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Sample records for elevates corticosterone content

  1. Exposure to coal combustion residues during metamorphosis elevates corticosterone content and adversely affects oral morphology, growth, and development in Rana sphenocephala

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    Peterson, J.D.; Peterson, V.A.; Mendonca, M.T. [Auburn University, Auburn, AL (USA). Dept. of Biological Science

    2009-01-15

    Coal combustion residues (CCRs) are documented to negatively impact oral morphology, growth, and development in larval amphibians. It is currently unclear what physiological mechanisms may mediate these effects. Corticosterone, a glucocorticoid hormone, is a likely mediator because when administered exogenously it, like CCRs, also negatively influences oral morphology, growth, and development in larval amphibians. In an attempt to identify if corticosterone mediates these effects, we raised larval Southern Leopard Frogs, Rana sphenocephala, on either sand or CCR substrate and documented effects of sediment type on whole body corticosterone, oral morphology, and time to and mass at key metamorphic stages. Coal combustion residue treated tadpoles contained significantly more corticosterone than controls throughout metamorphosis. However, significantly more oral abnormalities occurred early in metamorphosis when differences in corticosterone levels between treatments were minimal. Overall, CCR-treated tadpoles took significantly more time to transition between key stages and gained less mass between stages than controls, but these differences between treatments decreased during later stages when corticosterone differences between treatments were greatest. Our results suggest endogenous increase in corticosterone content and its influence on oral morphology, growth and development is more complex than previously thought.

  2. Reproduction elevates the corticosterone stress response in common fruit bats.

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    Klose, Stefan M; Smith, Carolynn L; Denzel, Andrea J; Kalko, Elisabeth K V

    2006-04-01

    Changes in reproductive state or the environment may affect the sensitivity of the hypothalamic-pituitary-andrenal (HPA) axis. However, little is known about the dynamics of the resulting corticosteroid stress response, in particular in tropical mammals. In this study, we address the modulation of corticosterone release in response to different reproductive conditions and seasonality in 326 free-living common fruit-eating bats (Artibeus jamaicensis) on Barro Colorado Island in Panama during dry and wet seasons. We present strong evidence that stress sensitivity is primarily modulated by reproductive condition. In reproductively active females, corticosterone increases were more rapid and reached higher levels, but also decreased significantly faster than in inactive females. The corticosterone response was weaker in reproducing males than in females and delayed compared to non-reproductive males. Testes volume in reproductively active males was negatively correlated with corticosterone concentrations. Our findings suggest differentiated dynamics in the corticosterone stress response between sexes, potentially reflecting conflicting ecological demands. In females, a strong acute corticosterone response may represent high stress- and risk-sensitivity that facilitates escape and thus helps to protect reproduction. In males, suppression during reproductive activity could reflect lowered stress sensitivity to avoid chronically elevated corticosterone levels in times of frequent aggressive and therefore costly inter-male encounters.

  3. Dietary restriction causes chronic elevation of corticosterone and enhances stress response in red-legged kittiwake chicks

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    Kitaysky, A.S.; Kitaiskaia, E.V.; Wingfield, J.C.; Piatt, John F.

    2001-01-01

    Release of corticosterone in hungry kittiwake chicks facilitates begging and allows them to restore depleted energy reserves by increasing parental food provisioning. However, in order to avoid detrimental effects of chronic elevation of corticosterone, chicks might suppress adrenocortical activity in response to prolonged food shortages. In this study we examined temporal dynamics of corticosterone release in red-legged kittiwake (Rissa brevirostris) chicks exposed to prolonged restrictions in energy content and/or nutritional quality (low versus high lipid content) of their food. Starting at the age of 15 days, chicks were fed either high- or low-lipid fish at 40%, 65%, and 100% of ad libitum energy intake. Body mass measurements and baseline plasma samples were taken on a weekly basis after beginning of the treatment. After 3 weeks of treatment, chicks were exposed to a standardized acute handling and restraint stress protocol, where in addition to a baseline sample, three plasma samples were taken at intervals up to 50 min. We found that food-restricted chicks had lower body mass, chronically (during 2-3 weeks) elevated baseline and higher acute stress-induced levels of corticosterone compared to chicks fed ad libitum. Low lipid content of food further exacerbated these effects. An increase in baseline levels of corticosterone was observed within a week after energy requirements of food-restricted chicks exceeded their daily energy intake. A tendency for suppression of adrenocortical activity was observed in treatments fed low-lipid diets only at the end of the experiment. We suggest that nest-bound chicks, if food-stressed, might suffer deleterious effects of chronic elevation of corticosterone.

  4. Immune responses of eastern fence lizards (Sceloporus undulatus) to repeated acute elevation of corticosterone.

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    McCormick, Gail L; Langkilde, Tracy

    2014-08-01

    Prolonged elevations of glucocorticoids due to long-duration (chronic) stress can suppress immune function. It is unclear, however, how natural stressors that result in repeated short-duration (acute) stress, such as frequent agonistic social encounters or predator attacks, fit into our current understanding of the immune consequences of stress. Since these types of stressors may activate the immune system due to increased risk of injury, immune suppression may be reduced at sites where individuals are repeatedly exposed to potentially damaging stressors. We tested whether repeated acute elevation of corticosterone (CORT, a glucocorticoid) suppresses immune function in eastern fence lizards (Sceloporus undulatus), and whether this effect varies between lizards from high-stress (high baseline CORT, invaded by predatory fire ants) and low-stress (low baseline CORT, uninvaded) sites. Lizards treated daily with exogenous CORT showed higher hemagglutination of novel proteins by their plasma (a test of constitutive humoral immunity) than control lizards, a pattern that was consistent across sites. There was no significant effect of CORT treatment on bacterial killing ability of plasma. These results suggest that repeated elevations of CORT, which are common in nature, produce immune effects more typical of those expected at the acute end of the acute-chronic spectrum and provide no evidence of modulated consequences of elevated CORT in animals from high-stress sites. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Variation in testosterone and corticosterone in amphibians and reptiles: relationships with latitude, elevation, and breeding season length.

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    Eikenaar, Cas; Husak, Jerry; Escallón, Camilo; Moore, Ignacio T

    2012-11-01

    Latitudinal variation in life-history traits has been the focus of numerous investigations, but underlying hormonal mechanisms have received much less attention. Steroid hormones play a central role in vertebrate reproduction and may be associated with life-history trade-offs. Consequently, circulating concentrations of these hormones vary tremendously across vertebrates, yet interspecific geographic variation in male hormone concentrations has been studied in detail only in birds. We here report on such variation in amphibians and reptiles, confirming patterns observed in birds. Using phylogenetic comparative analyses, we found that in amphibians, but not in reptiles, testosterone and baseline corticosterone were positively related to latitude. Baseline corticosterone was negatively related to elevation in amphibians but not in reptiles. For both groups, testosterone concentrations were negatively related to breeding-season length. In addition, testosterone concentrations were positively correlated with baseline corticosterone in both groups. Our findings may best be explained by the hypothesis that shorter breeding seasons increase male-male competition, which may favor increased testosterone concentrations that modulate secondary sexual traits. Elevated energetic demands resulting from greater reproductive intensity may require higher baseline corticosterone. Thus, the positive relationship between testosterone and corticosterone in both groups suggests an energetic demand for testosterone-regulated behavior that is met with increased baseline glucocorticoid concentrations.

  6. Elevated plasma corticosterone concentrations influence the onset of rigor mortis and meat color in broilers.

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    Kannan, G; Heath, J L; Wabeck, C J; Owens, S L; Mench, J A

    1998-02-01

    This experiment was conducted to determine the effect of elevated plasma corticosterone (CORT) levels on meat quality characteristics. Male broilers (Arbor Acres) were either 1) fed a diet containing corticosterone (CORT) prior to processing, 2) transported by truck for 3 h before processing, or 3) processed without either of the above treatments. Six crates of birds (10 birds per crate; two crates per treatment) were stunned or killed using CO2 gas. Six birds per crate were processed and blood samples were collected during exsanguination for plasma CORT analysis. Meat samples were collected from carcasses either at 20 min or at 4 h post-mortem. At each sampling time (ST), Pectoralis superficialis samples were collected and either individually quick frozen (IQF) in liquid nitrogen or aged on ice (AOI) for 24 h prior to pH, ratio of inosine to adenosine nucleotides (R-value), cooking loss, shear value, and color analyses. The IQF Biceps femoris samples were used for pH, R-value, color, and heme pigment analysis. Mean (+/- SEM) CORT concentrations were 12.9+/-2.57, 11.7+/-1.38 and 7.9+/-0.79 ng/mL, respectively, in the CORT, transported, and control groups. There were significant treatment by ST (P < 0.05) and ST (P < 0.001) effects on the R-value of IQF P. superficialis samples. The CORT group had the highest L* value (P < 0.01) and the lowest a* value (P < 0.06). There was also a significant main effect of ST on shear values (P < 0.05) of AOI P. superficialis samples, with the means higher at 4 h than at 20 min post-mortem. The R-value of IQF B. femoris samples was markedly influenced by treatment (P < 0.001) and ST (P < 0.001). The results indicate that artificially elevating circulating CORT concentrations results in lighter meat color in broilers.

  7. Stressful dieting: nutritional conditions but not compensatory growth elevate corticosterone levels in zebra finch nestlings and fledglings.

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    Mariam Honarmand

    Full Text Available Unfavourable conditions throughout the period of parental care can severely affect growth, reproductive performance, and survival. Yet, individuals may be affected differently, depending on the developmental period during which constraints are experienced. Here we tested whether the nestling phase compared to the fledgling phase is more susceptible to nutritional stress by considering biometry, physiology, sexually selected male ornaments and survival using zebra finches (Taeniopygia guttata as a model species. As nestlings (day 0-17 or fledglings (day 17-35, subjects were raised either on low or high quality food. A low quality diet resulted in significantly elevated baseline corticosterone titres in both nestlings and fledglings. Subjects showed substantial compensatory growth after they had experienced low quality food as nestlings but catch-up growth did neither lead to elevated baseline corticosterone titres nor did we detect long term effects on biometry, male cheek patch, or survival. The compensation for temporally unfavourable environmental conditions reflects substantial phenotypic plasticity and the results show that costs of catch-up growth were not mediated via corticosterone as a physiological correlate of allostatic load. These findings provide new insights into the mechanisms and plasticity with which animals respond to periods of constraints during development as they may occur in a mistiming of breeding.

  8. Elevated corticosterone during egg production elicits increased maternal investment and promotes nestling growth in a wild songbird.

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    Bowers, E Keith; Bowden, Rachel M; Thompson, Charles F; Sakaluk, Scott K

    2016-07-01

    Glucocorticoids circulating in breeding birds during egg production accumulate within eggs, and may provide a potent form of maternal effect on offspring phenotype. However, whether these steroids affect offspring development remains unclear. Here, we employed a non-invasive technique that experimentally elevated the maternal transfer of corticosterone to eggs in a wild population of house wrens. Feeding corticosterone-injected mealworms to free-living females prior to and during egg production increased the number of eggs that females produced and increased corticosterone concentrations in egg yolks. This treatment also resulted in an increase in the amount of yolk allocated to eggs. Offspring hatching from these eggs begged for food at a higher rate than control offspring and eventually attained increased prefledging body condition, a trait predictive of their probability of recruitment as breeding adults in the study population. Our results indicate that an increase in maternal glucocorticoids within the physiological range can enhance maternal investment and offspring development. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Delayed effects of elevated corticosterone level on volume of hippocampal formation in laboratory rat

    Czech Academy of Sciences Publication Activity Database

    Zach, P.; Mrzílková, J.; Řezáčová, Lenka; Stuchlík, Aleš; Valeš, Karel

    2010-01-01

    Roč. 59, č. 6 (2010), s. 985-990 ISSN 0862-8408 R&D Projects: GA MZd(CZ) NR9180 Institutional research plan: CEZ:AV0Z50110509 Keywords : corticosterone * hippocampus * lateralization Subject RIV: FH - Neurology Impact factor: 1.646, year: 2010

  10. Anti-depressant and anxiolytic like behaviors in PKCI/HINT1 knockout mice associated with elevated plasma corticosterone level

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    Wang Jia

    2009-11-01

    Full Text Available Abstract Background Protein kinase C interacting protein (PKCI/HINT1 is a small protein belonging to the histidine triad (HIT family proteins. Its brain immunoreactivity is located in neurons and neuronal processes. PKCI/HINT1 gene knockout (KO mice display hyper-locomotion in response to D-amphetamine which is considered a positive symptom of schizophrenia in animal models. Postmortem studies identified PKCI/HINT1 as a candidate molecule for schizophrenia and bipolar disorder. We investigated the hypothesis that the PKCI/HINT1 gene may play an important role in regulating mood function in the CNS. We submitted PKCI/HINT1 KO mice and their wild type (WT littermates to behavioral tests used to study anti-depressant, anxiety like behaviors, and goal-oriented behavior. Additionally, as many mood disorders coincide with modifications of hypothalamic-pituitary-adrenal (HPA axis function, we assessed the HPA activity through measurement of plasma corticosterone levels. Results Compared to the WT controls, KO mice exhibited less immobility in the forced swim (FST and the tail suspension (TST tests. Activity in the TST tended to be attenuated by acute treatment with valproate at 300 mg/kg in KO mice. The PKCI/HINT1 KO mice presented less thigmotaxis in the Morris water maze and spent progressively more time in the lit compartment in the light/dark test. In a place navigation task, KO mice exhibited enhanced acquisition and retention. Furthermore, the afternoon basal plasma corticosterone level in PKCI/HINT1 KO mice was significantly higher than in the WT. Conclusion PKCI/HINT1 KO mice displayed a phenotype of behavioral and endocrine features which indicate changes of mood function, including anxiolytic-like and anti-depressant like behaviors, in conjunction with an elevated corticosterone level in plasma. These results suggest that the PKCI/HINT 1 gene could be important for the mood regulation function in the CNS.

  11. Progesterone regulates corticosterone elevation and alterations in spatial memory and exploratory behavior induced by stress in Wistar rats

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    Diaz-Burke, Yolanda; Universidad de Guadalajara; Valencia-Alfonso, Carlos Eduardo; Netherlands Institute for Neuroscience; González-Sandoval, Claudia Elena; Universidad de Guadalajara; Huerta, Miguel; Centro Universitario de Investigaciones Biomédicas, Universidad de Colima; Trujillo, Xóchitl; Centro Universitario de Investigaciones Biomédicas, Universidad de Colima; Diaz, Lourdes; Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco; García-Estrada, Joaquín; Centro de Investigación Biomédica de Occidente, IMSS-Jalisco; Luquín, Sonia; Universidad de Guadalajara

    2010-01-01

    The hippocampus is sensitive to high levels of glucocorticoids. During stress response, it suffers biochemical and cellular changes that affect functions such as spatial memory and exploratory behavior. In this study, we analyzed the influence of the neurosteroid progesterone (PROG), on stress-induced changes in urinary corticosterone (CORT) levels, spatial memory and exploratory behavior. Castrated adult male rats were implanted with PROG or vehicle (VEHI), and then exposed to chronic stres...

  12. Differential effects of stable elevated levels of corticotropin-releasing hormone and systemic corticosterone on various types of rat learning

    Czech Academy of Sciences Publication Activity Database

    Řezáčová, Lenka; Svoboda, Jan; Stuchlík, Aleš; Valeš, Karel

    2011-01-01

    Roč. 32, č. 1 (2011), s. 64-76 ISSN 0172-780X R&D Projects: GA MZd(CZ) NR9180; GA ČR(CZ) GA309/09/0286; GA ČR(CZ) GCP303/10/J032; GA MŠk(CZ) LC554; GA MŠk(CZ) 1M0517 Institutional research plan: CEZ:AV0Z50110509 Keywords : corticosterone * CRH * behavior Subject RIV: FH - Neurology Impact factor: 1.296, year: 2011

  13. Elevated Corticosterone Levels and Changes in Amphibian Behavior Are Associated with Batrachochytrium dendrobatidis (Bd Infection and Bd Lineage.

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    Caitlin R Gabor

    Full Text Available Few studies have examined the role hormones play in mediating clinical changes associated with infection by the parasite Batrachochytrium dendrobatidis (Bd. Glucocorticoid (GC hormones such as corticosteroids (CORT regulate homeostasis and likely play a key role in response to infection in amphibians. We explore the relationship between CORT release rates and Bd infection in tadpoles of the common midwife toad, Alytes obstetricians, using a non-invasive water-borne hormone collection method across seven populations. We further examined whether tadpoles of A. muletensis infected with a hypervirulent lineage of Bd, BdGPL, had greater CORT release rates than those infected with a hypovirulent lineage, BdCAPE. Finally, we examined the relationship between righting reflex and CORT release rates in infected metamorphic toads of A. obstetricans. We found an interaction between elevation and Bd infection status confirming that altitude is associated with the overall severity of infection. In tandem, increasing elevation was associated with increasing CORT release rates. Tadpoles infected with the hypervirulent BdGPL had significantly higher CORT release rates than tadpoles infected with BdCAPE showing that more aggressive infections lead to increased CORT release rates. Infected metamorphs with higher CORT levels had an impaired righting reflex, our defined experimental endpoint. These results provide evidence that CORT is associated with an amphibian's vulnerability to Bd infection, and that CORT is also affected by the aggressiveness of infection by Bd. Together these results indicate that CORT is a viable biomarker of amphibian stress.

