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Michael L Romero - One of the best experts on this subject based on the ideXlab platform.
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chronic stress and the introduction to Captivity how wild house sparrows passer domesticus adjust to laboratory conditions
General and Comparative Endocrinology, 2017Co-Authors: Clare Parker Fischer, Jessica Wrightlichter, Michael L RomeroAbstract:Abstract The conditions of Captivity can cause chronic stress in wild animals. Newly-captured animals may experience weight loss, elevated glucocorticoid hormones, increased heart rate, increased resting adrenomedullary activation, and an altered heart rate response to acute stressors. As Captivity conditions persist, chronic stress may decrease as animals adjust to the stressors of Captivity. In this study, house sparrows (Passer domesticus) were captured from the wild, fitted with heart rate transmitters in a minor surgical process, and individually housed in an indoor bird facility. Mass, baseline corticosterone, resting heart rate, resting adrenomedullary activation, and the acute heart rate response to a sudden noise were measured over the course of the first 6 weeks of Captivity. Birds lost weight during the first weeks of Captivity, which was regained by week 5. Baseline corticosterone peaked at day 7, decreased sharply by day 11, and continued to decrease throughout the 6 weeks. Although heart rate in the first 24 h could not be collected, daytime heart rate decreased from day 1 through day 20, where it reached a stable plateau. Daytime heart rate variability decreased through the entire 6 weeks, which may indicate a gradual shift from sympathetic to parasympathetic nervous system regulation of heart rate. The acute heart rate response to a sudden noise lasted longer at day 6 than earlier or later in Captivity. In conclusion, the data indicate that the different physiological systems associated with chronic stress adjust to Captivity over different timelines.
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the use of α or β blockers to ameliorate the chronic stress of Captivity in the house sparrow passer domesticus
Conservation Physiology, 2016Co-Authors: Clare Parker Fischer, Michael L RomeroAbstract:When wild animals are brought into Captivity for the first time, they frequently develop chronic stress symptoms. Animals can develop glucocorticoid dysregulation or changes in the sympathetic nervous system over the course of the first week in Captivity. By blocking the action of epinephrine and norepinephrine using α- or β-blockers, we hoped to reduce the degree of chronic stress symptoms exhibited by newly captured house sparrows. We measured corticosterone, heart rate and heart rate variability in 24 house sparrows (Passer domesticus) over the first week of Captivity. The birds were treated with saline, propranolol (a β-blocker) or phentolamine (an α-blocker) for the first 3 days of Captivity. We also compared newly captured animals with animals that had been held in Captivity for 1 month. During the first week of Captivity, baseline corticosterone increased, but that increase was blocked by propranolol. Heart rate was not different between the treatment groups, but it was higher during the first week than after 1 month in Captivity. Sympathetic nervous system activity (as measured by heart rate variability) decreased over the first week of Captivity, but was not affected by treatment. β-Blockers, but not α-blockers, might help to improve some symptoms of chronic stress in newly captured animals.
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hypothalamus pituitary adrenal axis activity and the subsequent response to chronic stress differ depending upon life history stage
General and Comparative Endocrinology, 2012Co-Authors: Christine R Lattin, Carolyn M Bauer, Robert De Bruijn, Michael L RomeroAbstract:Abstract The hypothalamus–pituitary–adrenal (HPA) axis is modulated seasonally in many species, and chronic stress can alter HPA functioning. However, it is not known how these two factors interact – are there particular life history stages when animals are more or less vulnerable to chronic stress? We captured wild house sparrows ( Passer domesticus ) in Massachusetts during six different life history stages: early and late winter, pre-laying, breeding, late breeding, and molt. At each time point, we tested HPA function by measuring baseline and stress-induced corticosterone (CORT), negative feedback in response to an injection of dexamethasone, and maximum adrenal response through an injection of adrenocorticotropic hormone. We then brought birds into Captivity as a model for chronic stress, and repeated the four tests 5 days later. At capture, all HPA variables varied seasonally. Birds showed increased negative feedback during breeding and late winter compared to pre-laying. Furthermore, birds during the late breeding period had down-regulated their HPA axis, perhaps in preparation for molt. After 5 days of Captivity, house sparrows lost ∼11% of initial body mass, although birds lost more weight during molt and early winter. Overall, captive sparrows showed elevated baseline CORT and increased negative feedback, although negative feedback did not show a significant increase during any individual life history stage. During most of the year, adrenal sensitivity was unaffected by Captivity. However, during late breeding and molt, adrenal sensitivity increased during Captivity. Taken together, these data provide further support that HPA function naturally varies throughout the year, with the interesting consequence that molting birds may potentially be more vulnerable to a chronic stressor such as Captivity.
