107
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Tidskriftsartikel (refereegranskat)abstract
- Pigmentation often signals status and in general melanin-based pigmentation is indicative of aggression and stress resilience in vertebrates. This is evident in the salmonids Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss) where more melanin spotted individuals are more stress resilient. However, in the salmonid Arctic charr (Salvelinus alpinus) it seems as if it is carotenoid-based pigmentation that signals aggression and stress resilience. In our study, social stress effects on carotenoid-based spots, and behavioural and physiological stress responses were investigated. Socially stressed individuals have more spots, and behavioural stress responses were associated with spots. Some of the results concerning physiological stress responses, such as plasma cortisol levels and monoaminergic activity, are associated with spottiness. Further, the earlier proposed lateralization of spots, with left side connected to stress responsiveness and right side to aggression, is to some extent validated although not conclusively. In conclusion, this study provides further evidence that more stressed charr have more carotenoid spots, and for the first time monoaminergic activity is shown to be connected with carotenoid pigmentation.
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| 13. |
- Backström, Tobias, et al.
(författare)
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Stress effects on AVT and CRF systems in two strains of rainbow trout (Oncorhynchus mykiss) divergent in stress responsiveness
- 2011
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Ingår i: Hormones and Behavior. - : Elsevier BV. - 0018-506X .- 1095-6867. ; 59:1, s. 180-186
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Tidskriftsartikel (refereegranskat)abstract
- The aim for this study was to examine whether the F4 generation of two strains of rainbow trout divergent in their plasma cortisol response to confinement stress (HR: high responder or LR: low responder) would also differ in stress-induced effects on forebrain concentrations of mRNA for corticotropin-releasing factor (CRF). arginine vasotocin (AVT). CRF receptor type 1 (CRF-R1). CRF receptor type 2 (CRF-R2) and AVT receptor (AVT-R). In addition, plasma cortisol concentrations, brainstem levels of monoamines and monoamine metabolites, and behaviour during confinement were monitored. The results confirm that HR and LR trout differ in their cortisol response to confinement and show that fish of these strains also differ in their behavioural response to confinement. The HR trout displayed significantly higher locomotor activity while in confinement than LR trout. Moreover, following 180 min of confinement HR fish showed significantly higher forebrain concentrations of CRF mRNA than LR fish. Also, when subjected to 30 min of confinement HR fish showed significantly lower CRF-R2 mRNA concentrations than LR fish, whereas there were no differences in CRF-R1. AVT or AVT-R mRNA expression between LR and HR fish either at 30 or 180 min of confinement. Differences in the expression of CRF and CRF-R2 mRNA may be related to the divergence in stress coping displayed by these rainbow trout strains.
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| 14. |
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| 15. |
- Backström, Tobias, et al.
(författare)
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The effect of anesthetics on carotenoid pigmentation and behavior in Arctic char (Salvelinus alpinus)
- 2015
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Ingår i: Journal of Veterinary Behavior: Clinical Applications and Research. - : Elsevier BV. - 1558-7878 .- 1878-7517. ; 10, s. 179-184
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Tidskriftsartikel (refereegranskat)abstract
- Status of individual animals is often shown in pigmentation. For instance, stress responsiveness is associated with melanin-based pigmentation in vertebrates in general. This pattern is evident in Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss), with melanin-based spots indicating stress coping style. Arctic char (Salvelinus alpinus) differ from other salmonids in pigmentation but have an association between carotenoid-based pigmentation and stress coping style. These pigmentation differences could be used as a fast and simple tool for improving breeding programs. However, the procedure for photographing individuals is stressful. Therefore, we wanted to investigate if 3 common inhalation anesthetics could be used to reduce the stress involved in the procedure compared to a no-anesthetics group. Behavior was also monitored during the anesthetization. All 3 anesthetics (Aquacalm, Benzocaine, and MS-222) differed in pigmentation compared to the no-anesthetics group by having a higher number of spots. In the anesthetic treatments as well as the no-anesthetics group, the fish had elevated plasma cortisol levels. In fact, the no-anesthetics group had higher cortisol than treated fish. This was probably because of procedural differences such as time affecting the stress response. Furthermore, in a long-term experiment, all fish survived and had similar condition factors 1 week after photographing as before. Therefore, the method for photographing Arctic char is deemed safe and could be used as a tool for estimating stress coping style, but careful planning is needed for experiments using it
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| 16. |
- Bell, Alison M., et al.