  14. Chronic corticosterone exposure persistently elevates the expression of memory-related genes in the lateral amygdala and enhances the consolidation of a Pavlovian fear memory.

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    Melissa S Monsey

    Full Text Available Chronic exposure to stress has been widely implicated in the development of anxiety disorders, yet relatively little is known about the long-term effects of chronic stress on amygdala-dependent memory formation. Here, we examined the effects of a history of chronic exposure to the stress-associated adrenal steroid corticosterone (CORT on the consolidation of a fear memory and the expression of memory-related immediate early genes (IEGs in the lateral nucleus of the amygdala (LA. Rats received chronic exposure to CORT (50 μg/ml in their drinking water for 2 weeks and were then titrated off the CORT for an additional 6 days followed by a 2 week 'wash-out' period consisting of access to plain water. Rats were then either sacrificed to examine the expression of memory-related IEG expression in the LA or given auditory Pavlovian fear conditioning. We show that chronic exposure to CORT leads to a persistent elevation in the expression of the IEGs Arc/Arg3.1 and Egr-1 in the LA. Further, we show that rats with a history of chronic CORT exposure exhibit enhanced consolidation of a fear memory; short-term memory (STM is not affected, while long-term memory (LTM is significantly enhanced. Treatment with the selective serotonin reuptake inhibitor (SSRI fluoxetine following the chronic CORT exposure period was observed to effectively reverse both the persistent CORT-related increases in memory-related IEG expression in the LA and the CORT-related enhancement in fear memory consolidation. Our findings suggest that chronic exposure to CORT can regulate memory-related IEG expression and fear memory consolidation processes in the LA in a long-lasting manner and that treatment with fluoxetine can reverse these effects.

  15. Chronic corticosterone exposure persistently elevates the expression of memory-related genes in the lateral amygdala and enhances the consolidation of a Pavlovian fear memory.

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    Monsey, Melissa S; Boyle, Lara M; Zhang, Melinda L; Nguyen, Caroline P; Kronman, Hope G; Ota, Kristie T; Duman, Ronald S; Taylor, Jane R; Schafe, Glenn E

    2014-01-01

    Chronic exposure to stress has been widely implicated in the development of anxiety disorders, yet relatively little is known about the long-term effects of chronic stress on amygdala-dependent memory formation. Here, we examined the effects of a history of chronic exposure to the stress-associated adrenal steroid corticosterone (CORT) on the consolidation of a fear memory and the expression of memory-related immediate early genes (IEGs) in the lateral nucleus of the amygdala (LA). Rats received chronic exposure to CORT (50 μg/ml) in their drinking water for 2 weeks and were then titrated off the CORT for an additional 6 days followed by a 2 week 'wash-out' period consisting of access to plain water. Rats were then either sacrificed to examine the expression of memory-related IEG expression in the LA or given auditory Pavlovian fear conditioning. We show that chronic exposure to CORT leads to a persistent elevation in the expression of the IEGs Arc/Arg3.1 and Egr-1 in the LA. Further, we show that rats with a history of chronic CORT exposure exhibit enhanced consolidation of a fear memory; short-term memory (STM) is not affected, while long-term memory (LTM) is significantly enhanced. Treatment with the selective serotonin reuptake inhibitor (SSRI) fluoxetine following the chronic CORT exposure period was observed to effectively reverse both the persistent CORT-related increases in memory-related IEG expression in the LA and the CORT-related enhancement in fear memory consolidation. Our findings suggest that chronic exposure to CORT can regulate memory-related IEG expression and fear memory consolidation processes in the LA in a long-lasting manner and that treatment with fluoxetine can reverse these effects.

  16. Dietary fat and corticosterone levels are contributing factors to meal anticipation.

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    Namvar, Sara; Gyte, Amy; Denn, Mark; Leighton, Brendan; Piggins, Hugh D

    2016-04-15

    Daily restricted access to food leads to the development of food anticipatory activity and metabolism, which depends upon an as yet unidentified food-entrainable oscillator(s). A premeal anticipatory peak in circulating hormones, including corticosterone is also elicited by daily restricted feeding. High-fat feeding is associated with elevated levels of corticosterone with disrupted circadian rhythms and a failure to develop robust meal anticipation. It is not clear whether the disrupted corticosterone rhythm, resulting from high-fat feeding contributes to attenuated meal anticipation in high-fat fed rats. Our aim was to better characterize meal anticipation in rats fed a low- or high-fat diet, and to better understand the role of corticosterone in this process. To this end, we utilized behavioral observations, hypothalamic c-Fos expression, and indirect calorimetry to assess meal entrainment. We also used the glucocorticoid receptor antagonist, RU486, to dissect out the role of corticosterone in meal anticipation in rats given daily access to a meal with different fat content. Restricted access to a low-fat diet led to robust meal anticipation, as well as entrainment of hypothalamic c-Fos expression, metabolism, and circulating corticosterone. These measures were significantly attenuated in response to a high-fat diet, and animals on this diet exhibited a postanticipatory rise in corticosterone. Interestingly, antagonism of glucocorticoid activity using RU486 attenuated meal anticipation in low-fat fed rats, but promoted meal anticipation in high-fat-fed rats. These findings suggest an important role for corticosterone in the regulation of meal anticipation in a manner dependent upon dietary fat content. Copyright © 2016 the American Physiological Society.

  17. Corticosterone predicts foraging behavior and parental care in macaroni penguins.

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    Crossin, Glenn T; Trathan, Phil N; Phillips, Richard A; Gorman, Kristen B; Dawson, Alistair; Sakamoto, Kentaro Q; Williams, Tony D

    2012-07-01

    Corticosterone has received considerable attention as the principal hormonal mediator of allostasis or physiological stress in wild animals. More recently, it has also been implicated in the regulation of parental care in breeding birds, particularly with respect to individual variation in foraging behavior and provisioning effort. There is also evidence that prolactin can work either inversely or additively with corticosterone to achieve this. Here we test the hypothesis that endogenous corticosterone plays a key physiological role in the control of foraging behavior and parental care, using a combination of exogenous corticosterone treatment, time-depth telemetry, and physiological sampling of female macaroni penguins (Eudyptes chrysolophus) during the brood-guard period of chick rearing, while simultaneously monitoring patterns of prolactin secretion. Plasma corticosterone levels were significantly higher in females given exogenous implants relative to those receiving sham implants. Increased corticosterone levels were associated with significantly higher levels of foraging and diving activity and greater mass gain in implanted females. Elevated plasma corticosterone was also associated with an apparent fitness benefit in the form of increased chick mass. Plasma prolactin levels did not correlate with corticosterone levels at any time, nor was prolactin correlated with any measure of foraging behavior or parental care. Our results provide support for the corticosterone-adaptation hypothesis, which predicts that higher corticosterone levels support increased foraging activity and parental effort.

  18. Assessment of testicular corticosterone biosynthesis in adult male rats.

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    Naoyuki Maeda

    Full Text Available Corticosterone is synthesized in the adrenal glands and is circulated throughout the body to perform regulatory functions in various tissues. The testis is known to synthesize and secrete testosterone and other androgens. We developed an accurate method to measure steroid content using liquid chromatography-mass spectrometry analysis. In the present study, significant levels of the precursor compounds of testosterone and corticosterone synthesis could be detected in rat testis using this method. After adrenalectomy, corticosterone remained in the blood and testicular tissue at approximately 1% of the amount present in the control testis. When the excised testicular tissue was washed and incubated with NADH, NADPH and progesterone, not only testosterone and its precursors but also 11-deoxycorticosterone and corticosterone were produced; the levels of 11-deoxycorticosterone and corticosterone increased with incubation time. The production rate of 11-deoxycorticosterone from progesterone was estimated to be approximately 1/20 that of 17-hydroxyprogesterone, and the corticosterone level was approximately 1/10 that of testosterone. These ratios coincided with those in the testicular tissue of the adrenalectomized rats, indicating that corticosterone was synthesized in the testis and not in the blood. A primary finding of this study was that corticosterone and testosterone were synthesized in a 1/10-20 ratio in the testis. It is concluded that corticosterone, which has various functions, such as the regulation of glycolysis and mediating spermatogenesis, is produced locally in the testis and that this the local production is convenient and functional to respond to local needs.

  19. Repeated thermal stressor causes chronic elevation of baseline corticosterone and suppresses the physiological endocrine sensitivity to acute stressor in the cane toad (Rhinella marina).

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    Narayan, Edward J; Hero, Jean-Marc

    2014-04-01

    Extreme environmental temperature could impact the physiology and ecology of animals. The stress endocrine axis provides necessary physiological stress response to acute (day-day) stressors. Presently, there are no empirical evidences showing that exposure to extreme thermal stressor could cause chronic stress in amphibians. This could also modulate the physiological endocrine sensitivity to acute stressors and have serious implications for stress coping in amphibians, particularly those living in fragmented and disease prone environments. We addressed this important question using the cane toad (Rhinella marina) model from its introduced range in Queensland, Australia. We quantified their physiological endocrine sensitivity to a standard acute (capture and handling) stressor after exposing the cane toads to thermal shock at 35°C for 30min daily for 34 days. Corticosterone (CORT) responses to the capture and handling protocol were measured on three sampling intervals (days 14, 24, and 34) to determine whether the physiological endocrine sensitivity was maintained or modulated over-time. Two control groups (C1 for baseline CORT measurement only and C2 acute handled only) and two temperature treatment groups (T1 received daily thermal shock up to day 14 only and a recovery phase of 20 days and T2 received thermal shock daily for 34 days). Results showed that baseline CORT levels remained high on day 14 (combined effect of capture, captivity and thermal stress) for both T1 and T2. Furthermore, baseline CORT levels decreased for T1 once the thermal shock was removed after day 14 and returned to baseline by day 29. On the contrary, baseline CORT levels kept on increasing for T2 over the 34 days of daily thermal shocks. Furthermore, the magnitudes of the acute CORT responses or physiological endocrine sensitivity were consistently high for both C1 and T1. However, acute CORT responses for T2 toads were dramatically reduced between days 24 and 34. These novel findings

  20. Fecal corticosterone reflects serum corticosterone in Florida sandhill cranes.

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    Ludders, J W; Langenberg, J A; Czekala, N M; Erb, H N

    2001-07-01

    Florida sandhill cranes (Grus canadensis pratensis) were conditioned to confinement 6 hr/day for 7 days. On day 8, each bird's jugular vein was catheterized, blood samples were drawn, and each crane was confined for 6 hr. Using a randomized, restricted cross-over design, cranes were injected intravenously with either 0.9% NaCl solution or ACTH (cosyntropin; Cortrosyn; 0.25 mg). During the 6 hr of confinement, fecal samples (feces and urine) were collected from each of five cranes immediately after defecation. Individual fecal samples were collected approximately at hourly intervals and assayed for corticosterone. We showed previously that serum corticosterone did not vary significantly following saline injection, but peaked significantly 60 min after ACTH injection. Maximal fecal corticosterone concentrations (ng/g) were greater (P cranes under controlled conditions, fecal corticosterone concentration reflects serum corticosterone levels, fecal corticosterone, Grus canadensis pratensis, sandhill cranes, serum corticosterone levels.

  1. Feather corticosterone reveals developmental stress in seabirds.

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    Will, Alexis P; Suzuki, Yuya; Elliott, Kyle H; Hatch, Scott A; Watanuki, Yutaka; Kitaysky, Alexander S

    2014-07-01

    In nest-bound avian offspring, food shortages typically trigger a release of the stress hormone corticosterone (CORT). Recent studies indicate that CORT is passively deposited in the tissue of growing feathers and thus may provide an integrated measure of stress incurred during development in the nest. The current hypothesis predicts that, assuming a constant rate of feather growth, elevated CORT circulating in the blood corresponds to higher levels of CORT in feather tissue, but experimental evidence for nutritionally stressed chicks is lacking. Here, we examined how food limitation affects feather CORT content in the rhinoceros auklet (Cerorhinca moncerata). We (i) used captive chicks reared on control versus restricted diets, and (ii) applied this technique to free-living chicks with unknown nutritional histories that fledged at three separate colonies. We found that (i) feather growth was not affected by experimentally induced nutritional stress; (ii) captive chicks raised on a restricted diet had higher levels of CORT in their primary feathers; (iii) feather CORT deposition is a sensitive method of detecting nutritional stress; and (iv) free-living fledglings from the colony with poor reproductive performance had higher CORT in their primary feathers. We conclude that feather CORT is a sensitive integrated measure revealing the temporal dynamics of food limitations experienced by rhinoceros auklet nestlings. The use of feather CORT may be a powerful endocrine tool in ecological and evolutionary studies of bird species with similar preferential allocation of limited resources to feather development. © 2014. Published by The Company of Biologists Ltd.

  2. The metabolic clearance rate of corticosterone in lean and obese male Zucker rats

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    White, B.D.; Corll, C.B.; Porter, J.R.

    1989-01-01

    The obese Zucker rat is an animal model of human juvenile-onset obesity. These rats exhibit numerous endocrine and metabolic abnormalities. Adrenalectomy of obese rats has been shown to reduce or reverse several of these abnormalities, thereby implying that corticosterone may contribute to the expression of obesity in this animal. Furthermore, it has been shown that the circadian rhythm of plasma corticosterone is disturbed in obese Zucker rats resulting in elevated morning plasma corticosterone concentrations in obese rats as compared to lean rats. In a effort to better elucidate the mechanism of the elevated morning levels of plasma corticosterone, the metabolic clearance rate of corticosterone was determined in the morning for lean and obese male Zucker rats (12 to 20 weeks). Additionally, the biliary and urinary excretion of labeled corticosterone and/or its metabolites were determined. The metabolic clearance rate of corticosterone was significantly greater in obese rats than in their lean counterparts. Both the metabolic clearance rate and the volume of compartments significantly correlated with body weight. No correlation was found between body weight and the elimination rate constant. The increased metabolic clearance rate of obese rats appeared to be due to an increase in the physiologic distribution of corticosterone and not to an alteration in the enzymes responsible for corticosterone metabolism. It appears that the metabolic clearance rate of corticosterone in obese Zucker rats does not contribute to elevated morning concentrations of plasma corticosterone previously observed in these animals. It suggests that the adrenal corticosterone secretion rate must actually be greater than one would expect from the plasma corticosterone concentrations alone

  3. Protecting embryos from stress: Corticosterone effects and the corticosterone response to capture and confinement during pregnancy in a live-bearing lizard (Hoplodactylus maculatus)

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    Cree, A.; Tyrrell, C.L.; Preest, M.R.; Thorburn, D.; Guillette, L.J.

    2003-01-01

    Hormones in the embryonic environment, including those of the hypothalamo-pituitary-adrenal (HPA) axis, have profound effects on development in eutherian mammals. However, little is known about their effects in reptiles that have independently evolved viviparity. We investigated whether exogenous corticosterone affected embryonic development in the viviparous gecko Hoplodactylus maculatus, and whether pregnant geckos have a corticosterone response to capture and confinement that is suppressed relative to that in non-pregnant (vitellogenic) females and males. Corticosterone implants (5 mg, slow-release) administered to females in mid-pregnancy caused a large elevation of corticosterone in maternal plasma (P<0.001), probable reductions in embryonic growth and development (P=0.069-0.073), developmental abnormalities and eventual abortions. Cool temperature produced similar reductions in embryonic growth and development (P???0.036 cf. warm controls), but pregnancies were eventually successful. Despite the potentially harmful effects of elevated plasma corticosterone, pregnant females did not suppress their corticosterone response to capture and confinement relative to vitellogenic females, and both groups of females had higher responses than males. Future research should address whether lower maternal doses of corticosterone produce non-lethal effects on development that could contribute to phenotypic plasticity. Corticosterone implants also led to increased basking in pregnant females (P<0.001), and basal corticosterone in wild geckos (independent of reproductive condition) was positively correlated with body temperature (P<0.001). Interactions between temperature and corticosterone may have broad significance to other terrestrial ectotherms, and body temperature should be considered as a variable influencing plasma corticosterone concentrations in all future studies on reptiles. ?? 2003 Elsevier Inc. All rights reserved.

