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Baltic, M., Jenni-Eiermann, S., Arlettaz, R., & Palme, R. (2005). A noninvasive technique to evaluate human-generated stress in the black grouse. Ann N Y Acad Sci, 1046, 81–95.
Abstract: The continuous development of tourism and related leisure activities is exerting an increasingly intense pressure on wildlife. In this study, a novel noninvasive method for measuring stress in the black grouse, an endangered, emblematic species of European ecosystems that is currently declining in several parts of its European range, is tested and physiologically validated. A radiometabolism study and an ACTH challenge test were performed on four captive black grouse (two of each sex) in order to get basic information about the metabolism and excretion of corticosterone and to find an appropriate enzyme-immunoassay (EIA) to measure its metabolites in the feces. Peak radioactivity in the droppings was detected within 1 to 2 hours. Injected (3)H-corticosterone was excreted as polar metabolites and by itself was almost absent. A cortisone-EIA was chosen from among seven tested EIAs for different groups of glucocorticoid metabolites, because it cross-reacted with some of the formed metabolites and best reflected the increase of excreted corticosterone metabolites, after the ACTH challenge test. Concentrations of the metabolites from fecal samples collected from snow burrows of free-ranging black grouse were within the same range as in captive birds. The noninvasive method described may be appropriate for evaluating the stress faced by free-living black grouse populations in the wild, particularly in mountain ecosystems where human disturbance, especially by winter sports, is of increasing conservation concern.
Keywords: Adrenocorticotropic Hormone/metabolism; Animals; Bird Diseases/*metabolism; Conservation of Natural Resources; Corticosterone/*metabolism; Ecosystem; Feces/*chemistry; Female; Galliformes/*metabolism; Immunoenzyme Techniques/methods/veterinary; Male; Reproducibility of Results; Stress/metabolism/*veterinary; Tritium/diagnostic use
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Touma, C., Palme, R., & Sachser, N. (2004). Analyzing corticosterone metabolites in fecal samples of mice: a noninvasive technique to monitor stress hormones. Horm Behav, 45(1), 10–22.
Abstract: In small animals like mice, the monitoring of endocrine functions over time is constrained seriously by the adverse effects of blood sampling. Therefore, noninvasive techniques to monitor, for example, stress hormones in these animals are highly demanded in laboratory as well as in field research. The aim of our study was to evaluate the biological relevance of a recently developed technique to monitor stress hormone metabolites in fecal samples of laboratory mice. In total, six experiments were performed using six male and six female mice each. Two adrenocorticotropic hormone (ACTH) challenge tests, two dexamethasone (Dex) suppression tests and two control experiments [investigating effects of the injection procedure itself and the diurnal variation (DV) of glucocorticoids (GCs), respectively] were conducted. The experiments clearly demonstrated that pharmacological stimulation and suppression of adrenocortical activity was reflected accurately by means of corticosterone metabolite (CM) measurements in the feces of males and females. Furthermore, the technique proved sensitive enough to detect dosage-dependent effects of the ACTH/Dex treatment and facilitated to reveal profound effects of the injection procedure itself. Even the naturally occurring DV of GCs could be monitored reliably. Thus, our results confirm that measurement of fecal CM with the recently established 5alpha-pregnane-3beta,11beta,21-triol-20-one enzyme immunoassay is a very powerful tool to monitor adrenocortical activity in laboratory mice. Since mice represent the vast majority of all rodents used for research worldwide and the number of transgenic and knockout mice utilized as animal models is still increasing, this noninvasive technique can open new perspectives in biomedical and behavioral science.
Keywords: Adrenal Cortex/drug effects; Adrenal Cortex Function Tests; Adrenocorticotropic Hormone/pharmacology; Analysis of Variance; Animals; Circadian Rhythm; Corticosterone/*analysis/metabolism; Dexamethasone/pharmacology; Feces/*chemistry; Female; Immunoenzyme Techniques/*methods; Male; Mice; Mice, Inbred C57BL; Models, Animal; Reproducibility of Results; Stress, Psychological/*metabolism
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Ganswindt, A., Palme, R., Heistermann, M., Borragan, S., & Hodges, J. K. (2003). Non-invasive assessment of adrenocortical function in the male African elephant (Loxodonta africana) and its relation to musth. Gen Comp Endocrinol, 134(2), 156–166.