(författare)
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Variable neuroendocrine responses to ecologically-relevant challenges in sticklebacks
- 2007
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Ingår i: Physiology and Behavior. - : Elsevier BV. - 0031-9384 .- 1873-507X. ; 91:1, s. 15-25
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Tidskriftsartikel (refereegranskat)abstract
- Variable neuroendocrine responses to ecologically-relevant challenges in sticklebacks. PHYSIOL BEHAV 00(0) 000-000, 2006. Here, we compare the behavioral, endocrine and neuroendocrine responses of individual sticklebacks exposed to either an unfamiliar conspecific or to a predator. We found that the two stressors elicited a similar hypothalamic–pituitary–interrenal response as assessed by whole-body concentrations of cortisol, but produced quite different patterns of change in brain monoamine and monoamine metabolite content as assessed by concentrations of serotonin (5-HT), dopamine (DA), norepinephrine (NE) and the monoamine metabolites 5-hydroxyindole acetic acid (5-HIAA), homovanillic acid (HVA) and 3-4-dihydroxyphenylacetic acid (DOPAC). For example, relative to baseline levels, NE levels were elevated in individuals exposed to a predator but were lower in individuals confronted by a challenging conspecific. Levels of monoamine neurotransmitters in specific regions of the brain showed extremely close links with behavioral characteristics. Frequency of attacking a conspecific and inspecting a predator were both positively correlated with concentrations of NE. However, whereas serotonin was negatively correlated with frequency of attacking a conspecific, it was positively associated with predator inspection. The data indicate that the qualitative and quantitative nature of the neuroendocrine stress response of sticklebacks varies according to the nature of the stressor, and that interindividual variation in behavioural responses to challenge are reflected by neuroendocrine differences.
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| 17. |
- Brännäs, Eva, et al.
(författare)
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Behaviour, physiology and carotenoid pigmentation in Arctic charr Salvelinus alpinus
- 2014
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Ingår i: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 84, s. 1-9
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Tidskriftsartikel (refereegranskat)abstract
- The behaviour during an exploration task and the response to a confinement stress of Arctic charr Salvelinus alpinus were evaluated. Behaviour of individuals during 90 min of exploration was classified into high and low activity. High-activity individuals had higher plasma cortisol levels following stress compared to low-activity individuals. This indicates that high- and low-activity individuals correspond to reactive and proactive stress-coping styles. Further, a pigmentation analysis showed that high-activity individuals had a higher number of carotenoid spots cm(-2) than low-activity individuals. Thus, carotenoid pigmentation, as melanin pigmentation in other salmonids, could be linked to stress-coping style in S. alpinus. (C) 2013 The Fisheries Society of the British Isles
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| 18. |
- Brännäs, Eva, et al.
(författare)
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Distinguishing Arctic charr with different stress coping styles by visual screening of spottiness - reliability and consistency over time
- 2016
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Ingår i: Journal of Zoology. - : Wiley. - 0952-8369 .- 1469-7998. ; 300, s. 213-220
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Tidskriftsartikel (refereegranskat)abstract
- The salmonid fish Arctic charr Salvelinus alpinus shows pronounced individual variation in skin colouration and density of carotenoid-based spots. It has earlier been shown that spot density is a heritable trait, and may be used as an indicator of stress coping style in Arctic charr. Individuals with few spots tend to be more aggressive and less responsive to stress (proactive) than those with many spots (reactive). Here, we evaluate the potential of grading individuals into proactive and reactive individuals by the density of light-coloured spots. This non-invasive method would be useful for selective breeding and to reduce within-treatment variation in biological research. Our aim was to investigate stability of spot density over time and to compare methods to estimate spottiness on Arctic charr, using photographs as well as live fish. The consistency of spot density was significant over a period of 8months, but with stronger correlations between September and December than between May and September. Also, repeatability of spot number was higher between the two last months than when including May. The spots were more stable on the left than the right side, thus, it is more reliable to estimate spottiness on the left side. There was a significant relationship between the ratio of spotted area (rsa) from automated image analysis and number of spots from visual counts. Both methods fitted well into a visual grading into three categories (few, medium and many spots). In another test, a large number of live fish were visually categorized according to spot density. The previous validation process, in combination with a significant family effect showed that large numbers of fish can be effectively graded.