  4. Physiological actions of corticosterone and its modulation by an immune challenge in reptiles.

    Science.gov (United States)

    Meylan, Sandrine; Haussy, Claudy; Voituron, Yann

    2010-11-01

    Hormones are an important interface between genome and environment, because of their ability to modulate the animal's phenotype. In particular, corticosterone, the stress hormone in lizards, is known to reallocate energy from non-essential functions to affect morphological, physiological and behavioral traits that help the organism to deal with acute or chronic stressors. However, the effects of corticosterone on life history stages are still unclear primarily because of the dependence of life history stages on both internal and external factors. Using a cross-design, we tested the effect of elevated levels of exogenous corticosterone on the physiology of pregnant females in different immune contexts in a wild population of common lizards (Lacerta vivipara). Immune challenge was induced by the injection of sheep red blood cells (SRBC) and corticosterone levels were increased using a transdermal administration of corticosterone. Thereafter, reproductive traits, metabolism and cellular immune responses were measured. The elevation of corticosterone in pregnant females significantly altered reproductive and physiological performance. The corticosterone treatment decreased clutch success, juvenile size and body condition, but enhanced measures of physiological performance, such as metabolism and catalase activity. These first results reinforce the understanding of the physiological actions of corticosterone in reptiles. The data also demonstrated different direct impacts of immune challenge by SRBC on inflammatory response and antioxidant activity. The injection of SRBC stimulated the SOD activity in larger females. Finally, we demonstrated experimentally the modulation of the corticosterone action by the immune challenge on stamina and hatching date. Copyright © 2010 Elsevier Inc. All rights reserved.

  5. Elevated carbon dioxide and ozone alter productivity and ecosystem carbon content in northern temperate forests

    Science.gov (United States)

    Talhelm, Alan F; Pregitzer, Kurt S; Kubiske, Mark E; Zak, Donald R; Campany, Courtney E; Burton, Andrew J; Dickson, Richard E; Hendrey, George R; Isebrands, J G; Lewin, Keith F; Nagy, John; Karnosky, David F

    2014-01-01

    Three young northern temperate forest communities in the north-central United States were exposed to factorial combinations of elevated carbon dioxide (CO2) and tropospheric ozone (O3) for 11 years. Here, we report results from an extensive sampling of plant biomass and soil conducted at the conclusion of the experiment that enabled us to estimate ecosystem carbon (C) content and cumulative net primary productivity (NPP). Elevated CO2 enhanced ecosystem C content by 11%, whereas elevated O3 decreased ecosystem C content by 9%. There was little variation in treatment effects on C content across communities and no meaningful interactions between CO2 and O3. Treatment effects on ecosystem C content resulted primarily from changes in the near-surface mineral soil and tree C, particularly differences in woody tissues. Excluding the mineral soil, cumulative NPP was a strong predictor of ecosystem C content (r2 = 0.96). Elevated CO2 enhanced cumulative NPP by 39%, a consequence of a 28% increase in canopy nitrogen (N) content (g N m−2) and a 28% increase in N productivity (NPP/canopy N). In contrast, elevated O3 lowered NPP by 10% because of a 21% decrease in canopy N, but did not impact N productivity. Consequently, as the marginal impact of canopy N on NPP (ΔNPP/ΔN) decreased through time with further canopy development, the O3 effect on NPP dissipated. Within the mineral soil, there was less C in the top 0.1 m of soil under elevated O3 and less soil C from 0.1 to 0.2 m in depth under elevated CO2. Overall, these results suggest that elevated CO2 may create a sustained increase in NPP, whereas the long-term effect of elevated O3 on NPP will be smaller than expected. However, changes in soil C are not well-understood and limit our ability to predict changes in ecosystem C content. PMID:24604779

  6. Elevated carbon dioxide and ozone alter productivity and ecosystem carbon content in northern temperate forests.

    Science.gov (United States)

    Talhelm, Alan F; Pregitzer, Kurt S; Kubiske, Mark E; Zak, Donald R; Campany, Courtney E; Burton, Andrew J; Dickson, Richard E; Hendrey, George R; Isebrands, J G; Lewin, Keith F; Nagy, John; Karnosky, David F

    2014-08-01

    Three young northern temperate forest communities in the north-central United States were exposed to factorial combinations of elevated carbon dioxide (CO2 ) and tropospheric ozone (O3 ) for 11 years. Here, we report results from an extensive sampling of plant biomass and soil conducted at the conclusion of the experiment that enabled us to estimate ecosystem carbon (C) content and cumulative net primary productivity (NPP). Elevated CO2 enhanced ecosystem C content by 11%, whereas elevated O3 decreased ecosystem C content by 9%. There was little variation in treatment effects on C content across communities and no meaningful interactions between CO2 and O3 . Treatment effects on ecosystem C content resulted primarily from changes in the near-surface mineral soil and tree C, particularly differences in woody tissues. Excluding the mineral soil, cumulative NPP was a strong predictor of ecosystem C content (r(2) = 0.96). Elevated CO2 enhanced cumulative NPP by 39%, a consequence of a 28% increase in canopy nitrogen (N) content (g N m(-2) ) and a 28% increase in N productivity (NPP/canopy N). In contrast, elevated O3 lowered NPP by 10% because of a 21% decrease in canopy N, but did not impact N productivity. Consequently, as the marginal impact of canopy N on NPP (∆NPP/∆N) decreased through time with further canopy development, the O3 effect on NPP dissipated. Within the mineral soil, there was less C in the top 0.1 m of soil under elevated O3 and less soil C from 0.1 to 0.2 m in depth under elevated CO2 . Overall, these results suggest that elevated CO2 may create a sustained increase in NPP, whereas the long-term effect of elevated O3 on NPP will be smaller than expected. However, changes in soil C are not well-understood and limit our ability to predict changes in ecosystem C content. © 2014 The Authors Global Change Biology Published by John Wiley & Sons Ltd.

  7. Effect of Corticosterone and Hen Body Mass on Primary Sex Ratio in Laying Hen (Gallusgallus), Using Unincubated Eggs1

    NARCIS (Netherlands)

    Aslam, M.A.; Groothuis, T.G.G.; Smits, M.A.; Woelders, H.

    2014-01-01

    In various studies, chronic elevation of corticosterone levels in female birds under natural or experimental conditions resulted in female biased offspring sex ratios. In chicken, one study with injected corticosterone resulted in a male sex ratio bias. In the current study, we chronically elevated

  8. Effect of corticosterone and hen body mass on primary sex ratio in laying hen (Gallus gallus), using unincubated eggs

    NARCIS (Netherlands)

    Aslam, Muhammad Aamir; Groothuis, Ton G. G.; Smits, Mari A.; Woelders, Henri

    In various studies, chronic elevation of corticosterone levels in female birds under natural or experimental conditions resulted in female biased offspring sex ratios. In chicken, one study with injected corticosterone resulted in a male sex ratio bias. In the current study, we chronically elevated

  9. Equilibrium moisture content of radiata pine at elevated temperature and pressure reveals measurement challenges

    DEFF Research Database (Denmark)

    Pearson, Hamish; Gabbitas, Brian; Ormarsson, Sigurdur

    2012-01-01

    moisture contents were attributed to condensation of liquid water on the specimen with subsequent evaporation at a rate that was too slow for the moisture content to reach equilibrium before it was measured. Reliable EMC data at elevated temperatures require (1) tight process control of experimental......Relatively few studies have been performed on the equilibrium moisture content (EMC) of wood under conditions of elevated temperature and pressure. Eight studies indicated that EMC near saturation decreased between 100 and 150 °C, whilst five studies indicated that EMC increased. The aim...... of this study was to identify the likely source of the disagreement using radiata pine (Pinus radiata D. Don) sapwood which was conditioned to a moisture content of around 3 % and then exposed for 1 h at 150 °C and relative humidities of either 50, 70 or 90 %. Mean values of EMC, obtained through in situ...

  10. Pavlovian autoshaping procedures increase plasma corticosterone levels in rats.

    Science.gov (United States)

    Tomie, Arthur; Silberman, Yuval; Williams, Kayon; Pohorecky, Larissa A

    2002-06-01

    Pavlovian autoshaping conditioned responses (CRs) are complex sequences of conditioned stimulus (CS)-directed skeletal-motor responses that are elicited by CS objects predictive of food unconditioned stimulus (US). Autoshaping CRs are observed under conditions known to be conducive to elevations in plasma corticosterone levels, as, for example, in response to the eating of food as well as in response to signals predictive of food. Two experiments investigated the relationships between Pavlovian autoshaping procedures, the performance of Pavlovian autoshaping CRs, and plasma corticosterone levels in male Long-Evans rats. In Experiment 1, rats in the CS-US paired group (n=30) were given 20 daily sessions of Pavlovian autoshaping training wherein the insertion of a retractable lever CS was followed by the response-independent presentation of the food US. Tail blood samples obtained after the 20th autoshaping session revealed higher plasma corticosterone levels in the CS-US paired group than in the CS-US random control group (n=10). In Experiment 2, rats (n=35) were assessed for basal plasma corticosterone levels 2 weeks prior to autoshaping training. Plasma samples obtained immediately following the first autoshaping session, and prior to the acquisition of lever-press autoshaping CR performance, revealed higher plasma corticosterone levels in the CS-US paired group (n=24) relative to basal levels. This effect was not observed in the CS-US random control group (n=11). Data suggest that corticosterone release is a physiological endocrine Pavlovian CR induced by lever CS-food US pairings during Pavlovian autoshaping procedures, rather than a by-product of autoshaping CR performance. Implications of the link between autoshaping procedures and corticosterone release are discussed.

  11. Method for Measuring the Information Content of Terrain from Digital Elevation Models

    Directory of Open Access Journals (Sweden)

    Lujin Hu

    2015-10-01

    Full Text Available As digital terrain models are indispensable for visualizing and modeling geographic processes, terrain information content is useful for terrain generalization and representation. For terrain generalization, if the terrain information is considered, the generalized terrain may be of higher fidelity. In other words, the richer the terrain information at the terrain surface, the smaller the degree of terrain simplification. Terrain information content is also important for evaluating the quality of the rendered terrain, e.g., the rendered web terrain tile service in Google Maps (Google Inc., Mountain View, CA, USA. However, a unified definition and measures for terrain information content have not been established. Therefore, in this paper, a definition and measures for terrain information content from Digital Elevation Model (DEM, i.e., a digital model or 3D representation of a terrain’s surface data are proposed and are based on the theory of map information content, remote sensing image information content and other geospatial information content. The information entropy was taken as the information measuring method for the terrain information content. Two experiments were carried out to verify the measurement methods of the terrain information content. One is the analysis of terrain information content in different geomorphic types, and the results showed that the more complex the geomorphic type, the richer the terrain information content. The other is the analysis of terrain information content with different resolutions, and the results showed that the finer the resolution, the richer the terrain information. Both experiments verified the reliability of the measurements of the terrain information content proposed in this paper.

  12. Corticosterone and foraging behavior in a diving seabird: the Adélie penguin, Pygoscelis adeliae.

    Science.gov (United States)

    Angelier, Frédéric; Bost, Charles-André; Giraudeau, Mathieu; Bouteloup, Guillaume; Dano, Stéphanie; Chastel, Olivier

    2008-03-01

    Because hormones mediate physiological or behavioral responses to intrinsic or extrinsic stimuli, they can help us understand how animals adapt their foraging decisions to energetic demands of reproduction. Thus, the hormone corticosterone deserves specific attention because of its influence on metabolism, food intake and locomotor activities. We examined the relationships between baseline corticosterone levels and foraging behavior or mass gain at sea in a diving seabird, the Adélie penguin, Pygoscelis adeliae. Data were obtained from free-ranging penguins during the brooding period (Adélie Land, Antarctica) by using satellite transmitters and time-depth-recorders. The birds were weighed and blood sampled before and after a foraging trip (pre-trip and post-trip corticosterone levels, respectively). Penguins with elevated pre-trip corticosterone levels spent less time at sea and stayed closer to the colony than penguins with low pre-trip corticosterone levels. These short trips were associated with a higher foraging effort in terms of diving activity and a lower mass gain at sea than long trips. According to previous studies conducted on seabird species, these results suggest that penguins with elevated pre-trip corticosterone levels might maximize the rate of energy delivery to the chicks at the expense of their body reserves. Moreover, in all birds, corticosterone levels were lower post-foraging than pre-foraging. This decrease could result from either the restoration of body reserves during the foraging trip or from a break in activity at the end of the foraging trip. This study demonstrates for the first time in a diving predator the close relationships linking foraging behavior and baseline corticosterone levels. We suggest that slight elevations in pre-trip corticosterone levels could play a major role in breeding effort by facilitating foraging activity in breeding seabirds.

  13. Corticosterone mitigates the stress response in an animal model of PTSD.

    Science.gov (United States)

    Jia, Min; Smerin, Stanley E; Zhang, Lei; Xing, Guoqiang; Li, Xiaoxia; Benedek, David; Ursano, Robert; Li, He

    2015-01-01

    Activation of glucocorticoid receptor signaling in the stress response to traumatic events has been implicated in the pathogenesis of stress-associated psychiatric disorders such as post-traumatic stress disorder (PTSD). Elevated startle response and hyperarousal are hallmarks of PTSD, and are generally considered to evince fear (DSM V). To further examine the efficacy of corticosterone in treating hyperarousal and elevated fear, the present study utilized a learned helplessness stress model in which rats are restrained and subjected to tail shock for three days. These stressed rats develop a delayed long-lasting exaggeration of the acoustic startle response (ASR) and retarded body weight growth, similar to symptoms of PTSD patients (Myers et al., 2005; Speed et al., 1989). We demonstrate that both pre-stress and post-stress administration of corticosterone (3 mg/kg/day) mitigates a subsequent exaggeration of the ASR measured 14 days after cessation of the stress protocol. Furthermore, the mitigating efficacy of pre-stress administration of corticosterone (3 mg/kg/day for three days) appeared to last significantly longer, up to 21 days after the cessation of the stress protocol, in comparison to that of post-stress administration of corticosterone. However, pre-stress administration of corticosterone at 0.3 mg/kg/day for three days did not mitigate stress-induced exaggeration of the ASR measured at both 14 and 21 days after the cessation of the stress protocol. In addition, pre-stress administration of corticosterone (3 mg/kg/day for three days) mitigates the retardation of body weight growth otherwise resulting from the stress protocol. Congruently, co-administration of the corticosterone antagonist RU486 (40 mg/kg/day for three days) with corticosterone (3 mg/kg/day) prior to stress diminished the mitigating efficacy of the exogenous corticosterone on exaggerated ASR and stress-retarded body weight. The relative efficacy of pre versus post administration of

  14. Elevated Chitin Content Reduces the Susceptibility of Candida Species to Caspofungin

    Science.gov (United States)

    Walker, Louise A.; Gow, Neil A. R.

    2013-01-01

    The echinocandin antifungal drugs inhibit synthesis of the major fungal cell wall polysaccharide β(1,3)-glucan. Echinocandins have good efficacy against Candida albicans but reduced activity against other Candida species, in particular Candida parapsilosis and Candida guilliermondii. Treatment of Candida albicans with a sub-MIC level of caspofungin has been reported to cause a compensatory increase in chitin content and to select for sporadic echinocandin-resistant FKS1 point mutants that also have elevated cell wall chitin. Here we show that elevated chitin in response to caspofungin is a common response in various Candida species. Activation of chitin synthesis was observed in isolates of C. albicans, Candida tropicalis, C. parapsilosis, and C. guilliermondii and in some isolates of Candida krusei in response to caspofungin treatment. However, Candida glabrata isolates demonstrated no exposure-induced change in chitin content. Furthermore, isolates of C. albicans, C. krusei, C. parapsilosis, and C. guilliermondii which were stimulated to have higher chitin levels via activation of the calcineurin and protein kinase C (PKC) signaling pathways had reduced susceptibility to caspofungin. Isolates containing point mutations in the FKS1 gene generally had higher chitin levels and did not demonstrate a further compensatory increase in chitin content in response to caspofungin treatment. These results highlight the potential of increased chitin synthesis as a potential mechanism of tolerance to caspofungin for the major pathogenic Candida species. PMID:23089748

  15. Hot coiled steel strip with elevated niobium content for pipelines and its weldability

    International Nuclear Information System (INIS)

    Brozda, J.; Zeman, M.

    2010-01-01

    Examinations and tests have been performed on thermomechanically rolled and hot coiled 14 mm thick steel strips with a low carbon and elevated niobium content, assigned for the production of pipelines. There were examined basic mechanical properties of the steels, brittle fracture resistance of the parent material and simulated HAZ's, susceptibility to cold cracking as well as properties of MMA and GMA welded joints. It was found that the tested steels are characterized by a good weldability, are not prone to cold cracking, have a low brittle fracture transition temperature and the HAZ of welded joints shows a sufficient high brittle fracture resistance. (authors)

  16. Corticosterone levels predict survival probabilities of Galapagos marine iguanas during El Nino events.

    Science.gov (United States)

    Romero, L M; Wikelski, M

    2001-06-19

    Plasma levels of corticosterone are often used as a measure of "stress" in wild animal populations. However, we lack conclusive evidence that different stress levels reflect different survival probabilities between populations. Galápagos marine iguanas offer an ideal test case because island populations are affected differently by recurring El Niño famine events, and population-level survival can be quantified by counting iguanas locally. We surveyed corticosterone levels in six populations during the 1998 El Niño famine and the 1999 La Niña feast period. Iguanas had higher baseline and handling stress-induced corticosterone concentrations during famine than feast conditions. Corticosterone levels differed between islands and predicted survival through an El Niño period. However, among individuals, baseline corticosterone was only elevated when body condition dropped below a critical threshold. Thus, the population-level corticosterone response was variable but nevertheless predicted overall population health. Our results lend support to the use of corticosterone as a rapid quantitative predictor of survival in wild animal populations.