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wild european starlings sturnus vulgaris adjust to Captivity with sustained sympathetic nervous system drive and a reduced fight or flight response
Physiological and Biochemical Zoology, 2009Co-Authors: Molly J Dickens, Michael L RomeroAbstract:Abstract Although research on wild species typically involves capture, handling, and some degree of Captivity, few studies examine how these actions affect and/or alter the animal’s underlying stress physiology. Furthermore, we poorly understand the immediate changes that occur as wild animals adjust to captive conditions. Most studies to date have investigated relatively long‐term changes in the glucocorticoid response to an acute stressor, but immediate changes in the fight‐or‐flight response are relatively understudied in wild‐caught species. In this study, we investigated changes to the cardiovascular stress response during the first 10 d of Captivity of freshly captured wild European starlings (Sturnus vulgaris). We demonstrated that (1) baseline heart rate (HR) remains elevated for several days following transport into Captivity, (2) the normal balance between sympathetic nervous system (SNS) and parasympathetic nervous system regulation of HR is disrupted, with the SNS exerting relatively greater c...
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initial transference of wild birds to Captivity alters stress physiology
General and Comparative Endocrinology, 2009Co-Authors: Molly J Dickens, Kristen A Earle, Michael L RomeroAbstract:Abstract Maintaining wild animals in Captivity has long been used for conservation and research. While often suggested that Captivity causes chronic stress, impacts on the underlying stress physiology are poorly understood. We used wild-caught chukar (Alectoris chukar) as a model avian species to assess how the initial 10 days of Captivity alters the corticosterone (CORT) secretory pathway. In the first few days of Captivity, birds lost weight, had lower hematocrit and demonstrated changes in CORT concentrations. Both baseline and restraint-stress-induced CORT concentrations decreased by days 3–5 of Captivity and remained significantly lower throughout the 10 days although stress-induced concentrations began to recover by day 9. To delineate potential mechanisms underlying these CORT changes, we evaluated alterations to the hypothalamic–pituitary–adrenal (HPA) axis. Although chukar appear to be resistant to arginine vasotocin’s (AVT) effects on CORT release, adrenocorticotropin hormone (ACTH) stimulated CORT release; however, ACTH stimulation did not differ during the 10 days of Captivity. In contrast, negative feedback axis sensitivity, as determined by both dexamethasone suppression as well as endogenous negative feedback, decreased by day 5 but was regained by day 9. In addition, the combined stressors of capture and long distance transport eliminated the animals’ ability to mount an acute CORT response on the day following the move. Therefore, introduction into Captivity appeared to shift the chukar into a temporary state of chronic stress that began to recover within 9 days. The duration of these alterations likely varies due to differences in capture techniques, transport distance, and species studied.
Andreas Kurth - One of the best experts on this subject based on the ideXlab platform.
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microbiomes in the insectivorous bat species mops condylurus rapidly converge in Captivity
PLOS ONE, 2020Co-Authors: Kathryn M Edenborough, Kristin Muhldorfer, Johanna Lechner, Angelika Lander, Marcel Bokelmann, Emmanuel Couacyhymann, Aleksandar Radonic, Andreas KurthAbstract:Bats are well known reservoir hosts for RNA and DNA viruses. The use of captive bats in research has intensified over the past decade as researchers aim to examine the virus-reservoir host interface. In this study, we investigated the effects of Captivity on the fecal bacterial microbiome of an insectivorous microbat, Mops condylurus, a species that roosts in close proximity to humans and has likely transmitted viral infections to humans. Using amplicon 16S rRNA gene sequencing, we characterized changes in fecal bacterial community composition for individual bats directly at the time of capture and again after six weeks in Captivity. We found that microbial community richness by measure of the number of observed operational taxonomic units (OTUs) in bat feces increases in Captivity. Importantly, we found the similarity of microbial community structures of fecal microbiomes between different bats to converge during Captivity. We propose a six week-acclimatization period prior to carrying out infection studies or other research influenced by the microbiome composition, which may be advantageous to reduce variation in microbiome composition and minimize biological variation inherent to in vivo experimental studies.
