| 1. |
- Höglund, Erik, et al.
(författare)
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Stress-induced changes in brain serotonergic activity, plasma cortisol and aggressive behavior in Arctic charr (Salvelinus alpinus) is counteracted by L-DOPA
- 2001
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Ingår i: Physiology and Behavior. - 0031-9384 .- 1873-507X. ; 74:3, s. 381-389
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Tidskriftsartikel (refereegranskat)abstract
- Arctic charr (Salvelinus alpinus) were tested for aggressive behavior using intruder tests, before and after 2 days of dyadic social interaction. Following social interaction, half of the dominant and half of the subordinate fish were given l-DOPA (10 mg/kg, orally), whereas the remaining dominant and subordinate fish were given vehicle. One hour following drug treatment, the fish were tested for aggressive behavior again in a third and final intruder test, after which blood plasma and brain tissue were sampled for analysis of plasma cortisol concentrations and brain levels of monoamines and monoamine metabolites. Subordinate fish showed a reduction in the number of attacks launched against the intruder, as well as an increase in attack latency, as compared to prior to dyadic social interactions. Social subordination also resulted in an elevation of brain serotonergic activity. Fish receiving l-DOPA prior to the final intruder test showed shorter attack latency than vehicle controls. Drug treatment was a stressful experience and vehicle controls showed elevated plasma cortisol levels and longer attack latency as compared to before treatment. l-DOPA-treated fish showed lower plasma levels of cortisol and lower serotonergic activity in certain brain areas than vehicle controls. These results suggest that l-DOPA counteracts the stress-induced inhibition of aggressive behavior, and at the same time inhibits stress-induced effects on brain serotonergic activity and plasma cortisol concentrations.
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| 2. |
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| 3. |
- 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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| 4. |
- 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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| 5. |
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| 6. |
- Blokhuis, Harry
(författare)
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The benzodiazepine brotizolam reduces fear in calves exposed to a novel object test
- 2009
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Ingår i: Physiology and Behavior. - : Elsevier BV. - 0031-9384 .- 1873-507X. ; 96, s. 307-314
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Tidskriftsartikel (refereegranskat)abstract
- The present Study examined the effects of the intravenous administration of the anxiolytic drug brotizolam on the behavioral and physiological responsiveness of calves to novelty in a dose response fashion. Holstein Friesian heifer calves (39-41 weeks of age: body weight 200-300 kg) received an intravenous injection of either a vehicle control (12 calves) or one of four doses of brotizolam (8 calves per dose): 0.0125. 0.05, 0.2 and 0.8 mg/100 kg body weight. They were then individually subjected to a 'combined' test involving exposure to a novel environment (open field, OF) for 5 min followed by the sudden introduction of a novel object (NO) that remained in place for a further 10 min. Behavioral, heart rate and plasma cortisol responses were recorded in all animals. Compared to vehicle treatment. the highest dose of brotizolam dose-dependently and significantly increased the time spent in locomotion and the distance travelled near the NO, as well as the time spent in contact with the NO. in addition, post-test plasma cortisol concentrations changed in a dose-dependent manner over time: they decreased between 0 and 10 min after the test in calves that had received the two highest doses of brotizolam, whereas they increased in vehicle-treated and low-dosage calves. There were no effects of brotizolam on vocalization or locomotion during the OF phase of the test or on vocalization following introduction of the NO. These findings strongly support the notion that interaction with a novel object in a novel arena represents a behavioral index of fear and fearfulness in calves, and that vocalization and locomotion in an OF reflect other independent characteristics. (C) 2008 Elsevier Inc. All rights reserved.
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| 7. |
- Cubitt, K. Fiona, et al.
(författare)
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Social hierarchies, growth and brain serotonin metabolism in Atlantic salmon (Salmo salar) kept under commercial rearing conditions
- 2008
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Ingår i: Physiology and Behavior. - : Elsevier BV. - 0031-9384 .- 1873-507X. ; 94:4, s. 529-535
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Tidskriftsartikel (refereegranskat)abstract
- Monitoring social interactions between individuals in large, high-density groups poses several challenges. Here we demonstrate that relative concentrations of serotonin (5-Hydroxytryptamine, 5-HT) and its principal catabolite 5-Hydroxyindoleacetic acid (5-HIAA) in brain tissue of individual fish reflect social organisation in large groups of farmed Atlantic salmon. In the central nervous system of vertebrates, the monoamine neurotransmitter/neuromodulator 5-HT is critical for maintaining adaptive physiological, cognitive and emotional processes. In both teleost fish and mammals it has previously been shown that social interactions in small groups lead to elevated 5-HT release and/or metabolism in subordinate individuals, as indicated by the 5-HIAA/5-HT concentration ratio. In the current study, evidence is presented of non-linear dominance hierarchies in farmed Atlantic salmon (Salmo salar) kept at high rearing densities. The physiological effect of these hierarchies was decreased when food resources were abundant, although some subordinate fish still showed altered brain serotonergic activity and failed to grow even feed was available in excess. The largest effect of decreased feed rations was seen in fish of intermediate size, where competition appeared to increase with reduced access to feed. The largest individuals in each rearing unit showed low 5-HIAA/5-HT ratios independent of feeding regime. A novel observation, with respect to previous studies, was that elevated brain 5-HIAA/5-HT ratios resulted from decreased 5-HT concentrations rather than elevated 5-HIAA in small fish. Thus, in light of the serotonin deficit hypothesis of depression, it cannot be excluded that social stress is important for animal welfare even in large, relatively homogenous groups of animals reared in captivity.
