| 1. |
|
|
| 2. |
- Schjolden, Joachim, et al.
(author)
-
Divergence in behavioural responses to stress in two strains of rainbow trout (Oncorhynchus mykiss) with contrasting stress responsiveness
- 2005
-
In: Hormones and Behavior. - : Elsevier BV. - 0018-506X .- 1095-6867. ; 48:5, s. 537-544
-
Journal article (peer-reviewed)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.
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
- Schjolden, Joachim, et al.
(author)
-
Serotonergic characteristics of rainbow trout divergent in stress responsiveness
- 2006
-
In: PHYSIOLOGY & BEHAVIOR. - 0031-9384. ; 87:5, s. 938-947
-
Journal article (pop. science, debate, etc.)abstract
- Juvenile rainbow trout divergent in their cortisol response to confinement stress (HR: high responsive or LR: low responsive fish) were exposed to either I or 3 h of confinement stress. Untreated fish served as control. After the exposure blood and brain samples were collected. From the blood samples, the levels of cortisol and catecholamines were determined, while the brain serotonergic and monoamineoxidase (MAO) activity was determined in four different brain areas (brain stem, hypothalamus, telencephalon and optic rectum). Our results show that the LR fish responds to handling stress with a higher increase in plasma epinephrine compared to HR fish. Our results also show that confinement stress leads to a larger increase in the serotonergic activity in the brain stem and telencephalon in LR fish compared to HR fish. These results support the hypothesis that stress coping strategies similar to those described in mammals also exists in fish. Further, our results have shown that the MAO activity increases in optic tectum and hypothalamus of rainbow trout during confinement stress, while it remains unchanged or decreases in brain stem and telencephalon. Moreover, the MAO activity does not differ between the two selection lines. This indicates that MAO participates actively in the stress response without contributing to the differences in stress coping strategies. (c) 2006 Elsevier Inc. All rights reserved.
|
|