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microbiomes in the insectivorous bat species mops condylurus rapidly converge in Captivity
bioRxiv, 2019Co-Authors: Kathryn M Edenborough, Kristin Muhldorfer, Johanna Lechner, Angelika Lander, Marcel Bokelmann, Emmanuel Couacyhymann, Aleksandar Radonic, Andreas KurthAbstract:Abstract Bats are well known reservoir hosts for RNA and DNA viruses. The use of captive bats in research has intensified over the past decade as researchers aim to examine the virus-reservoir host interface. In this study, we investigated the effects of Captivity on the fecal bacterial microbiome of an insectivorous microbat, Mops condylurus, a bat species that roosts in close proximity to humans and has likely transmitted viral infections to humans. Using amplicon 16S rRNA gene sequencing, we characterized changes in fecal bacterial community composition for individual bats directly at the time of capture and again after six weeks in Captivity. We found that microbial community richness by measure of the number of observed operational taxonomic units (OTUs) in bat feces does increase significantly in Captivity. Importantly, we found the similarity of microbial community structures of fecal microbiomes between different bats to converge during Captivity. We propose a six week-acclimatization period prior to carrying out infection studies or other research influenced by the microbiome composition, which may be advantageous to reduce variation in microbiome composition and minimize biological variation inherent to in vivo experimental studies.
Kathryn M Edenborough - One of the best experts on this subject based on the ideXlab platform.
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microbiomes in the insectivorous bat species mops condylurus rapidly converge in Captivity
PLOS ONE, 2020Co-Authors: Kathryn M Edenborough, Kristin Muhldorfer, Johanna Lechner, Angelika Lander, Marcel Bokelmann, Emmanuel Couacyhymann, Aleksandar Radonic, Andreas KurthAbstract:Bats are well known reservoir hosts for RNA and DNA viruses. The use of captive bats in research has intensified over the past decade as researchers aim to examine the virus-reservoir host interface. In this study, we investigated the effects of Captivity on the fecal bacterial microbiome of an insectivorous microbat, Mops condylurus, a species that roosts in close proximity to humans and has likely transmitted viral infections to humans. Using amplicon 16S rRNA gene sequencing, we characterized changes in fecal bacterial community composition for individual bats directly at the time of capture and again after six weeks in Captivity. We found that microbial community richness by measure of the number of observed operational taxonomic units (OTUs) in bat feces increases in Captivity. Importantly, we found the similarity of microbial community structures of fecal microbiomes between different bats to converge during Captivity. We propose a six week-acclimatization period prior to carrying out infection studies or other research influenced by the microbiome composition, which may be advantageous to reduce variation in microbiome composition and minimize biological variation inherent to in vivo experimental studies.
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microbiomes in the insectivorous bat species mops condylurus rapidly converge in Captivity
bioRxiv, 2019Co-Authors: Kathryn M Edenborough, Kristin Muhldorfer, Johanna Lechner, Angelika Lander, Marcel Bokelmann, Emmanuel Couacyhymann, Aleksandar Radonic, Andreas KurthAbstract:Abstract Bats are well known reservoir hosts for RNA and DNA viruses. The use of captive bats in research has intensified over the past decade as researchers aim to examine the virus-reservoir host interface. In this study, we investigated the effects of Captivity on the fecal bacterial microbiome of an insectivorous microbat, Mops condylurus, a bat species that roosts in close proximity to humans and has likely transmitted viral infections to humans. Using amplicon 16S rRNA gene sequencing, we characterized changes in fecal bacterial community composition for individual bats directly at the time of capture and again after six weeks in Captivity. We found that microbial community richness by measure of the number of observed operational taxonomic units (OTUs) in bat feces does increase significantly in Captivity. Importantly, we found the similarity of microbial community structures of fecal microbiomes between different bats to converge during Captivity. We propose a six week-acclimatization period prior to carrying out infection studies or other research influenced by the microbiome composition, which may be advantageous to reduce variation in microbiome composition and minimize biological variation inherent to in vivo experimental studies.