  17. Isolation and partial characterization of mutants with elevated lipid content in Chlorella sorokiniana and Scenedesmus obliquus.

    Science.gov (United States)

    Vigeolas, Hélène; Duby, Francéline; Kaymak, Esra; Niessen, Guillaume; Motte, Patrick; Franck, Fabrice; Remacle, Claire

    2012-11-30

    This paper describes the isolation and partial biomass characterization of high triacylglycerol (TAG) mutants of Chlorella sorokiniana and Scenedesmus obliquus, two algal species considered as potential source of biodiesel. Following UV mutagenesis, 2000 Chlorella and 2800 Scenedesmus colonies were screened with a method based on Nile Red fluorescence. Several mutants with high Nile Red fluorescence were selected by this high-throughput method in both species. Growth and biomass parameters of the strongest mutants were analyzed in detail. All of the four Chlorella mutants showed no significant changes in growth rate, cell weight, cell size, protein and chlorophyll contents on a per cell basis. Whereas all contained elevated total lipid and TAG content per unit of dry weight, two of them were also affected for starch metabolism, suggesting a change in biomass/storage carbohydrate composition. Two Scenedesmus mutants showed a 1.5 and 2-fold increased cell weight and larger cells compared to the wild type, which led to a general increase of biomass including total lipid and TAG content on a per cell basis. Such mutants could subsequently be used as commercial oleaginous algae and serve as an alternative to conventional petrol. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Does elevated CO2 ameliorate the impact of O3 on chlorophyll content and photosynthesis in potato (Solanum tuberosum)?

    Science.gov (United States)

    Donnelly, Alison; Craigon, Jim; Black, Colin R.; Colls, Jeremy J.; Landon, Geoff

    2001-04-01

    This study examined the impact of season-long exposure to elevated carbon dioxide (CO2) and ozone (O3), individually and in combination, on leaf chlorophyll content and gas exchange characteristics in potato (Solanum tuberosum L. cv. Bintje). Plants grown in open-top chambers were exposed to three CO2 (ambient, 550 and 680 µmol mol-1) and two O3 treatments (ambient and elevated; 25 and 65 nmol mol-1, 8 h day-1 means, respectively) between crop emergence and maturity; plants were also grown in unchambered field plots. Non-destructive measurements of chlorophyll content and visible foliar injury were made for all treatments at 2-week intervals between 43 and 95 days after emergence. Gas exchange measurements were made for all except the intermediate 550 µmol mol-1 CO2 treatment. Season-long exposure to elevated O3 under ambient CO2 reduced chlorophyll content and induced extensive visible foliar damage, but had little effect on net assimilation rate or stomatal conductance. Elevated CO2 had no significant effect on chlorophyll content, but greatly reduced the damaging impact of O3 on chlorophyll content and visible foliar damage. Light-saturated assimilation rates for leaves grown under elevated CO2 were consistently lower when measured under either elevated or ambient CO2 than in equivalent leaves grown under ambient CO2. Analysis of CO2 response curves revealed that CO2-saturated assimilation rate, maximum rates of carboxylation and electron transport and respiration decreased with time. CO2-saturated assimilation rate was reduced by elevated O3 during the early stages of the season, while respiration was significantly greater under elevated CO2 as the crop approached maturity. The physiological origins of these responses and their implications for the performance of potato in a changing climate are discussed.

  19. Parental investment and its sensitivity to corticosterone is linked to melanin-based coloration in barn owls.

    Science.gov (United States)

    Almasi, Bettina; Roulin, Alexandre; Jenni-Eiermann, Susanne; Jenni, Lukas

    2008-06-01

    Behavioral and physiological responses to unpredictable changes in environmental conditions are, in part, mediated by glucocorticoids (corticosterone in birds). In polymorphic species, individuals of the same sex and age display different heritable melanin-based color morphs, associated with physiological and reproductive parameters and possibly alternative strategies to cope with variation in environmental conditions. We examined whether the role of corticosterone in resolving the trade-off between self-maintenance and reproductive activities covaries with the size of melanin-based spots displayed on the ventral body side of male barn owls. Administration of corticosterone to simulate physiological stress in males revealed pronounced changes in their food-provisioning rates to nestlings compared to control males. Corticosterone-treated males with small eumelanic spots reduced nestling provisioning rates as compared to controls, and also to a greater degree than did corticosterone-treated males with large spots. Large-spotted males generally exhibited lower parental provisioning and appear insensitive to exogenous corticosterone suggesting that the size of the black spots on the breast feathers predicts the ability to cope with stressful situations. The reduced provisioning rate of corticosterone-treated males caused a temporary reduction in nestling growth rates but, did not affect fledgling success. This suggests that moderately elevated corticosterone levels are not inhibitory to current reproduction but rather trigger behavioral responses to maximize lifetime reproductive success.

  20. Increased corticosterone in peripubertal rats leads to long-lasting alterations in social exploration and aggression

    Directory of Open Access Journals (Sweden)

    Vandana eVeenit

    2013-04-01

    Full Text Available Stress during childhood and adolescence enhances the risk of psychopathology later in life. We have previously shown that subjecting male rats to stress during the peripubertal period induces long-lasting effects on emotion and social behaviors. As corticosterone is increased by stress and known to exert important programming effects, we reasoned that increasing corticosterone might mimic the effects of peripubertal stress. To this end, we injected corticosterone (5 mg/kg on 7 scattered days during the peripuberty period (P28-P30, P34, P36, P40 and P42, following the same experimental schedule as for stress administration in our peripubertal paradigm. We measured play behavior in the homecage and, at adulthood, the corticosterone response to novelty and behavioral responses in tests for anxiety- and depression-like behaviors, aggression and social exploration. As compared to vehicle, corticosterone-treated animals exhibit more aggressive play behavior during adolescence, increased aggressive behavior in a resident-intruder test while reduced juvenile exploration and corticosterone reactivity at adulthood. Whereas the corticosterone treatment mimicked alterations induced by the peripuberty stress protocol in the social domain, it did not reproduce previously observed effects of peripuberty stress on increasing anxiety-like and depression-like behaviors, respectively evaluated in the elevated plus maze and the forced swim tests. Our findings indicate that increasing corticosterone levels during peripuberty might be instrumental to program alterations in the social domain observed following stress, whereas other factors might need to be recruited for the programming of long-term changes in emotionality. Our study opens the possibility that individual differences on the degree of glucocorticoid activation during peripuberty might be central to defining differences in vulnerability to develop psychopathological disorders coursing with alterations in

  1. What ecological factors can affect albumen corticosterone levels in the clutches of seabirds? Timing of breeding, disturbance and laying order in rockhopper penguins (Eudyptes chrysocome chrysocome).

    Science.gov (United States)

    Poisbleau, M; Demongin, L; Angelier, F; Dano, S; Lacroix, A; Quillfeldt, P

    2009-06-01

    Female birds deposit corticosterone into their eggs. Elevated concentrations of this hormone may interfere with the development of their offspring, and mothers should thus regulate corticosterone levels deposited into the eggs adaptively. However, if females are unable to regulate deposition, then the corticosterone concentration in eggs should reflect that in female plasma and should be influenced by stressors to the females. We measured corticosterone levels in the albumen of rockhopper penguins, and assessed their relationship with hatching order, human disturbance and laying date. Rockhopper penguins (Eudyptes chrysocome chrysocome) lay two eggs, of which the second egg (B-egg) is larger and hatches faster than the first egg (A-egg). The chick hatching from the B-egg is also much more likely to survive than its sibling. Albumen corticosterone concentrations were lower in B-eggs. However, as B-eggs contained more albumen than A-eggs, the total corticosterone deposited in the albumen was not significantly different between the two eggs. Daily disturbance by human observers during albumen production did not influence albumen corticosterone levels. Laying date had an effect on total albumen corticosterone through a higher albumen mass. However, we observed a high individual component in the composition of eggs from the same clutch. Thus, more work is required to explore the hypotheses of passive versus active transfer to eggs and to understand the adaptive value of contrary effects on the amount and concentration of corticosterone.

  2. Corticosterone levels predict survival probabilities of Galápagos marine iguanas during El Niño events

    Science.gov (United States)

    Romero, L. Michael; Wikelski, Martin

    2001-01-01

    Plasma levels of corticosterone are often used as a measure of “stress” in wild animal populations. However, we lack conclusive evidence that different stress levels reflect different survival probabilities between populations. Galápagos marine iguanas offer an ideal test case because island populations are affected differently by recurring El Niño famine events, and population-level survival can be quantified by counting iguanas locally. We surveyed corticosterone levels in six populations during the 1998 El Niño famine and the 1999 La Niña feast period. Iguanas had higher baseline and handling stress-induced corticosterone concentrations during famine than feast conditions. Corticosterone levels differed between islands and predicted survival through an El Niño period. However, among individuals, baseline corticosterone was only elevated when body condition dropped below a critical threshold. Thus, the population-level corticosterone response was variable but nevertheless predicted overall population health. Our results lend support to the use of corticosterone as a rapid quantitative predictor of survival in wild animal populations. PMID:11416210

  3. Comparative genome analysis to identify SNPs associated with high oleic acid and elevated protein content in soybean.

    Science.gov (United States)

    Kulkarni, Krishnanand P; Patil, Gunvant; Valliyodan, Babu; Vuong, Tri D; Shannon, J Grover; Nguyen, Henry T; Lee, Jeong-Dong

    2018-03-01

    The objective of this study was to determine the genetic relationship between the oleic acid and protein content. The genotypes having high oleic acid and elevated protein (HOEP) content were crossed with five elite lines having normal oleic acid and average protein (NOAP) content. The selected accessions were grown at six environments in three different locations and phenotyped for protein, oil, and fatty acid components. The mean protein content of parents, HOEP, and NOAP lines was 34.6%, 38%, and 34.9%, respectively. The oleic acid concentration of parents, HOEP, and NOAP lines was 21.7%, 80.5%, and 20.8%, respectively. The HOEP plants carried both FAD2-1A (S117N) and FAD2-1B (P137R) mutant alleles contributing to the high oleic acid phenotype. Comparative genome analysis using whole-genome resequencing data identified six genes having single nucleotide polymorphism (SNP) significantly associated with the traits analyzed. A single SNP in the putative gene Glyma.10G275800 was associated with the elevated protein content, and palmitic, oleic, and linoleic acids. The genes from the marker intervals of previously identified QTL did not carry SNPs associated with protein content and fatty acid composition in the lines used in this study, indicating that all the genes except Glyma.10G278000 may be the new genes associated with the respective traits.

  4. Serum corticosterone response to adrenocorticotropic hormone stimulation in Florida sandhill cranes.

    Science.gov (United States)

    Ludders, J W; Langenberg, J A; Czekala, N M; Erb, H N; McCormick, H

    1998-10-01

    Florida sandhill cranes (Grus canadensis pratensis) were conditioned to confinement in an enclosure for 7 days, 6 hr a day. On day 8, cranes were catheterized and then confined in an enclosure. Venous blood (2 ml) was collected through the catheter and an attached IV line immediately before (-60 min) and 60 min after (0 min) confinement. Using a randomization table and a restricted cross-over experimental design, cranes were injected intravenously with either saline (control) or adrenocorticotropic hormone (ACTH; cosyntropin, Cortrosyn; 0.25 mg). At 30, 60, 120, 180, 240 and 300 min after injection, blood samples were collected and assayed for corticosterone. The cranes receiving ACTH increased their serum corticosterone concentrations as much as fivefold above baseline concentrations. Serum corticosterone concentrations remained significantly elevated for approximately 60 min after ACTH stimulation. Physical restraint and catheterization caused an increase in serum corticosterone almost comparable to that induced by ACTH stimulation. In cranes injected with saline, serum corticosterone decreased within 1 hr after physical restraint and catheterization, and remained at lower levels throughout the remaining 5 hr of confinement.

  5. Effect of Elevated Atmospheric CO2 and Temperature on Leaf Optical Properties and Chlorophyll Content in Acer saccharum (Marsh.)

    Science.gov (United States)

    Carter, Gregory A.; Bahadur, Raj; Norby, Richard J.

    1999-01-01

    Elevated atmospheric CO2 pressure and numerous causes of plant stress often result in decreased leaf chlorophyll contents and thus would be expected to alter leaf optical properties. Hypotheses that elevated carbon dioxide pressure and air temperature would alter leaf optical properties were tested for sugar maple (Acer saccharum Marsh.) in the middle of its fourth growing season under treatment. The saplings had been growing since 1994 in open-top chambers at Oak Ridge, Tennessee under the following treatments: 1) Ambient CO2 pressure and air temperature (control); 2) CO2 pressure approximately 30 Pa above ambient; 3) Air temperatures 3 C above ambient; 4) Elevated CO2 and air temperature. Spectral reflectance, transmittance, and absorptance in the visible spectrum (400-720 nm) did not change significantly (rho = 0.05) in response to any treatment compared with control values. Although reflectance, transmittance, and absorptance at 700 nm correlated strongly with leaf chlorophyll content, chlorophyll content was not altered significantly by the treatments. The lack of treatment effects on pigmentation explained the non-significant change in optical properties in the visible spectrum. Optical properties in the near-infrared (721-850 nm) were similarly unresponsive to treatment with the exception of an increased absorptance in leaves that developed under elevated air temperature alone. This response could not be explained by the data, but might have resulted from effects of air temperature on leaf internal structure. Results indicated no significant potential for detecting leaf optical responses to elevated CO2 or temperature by the remote sensing of reflected radiation in the 400-850 nm spectrum.

  6. Multi-year longitudinal profiles of cortisol and corticosterone recovered from baleen of North Atlantic right whales (Eubalaena glacialis).

    Science.gov (United States)

    Hunt, Kathleen E; Lysiak, Nadine S; Moore, Michael; Rolland, Rosalind M

    2017-12-01

    Research into stress physiology of mysticete whales has been hampered by difficulty in obtaining repeated physiological samples from individuals over time. We investigated whether multi-year longitudinal records of glucocorticoids can be reconstructed from serial sampling along full-length baleen plates (representing ∼10years of baleen growth), using baleen recovered from two female North Atlantic right whales (Eubalaena glacialis) of known reproductive history. Cortisol and corticosterone were quantified with immunoassay of subsamples taken every 4cm (representing ∼60d time intervals) along a full-length baleen plate from each female. In both whales, corticosterone was significantly elevated during known pregnancies (inferred from calf sightings and necropsy data) as compared to intercalving intervals; cortisol was significantly elevated during pregnancies in one female but not the other. Within intercalving intervals, corticosterone was significantly elevated during the first year (lactation year) and/or the second year (post-lactation year) as compared to later years of the intercalving interval, while cortisol showed more variable patterns. Cortisol occasionally showed brief high elevations ("spikes") not paralleled by corticosterone, suggesting that the two glucocorticoids might be differentially responsive to certain stressors. Generally, immunoreactive corticosterone was present in higher concentration in baleen than immunoreactive cortisol; corticosterone:cortisol ratio was usually >4 and was highly variable in both individuals. Further investigation of baleen cortisol and corticosterone profiles could prove fruitful for elucidating long-term, multi-year patterns in stress physiology of large whales, determined retrospectively from stranded or archived specimens. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Seasonal changes of Rubisco content and activity in Fagus sylvatica and Picea abies affected by elevated CO2 concentration

    Czech Academy of Sciences Publication Activity Database

    Hrstka, M.; Urban, Otmar; Babák, L.

    2012-01-01

    Roč. 66, č. 9 (2012), s. 836-841 ISSN 0366-6352 R&D Projects: GA AV ČR IAA600870701; GA MŠk(CZ) LM2010007; GA MŠk(CZ) ED1.1.00/02.0073 Institutional research plan: CEZ:AV0Z60870520 Keywords : Rubisco content * Rubisco activity * seasonal changes * elevated CO2 concentrations * Fagus sylvatica * Picea abies Subject RIV: EH - Ecology, Behaviour Impact factor: 0.879, year: 2012

  8. Calprotectin in serum and zonulin in serum and feces are elevated after introduction of a diet with lower carbohydrate content and higher fiber, fat and protein contents.

    Science.gov (United States)

    Ohlsson, Bodil; Roth, Bodil; Larsson, Ewa; Höglund, Peter

    2017-04-01

    Calprotectin is a marker of inflammation and zonulin is a marker of intestinal permeability. Diets with lower carbohydrate content and higher contents of fat, fiber and protein, e.g., Okinawan-based diet, are considered to reduce inflammation and intestinal permeability. The aim of the present study was to evaluate calprotectin and zonulin levels in serum and feces after intervention with an Okinawan-based Nordic diet. Thirty patients (17 women) with type 2 diabetes, mean age 57.5±8.2 years, BMI 29.9±4.1 kg/m 2 , were served the diet during 12 weeks, and were followed for another 16 weeks. Anthropometric and metabolic parameters were registered. Fasting levels of calprotectin and zonulin in serum and feces, and hormones in plasma, were measured by Luminex or ELISA before study start and after 12 and 28 weeks. Calprotectin in serum tended to be increased (P=0.074) after 12 weeks. Zonulin in serum and feces were elevated after 12 weeks (P=0.019 vs. Pvs. P=0.079). Energy percentage of protein in breakfast correlated with serum calprotectin (P=0.008) and tended to correlate with serum zonulin (P=0.059). Calprotectin in serum tended to be elevated, and zonulin in serum and feces are elevated after introduction of an Okinawan-based Nordic diet. These biomarkers correlate with energy percentage of protein.