Abstract: Adult male elephants periodically show the phenomenon of musth, a condition associated with increased aggressiveness, restlessness, significant weight reduction and markedly elevated androgen levels. It has been suggested that musth-related behaviours are costly and that therefore musth may represent a form of physiological stress. In order to provide data on this largely unanswered question, the first aim of this study was to evaluate different assays for non-invasive assessment of adrenocortical function in the male African elephant by (i) characterizing the metabolism and excretion of [3H]cortisol (3H-C) and [14C]testosterone (14C-T) and (ii) using this information to evaluate the specificity of four antibodies for determination of excreted cortisol metabolites, particularly with respect to possible cross-reactions with androgen metabolites, and to assess their biological validity using an ACTH challenge test. Based on the methodology established, the second objective was to provide data on fecal cortisol metabolite concentrations in bulls during the musth and non-musth condition. 3H-C (1 mCi) and 14C-T (100 microCi) were injected simultaneously into a 16 year old male and all urine and feces collected for 30 and 86 h, respectively. The majority (82%) of cortisol metabolites was excreted into the urine, whereas testosterone metabolites were mainly (57%) excreted into the feces. Almost all radioactive metabolites recovered from urine were conjugated (86% 3H-C and 97% 14C-T). In contrast, 86% and >99% of the 3H-C and 14C-T metabolites recovered from feces consisted of unconjugated forms. HPLC separations indicated the presence of various metabolites of cortisol in both urine and feces, with cortisol being abundant in hydrolysed urine, but virtually absent in feces. Although all antibodies measured substantial amounts of immunoreactivity after HPLC separation of peak radioactive samples and detected an increase in glucocorticoid output following the ACTH challenge, only two (in feces against 3alpha,11-oxo-cortisol metabolites, measured by an 11-oxo-etiocholanolone-EIA and in urine against cortisol, measured by a cortisol-EIA) did not show substantial cross-reactivity with excreted 14C-T metabolites and could provide an acceptable degree of specificity for reliable assessment of glucocorticoid output from urine and feces. Based on these findings, concentrations of immunoreactive 3alpha,11-oxo-cortisol metabolites were determined in weekly fecal samples collected from four adult bulls over periods of 11-20 months to examine whether musth is associated with increased adrenal activity. Results showed that in each male levels of these cortisol metabolites were not elevated during periods of musth, suggesting that in the African elephant musth is generally not associated with marked elevations in glucocorticoid output. Given the complex nature of musth and the variety of factors that are likely to influence its manifestation, it is clear, however, that further studies, particularly on free-ranging animals, are needed before a possible relationship between musth and adrenal function can be resolved. This study also clearly illustrates the potential problems associated with cross-reacting metabolites of gonadal steroids in EIAs measuring glucocorticoid metabolites. This has to be taken into account when selecting assays and interpreting results of glucocorticoid metabolite analysis, not only for studies in the elephant but also in other species.
Keywords: Adrenal Cortex/*metabolism/secretion; Adrenal Cortex Function Tests/methods/*veterinary; Adrenocorticotropic Hormone/physiology; Animals; Carbon Isotopes/diagnostic use; Chromatography, High Pressure Liquid/veterinary; Elephants/*metabolism/urine; Feces/*chemistry; Glucocorticoids/analysis/urine; Hydrocortisone/*analysis/diagnostic use/urine; Immunoenzyme Techniques/methods/veterinary; Male; Reproduction/physiology; Sexual Behavior, Animal/physiology; Stress, Psychological/diagnosis/*physiopathology; Testosterone/*analysis/diagnostic use/urine
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Zhang, T. - Y., Parent, C., Weaver, I., & Meaney, M. J. (2004). Maternal programming of individual differences in defensive responses in the rat. Ann N Y Acad Sci, 1032, 85–103.
Abstract: This paper describes the results of a series of studies showing that variations in mother-pup interactions program the development of individual differences in behavioral and endocrine stress responses in the rat. These effects are associated with altered expression of genes in brain regions, such as the amygdala, hippocampus, and hypothalamus, that regulate the expression of stress responses. Studies from evolutionary biology suggest that such “maternal effects” are common and often associated with variations in the quality of the maternal environment. Together these findings suggest an epigenetic process whereby the experience of the mother alters the nature of the parent-offspring interactions and thus the phenotype of the offspring.
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Detmer, D. (1992). Response: of pigs and primitive notions. Between Species, 8(4), 203–208. |
Graham, M., & Letz, R. (1979). Within-species variation in the development of ultrasonic signaling of preweanling rats. Dev Psychobiol, 12(2), 129–136.
Abstract: The development of litter and individual differences in the rate of ultrasonic signaling of neonatal rats was studied. Systematic variations among litters and individuals emerged, without differential treatment. These differences were not correlated with variations in general development as indexed by body weight. Two experiments using a cross-fostering design showed that litter differences developed independently of variations in postnatal environment. These results indicate that the variations among litters in ultrasound rate have a prenatal, possibly genetic, etiology and may represent reliable indicants of response to environmental stress.
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Reimers, M., Schwarzenberger, F., & Preuschoft, S. (2007). Rehabilitation of research chimpanzees: stress and coping after long-term isolation. Horm Behav, 51(3), 428–435.