Christine R Lattin - One of the best experts on this subject based on the ideXlab platform.
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in vivo imaging of d 2 receptors and corticosteroids predict behavioural responses to Captivity stress in a wild bird
Scientific Reports, 2019Co-Authors: Christine R Lattin, Devin P Merullo, Lauren V Riters, Richard E CarsonAbstract:Individual physiological variation may underlie individual differences in behaviour in response to stressors. This study tested the hypothesis that individual variation in dopamine and corticosteroid physiology in wild house sparrows (Passer domesticus, n = 15) would significantly predict behaviour and weight loss in response to a long-term stressor, Captivity. We found that individuals that coped better with Captivity (fewer anxiety-related behaviours, more time spent feeding, higher body mass) had lower baseline and higher stress-induced corticosteroid titres at capture. Birds with higher striatal D2 receptor binding (examined using positron emission tomography (PET) with 11C-raclopride 24 h post-capture) spent more time feeding in Captivity, but weighed less, than birds with lower D2 receptor binding. In the subset of individuals imaged a second time, D2 receptor binding decreased in Captivity in moulting birds, and larger D2 decreases were associated with increased anxiety behaviours 2 and 4 weeks post-capture. This suggests changes in dopaminergic systems could be one physiological mechanism underlying negative behavioural effects of chronic stress. Non-invasive technologies like PET have the potential to transform our understanding of links between individual variation in physiology and behaviour and elucidate which neuroendocrine phenotypes predict stress resilience, a question with important implications for both humans and wildlife.
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experimentally reducing corticosterone mitigates rapid Captivity effects on behavior but not body composition in a wild bird
Hormones and Behavior, 2017Co-Authors: Christine R Lattin, Anita V Pechenenko, Richard E CarsonAbstract:Wild animals and captives display physiological and behavioral differences, and it has been hypothesized, but rarely tested, that these differences are caused by sustained elevation of the hormone corticosterone. We used repeated computed tomography (CT) imaging to examine body composition changes in breeding male and female wild house sparrows (Passer domesticus; n=20) in response to two weeks of Captivity, and assessed behavioral changes using video recordings. Half of the birds received the drug mitotane, which significantly decreased stress-induced corticosterone titers compared to controls. Based on the CT images, fat volumes increased, and pectoralis muscle density and heart and testes volumes decreased, over the two weeks of Captivity in both groups of birds. However, beak-wiping, a behavior that can indicate anxiety and aggression, showed increased occurrence in controls compared to mitotane-treated birds. While our results do not support the hypothesis that these body composition changes were primarily driven by stress-induced corticosterone, our data suggest that experimentally reducing stress-induced corticosterone may mitigate some Captivity-induced behavioral changes. Broadly, our results emphasize that researchers should take behavioral and physiological differences between free-living animals and captives into consideration when designing studies and interpreting results. Further, time in Captivity should be minimized when birds will be reintroduced back to the wild.