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| 19. |
- Dahlbom, S. Josefin, et al.
(författare)
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Aggression and monoamines : Effects of sex and social rank in zebrafish (Danio rerio)
- 2012
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Ingår i: Behavioural Brain Research. - : Elsevier BV. - 0166-4328 .- 1872-7549. ; 228:2, s. 333-338
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Tidskriftsartikel (refereegranskat)abstract
- Social defeat is a common model for studies on depression. However, such models are most often used to study aggression in males and sex differences in depression may therefore be overseen. This study investigated the potential of the zebrafish (Danio rerio) as a model for male and female aggression. In addition, effects on the brain serotonergic and dopaminergic neurotransmitter systems after agonistic interaction are well studied in many species, but not in zebrafish. We wanted to explore whether the zebrafish follows the same patterns as many other species. Therefore, the effects of agonistic interaction on brain monoaminergic activity were studied in adult male and female wild-type zebrafish. The fish interacted in pairs with one of the same sex for five days during which agonistic behaviour was quantified daily. Clear dominant/subordinate relationships developed in all pairs, both in males and females. The frequency of aggressive acts increased over time but did not differ between male and female pairs. Further, we found that dyadic agonistic interaction resulted in elevated brain serotonergic activity in subordinate zebrafish, as indicated by elevated hindbrain 5-hydroxyindoleacetic acid to serotonin ratios (5-hydroxyindolacetic acid (5-HIAA)/5-hydroxytryptamine (5-HT) ratios). We also observed a sex difference in forebrain dopamine levels and forebrain 5-HIAA/5-HT ratios, with females displaying higher concentrations of dopamine but lower 5-HIAA/5-HT ratios than males. These results suggest that zebrafish is a suitable model for studies on female aggression and sex differences in brain monoaminergic neurotransmission.
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| 20. |
- Doving, Kjell B., et al.
(författare)
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Visualizing a set of olfactory sensory neurons responding to a bile salt
- 2011
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Ingår i: Journal of Experimental Biology. - : The Company of Biologists. - 0022-0949 .- 1477-9145. ; 214:1, s. 80-87
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Tidskriftsartikel (refereegranskat)abstract
- In the present study, we exposed the olfactory epithelia of crucian carp, Carassius carassius, and brown trout, Salmo trutta, to dextran coupled with Alexa dyes together with odorants. Dye uptake was severely reduced after pre-exposure to nocodazole, an inhibitor of microtubule polymerization that impairs endocytosis, supporting the hypothesis that odour-activated olfactory receptor molecules undergo endocytosis. Application of the bile acid taurolithocholate, a potent and specific odorant for fish, resulted in the labelling of a sparse (less than 3%) cell population with the typical morphology of ciliated sensory neurons (CSNs) - long dendrites and cell somata deep in the sensory epithelium. The dye was distributed throughout the sensory neuron, also revealing axons and target glomeruli. Stained axons redistribute at the entrance of the olfactory bulb and terminate in two small target areas, a dorsal and a medial one. These results are consistent with the notion that taurolithocholate is detected specifically by a few ciliated sensory neurons. Application of the olfactory epithelium of brown trout to bile acid stained cells with the appearance of CSNs. Application of an alarm agonist, hypxanthine-3-N-oxide, to crucian carp olfactory organ caused staining of another set of sensory neurons. Furthermore, our results show that odour-induced uptake of a dye can serve to identify the subtype of olfactory sensory neurons responding to a particular odorant, and to pinpoint the target regions of these neurons in the olfactory bulb as a first step to elucidating the neuronal network responding to a particular odour.