  9. The effect of elevated cadmium content in soil on the uptake of nitrogen by plants

    Energy Technology Data Exchange (ETDEWEB)

    Ciecko, Z.; Kalembasa, S.; Wyszkowski, M.; Rolka, E. [University of Warmia & Mazury Olsztyn, Olsztyn (Poland). Dept. of Environmental Chemistry

    2004-07-01

    The aim of this study was to determine the effect of cadmium (10, 20, 30 and 40 mg Cd/kg of soil) contamination in soil with the application of different substances (compost, brown coal, lime and bentonite) on the intake of nitrogen by some plants. The correlations between the nitrogen content in the plants and the cadmium concentration in the soil, as well as the plant yield and the content of micro- and macroelements in the plants were determined. Plant species and cadmium dose determined the effects of soil contamination with cadmium on the content of nitrogen. Large doses of cadmium caused an increase in nitrogen content in the Avena sativa straw and roots and in the Zea mays roots. Soil contamination with cadmium resulted in a decrease of nitrogen content in the Avena sativa grain, in above-ground parts and roots of the Lupinus luteus, in the above-ground parts of the Zea mays and in the above-ground parts and roots of Phacelia tanacaetifolia. Among the experimental different substances, the application of bentonite had the strongest and a usually negative effect on the nitrogen content in plants. The greatest effect of bentonite was on Avena sativa grain, above-ground parts Zea mays and Lupinus luteus and Phacelia tanacaetifolia. The content of nitrogen in the plants was generally positively correlated with the content of the macroelements and some of the microelements, regardless of the substances added to the soil.

  10. Elevated carbon dioxide and ozone alter productivity and ecosystem carbon content in northern temperate forests

    Science.gov (United States)

    Alan F. Talhelm; Kurt S. Pregitzer; Mark E. Kubiske; Donald R. Zak; Courtney E. Campany; Andrew J. Burton; Richard E. Dickson; George R. Hendrey; J. G. Isebrands; Keith F. Lewin; John Nagy; David F. Karnosky

    2014-01-01

    Three young northern temperate forest communities in the north-central United States were exposed to factorial combinations of elevated carbon dioxide (CO2) and tropospheric ozone (O3) for 11 years. Here, we report results from an extensive sampling of plant biomass and soil conducted at the conclusion of the experiment...

  11. Tensile behaviour of radiata pine with different moisture contents at elevated temperatures

    DEFF Research Database (Denmark)

    Pearson, Hamish; Gabbitas, Brian; Ormarsson, Sigurdur

    2012-01-01

    that moisture and temperature can play a significant role in reducing stress during drying, regardless of the drying time. Properties of wood, such as tensile elastic information at elevated temperatures, are important for mechanical design, distortion modelling and understanding the fundamental behaviour...

  12. 21 CFR 862.1200 - Corticosterone test system.

    Science.gov (United States)

    2010-04-01

    ... to measure corticosterone (a steroid secreted by the adrenal gland) levels in plasma. Measurements of corticosterone are used in the diagnosis and treatment of adrenal disorders such as adrenal cortex disorders and...

  13. Reduction in (/sup 3/H)-corticosterone binding to cytoplasmic receptors in the brain of diabetic rats

    Energy Technology Data Exchange (ETDEWEB)

    Fridman, O; Foglia, V G; de Nicola, A F [Instituto de Biologia y Medicina Experimental, Buenos Aires (Argentina). Lab. de Esteroides

    1978-07-01

    The binding of (1,2,6,7-/sup 3/H)-corticosterone was studied in brain cytosol from normal and streptozotocin-diabetic male rats. The experiments were performed under conditions of incubation time (4h), temperature (0-4/sup 0/C), time after adrenalectomy (6 days) and corticosterone concentrations (1.2 x 10/sup -8/ and 1.15 x 10/sup -9/M) previously established for determining binding activity in the brain of normal rats. The binding of (/sup 3/H)-corticosterone was found invariably lower in cytosol of the brain from diabetic rats, studied under three different conditions in non-adrenalectomized animals, in adrenalectomized using a non-saturating corticosterone concentration, and in adrenalectomized plus a saturating steroid concentration. These results support previous contentions that the diminished sensitivity to the negative feedback for steroids which is present in diabetics, may be related to a reduction in binding capacity for corticoids in the central nervous system.

  14. Corticosterone Concentrations Reflect Parental Expenditure in Contrasting Mating Systems of Two Coucal Species

    Directory of Open Access Journals (Sweden)

    Wolfgang Goymann

    2017-03-01

    Full Text Available The period of parental care can be a demanding life-history stage because parents need to find sufficient resources to feed themselves and their offspring. Often, this is reflected by elevated baseline levels of glucocorticoids—hormones that regulate metabolism and energy allocation. During 10 breeding seasons, we studied plasma corticosterone (the major avian glucocorticoid concentrations as a physiological correlate of parental expenditure in two closely related coucal species with fundamentally different mating systems: the sex-role reversed black coucal (Centropus grillii with female competition and male-only care and the socially monogamous and biparental white-browed coucal (C. superciliosus. The two species live in the same habitat and share a similar breeding biology. However, female black coucals aggressively defend a territory and produce many eggs for their various male partners, and male black coucals feed their offspring much more frequently and rest less often than female and male white-browed coucals. These differences were reflected in baseline and stress-induced concentrations of corticosterone: male black coucals had higher baseline and stress-induced corticosterone concentrations when they were feeding young than outside a feeding context, and also the concentrations of female black coucals were higher during the main period of breeding when they defended territories and produced multiple clutches. In contrast, baseline and stress-induced concentrations of corticosterone in female and male white-browed coucals did not differ between periods when they were feeding young and periods without dependent offspring. Paradoxically, on an individual basis feeding effort was negatively related to baseline corticosterone in male black coucals and female white-browed coucals. In conclusion, corticosterone concentrations of coucals reflected differences in competition and parental roles and support the notion that a switch from

  15. Corticosterone response to gestational stress and postpartum memory function in mice.

    Science.gov (United States)

    Jafari, Zahra; Mehla, Jogender; Afrashteh, Navvab; Kolb, Bryan E; Mohajerani, Majid H

    2017-01-01

    Maternal stress is a common adversity during pregnancy. Gestational corticosterone alternations are thought to contribute to the etiology of postpartum behavioral disturbances. However, the impact of stress during pregnancy, in particular noise exposure, on gestational corticosterone fluctuations and spatial cognition in postpartum mice has not been fully understood yet. We hypothesized that noise exposure during pregnancy negatively affects gestational corticosterone levels and postpartum memory function in the dams similar to the physical stressors. Pregnant C57BL/6 mice were randomly assigned to either one of two stress conditions or a control condition. The noise stress (NS) was induced by presenting a loud intermittent 3000 Hz frequency on gestational days (GDs) 12, 14, and 16 for 24 hours, whereas the physical stress (PS) consisted of restraint and exposure to an elevated platform on GDs 12-16. Plasma corticosterone level was collected on GDs 11 and 17, and Morris water task (MWT) was carried out 30 days after parturition. Compared to the control group, the level of corticosterone in the stressed groups was significantly increased on GD17 relative to GD11. Significantly longer swim time and lower swim speed were observed in both stressed groups relative to the control group. Probe time was significantly shorter in the NS group than the other groups. The delta corticosterone level was significantly correlated with the swim time as well as the probe time in the three groups. Given the results, the adverse effects of gestational noise exposure on the hypothalamic pituitary-adrenal (HPA) axis activation and postpartum spatial learning and memory function were as large as/ or a bit stronger than the physical stresses. The findings suggest the significance of conservation against loud noise exposure in daily living, as well as need to further notice to the different aspects of gestational stress in mothers' behavior like offspring.

  16. Pavlovian autoshaping procedures increase plasma corticosterone and levels of norepinephrine and serotonin in prefrontal cortex in rats.

    Science.gov (United States)

    Tomie, Arthur; Tirado, Aidaluz D; Yu, Lung; Pohorecky, Larissa A

    2004-08-12

    Pavlovian autoshaping procedures provide for pairings of a small object conditioned stimulus (CS) with a rewarding substance unconditioned stimulus (US), resulting in the acquisition of complex sequences of CS-directed skeletal-motor responses or autoshaping conditioned responses (CRs). Autoshaping procedures induce higher post-session levels of corticosterone than in controls receiving CS and US randomly, and the enhanced post-session corticosterone levels have been attributed to the appetitive or arousal-inducing effects of autoshaping procedures. Enhanced corticosterone release can be induced by aversive stimulation or stressful situations, where it is often accompanied by higher levels of norepinephrine (NE) and serotonin (5-HT) in prefrontal cortex (PFC) but not in striatum (ST). Effects of autoshaping procedures on post-session corticosterone levels, NE contents in PFC, and 5-HT contents in PFC and ST were investigated in male Long-Evans rats. Post-session blood samples revealed higher corticosterone levels in the CS-US Paired group (n = 46) than in the CS-US Random control group (n = 21), and brain samples revealed higher levels of PFC NE and 5-HT in CS-US Paired group. Striatal 5-HT levels were unaltered by the autoshaping procedures. Autoshaping procedures provide for appetitive stimulation and induce an arousal-like state, as well as simultaneous stress-like changes in plasma corticosterone and monoamine levels in PFC. Autoshaping, therefore, may be useful for the study of endocrine and central processes associated with appetitive conditions.

  17. Adrenal and plasma corticosterone changes in continuously irradiated rats. I. The dynamics in the course of irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Malatova, Z; Ahlers, I; Praslicka, M [Univerzita P.J. Safarika, Kosice (Czechoslovakia). Katedra Vseobecnej Biologie

    1978-01-01

    Adrenal and plasma corticosterone concentration changes in the course of 25 day continuous irradiation of rats with a daily dose of 15.48x10/sup -3/ C/kg (60 R) of gamma radiation on an open experimental field were followed. The changes were evaluated by a comparison with control rats kept in the same conditions but protected against the radiation effect. The first increase in adrenal corticosterone occurred after one day of irradiation and the maximal increase occurred after 7 days of irradiation. The changes in plasma were insignificant within this period. After 14 days of irradiation the adrenal corticosterone concentration decreased to a minimum during the whole period but it remained increased as against controls. Plasma corticosterone, however, increased to the maximal values within this period. A second peak of elevated adrenal corticosterone concentration was evident after 21 days of irradiation; the plasma values decreased. Corticosterone tended to decrease down to the level of the control group 25 days after irradiation.

  18. Effects of acute temperature change, confinement and housing on plasma corticosterone in water snakes, Nerodia sipedon (Colubridae: Natricinae).

    Science.gov (United States)

    Sykes, Kyle Lea; Klukowski, Matthew

    2009-03-01

    Body temperature affects many aspects of reptilian behavior and physiology, but its effect on hormonal secretion has been little studied, especially in snakes. Major objectives of this study were to determine if acute changes in body temperature during confinement influenced plasma corticosterone levels and if initial body temperatures upon capture in the field were related to baseline corticosterone levels in water snakes (Nerodia sipedon). Water snakes were bled upon capture in the field and after one hour of confinement in a cooled, control, or heated incubator. Since little is known about the potential metabolic changes in response to stress in reptiles, plasma triglyceride levels were also measured. Upon completion of the field study, snakes were housed for 5-8 days without food to determine the effect of chronic stress on both corticosterone and triglyceride levels. Plasma corticosterone concentrations were measured using enzyme-linked immunosorbant assay (ELISA) and plasma triglycerides were determined enzymatically. In the field, experimental alterations of body temperature during confinement had no effect on corticosterone levels. Similarly, there was no correlation between initial body temperature and baseline plasma corticosterone concentrations. However, post-confinement corticosterone levels were approximately three-times greater in females than males. Plasma triglyceride levels were not affected by temperature treatment, confinement, or sex. Compared to field values, both baseline and post-confinement corticosterone levels were elevated after the chronic stress of short-term laboratory housing but triglyceride levels decreased. Overall, these results indicate that sex but not body temperature has a major influence on the adrenocortical stress response in Nerodia sipedon.

  19. Effects of high-intensity interval versus mild-intensity endurance training on metabolic phenotype and corticosterone response in rats fed a high-fat or control diet.

    Science.gov (United States)

    Shen, Youqing; Huang, Guoyuan; McCormick, Bryan P; Song, Tao; Xu, Xiangfeng

    2017-01-01

    The aim of the present study was to compare the effects of high-intensity interval training (HI) to mild-intensity endurance training (ME), combined with a high-fat diet (HFD) or control diet (CD) on metabolic phenotype and corticosterone levels in rats. Fifty-three rats were randomized to 6 groups according to diet and training regimen as follows: CD and sedentary (CS, n = 11), CD and ME (CME, n = 8), CD and HI (CHI, n = 8), HFD and sedentary (HS, n = 10), HFD and ME (HME, n = 8), and HFD and HI (HHI, n = 8). All exercise groups were trained for 10 weeks and had matched running distances. Dietary intake, body composition, blood metabolites, and corticosterone levels were measured. Histological lipid droplets were observed in the livers. The HFD led to hyperglycemia, hyperlipidemia and higher body fat (all, P 0.06), as well as higher corticosterone levels (P training improved fat weight, glucose, and lipid profiles, and reduced corticosterone levels (P body and fat weight, serum glucose and triglycerides, lipid content in the liver, and corticosterone levels (P training compared to ME training. Reductions in HFD-induced body weight gain, blood glucose and lipid profiles, and corticosterone levels, as well as improvements in QUICKI were better with HHI compared to HME. Correlation analyses revealed that corticosterone levels were significantly associated with phenotype variables (P training, HI training contributes to greater improvements in metabolic and corticosterone responses, leading to a greater reduction in susceptibility to HFD-induced disorders.

  20. Quantification of extracellular levels of corticosterone in the basolateral amygdaloid complex of freely-moving rats: a dialysis study of circadian variation and stress-induced modulation.

    Science.gov (United States)

    Bouchez, Gaëlle; Millan, Mark J; Rivet, Jean-Michel; Billiras, Rodolphe; Boulanger, Raphaël; Gobert, Alain

    2012-05-03

    Corticosterone influences emotion and cognition via actions in a diversity of corticolimbic structures, including the amygdala. Since extracellular levels of corticosterone in brain have rarely been studied, we characterized a specific and sensitive enzymatic immunoassay for microdialysis quantification of corticosterone in the basolateral amygdaloid complex of freely-moving rats. Corticosterone levels showed marked diurnal variation with an evening (dark phase) peak and stable, low levels during the day (light phase). The "anxiogenic agents", FG7142 (20 mg/kg) and yohimbine (10 mg/kg), and an environmental stressor, 15-min forced-swim, induced marked and sustained (1-3 h) increases in dialysis levels of corticosterone in basolateral amygdaloid complex. They likewise increased dialysis levels of dopamine and noradrenaline, but not serotonin and GABA. As compared to basal corticosterone levels of ~200-300 pg/ml, the elevation provoked by forced-swim was ca. 20-fold and this increase was abolished by adrenalectomy. Interestingly, stress-induced rises of corticosterone levels in basolateral amygdaloid complex were abrogated by combined but not separate administration of the corticotrophin releasing factor(1) (CRF(1)) receptor antagonist, CP154,526, and the vasopressin(1b) (V(1b)) receptor antagonist, SSR149,415. Underpinning their specificity, they did not block forced-swim-induced elevations in dopamine and noradrenaline. In conclusion, extracellular levels of corticosterone in the basolateral amygdaloid complex display marked diurnal variation. Further, they are markedly elevated by acute stressors, the effects of which are mediated (in contrast to concomitant elevations in levels of monoamines) by co-joint recruitment of CRF(1) and V(1b) receptors. Copyright © 2012 Elsevier B.V. All rights reserved.

  1. Effects of high-intensity interval versus mild-intensity endurance training on metabolic phenotype and corticosterone response in rats fed a high-fat or control diet.