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| 8. |
- Elfhag, K, et al.
(författare)
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Sweet and fat taste preference in obesity have different associations with personality and eating behavior
- 2006
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Ingår i: Physiology & Behavior. - : Elsevier BV. - 1873-507X .- 0031-9384. ; 88:1-2, s. 61-66
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to test associations between self-reported attitudes of sweet and fat taste preferences and psychological constructs of eating behavior and personality in obesity. Sixty obese patients were included. The Three Factor Eating Questionnaire was used for the assessment of psychological constructs of eating behavior, and the Swedish universities Scales of Personality was used for measuring personality traits. A strong sweet taste preference was associated with more neurotic personality traits (P = .003), in particular lack of assertiveness (P = .001) and embitterment (P = .002). Strong fat taste preference was rather related to lower levels of the eating characteristic cognitive restraint (P = .017), implying less attempts to restrict and control food intake. Whereas strong sweet taste preference was linked to a personality style in obesity, strong fat preference could be more an aspect of eating behavior. A psychobiological stress model is discussed in relation to the results on sweet preference and hampered personality functioning. (c) 2006 Elsevier Inc. All rights reserved.
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| 9. |
- Elinder, Fredrik, et al.
(författare)
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On the opening of voltage-gated ion channels
- 2007
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Ingår i: Physiology and Behavior. - : Elsevier BV. - 0031-9384 .- 1873-507X. ; 92:1-2, s. 1-7
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Tidskriftsartikel (refereegranskat)abstract
- Voltage-gated ion channels are key players in fast neuronal signalling Detailed knowledge about channel gating is essential for our understanding of channel function in general and of drug action of channels in particular. Despite a number of recent atomic channel structures, the opening of voltage-gated channels is the subject of heated debates. Here we will discuss two of the controversies: one concerning the mechanism of opening and closing the pore, and the other concerning the location and movement of the voltage sensor. The channels were originally suggested to open at a conserved proline rich sequence (PVP) at the intracellular end of the transmembrane segment 6 (S6). The crystallization of a channel in the open state instead suggested an opening involving a conserved glycine hinge located in the middle portion of S6. Based on pharmacological studies, autodocking and molecular dynamics simulations we have found support for the PVP-bend model. The voltage sensor, transmembrane segment 4 (S4), was originally suggested to be buried in the channel protein, undergoing a helical-screw-like motion to open the channel. A recent crystallographic study suggested that S4 is located in the periphery, facing lipid, and undergoing a paddle-like motion to open the channel We have found experimental evidence for a novel helical-screw model; with the voltage sensor moving in a screw-like fashion but being located in the periphery of the channel. This model opens up for understanding how lipophilic drugs and toxins directly affect the voltage sensor.
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| 10. |
- Fratiglioni, Laura, et al.
(författare)
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Prevention of Alzheimer's disease and dementia : Major findings from the Kungsholmen Project
- 2007
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Ingår i: Physiology and Behavior. - : Elsevier. - 0031-9384 .- 1873-507X. ; 92:1-2, s. 98-104
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Tidskriftsartikel (refereegranskat)abstract
- The aging of the population is a worldwide phenomenon, and studying age-related diseases has become a relevant issue from both a scientific and a public health perspective. This review summarises the major findings concerning prevention of Alzheimer's disease (AD) and other dementias from a population-based study, the Kungsholmen Project. The study addresses risk- and protective factors for AD and dementia from a lifetime perspective: at birth, during childhood, in adult life, and in old age. Although many aspects of the dementias are still unclear, some risk factors have been identified and interesting hypotheses have been suggested for other putative risk or protective factors. At the moment it is also possible to delineate some preventative strategies for dementia.
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