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| 21. |
- Heynen, Martina, et al.
(författare)
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Home alone : the effects of isolation on uptake of a pharmaceutical contaminant in a social fish
- 2016
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Ingår i: Aquatic Toxicology. - : Elsevier. - 0166-445X .- 1879-1514. ; 180, s. 71-77
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Tidskriftsartikel (refereegranskat)abstract
- A wide range of biologically active pharmaceutical residues is present in aquatic systems worldwide. As uptake potential and the risk of effects in aquatic wildlife are directly coupled, the aim of this study was to investigate the relationships between stress by isolation, uptake and effects of the psychiatric pharmaceutical oxazepam in fish. To do this, we measured cortisol levels, behavioral stress responses, and oxazepam uptake under different stress and social conditions, in juvenile perch (Percafluviatilis) that were either exposed (1.03 mu gl(-1)) or not exposed to oxazepam. We found single exposed individuals to take up more oxazepam than individuals exposed in groups, likely as a result of stress caused by isolation. Furthermore, the bioconcentration factor (BCF) was significantly negatively correlated with fish weight in both social treatments. We found no effect of oxazepam exposure on body cortisol concentration or behavioral stress response. Most laboratory experiments, including standardized bioconcentration assays, are designed to minimize stress for the test organisms, however wild animals experience stress naturally. Hence, differences in stress levels between laboratory and natural environments can be one of the reasons why predictions from artificial laboratory experiments largely underestimate uptake of oxazepam, and other pharmaceuticals, in the wild.
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| 22. |
- Johansson, Kajsa, et al.
(författare)
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Stress Response and Habituation to Motorboat Noise in Two Coastal Fish Species in the Bothnian Sea
- 2016
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Ingår i: EFFECTS OF NOISE ON AQUATIC LIFE II. - New York, NY : SPRINGER-VERLAG BERLIN. ; 875:875, s. 513-521
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Konferensbidrag (refereegranskat)abstract
- The effect of motorboat noise on stress responsiveness in Eurasian perch and roach was tested in field enclosure experiments. Perch showed elevated cortisol levels after one 30-min noise exposure but not when exposed to noise repeatedly for 11 days. Roach had higher cortisol levels when exposed to noise than without noise when short- and long-term experiments were pooled. Both species had more cortisol in enclosures with mixed species compared with single-species enclosures. Both species also had higher cortisol levels in the short-term compared with the longterm experiment. Thus, a stress effect of motorboat noise may decrease with time due to habituation.
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| 23. |
- Magnhagen, Carin, et al.
(författare)
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Behavioural responses in a net restraint test predict interrenal reactivity in Arctic charr Salvelinus alpinus
- 2015
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Ingår i: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 87:1, s. 88-99
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Tidskriftsartikel (refereegranskat)abstract
- In this study, a 1 min net restraint test was evaluated as a method to predict stress-coping style in Arctic charr Salvelinus alpinus, by investigating the relationship between behaviour during the test and levels of plasma cortisol sampled after 30 min confinement. In two separate groups of S. alpinus, general linearized model revealed significant correlations between cortisol levels and principal component scores extracted from principal component analysis, combining measures of activity in the tests. With the use of glmulti, the model selection ruled out any effects of size, sex and order of capture on interrenal reactivity. In general, S. alpinus that were more active in the net restraint test also had low levels of circulating cortisol, suggesting a proactive coping style. The results from two repeated runs were not correlated, but both runs, performed eight days apart, show a negative correlation between post-stress cortisol level and activity in the net. The lack of consistency could be explained by different treatments before each run and individual differences in behavioural plasticity. The net restraint test is thus predictive of stress-coping style in S. alpinus, and has the benefit of being less time-consuming than the commonly used confinement stress test.