Abstract: We report on the permanent retirement of chimpanzees from biomedical research and on resocialization after long-term social isolation. Our aim was to investigate to what extent behavioral and endocrine measures of stress in deprived laboratory chimpanzees can be improved by a more species-typical social life style. Personality in terms of novelty responses, social dominance after resocialization and hormonal stress susceptibility were affected by the onset of maternal separation of infant chimpanzees and duration of deprivation. Chimpanzees, who were separated from their mothers at a younger age and kept in isolation for more years appeared to be more timid personalities, less socially active, less dominant and more susceptible to stress, as compared to chimpanzees with a less severe deprivation history. However, permanent retirement from biomedical research in combination with therapeutic resocialization maximizing chimpanzees' situation control resulted in reduced fecal cortisol metabolite levels. Our results indicate that chimpanzees can recover from severe social deprivation, and may experience resocialization as less stressful than solitary housing.
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Overli, O., Korzan, W. J., Hoglund, E., Winberg, S., Bollig, H., Watt, M., et al. (2004). Stress coping style predicts aggression and social dominance in rainbow trout. Horm Behav, 45(4), 235–241.
Abstract: Social stress is frequently used as a model for studying the neuroendocrine mechanisms underlying stress-induced behavioral inhibition, depression, and fear conditioning. It has previously been shown that social subordination may result in increased glucocorticoid release and changes in brain signaling systems. However, it is still an open question which neuroendocrine and behavioral differences are causes, and which are consequences of social status. Using juvenile rainbow trout of similar size and with no apparent differences in social history, we demonstrate that the ability to win fights for social dominance can be predicted from the duration of a behavioral response to stress, in this case appetite inhibition after transfer to a new environment. Moreover, stress responsiveness in terms of confinement-induced changes in plasma cortisol was negatively correlated to aggressive behavior. Fish that exhibited lower cortisol responses to a standardized confinement test were markedly more aggressive when being placed in a dominant social position later in the study. These findings support the view that distinct behavioral-physiological stress coping styles are present in teleost fish, and these coping characteristics influence both social rank and levels of aggression.
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Abeyesinghe, S. M., Nicol, C. J., Wathes. C.M., & Randall, J. M. (2001). Development of a raceway method to assess aversion of domestic fowl to concurrent stressors. Behav. Process., 56(3), 175–194.
Abstract: The requirement for assessing the effects of stressor combinations in improving the welfare of animals has not been widely recognised. Knowledge of the effects of concurrent stressors is needed to improve environments such as transport, where animals are presented with many simultaneous challenges. However, no method for measuring the effects of different stressors with a common unit is currently available. A locomotor passive avoidance method was developed as a common currency measure of the aversion of domestic fowl to concurrent stressors, using vibrational and thermal stressors as an exemplar. Juvenile fowl, fasted overnight, were trained to run a raceway into a goal-box for small food rewards (FR1). When running consistently, the reinforcement schedule was superimposed with a FR5 treatment schedule (60 min confinement in the goal-box with either a control of no other stressors [N] or concurrent vibration and thermal stressors [VT]). Subsequent latency to return to the goal-box was recorded as a measure of aversion. The factors affecting bird response were addressed in a series of experiments to optimise the method and clarify interpretation of results. Pre-feeding (20% ration 2 h prior to testing) did not affect response, but increasing the number of treatment presentations facilitated learning and increased method sensitivity. Treatment responses were consistent across experiments; overall VT was avoided (P<0.001), but N was not. However, there was large individual variation in response to VT. A final experiment indicated that, given a visual discriminatory cue, birds were capable of learning the required association between entering the goal-box and receiving the treatment, suggesting that the delay responses were due to aversion rather than the immediate impact of treatment on ability to respond. Further work is required to test the singular stressors, but the method retains common currency potential for assessing aversion to multiple stressors.
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Aureli, F., & de Waal, F. B. (1997). Inhibition of social behavior in chimpanzees under high-density conditions. Am. J. Primatol., 41(3), 213–228.
Abstract: This is the first study to investigate the short-term effects of high population density on captive chimpanzees (Pan troglodytes). Subjects of the study were 45 chimpanzees living in five different groups at the Yerkes Regional Primate Research Center. The groups were observed under two conditions: 1) when they had access to both the indoor and outdoor sections of their enclosures; 2) during cold days when they were locked into the indoor runs, which reduced the available space by more than half. Under the high-density condition, allogrooming and submissive greetings decreased, but juvenile play increased. Remarkably, the rate of various forms of agonistic behavior, such as aggression, bluff charge, bluff display, and hooting, occurred less frequently under the high-density condition. This general decrease in adult social activity, including agonistic behavior, can be interpreted as an inhibition strategy to reduce opportunities for conflict when interindividual distances are reduced. This strategy is probably effective only in the short run, however. Behavioral indicators of anxiety, such as rough scratching and yawning, showed elevated rates, suggesting increased social tension under the high-density condition.
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