Search results for " corticosterone"
showing 8 items of 8 documents
Involvement of interleukin-1 type 1 receptors in lipopolysaccharide-induced sickness responses
2017
Sickness responses to lipopolysaccharide (LPS) were examined in mice with deletion of the interleukin (IL)-1 type 1 receptor (IL-1R1). IL-1R1 knockout (1(0) mice displayed intact anorexia and HPA-axis activation to intraperitoneally injected LPS (anorexia: 10 or 120 mu g/kg; HPA-axis: 120 mu g/kg), but showed attenuated but not extinguished fever (120 g/kg). Brain PGE2 synthesis was attenuated, but Cox-2 induction remained intact. Neither the tumor necrosis factor-alpha (TNF alpha) inhibitor etanercept nor the IL -6 receptor antibody tocilizumab abolished the LPS induced fever in IL -1R1 KO mice. Deletion of IL -1R1 specifically in brain endothelial cells attenuated the LPS induced fever, b…
Context dependent variation in corticosterone and phenotypic divergence of Rana arvalis populations along an acidification gradient
2022
Background Physiological processes, as immediate responses to the environment, are important mechanisms of phenotypic plasticity and can influence evolution at ecological time scales. In stressful environments, physiological stress responses of individuals are initiated and integrated via the release of hormones, such as corticosterone (CORT). In vertebrates, CORT influences energy metabolism and resource allocation to multiple fitness traits (e.g. growth and morphology) and can be an important mediator of rapid adaptation to environmental stress, such as acidification. The moor frog, Rana arvalis, shows adaptive divergence in larval life-histories and predator defense traits along an acidi…
Physiological stress does not increase with urbanization in European blackbirds: Evidence from hormonal, immunological and cellular indicators
2020
Urbanization changes the landscape structure and ecological processes of natural habitats. While urban areas expose animal communities to novel challenges, they may also provide more stable environments in which environmental fluctuations are buffered. Species´ ecology and physiology may determine their capacity to cope with the city life. However, the physiological mechanisms underlying organismal responses to urbanization, and whether different physiological systems are equally affected by urban environments remain poorly understood. This severely limits our capacity to predict the impact of anthropogenic habitats on wild populations. In this study, we measured indicators of physiological…
Neuroendocrine responses in neonatal mother-deprived rabbits.
2009
To study both short- and long-term adaptation mechanisms activated by rabbits which were separated from their mothers (DLS) for 48 h between postnatal days 9 and 11, we examined plasma corticosterone concentrations before, during, and after DLS as well as the expression of glucocorticoid receptor (GR) in the hippocampus and the adrenal axis responses to a mild stress stimuli or exogenous ACTH injection. At postnatal day 10, plasma corticosterone concentration of DLS rabbits was similar to that of controls, but rose two-fold at day 11 (17.7 + or - 1.3 vs. 9.3 + or - 1.2 microg/dl, P0.01) and then decreased at day 12, when suckling was allowed again, to match those of controls with no differe…
Effects of human disturbance on cave-nesting seabirds: The case of the storm petrel
2015
We tested the effects of human disturbance in two sub-colonies of Mediterranean storm petrel. We conducted three experiments to measure the capacity of the storm petrels to respond to stress. The part of the colony exposed to human disturbance resulted to be habituated and did not show chronic stress related to anthropogenic disturbance.
Single, intense prenatal stress decreases emotionality and enhances learning performance in the adolescent rat offspring: Interaction with a brief, d…
2006
Perinatal manipulations can lead to neurobehavioural changes in the progeny. In this study we investigated, in adolescent male rat offspring, the consequences of a single, intense prenatal stress induced by a 120 min-maternal immobilization at gestational day 16, and of a daily, brief maternal separation from postnatal day 2 until 21, on: unconditioned fear/anxiety-like behaviour in open field and in elevated plus-maze; learning performance in the "Can test", a non-aversive spatial and tactile/visual task; corticosterone plasma levels under basal and stress-induced conditions. Our results indicate that both prenatal stress and maternal separation procedures decrease emotionality and enhance…
A novel arousal-based individual screening reveals susceptibility and resilience to PTSD-like phenotypes in mice
2021
Translational animal models for studying post-traumatic stress disorder (PTSD) are valuable for elucidating the poorly understood neurobiology of this neuropsychiatric disorder. These models should encompass crucial features, including persistence of PTSD-like phenotypes triggered after exposure to a single traumatic event, trauma susceptibility/resilience and predictive validity. Here we propose a novel arousal-based individual screening (AIS) model that recapitulates all these features. The AIS model was designed by coupling the traumatization (24 h restraint) of C57BL/6 J mice with a novel individual screening. This screening consists of z-normalization of post-trauma changes in startle …
Short-term responses of Rana arvalis tadpoles to pH and predator stress: adaptive divergence in behavioural and physiological plasticity?
2022
Environmental stress is a major driver of ecological and evolutionary processes in nature. To cope with stress, organisms can adjust through phenotypic plasticity and/or adapt through genetic change. Here, we compared short-term behavioural (activity) and physiological (corticosterone levels, CORT) responses of Rana arvalis tadpoles from two divergent populations (acid origin, AOP, versus neutral origin, NOP) to acid and predator stress. Tadpoles were initially reared in benign conditions at pH 7 and then exposed to a combination of two pH (acid versus neutral) and two predator cue (predator cue versus no predator cue) treatments. We assessed behavioural activity within the first 15 min, an…