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| 24. |
- Magnhagen, Carin, et al.
(författare)
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Oxygen consumption and swimming performance in Arctic charr with different pigmentation patterns
- 2018
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Ingår i: Applied Animal Behaviour Science. - : Elsevier BV. - 0168-1591 .- 1872-9045. ; 202, s. 119-124
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Tidskriftsartikel (refereegranskat)abstract
- Pigmentation in animals often reflects behavioural and physiological traits, such as health status, stress responsiveness, and dominance. Individual variation in stress response and behaviour has earlier been proposed to be connected to differences in metabolism. The aim of this study was to investigate the connection between pigmentation, behaviour, and oxygen consumption in Arctic charr (Salvelinus alpinus). In this species, we have earlier found an association between number of carotenoid spots on the skin and physiological response to stress (stress coping style). Swimming endurance and respiration rates were estimated from video recorded behaviour and oxygen consumption in a swim tunnel. Flow velocity was kept as 1.6 BL (body lengths) s(-2) for 60 min, and oxygen consumption (mg min(-1) g(-1)) during that time was used as a proxy for metabolism. Oxygen consumption was negatively correlated with number of spots. Also behaviour scores from a principal component analysis varied with pigmentation, with a negative correlation between number of spots and behaviour scores connected with endurance. Fish with fewer spots rested more against the rear of the chamber, and fish with more spots were sooner, and more often, pressed to the rear grid by the water current. The variation in oxygen consumption in the swim tunnel indicates a relation between respiration rate, swimming endurance, and pigmentation in the Arctic charr. With earlier findings on covariations between spot numbers and stress coping in this species, there seems to be connections between stress coping style, behaviour, and metabolism. Thus, it would be possible to identify individual expression of these features, based on the pigmentation patterns of the fish.
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| 25. |
- Magnhagen, Carin, et al.
(författare)
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Spotted personality - connection between pigmentation and stress coping style in the Arctic charr, Salvelinus alpinus
- 2014
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Pigmentation is a common cue in the animal kingdom, used, for example, to signal reproductive status, quality, and aggression. The Arctic charr is a salmonid fish, with an individual variation in skin coloration and spottiness. In this study we are looking at the connection between number of light-coloured spots and several aspects of behaviour in laboratory studies. Further, the physiological stress response was measured as plasma cortisol levels after a net constraint test and a confinement test. There were negative correlations between cortisol levels and activity levels. Individuals with low cortisol levels had a higher feeding activity and moved more both in the net and in confinement. Fish with the highest number of spots were the least active. Lowest cortisol levels were found in fish with an intermediate number of spots. Thus, there seems to be a complex connection between pigmentation and stress coping style in the Arctic charr which needs further investigation.
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| 26. |
- Nilsson, Jan, et al.
(författare)
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Effects of age and rearing environment on genetic parameters of growth and body weight and heritability of skin pigmentation in Arctic charr (Salvelinus alpinus L.)