    Directory of Open Access Journals (Sweden)

    Youqing Shen

    Full Text Available The aim of the present study was to compare the effects of high-intensity interval training (HI to mild-intensity endurance training (ME, combined with a high-fat diet (HFD or control diet (CD on metabolic phenotype and corticosterone levels in rats. Fifty-three rats were randomized to 6 groups according to diet and training regimen as follows: CD and sedentary (CS, n = 11, CD and ME (CME, n = 8, CD and HI (CHI, n = 8, HFD and sedentary (HS, n = 10, HFD and ME (HME, n = 8, and HFD and HI (HHI, n = 8. All exercise groups were trained for 10 weeks and had matched running distances. Dietary intake, body composition, blood metabolites, and corticosterone levels were measured. Histological lipid droplets were observed in the livers. The HFD led to hyperglycemia, hyperlipidemia and higher body fat (all, P 0.06, as well as higher corticosterone levels (P < 0.01, η2 = 0.09 compared with the CD groups. Exercise training improved fat weight, glucose, and lipid profiles, and reduced corticosterone levels (P < 0.01, η2 = 0.123. Furthermore, body and fat weight, serum glucose and triglycerides, lipid content in the liver, and corticosterone levels (P < 0.05 were lower with HI training compared to ME training. Reductions in HFD-induced body weight gain, blood glucose and lipid profiles, and corticosterone levels, as well as improvements in QUICKI were better with HHI compared to HME. Correlation analyses revealed that corticosterone levels were significantly associated with phenotype variables (P < 0.01. Corticosterone level was inversely correlated with QUICKI (r = -0.38, P < 0.01. Altogether, these results indicate that HFD may elicit an exacerbated basal serum corticosterone level and thus producing a metabolic imbalance. Compared with ME training, HI training contributes to greater improvements in metabolic and corticosterone responses, leading to a greater reduction in susceptibility to HFD-induced disorders.

  2. Neuroendocrine stress reactivity of male C57BL/6N mice following chronic oral corticosterone exposure during adulthood or adolescence.

    Science.gov (United States)

    Shahanoor, Ziasmin; Sultana, Razia; Baker, Madelyn R; Romeo, Russell D

    2017-12-01

    Adolescence is associated with the maturation of the hypothalamic-pituitary-adrenal (HPA) axis, the major neuroendocrine axis mediating the hormonal stress response. Adolescence is also a period in development marked by a variety of stress-related vulnerabilities, including psychological and physiological dysfunctions. Many of these vulnerabilities are accompanied by a disrupted HPA axis. In adult mice, a model of disrupted HPA function has been developed using oral chronic corticosterone administration via the drinking water, which results in various physiological and neurobehavioral abnormalities, including changes in stress reactivity and anxiety-like behaviors. In an effort to further complement and extend this model, we tested the impact of HPA disruption in adolescent mice. We also examined whether this disruption led to different outcomes depending on whether the treatment happened during adolescence or adulthood. In the current set of experiments, we exposed adult (70days of age) or adolescent (30days of age) male C57BL/6N mice to 4 weeks of either 0 or 25μg/ml oral corticosterone via their drinking water. We measured body weight during treatment and plasma corticosterone levels and activation of the paraventricular nucleus (PVN), as indexed by FOS immunohistochemistry, before and after a 30min session of restraint stress. Our data indicate that adolescent animals exposed to chronic corticosterone showed weight loss during treatment, an effect not observed in adults. Further, we found stress failed to elevate plasma corticosterone levels in treated mice, regardless of whether exposure occurred in adulthood or adolescence. Despite this reduced hormonal responsiveness, we found significant neural activation in the PVN of both adult- and adolescent-treated mice, indicating a dissociation between stress-induced peripheral and central stress responses following chronic corticosterone exposure. Moreover, stress-induced neural activation in the PVN was unaffected

  3. Blood corticosterone concentration reaches critical illness levels early during acute malnutrition in the weanling mouse.

    Science.gov (United States)

    Monk, Jennifer M; Makinen, Kimberley; Shrum, Bradly; Woodward, Bill

    2006-03-01

    Acute (i.e., wasting) pediatric malnutrition consistently elevates blood glucocorticoid levels, but neither the magnitude of the rise in concentration nor its kinetics is clear. Male and female C57BL/6J mice, initially 19 days old, and CBA/J mice, initially 23 days old, consumed a complete purified diet either ad libitum (age-matched control) or in restricted daily quantities (mimicking marasmus), or they consumed a purified isocaloric low-protein diet ad libitum (mimicking incipient kwashiorkor). Serum levels of corticosterone were assessed by double antibody radioimmunoassay after 3, 6, and 14 days (C57BL/6J strain) or after 6 and 14 days in the genetically distant CBA/J strain. Age-matched control groups of both strains exhibited mean corticosterone levels of 5-30 ng/ml, whereas the acutely malnourished groups exhibited mean levels of this hormone that were elevated by more than an order of magnitude as early as 3 days after initiation of weight loss. This outcome was confirmed in a second experiment in which the serum corticosterone level of C57BL/6J weanlings was examined by competitive binding enzyme immunoassay 3 and 14 days after initiation of the dietary protocols. Therefore, deficits of protein and/or energy in weanling murine systems relevant to acute pediatric malnutrition elicit early elevations in blood glucocorticoid levels to a magnitude reminiscent of critical illness and multiple trauma. The key to this novel finding was an exsanguination method that permitted accurate assessment of the blood corticosterone level of the healthy, quiescent mouse. Overall, the results of this investigation provide a new perspective on the glucocorticoids as part of the early hormonal response to acute weanling malnutrition coincident with the shift toward catabolic metabolism and the initiation of depression in cellular immune competence.

  4. A novel wheat variety with elevated content of amylose increases resistant starch formation and may beneficially influence glycaemia in healthy subjects

    Directory of Open Access Journals (Sweden)

    Elin Östman

    2011-08-01

    Full Text Available Previous studies indicate that elevated amylose content in products from rice, corn, and barley induce lower postprandial glycaemic responses and higher levels of resistant starch (RS. Consumption of slowly digestible carbohydrates and RS has been associated with health benefits such as decreased risk of diabetes and cardiovascular disease.To evaluate the postprandial glucose and insulin responses in vivo to bread products based on a novel wheat genotype with elevated amylose content (38%.Bread was baked from a unique wheat genotype with elevated amylose content, using baking conditions known to promote amylose retrogradation. Included test products were bread based on whole grain wheat with elevated amylose content (EAW, EAW with added lactic acid (EAW-la, and ordinary whole grain wheat bread (WGW. All test breads were baked at pumpernickel conditions (20 hours, 120°C. A conventionally baked white wheat bread (REF was used as reference. Resistant starch (RS content was measured in vitro and postprandial glucose and insulin responses were tested in 14 healthy subjects.The results showed a significantly higher RS content (on total starch basis in breads based on EAW than in WGW (p<0.001. Lactic acid further increased RS (p<0.001 compared with both WGW and EAW. Breads baked with EAW induced lower postprandial glucose response than REF during the first 120 min (p<0.05, but there were no significant differences in insulin responses. Increased RS content per test portion was correlated to a reduced glycaemic index (GI (r= − 0.571, p<0.001.This study indicates that wheat with elevated amylose content may be preferable to other wheat genotypes considering RS formation. Further research is needed to test the hypothesis that bread with elevated amylose content can improve postprandial glycaemic response.

  5. Effects of environmental stress during pregnancy on maternal and fetal plasma corticosterone and progesterone in the rat

    International Nuclear Information System (INIS)

    Fleming, D.E.; Rhees, R.W.; Williams, S.R.; Kurth, S.M.

    1986-01-01

    Prenatal stress applied during a presumed critical period (third trimester) for sexual differentiation of the brain has been shown to alter development and influence sexual behavior. This experiment was designed to study the effects of environmental stress (restraint/illumination/heat) on maternal and fetal plasma corticosterone and progesterone titers. These hormones were studied since corticosterone has been shown to alter brain differentiation and progesterone has anti-androgen properties and since the secretion of both from the adrenal cortex is stimulated by ACTH. Plasma corticosterone and progesterone titers of both stressed and control gravid rats and their fetuses were measured on gestational days 18 and 20 by radioimmunoassay. Prenatal stress significantly reduced fetal body weight and fetal adrenal weight. Maternal pituitary weight was significantly increased. Prenatal stress caused a significant elevation in maternal corticosterone and progesterone titers and in fetal corticosterone titers. There was no difference between prenatal stressed and control fetal plasma progesterone levels. These data demonstrate that environmental stress significantly increases adrenal activity beyond that brought about naturally by pregnancy, and therefore may modify sequential hormonal events during fetal development

  6. Hypergravity-induced increase in plasma catecholamine and corticosterone levels in telemetrically collected blood of rats during centrifugation.

    Science.gov (United States)

    Petrak, Juraj; Mravec, Boris; Jurani, Marian; Baranovska, Magda; Tillinger, Andrej; Hapala, Ivan; Frollo, Ivan; Kvetnanský, Richard

    2008-12-01

    Rats subjected to various accelerations (+G) exhibited increased levels of plasma epinephrine (EPI), norepinephrine (NE), and corticosterone. However, the collection of blood was performed after a centrifugation finished, and therefore the levels could be affected by the process of deceleration. The aim of this study was to evaluate plasma EPI, NE, and corticosterone levels in blood collected directly during centrifugation after reaching different G (2-6), using newly developed remote-controlled equipment. Animals placed into the centrifuge cabins had inserted polyethylene tubing in the tail artery, which was connected with a preprogrammed device for blood withdrawals. Plasma EPI, NE, and corticosterone levels were measured at different time intervals of hypergravity of 2-6G. Plasma EPI levels showed a huge, hypergravity-level-dependent increase. After the last blood collection was completed during hypergravity, the centrifuge was turned off and another blood sampling was performed immediately after the centrifuge stopped (10 min). In these samples, plasma EPI showed significantly lower levels compared to centrifugation intervals. Plasma NE levels were significantly increased after 6G only. The increase in plasma corticosterone was dependent on level of G, however after the centrifuge stopped, corticosterone levels remained elevated. Thus, our data show that hypergravity highly activates the adrenomedullary and hypothalamo-pituitary-adrenocortical systems, whereas the sympathoneural system is activated only at high hypergravity. Immediately after centrifugation is over, EPI levels quickly return to control values. Our technique of blood collection during centrifugation allows assessment of the real hormonal levels at the particular hypergravity value.

  7. Maternal corticosterone exposure has transgenerational effects on grand-offspring.

    Science.gov (United States)

    Khan, Nicola; Peters, Richard A; Richardson, Emily; Robert, Kylie A

    2016-11-01

    The hormone fluctuations that an animal experiences during ovulation can have lifelong effects on developing offspring. These hormones may act as an adaptive mechanism, allowing offspring to be 'pre-programmed' to survive in an unstable environment. Here, we used a transgenerational approach to examine the effects of elevated maternal corticosterone (CORT) on the future reproductive success of female offspring. We show that female zebra finches (Taeniopygia guttata) exposed to embryonic CORT produce daughters that have equal reproductive success (clutch sizes, fertility, hatching success) compared with the daughters produced from untreated mothers, but their offspring had accelerated post-hatching growth rates and were significantly heavier by nutritional independence. Although there was no significant effect on primary offspring sex ratio, females from CORT-treated mothers produced significantly female-biased clutches by nutritional independence. To the best of our knowledge, this is the first record of a transgenerational sex ratio bias in response to elevated maternal CORT in any avian species. © 2016 The Author(s).

  8. Corticosterone mediates some but not other behavioural changes induced by prenatal stress in rats.

    Science.gov (United States)

    Salomon, S; Bejar, C; Schorer-Apelbaum, D; Weinstock, M

    2011-02-01

    The effect of daily varied stress from days 13-21 of gestation in Wistar rats was investigated by tests of learning and memory and anxiogenic behaviour in the 60-day-old offspring of both sexes. Prenatal stress decreased the anogenital distance in males at 1 day of age. Anxiogenic behaviour in the elevated plus maze was seen in prenatally-stressed rats of both genders. There was no significant gender difference in the rate of spatial learning in the Morris water maze but prenatal stress only slowed that of males. In the object recognition test with an inter-trial interval of 40 min, females but not males, discriminated between a familiar and novel object. Prenatal stress did not affect object discrimination in females but feminised that in males. Maternal adrenalectomy with replacement of basal corticosterone levels in the drinking fluid prevented all of the above effects of prenatal stress in the offspring. To mimic the peak corticosterone levels and time course of elevation in response to stress, corticosterone (3 mg/kg) was injected twice (0 and 30 min) on days 13-16 and once on days 17-20 of gestation to adrenalectomised mothers. This treatment re-instated anxiogenic behaviour similar to that induced by prenatal stress, indicating that it is mediated by exposure of the foetal brain to raised levels of corticosterone. However, steroid administration to adrenalectomised dams did not decrease anogenital distance, feminise object recognition memory or slow spatial learning in their male offspring. The findings indicate that other adrenal hormones are necessary to induce these effects of prenatal stress. © 2011 The Authors. Journal of Neuroendocrinology © 2011 Blackwell Publishing Ltd.

  9. Concentration of fecal corticosterone metabolites in dominant versus ...

    African Journals Online (AJOL)

    The objective of this work was to evaluate the concentration of fecal metabolites of corticosterone and to verify if there are differences between dominant and subordinate heifers. The feces of 18 buffalo heifers were collected in the estrous period, to quantify the corticosterone concentrations. The heifers were separated into ...

  10. Studies into the anxiolytic actions of agomelatine in social isolation reared rats: Role of corticosterone and sex.

    Science.gov (United States)

    Regenass, Wilmie; Möller, Marisa; Harvey, Brian H

    2018-02-01

    Anxiety disorders are severely disabling, while current pharmacological treatments are complicated by delayed onset, low remission rates and side-effects. Sex is also noted to contribute towards illness severity and treatment response. Agomelatine is a melatonin (MT 1 /MT 2 ) agonist and serotonin (5-HT 2C ) antagonist purported to be anxiolytic in clinical and some pre-clinical studies. We undertook a detailed analysis of agomelatine's anxiolytic activity in a neurodevelopmental model of anxiety, the social isolation reared rat. Rats received sub-chronic treatment with vehicle or agomelatine (40 mg/kg per day intraperitoneally at 16:00 h for 16 days), with behaviour analysed in the open field test, social interaction test and elevated plus maze. The contribution of corticosterone and sex was also studied. Social isolation rearing increased locomotor activity and reduced social interaction in the social interaction test, and was anxiogenic in the elevated plus maze in males and females. Agomelatine reversed these behaviours. Male and female social isolation reared rats developed anxiety-like behaviours to a similar degree, although response to agomelatine was superior in male rats. Social isolation rearing decreased plasma corticosterone in both sexes and tended to higher levels in females, although agomelatine did not affect corticosterone in either sex. Concluding, agomelatine is anxiolytic in SIR rats, although correcting altered corticosterone could not be implicated. Sex-related differences in the response to agomelatine are evident.

  11. Reduced emotional and corticosterone responses to stress in μ-opioid receptor knockout mice

    Science.gov (United States)

    Ide, Soichiro; Sora, Ichiro; Ikeda, Kazutaka; Minami, Masabumi; Uhl, George R.; Ishihara, Kumatoshi

    2014-01-01

    The detailed mechanisms of emotional modulation in the nervous system by opioids remain to be elucidated, although the opioid system is well known to play important roles in the mechanisms of analgesia and drug dependence. In the present study, we conducted behavioral tests of anxiety and depression and measured corticosterone concentrations in both male and female μ-opioid receptor knockout (MOP-KO) mice to reveal the involvement of μ-opioid receptors in stress-induced emotional responses. MOP-KO mice entered more and spent more time in the open arms of the elevated plus maze compared with wild-type mice. MOP-KO mice also displayed significantly decreased immobility in a 15 min tail-suspension test compared with wild-type mice. Similarly, MOP-KO mice exhibited significantly decreased immobility on days 2, 3, and 4 in a 6 min forced swim test conducted for 5 consecutive days. The increase in plasma corticosterone concentration induced by tail-suspension, repeated forced swim, or restraint stress was reduced in MOP-KO mice compared with wild-type mice. Corticosterone levels were not different between wild-type and MOP-KO mice before stress exposure. In contrast, although female mice tended to exhibit fewer anxiety-like responses in the tail-suspension test in both genotypes, no significant gender differences were observed in stress-induced emotional responses. These results suggest that MOPs play an important facilitatory role in emotional responses to stress, including anxiety- and depression-like behavior and corticosterone levels. PMID:19596019

  12. Corticosterone mediated costs of reproduction link current to future breeding.

    Science.gov (United States)

    Crossin, Glenn T; Phillips, Richard A; Lattin, Christine R; Romero, L Michael; Williams, Tony D

    2013-11-01

    Life-history theory predicts that costs are associated with reproduction. One possible mediator of costs involves the secretion of glucocorticoid hormones, which in birds can be measured in feathers grown during the breeding period. Glucocorticoids mediate physiological responses to unpredictable environmental or other stressors, but they can also function as metabolic regulators during more predictable events such as reproduction. Here we show that corticosterone ("Cort") in feathers grown during the breeding season reflects reproductive effort in two Antarctic seabird species (giant petrels, Macronectes spp.). In females of both species, but not males, feather Cort ("fCort") was nearly 1.5-fold higher in successful than failed breeders (those that lost their eggs/chicks), suggesting a cost of successful reproduction, i.e., high fCort levels in females reflect the elevated plasma Cort levels required to support high metabolic demands of chick-rearing. Successful breeding also led to delayed moult prior to winter migration. The fCort levels and pre-migration moult score that we measured at the end of current breeding were predictive of subsequent reproductive effort in the following year. Birds with high fCort and a delayed initiation of moult were much more likely to defer breeding in the following year. Cort levels and the timing of moult thus provide a potential mechanism for the tradeoff between current and future reproduction. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.