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hypothalamus pituitary adrenal axis activity and the subsequent response to chronic stress differ depending upon life history stage
General and Comparative Endocrinology, 2012Co-Authors: Christine R Lattin, Carolyn M Bauer, Robert De Bruijn, Michael L RomeroAbstract:Abstract The hypothalamus–pituitary–adrenal (HPA) axis is modulated seasonally in many species, and chronic stress can alter HPA functioning. However, it is not known how these two factors interact – are there particular life history stages when animals are more or less vulnerable to chronic stress? We captured wild house sparrows ( Passer domesticus ) in Massachusetts during six different life history stages: early and late winter, pre-laying, breeding, late breeding, and molt. At each time point, we tested HPA function by measuring baseline and stress-induced corticosterone (CORT), negative feedback in response to an injection of dexamethasone, and maximum adrenal response through an injection of adrenocorticotropic hormone. We then brought birds into Captivity as a model for chronic stress, and repeated the four tests 5 days later. At capture, all HPA variables varied seasonally. Birds showed increased negative feedback during breeding and late winter compared to pre-laying. Furthermore, birds during the late breeding period had down-regulated their HPA axis, perhaps in preparation for molt. After 5 days of Captivity, house sparrows lost ∼11% of initial body mass, although birds lost more weight during molt and early winter. Overall, captive sparrows showed elevated baseline CORT and increased negative feedback, although negative feedback did not show a significant increase during any individual life history stage. During most of the year, adrenal sensitivity was unaffected by Captivity. However, during late breeding and molt, adrenal sensitivity increased during Captivity. Taken together, these data provide further support that HPA function naturally varies throughout the year, with the interesting consequence that molting birds may potentially be more vulnerable to a chronic stressor such as Captivity.
Denise M Dearing - One of the best experts on this subject based on the ideXlab platform.
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wild caught rodents retain a majority of their natural gut microbiota upon entrance into Captivity
Environmental Microbiology Reports, 2014Co-Authors: Kevin D Kohl, Denise M DearingAbstract:Summary Experiments conducted on captive animals allow scientists to control many variables; however, these settings are highly unnatural. Previous research has documented a large difference in microbial communities between wild animals and captive-bred individuals. However, wild-caught animals brought into Captivity might retain their natural microbiota and thus provide a better study system in which to investigate the ecology of the gut microbiome. We collected individuals of the desert woodrat (Neotoma lepida) from nature and investigated changes in the microbial community over 6 months in Captivity. Additionally, we inventoried potential environmental sources of microbes (food, bedding) from the wild and Captivity. We found that environmental sources do not make large contributions to the woodrat gut microbial community. We documented a slight decrease in several biodiversity metrics over 6 months in Captivity, yet the magnitude of change was small compared with other studies. Wild and captive animals shared 64% of their microbial species, almost twice that observed in other studies of wild and captive-bred individuals (≤ 37% shared). We conclude that wild-caught animals brought into Captivity retain a substantial proportion of their natural microbiota and represent an acceptable system in which to study the gut microbiome.
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Captivity results in disparate loss of gut microbial diversity in closely related hosts
Conservation Physiology, 2014Co-Authors: Kevin D Kohl, Michele M Skopec, Denise M DearingAbstract:The gastrointestinal tracts of animals contain diverse communities of microbes that provide a number of services to their hosts. There is recent concern that these communities may be lost as animals enter captive breeding programmes, due to changes in diet and/or exposure to environmental sources. However, empirical evidence documenting the effects of Captivity and captive birth on gut communities is lacking. We conducted three studies to advance our knowledge in this area. First, we compared changes in microbial diversity of the gut communities of two species of woodrats (Neotoma albigula, a dietary generalist, and Neotoma stephensi, which specializes on juniper) before and after 6-9 months in Captivity. Second, we investigated whether reintroduction of the natural diet of N. stephensi could restore microbial diversity. Third, we compared the microbial communities between offspring born in Captivity and their mothers. We found that the dietary specialist, N. stephensi, lost a greater proportion of its native gut microbiota and overall diversity in response to Captivity compared with N. albigula. Addition of the natural diet increased the proportion of the original microbiota but did not restore overall diversity in N. stephensi. Offspring of N. albigula more closely resembled their mothers compared with offspring-mother pairs of N. stephensi. This research suggests that the microbiota of dietary specialists may be more susceptible to Captivity. Furthermore, this work highlights the need for further studies investigating the mechanisms underlying how loss of microbial diversity may vary between hosts and what an acceptable level of diversity loss may be to a host. This knowledge will aid conservation biologists in designing captive breeding programmes effective at maintaining microbial diversity. Sequence Accession Numbers: NCBI's Sequence Read Archive (SRA) - SRP033616.