- 2016
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Ingår i: Aquaculture. - : Elsevier BV. - 0044-8486 .- 1873-5622. ; 453, s. 67-72
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Tidskriftsartikel (refereegranskat)abstract
- The Swedish breeding programme for Arctic charr aims to improve traits that are important for farming. Selection has been ongoing since the 1980s, and the aim of this study was to re-estimate the genetic parameters in the selected population. In addition, the genetics of skin pigmentation was studied, as previous work indicated a relationship between pigmentation and the ability to cope with stress.One hundred twenty-five full sib families of Arctic charr were hatched and reared separately until they were individually tagged (n = 12,266). In connection with the tagging, three replicates were formed, which were subsequently reared at different sites. The genetic relationships were known from a seven-generation pedigree. Body weight and length were at one site measured at six occasions until 27 months old, and these measurements were used to estimate the DGC (daily growth coefficient) and condition factor. At a second site fish were measured at 21 and 27 months age and at a third site at 27 months age.Skin pigmentation was measured using image analysis. The final weight at 27 months of age varied widely between rearing sites, ranging from 529 g to 1443 g. Weight heritability differed among the sites, at 0.45, 0.11, and 0.07. At one of the sites, where growth was followed closely, weight heritability varied among growth periods, ranging from 0.01 to 0.25, and similar results were obtained for the DGC. In contrast, condition factor heritability did not show such pronounced variations within and among sites. The magnitude of the differences in heritability of weight and growth among different sites that was observed here was not observed previously with this charr population. In particular, the low heritability among the fastest growing fish is unprecedented. Skin pigmentation showed a high heritability of 0.76, indicating a strong additive genetic component. At most ages, pigmentation showed a weak positive genetic correlation with growth. The genotype environment interaction (GEI) was estimated using genetic correlations among sites. For the final weight, genetic correlations were high, indicating weak GEI, although the presence of GEI was suggested from the DGC data.Statement of relevance: The ms will impact charr breeding for commercial farming. (C) 2015 Elsevier B.V. All rights reserved.
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| 27. |
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| 28. |
- Schjolden, Joachim, et al.
(författare)
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Divergence in behavioural responses to stress in two strains of rainbow trout (Oncorhynchus mykiss) with contrasting stress responsiveness
- 2005
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Ingår i: Hormones and Behavior. - : Elsevier BV. - 0018-506X .- 1095-6867. ; 48:5, s. 537-544
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to establish whether two lines of rainbow trout divergent for their plasma cortisol response to a standardized stressor would show consistent differences in their behavioural response to a range of challenging situations. Our results show that the high- and low-responding (HR and LR) lines of rainbow trout did not differ in the aggression shown towards an intruder or in their response to the introduction of a novel object to their home environment. However, there was a difference in behaviour between the two selection lines when they were exposed to two unfamiliar environments. These results suggest that the behaviour of the HR and LR fish differs when they are challenged in unfamiliar environments, while their behaviour does not differ when they are challenged in their home environment. These observations are in agreement with studies on mammals that show that individuals with reactive coping styles perform similarly to proactive animals when they are challenged in a familiar environment, while they show different behaviour when they are challenged in unfamiliar environments. Thus, these results provide further evidence that the HR and LR selection lines of rainbow trout exemplify the two different coping styles described in mammals.
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| 29. |
- Vindas, Marco A., et al.
(författare)
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Brain cortisol receptor expression differs in Arctic charr displaying opposite coping styles
- 2017
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Ingår i: Physiology and Behavior. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0031-9384 .- 1873-507X. ; 177, s. 161-168
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Tidskriftsartikel (refereegranskat)abstract
- Individually consistent behavioral and physiological responses to stressful situations (often referred to as coping styles) has been reported in many animal species. Differences in hypothalamic-pituitary axis reactivity characterize individuals, and it has been proposed that the glucocorticoid (gr) and mineralocorticoid (mr) receptors are fundamental in regulating coping styles. We sorted individuals into reactive and proactive coping styles by collapsing behavioral outputs from net restraint and confinement stress tests in a principal component analysis. We then analyzed plasma cortisol levels, serotonin neurochemistry and the relative mRNA expression of gr1 and mr in stressed individuals per coping style. Proactive fish were characterized as having a lower serotonergic activity and being more active under stress. In addition, proactive fish had higher hypothalamic gr1 and mr abundance and a higher mr/gr1 ratio, compared to reactive fish. We found no significant differences in cortisol or telencephalic mRNA, gr1 and mr expression, or their ratio. Brain MR and GR have been proven to have an important role in the appraisal, coping and adaptation to stressful stimuli, so that a higher expression of these receptors in proactive fish suggests increased tolerance and performance under stress, compared to reactive individuals. We present evidence of a conserved neuroendocrine mechanism associated with coping styles in a fish species which is ecologically very diverse and considered to be the most cold-adapted fish in freshwater. We propose that this may be a first step into exploiting this model in order to better understand climate-change related effects in sub populations and ecophenotypes.
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