  13. A chronic increase of corticosterone age-dependently reduces systemic DNA damage from oxidation in rats

    DEFF Research Database (Denmark)

    Jorgensen, Anders; Kalliokoski, Otto; Forsberg, Kristin

    2017-01-01

    Stress and depression are associated with an acceleration of brain and bodily aging; effects which have been attributed to chronic elevations of glucocorticoids. We tested the hypothesis that a three week administration of stress-associated levels of corticosterone (CORT, the principal rodent...... glucocorticoid) would increase systemic and CNS DNA and RNA damage from oxidation; a phenomenon known to be centrally involved in the aging process. We also hypothesized that older individuals would be more sensitive to this effect and that the chronic CORT administration would exacerbate age-related memory...

  14. Mercury exposure may suppress baseline corticosterone levels in juvenile birds.

    Science.gov (United States)

    Herring, Garth; Ackerman, Joshua T; Herzog, Mark P

    2012-06-05

    Mercury exposure has been associated with a wide variety of negative reproductive responses in birds, however few studies have examined the potential for chick impairment via the hypothalamic-pituitary-adrenal (HPA) axis. The HPA axis regulates corticosterone levels during periods of stress. We examined the relationship between baseline fecal corticosterone metabolite concentrations and mercury concentrations in down feathers of recently hatched (feathers (decreasing by 45% across the range of observed mercury concentrations) while accounting for stronger positive correlations between corticosterone concentrations and colony nest abundance and date. These results indicate that chronic mercury exposure may suppress baseline corticosterone concentrations in tern chicks and suggests that a juvenile bird's ability to respond to stress may be reduced via the downregulation of the HPA axis.

  15. Content

    DEFF Research Database (Denmark)

    Keiding, Tina Bering

    secondary levels. In subject matter didactics, the question of content is more developed, but it is still mostly confined to teaching on lower levels. As for higher education didactics, discussions on selection of content are almost non-existent on the programmatic level. Nevertheless, teachers are forced...... curriculum, in higher education, and to generate analytical categories and criteria for selection of content, which can be used for systematic didactical reflection. The larger project also concerns reflection on and clarification of the concept of content, including the relation between content at the level......Aim, content and methods are fundamental categories of both theoretical and practical general didactics. A quick glance in recent pedagogical literature on higher education, however, reveals a strong preoccupation with methods, i.e. how teaching should be organized socially (Biggs & Tang, 2007...

  16. Corticosterone regulation in house sparrows invading Senegal.

    Science.gov (United States)

    Martin, Lynn B; Kilvitis, Holly J; Thiam, Massamba; Ardia, Daniel R

    2017-09-01

    What traits help organisms expand their ranges? Several behavioral and life history traits have been identified, but physiological and especially endocrinological factors have been minimally considered. Here, we asked whether steroid hormonal responses to stressors might be important. Previously, we found that corticosterone (CORT) responses to a standard restraint stressor were stronger at a range edge than at the core of the recent house sparrow (Passer domesticus) invasion of Kenya. In related work in the same system, we found that various behaviors (exploratory activity, responses to novelty, etc.) that are affected by CORT in other systems varied among sparrow populations in a manner that would suggest that CORT regulation directly influenced colonization success; birds at the range edge were less averse to novelty and more exploratory than birds from the core. Here, we asked whether the pattern in CORT regulation we observed in Kenya was also detectable in the more recent (∼1970) and independent invasion of Senegal. We found, as in Kenya, that Senegalese range-edge birds mounted stronger CORT responses to restraint than core birds. We also found lower baseline CORT in range-edge than core Senegalese birds, but little evidence for effects of individual sex, body mass or body size on CORT. Follow-up work will be necessary to resolve whether CORT regulation in Senegal (and Kenya) actively facilitated colonization success, but our work implicates glucocorticoids as a mediator of range expansion success, making stress responses potentially useful biomarkers of invasion risk. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Protective effects of peony glycosides against corticosterone-induced cell death in PC12 cells through antioxidant action.

    Science.gov (United States)

    Mao, Qing-Qiu; Xian, Yan-Fang; Ip, Siu-Po; Tsai, Sam-Hip; Che, Chun-Tao

    2011-02-16

    Previous studies in our laboratory have shown that total glycosides of peony (TGP) produced antidepressant-like action in various mouse models of behavioral despair. However, the molecular mechanism by which TGP exerts antidepressant-like effect is not fully understood. This study examined the protective effects of TGP against corticosterone-induced neurotoxicity in rat pheochromocytoma (PC12) cells and ts possible mechanisms. The direct antioxidant effect of TGP was investigated by using a 2,2'-azinobis-(3-ethylbenzothiazoline- 6-sulphonic acid) (ABTS) radical cation-scavenging assay in a cell-free system. PC12 cells were treated with 200 μM of corticosterone in the absence or presence of TGP in varying concentrations for 48 h. Cell viability, lactate dehydrogenase (LDH) activity, intracellular reactive oxygen species (ROS) level, malondialdehyde (MDA) content, glutathione (GSH) content, superoxide dismutase (SOD) activity, and catalase (CAT) activity were then determined. TGP displayed antioxidant properties in the cell-free system, and the IC50 value in the ABTS radical cation-scavenging assay was 9.9 mg/L. TGP treatment at increasing doses (1-10 mg/L) protected against corticosterone-induced cytotoxicity in PC12 cells in a dose-dependent manner. The cytoprotection afforded by TGP treatment was associated with decreases in the intracellular ROS and MDA levels, and increases in the GSH level, SOD activity, and CAT activity in corticosterone-treated PC12 cells. The results suggest that TGP has a neuroprotective effect on corticosterone-induced neurotoxicity in PC12 cells, which may be related to its antioxidant action. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  18. Prior exposure to capture heightens the corticosterone and behavioural responses of little penguins (Eudyptula minor) to acute stress.

    Science.gov (United States)

    Carroll, Gemma; Turner, Emma; Dann, Peter; Harcourt, Rob

    2016-01-01

    Studies of physiology can provide important insight into how animals are coping with challenges in their environment and can signal the potential effects of exposure to human activity in both the short and long term. In this study, we measured the physiological and behavioural response of little penguins (Eudyptula minor) that were naïve to human activity over 30 min of capture and handling. We assessed relationships between corticosterone secretion, behaviour, sex and time of day in order to characterize the determinants of the natural stress response. We then compared the response of these naïve penguins with the responses of female little penguins that had been exposed to research activity (bimonthly nest check and weighing) and to both research activity (monthly nest check and weighing) and evening viewing by tourists. We found that corticosterone concentrations increased significantly over 30 min of capture, with naïve penguins demonstrating a more acute stress response during the day than at night. Penguins that had previously been exposed to handling at the research and research/visitor sites showed elevated corticosterone concentrations and consistently more aggressive behaviour after 30 min compared with naïve birds, although there were no significant differences in baseline corticosterone concentrations. Our findings demonstrate that these little penguins have not habituated to routine capture, but rather mount a heightened physiological and behavioural response to handling by humans. Less invasive research monitoring techniques, such as individual identification with PIT tags and automatic recording and weighing, and a reduction in handling during the day should be considered to mitigate some of the potentially negative effects of disturbance. Given the paucity of data on the long-term consequences of heightened stress on animal physiology, our study highlights the need for further investigation of the relationship between the corticosterone

  19. Spatial and temporal dynamics of corticosterone and corticosterone binding globulin are driven by environmental heterogeneity.

    Science.gov (United States)

    Shultz, Michael Todd; Kitaysky, Alexander Stanislav

    2008-02-01

    The question of whether changes in glucocorticoid concentrations reflect consistent changes in physiology associated with transitions between different stages of reproduction, or whether they reflect responses to environmental conditions, is one the central issues in field endocrinology studies. We examined the temporal and spatial dynamics of corticosterone (CORT, baseline, and acute stress-induced) and corticosterone binding globulin (CBG) concentrations in blood of Black-legged Kittiwakes (Rissa tridactyla) breeding at four major colonies in the Bering Sea, Alaska, during 1999-2005. We found that total CORT, free CORT, and CBG capacity varied inconsistently among reproductive stages, colonies, and years. Total CORT levels were positively correlated with CBG capacity. Variation in free CORT was largely driven by variation in total CORT. Results suggest that the adrenocortical function and CBG in breeding kittiwakes do not vary as a consequence of stage-specific modulation associated with a particular reproductive stage as in some short-lived passerine birds. Rather, in accord with predictions for a long-lived species, the lack of consistent colony, year, and reproductive stage patterns in baseline and maximum CORT, and CBG indicates that environmental factors, probably local dynamics of food availability, drive variation in these factors.

  20. Effects of soil water content and elevated CO2 concentration on the monoterpene emission rate of Cryptomeria japonica.

    Science.gov (United States)

    Mochizuki, Tomoki; Amagai, Takashi; Tani, Akira

    2018-04-11

    Monoterpenes emitted from plants contribute to the formation of secondary pollution and affect the climate system. Monoterpene emission rates may be affected by environmental changes such as increasing CO 2 concentration caused by fossil fuel burning and drought stress induced by climate change. We measured monoterpene emissions from Cryptomeria japonica clone saplings grown under different CO 2 concentrations (control: ambient CO 2 level, elevated CO 2 : 1000μmolmol -1 ). The saplings were planted in the ground and we did not artificially control the SWC. The relationship between the monoterpene emissions and naturally varying SWC was investigated. The dominant monoterpene was α-pinene, followed by sabinene. The monoterpene emission rates were exponentially correlated with temperature for all measurements and normalized (35°C) for each measurement day. The daily normalized monoterpene emission rates (E s0.10 ) were positively and linearly correlated with SWC under both control and elevated CO 2 conditions (control: r 2 =0.55, elevated CO 2 : r 2 =0.89). The slope of the regression line of E s0.10 against SWC was significantly higher under elevated CO 2 than under control conditions (ANCOVA: P<0.01), indicating that the effect of CO 2 concentration on monoterpene emission rates differed by soil water status. The monoterpene emission rates estimated by considering temperature and SWC (Improved G93 algorithm) better agreed with the measured monoterpene emission rates, when compared with the emission rates estimated by considering temperature alone (G93 algorithm). Our results demonstrated that the combined effects of SWC and CO 2 concentration are important for controlling the monoterpene emissions from C. japonica clone saplings. If these relationships can be applied to the other coniferous tree species, our results may be useful to improve accuracy of monoterpene emission estimates from the coniferous forests as affected by climate change in the present and

  1. Effects of elevated root zone CO2 and air temperature on photosynthetic gas exchange, nitrate uptake, and total reduced nitrogen content in aeroponically grown lettuce plants.

    Science.gov (United States)

    He, Jie; Austin, Paul T; Lee, Sing Kong

    2010-09-01

    Effects of elevated root zone (RZ) CO(2) and air temperature on photosynthesis, productivity, nitrate (NO(3)(-)), and total reduced nitrogen (N) content in aeroponically grown lettuce plants were studied. Three weeks after transplanting, four different RZ [CO(2)] concentrations [ambient (360 ppm) and elevated concentrations of 2000, 10,000, and 50,000 ppm] were imposed on plants grown at two air temperature regimes of 28 degrees C/22 degrees C (day/night) and 36 degrees C/30 degrees C. Photosynthetic CO(2) assimilation (A) and stomatal conductance (g(s)) increased with increasing photosynthetically active radiation (PAR). When grown at 28 degrees C/22 degrees C, all plants accumulated more biomass than at 36 degrees C/30 degrees C. When measured under a PAR >or=600 micromol m(-2) s(-1), elevated RZ [CO(2)] resulted in significantly higher A, lower g(s), and higher midday leaf relative water content in all plants. Under elevated RZ [CO(2)], the increase of biomass was greater in roots than in shoots, causing a lower shoot/root ratio. The percentage increase in growth under elevated RZ [CO(2)] was greater at 36 degrees C/30 degrees C although the total biomass was higher at 28 degrees C/22 degrees C. NO(3)(-) and total reduced N concentrations of shoot and root were significantly higher in all plants under elevated RZ [CO(2)] than under ambient RZ [CO(2)] of 360 ppm at both temperature regimes. At each RZ [CO(2)], NO(3)(-) and total reduced N concentration of shoots were greater at 28 degrees C/22 degrees C than at 36 degrees C/30 degrees C. At all RZ [CO(2)], roots of plants at 36 degrees C/30 degrees C had significantly higher NO(3)(-) and total reduced N concentrations than at 28 degrees C/22 degrees C. Since increased RZ [CO(2)] caused partial stomatal closure, maximal A and maximal g(s) were negatively correlated, with a unique relationship for each air temperature. However, across all RZ [CO(2)] and temperature treatments, there was a close correlation between

  2. Eggshell appearance does not signal maternal corticosterone exposure in Japanese quail: an experimental study with brown-spotted eggs.

    Directory of Open Access Journals (Sweden)

    Camille Duval

    Full Text Available Reproduction is a critical period for birds as they have to cope with many stressful events. One consequence of an acute exposure to stress is the release of corticosterone, the avian stress hormone. Prolonged stress can have negative impacts on the immune system, resulting in, for example, increased oxidative stress. Through maternal effects, females are known to modulate their investment in eggs content according to their own physiological condition. Less is known about maternal investment in eggshells, especially in pigments. The two main eggshell pigments may possess opposite antioxidant properties: protoporphyrin (brown is a pro-oxidant, whereas biliverdin (blue-green is an antioxidant. In Japanese quail, we know that the deposition of both pigments is related to female body condition. Thus, a chronic stress response may be reflected in eggshell coloration. Using female Japanese quails that lay brown-spotted eggs, we explored whether physiological exposure to corticosterone induces a change in female basal stress and antioxidant factors, and eggshell pigment concentration, spectrophotometric reflectance, and maculation coverage. We supplemented adult females over a 2 week period with either peanut oil (control or corticosterone (treatment. We collected pre- and post-supplementation eggs and analysed the effect of corticosterone treatment on female physiology and eggshell appearance parameters. Except for corticosterone-fed birds which laid eggs with brighter spots, supplementation had no significant effect on female physiology or eggshell pigment concentration, reflectance and maculation. The change in eggshell spot brightness was not detected by a photoreceptor noise-limited color opponent model of avian visual perception. Our data confirms that eggshell reflectance in spotted eggs varies over the laying sequence, and spot reflectance may be a key factor that is affected by females CORT exposure, even if the changes are not detected by an

  3. Exposure to retrieval cues improves retention performance and induces changes in ACTH and corticosterone release.

    Science.gov (United States)

    Gisquet-Verrier, Pascale; Botreau, Fanny; Venero, Cesar; Sandi, Carmen

    2004-05-01

    Memory retrieval can be facilitated by pretest exposure to cues associated with the original training. The present series of experiments was aimed at investigating whether the effectiveness of the retrieval cues might be due to their emotional value and thus be associated to a particular pattern of activation of stress systems. Therefore, the effects of exposing rats to different cueing conditions were investigated both on retention performance and on the level of different stress hormones (ACTH, corticosterone and glucose; the latter as an indirect index of adrenergic/sympathetic nervous system activation). Rats trained in a brightness avoidance discrimination task exhibited an enhancement of the retention performance following exposure to the light discriminative stimulus when delivered 1-day after training and not after 21 days, while exposure to contextual cues led to opposite effects on the retention performance, confirming our previous results. Analyses of the level of stress hormones at the time of testing indicated that when the retrieval cues were effective at the behavioral level, cued rats exhibited higher ACTH plasmatic levels than controls, but did not differ in their glucose or corticosterone levels. Further experiments showed that one day after training, both ACTH and corticosterone levels were elevated in light-cued rats if hormone samples were taken 15 min after cueing. These results show that exposure to an effective retrieval cue is accompanied by the activation of the hypothalamus-pituitary-adrenal axis. The possible involvement of the Corticotropin Releasing Factor at the level of the hypothalamus and amygdala (particularly the central nucleus) on the facilitating effect on retention performance following exposure to aversive training-associated cues is discussed. The present results strengthen the notion that emotion can interact with retrieval processes.

  4. Ready-to-use therapeutic food with elevated n-3 polyunsaturated fatty acid content, with or without fish oil, to treat severe acute malnutrition: a randomized controlled trial.

    LENUS (Irish Health Repository)

    Jones, Kelsey D J

    2015-01-01

    Ready-to-use therapeutic foods (RUTF) are lipid-based pastes widely used in the treatment of acute malnutrition. Current specifications for RUTF permit a high n-6 polyunsaturated fatty acid (PUFA) content and low n-3 PUFA, with no stipulated requirements for preformed long-chain n-3 PUFA. The objective of this study was to develop an RUTF with elevated short-chain n-3 PUFA and measure its impact, with and without fish oil supplementation, on children\\'s PUFA status during treatment of severe acute malnutrition.

  5. Genetic variation of γ-tocopherol methyltransferase gene contributes to elevated α-tocopherol content in soybean seeds.

    Science.gov (United States)

    Dwiyanti, Maria S; Yamada, Tetsuya; Sato, Masako; Abe, Jun; Kitamura, Keisuke

    2011-11-07

    Improvement of α-tocopherol content is an important breeding aim to increase the nutritional value of crops. Several efforts have been conducted to improve the α-tocopherol content in soybean [Glycine max (L.) Merr.] through transgenic technology by overexpressing genes related to α-tocopherol biosynthesis or through changes to crop management practices. Varieties with high α-tocopherol content have been identified in soybean germplasms. The heritability of this trait has been characterized in a cross between high α-tocopherol variety Keszthelyi Aproszemu Sarga (KAS) and low α-tocopherol variety Ichihime. In this study, the genetic mechanism of the high α-tocopherol content trait of KAS was elucidated. Through QTL analysis and fine mapping in populations from a cross between KAS and a Japanese variety Ichihime, we identified γ-TMT3, which encodes γ-tocopherol methyltransferase, as a candidate gene responsible for high α-tocopherol concentration in KAS. Several nucleotide polymorphisms including two nonsynonymous mutations were found in the coding region of γ-TMT3 between Ichihime and KAS, but none of which was responsible for the difference in α-tocopherol concentration. Therefore, we focused on transcriptional regulation of γ-TMT3 in developing seeds and leaves. An F5 line that was heterozygous for the region containing γ-TMT3 was self-pollinated. From among the progeny, plants that were homozygous at the γ-TMT3 locus were chosen for further evaluation. The expression level of γ-TMT3 was higher both in developing seeds and leaves of plants homozygous for the γ-TMT3 allele from KAS. The higher expression level was closely correlated with high α-tocopherol content in developing seeds. We generated transgenic Arabidopsis plants harboring GUS gene under the control of γ-TMT3 promoter from KAS or Ichihime. The GUS activity assay showed that the activity of γ-TMT3 promoter from KAS was higher than that of Ichihime. The genetic variation in γ-TMT3

  6. Genetic variation of γ-tocopherol methyltransferase gene contributes to elevated α-tocopherol content in soybean seeds

    Directory of Open Access Journals (Sweden)

    Abe Jun

    2011-11-01

    Full Text Available Abstract Background Improvement of α-tocopherol content is an important breeding aim to increase the nutritional value of crops. Several efforts have been conducted to improve the α-tocopherol content in soybean [Glycine max (L. Merr.] through transgenic technology by overexpressing genes related to α-tocopherol biosynthesis or through changes to crop management practices. Varieties with high α-tocopherol content have been identified in soybean germplasms. The heritability of this trait has been characterized in a cross between high α-tocopherol variety Keszthelyi Aproszemu Sarga (KAS and low α-tocopherol variety Ichihime. In this study, the genetic mechanism of the high α-tocopherol content trait of KAS was elucidated. Results Through QTL analysis and fine mapping in populations from a cross between KAS and a Japanese variety Ichihime, we identified γ-TMT3, which encodes γ-tocopherol methyltransferase, as a candidate gene responsible for high α-tocopherol concentration in KAS. Several nucleotide polymorphisms including two nonsynonymous mutations were found in the coding region of γ-TMT3 between Ichihime and KAS, but none of which was responsible for the difference in α-tocopherol concentration. Therefore, we focused on transcriptional regulation of γ-TMT3 in developing seeds and leaves. An F5 line that was heterozygous for the region containing γ-TMT3 was self-pollinated. From among the progeny, plants that were homozygous at the γ-TMT3 locus were chosen for further evaluation. The expression level of γ-TMT3 was higher both in developing seeds and leaves of plants homozygous for the γ-TMT3 allele from KAS. The higher expression level was closely correlated with high α-tocopherol content in developing seeds. We generated transgenic Arabidopsis plants harboring GUS gene under the control of γ-TMT3 promoter from KAS or Ichihime. The GUS activity assay showed that the activity of γ-TMT3 promoter from KAS was higher than that of

  7. Organization of radiation inspection for strip-mining development for ores with elevated content of natural radionuclides on the Karazhyra coal mine

    International Nuclear Information System (INIS)

    Lukashenko, S.N.; Subbotin, S.B.; Ajdarkhanov, A.O.; Medvedev, P.P.

    2003-01-01

    Due to existence of anomalous areas of ores with elevated content of natural radionuclides on the Karazhyra coal mine the project of its selective development was implemented. The project provides a set of measures on radiation safety. In the present paper the order of radiological operations organization and performance are shown, and methodical provision of these works is considered. Results of the preliminary radiological examination of the area, fulfilment the measures on mine works technology radiological safety, and strip-mining ores deposition are analyzed. The evaluations of natural radionuclides content with taking into account its influence on personnel during works fulfilment are made. The results of soil samples analysis are presented in the graphical form. The suggestions and recommendations on radiation monitoring improvement on the area are given

  8. Effects of augmented corticosterone in painted turtle eggs on offspring development and behavior.

    Science.gov (United States)

    Polich, Rebecca L; Bodensteiner, Brooke L; Adams, Clare I M; Janzen, Fredric J

    2018-01-01

    Maternal stressors can play an integral role in offspring development and ultimate behaviors in many vertebrates. Increased circulating stress avoidance hormones can be reflected in elevated concentrations in ova, thus providing a potential mechanism for maternal stress to be transmitted to offspring even in taxa without parental care. In this study, we assessed the potential impacts of augmented stress avoidance hormones on offspring development and anti-predator behaviors in a freshwater turtle, Chrysemys picta. We exposed C. picta eggs to biologically relevant amounts of the stress avoidance hormone, corticosterone, as a proxy for maternal stressors. We allowed the eggs to incubate in the field, then measured offspring phenotypes, conducted performance trials, and simulated nest emergence in a field experiment. Exogenous corticosterone reduced survivorship to hatch, but did not affect incubation duration, offspring size, overwinter survival, or size after hibernation. In performance trials, this hormone treatment reduced the frequency of righting, yet enhanced the righting speed of neonates. Regardless, these performance differences did not detectably alter survivorship in the nest emergence experiment. These results lend insight into the potential effects of maternal stress levels on offspring phenotypes, as well as the robustness of offspring fitness to altered levels of maternal stress in freshwater turtles. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. The development of a radioimmunoassay for 18-hydroxy-corticosterone

    International Nuclear Information System (INIS)

    Martin, V.I.

    1980-03-01

    It has been suggested that 18-hydroxy-corticosterone (18-OH-B) is a precursor for aldosterone in the biosynthetic pathway. This steroid had not been measured in peripheral plasma and therefore to evaluate its clinical role a sensitive and specific radioimmunoassay was developed. The assay is described and was applied to measure the levels of 18-hydroxy-corticosterone in normal human subjects on (a) an ad libitum sodium intake whilst lying or standing, (b) on a high or low sodium intake whilst recumbent, (c) before and after treatment with either ACTH, metyrapone or dexamethasone on a high or low sodium intake whilst recumbent (d) after insulin induced hypoglycaemia and (e) after infusions of 18-hydroxy-corticosterone. The levels of 18-hydroxy-corticosterone were also measured in patients with (a) 17α-hydroxylase deficiency, (b) primary or secondary aldosteronism, (c) Bartter's syndrome, (d) Cushing's syndrome, (e) adrenalectomised patients or patient's with Addison's disease and (f) patients with essential hypertension. (author)

  10. Development of a radioimmunoassay for 18-hydroxy-corticosterone

    Energy Technology Data Exchange (ETDEWEB)

    Martin, V I

    1980-03-01

    It has been suggested that 18-hydroxy-corticosterone (18-OH-B) is a precursor for aldosterone in the biosynthetic pathway. This steroid had not been measured in peripheral plasma and therefore to evaluate its clinical role a sensitive and specific radioimmunoassay was developed. The assay is described and was applied to measure the levels of 18-hydroxy-corticosterone in normal human subjects on (a) an ad libitum sodium intake whilst lying or standing, (b) on a high or low sodium intake whilst recumbent, (c) before and after treatment with either ACTH, metyrapone or dexamethasone on a high or low sodium intake whilst recumbent (d) after insulin induced hypoglycaemia and (e) after infusions of 18-hydroxy-corticosterone. The levels of 18-hydroxy-corticosterone were also measured in patients with (a) 17chemically bond-hydroxylase deficiency, (b) primary or secondary aldosteronism, (c) Bartter's syndrome, (d) Cushing's syndrome, (e) adrenalectomised patients or patient's with Addison's disease and (f) patients with essential hypertension. (author).

  11. Elevating your elevator talk

    Science.gov (United States)

    An important and often overlooked item that every early career researcher needs to do is compose an elevator talk. The elevator talk, named because the talk should not last longer than an average elevator ride (30 to 60 seconds), is an effective method to present your research and yourself in a clea...

  12. Contents

    Directory of Open Access Journals (Sweden)

    Editor IJRED

    2012-11-01

    Full Text Available International Journal of Renewable Energy Development www.ijred.com Volume 1             Number 3            October 2012                ISSN 2252- 4940   CONTENTS OF ARTICLES page Design and Economic Analysis of a Photovoltaic System: A Case Study 65-73 C.O.C. Oko , E.O. Diemuodeke, N.F. Omunakwe, and E. Nnamdi     Development of Formaldehyde Adsorption using Modified Activated Carbon – A Review 75-80 W.D.P Rengga , M. Sudibandriyo and M. Nasikin     Process Optimization for Ethyl Ester Production in Fixed Bed Reactor Using Calcium Oxide Impregnated Palm Shell Activated Carbon (CaO/PSAC 81-86 A. Buasri , B. Ksapabutr, M. Panapoy and N. Chaiyut     Wind Resource Assessment in Abadan Airport in Iran 87-97 Mojtaba Nedaei       The Energy Processing by Power Electronics and its Impact on Power Quality 99-105 J. E. Rocha and B. W. D. C. Sanchez       First Aspect of Conventional Power System Assessment for High Wind Power Plants Penetration 107-113 A. Merzic , M. Music, and M. Rascic   Experimental Study on the Production of Karanja Oil Methyl Ester and Its Effect on Diesel Engine 115-122 N. Shrivastava,  , S.N. Varma and M. Pandey  

  13. Perches and elevated platforms in commercial broiler farms: use and effect on walking ability, incidence of tibial dyschondroplasia and bone mineral content.

    Science.gov (United States)

    Kaukonen, E; Norring, M; Valros, A

    2017-05-01

    Modern fast-growing broilers spend excessive periods resting and their activity further decreases with age. Inactivity has been suggested to increase impaired gait and the incidence of leg disorders. Tibial dyschondroplasia (TD) is a common leg pathology in broilers. A more complex environment might facilitate more activity and improve leg health. Perches or elevated platforms bring variety to broilers' environment and could motivate more locomotion. This study examined the impact of perches and elevated platforms on walking ability, the occurrence of TD and level of bone ash and mineral contents. The investigation was performed on four commercial broiler farms throughout six consecutive batches with platforms and four to five with perches. On each farm at least two separate houses were included, enabling the comparison of furnished flocks to control flocks during each batch. Plastic slats with ramp access elevated by 30 cm or wooden perches of 10 and 30 cm height were offered in the furnished house. Farmers recorded the platform and perch usage twice a week with a five-point scale. Gait was scored before slaughter on a six-point scale according to the Welfare Quality® assessment protocol for poultry. The severity of TD was determined using a four-point scale on farm from all birds gait scored as 3 and at slaughter from 200 birds/flock. Farmers estimated 50% to 100% of the platforms to be occupied in all flocks throughout the entire growing period. Only single birds were perching, thus perch structures were constantly evaluated to be empty. Due to the low use, the perch-equipped houses were excluded when analysing bone content, walking ability and TD. On average, 30% of the tested birds exhibited gait score ⩾3. Younger scoring age resulted in a lower mean gait score and a lower percentage of scores 3 and 4 to 5. Overall, 2.3% of the birds examined at slaughter and 3.5% of the birds with gait score 3 were affected by TD. Leg health was better in birds with access

  14. Experimentally reduced corticosterone release promotes early breeding in black-legged kittiwakes.

    Science.gov (United States)

    Goutte, Aurélie; Clément-Chastel, Céline; Moe, Børge; Bech, Claus; Gabrielsen, Geir Wing; Chastel, Olivier

    2011-06-15

    Breeding at the right time is important for successful reproduction. In birds, stressful environmental conditions are known to delay the timing of breeding but the underlying mechanisms are poorly understood. The stress hormone corticosterone appears to be a good candidate for mediating egg-laying date according to early environmental conditions and physiological state. By experimentally reducing the release of corticosterone in black-legged kittiwakes during the pre-laying period, we tested whether egg-laying date was mechanistically linked to corticosterone levels. Male and female kittiwakes were implanted with a low dose of exogenous corticosterone to inhibit endogenous corticosterone production. According to our predictions, the experimental reduction of corticosterone release was paralleled by a significant advancement of egg laying in females (around 4 days earlier). In addition, females with experimentally reduced corticosterone release gained mass during the pre-laying period compared with controls. Ultimately, the advancement of egg laying in females with experimentally reduced corticosterone levels was associated with an enhanced breeding success. This effect was strongly sex specific. In corticosterone-treated male kittiwakes, egg-laying date and reproductive success were not affected, but breeding probability was lower than in controls. This corticosterone treatment did not influence immediate clutch size, or return rate and breeding decision the following year. Our results support the hypothesis that corticosterone secretion during the pre-laying period mediates the timing of breeding in this long-lived seabird, possibly through the dynamics of energy reserves.

  15. Patterns of circulating corticosterone in a population of rattlesnakes afflicted with snake fungal disease: Stress hormones as a potential mediator of seasonal cycles in disease severity and outcomes

    Science.gov (United States)

    Lind, Craig M.; Moore, Ignacio T.; Akçay, Çağlar; Vernasco, Ben J.; Lorch, Jeffrey M.; Farrell, Terence M.

    2018-01-01

    Snake fungal disease (SFD) is an emerging threat to snake populations in the United States. Fungal pathogens are often associated with a physiological stress response mediated by the hypothalamo-pituitary-adrenal axis (HPA), and afflicted individuals may incur steep coping costs. The severity of SFD can vary seasonally; however, little is known regarding (1) how SFD infection relates to HPA activity and (2) how seasonal shifts in environment, life history, or HPA activity may interact to drive seasonal patterns of infection severity and outcomes. To test the hypothesis that SFD is associated with increased HPA activity and to identify potential environmental or physiological drivers of seasonal infection, we monitored baseline corticosterone, SFD infection severity, foraging success, body condition, and reproductive status in a field-active population of pigmy rattlesnakes. Both plasma corticosterone and the severity of clinical signs of SFD peaked in the winter. Corticosterone levels were also elevated in the fall before the seasonal rise in SFD severity. Severely symptomatic snakes were in low body condition and had elevated corticosterone levels compared to moderately infected and uninfected snakes. The monthly mean severity of SFD in the population was negatively related to population-wide estimates of body condition and temperature measured in the precedent month and positively correlated with corticosterone levels measured in the precedent month. Symptomatic females were less likely to enter reproductive bouts compared to asymptomatic females. We propose the hypothesis that the seasonal interplay among environment, host energetics, and HPA activity initiates trade-offs in the fall that drive the increase in SFD prevalence, symptom severity, and decline in condition observed in the population through winter.

  16. Synergized resmethrin and corticosterone alter the chicken's response to west nile virus

    Energy Technology Data Exchange (ETDEWEB)

    Jankowski, Mark David [Los Alamos National Laboratory; Franson, J Christian [US GEOLOGICAL SURVEY; Mostl, Erich [UNIV OF VIENNA; Porter, Warren P [UNIV OF WISCONSIN; Hofmeister, Erik K [US GEOLOGICAL SURVEY

    2009-01-01

    Debate concerning arbovirus control strategies remains contentious because concern regarding the relative risk of viral infection and environmental toxicant exposure is high but inadequately characterized. Taking this into account, mosquito control agencies employ aerial insecticides only after arbovirus surveillance data indicate high local mosquito-infection-rates. Successfully mitigating the risk of adult-mosquito-control insecticides ('adulticides') to non-target species such as humans, domestic animals, fish, beneficial insects and wildlife, while increasing their efficacy to reduce arbovirus outbreak intensity requires targeted scientific data from animal toxicity studies and environmental monitoring activities. Wild birds are an important reservoir host for WNv and are potentially exposed to insecticides used for mosquito control. However, no risk assessments have evaluated whether insecticides augment or extend the potential transmissibility of West Nile virus (WNv) in birds. In order to augment existing resmethrin risk assessments, we aimed to determine whether synergized resmethrin (SR) may cause chickens to develop an elevated or extended WN viremia and if subacute stress may affect its immunotoxicity. We distributed 40 chickens into four groups then exposed them prior to and during WNv infection with SR (50 {mu}g/l resmethrin + 150 {mu}g/l piperonyl butoxide) and/or 20 mg/I corticosterone (CORT) in their drinking-water. Corticosterone was given for 10 continuous days and SR was given for 3 alternate days starting the 3rd day of CORT exposure, then chickens were subcutaneously inoculated with WNv on the 5th day of CORT treatment. Compared to controls, CORT treatment extended and elevated viremia, enhanced WNv-specific antibody and increased the percentage of birds that shed oral virus, whereas SR treatment extended viremia, depressed WNv-specific IgG, and increased the percentage of CORT-treated birds that shed oral virus. Corticosterone and SR

  17. Corticosterone Facilitates Fluoxetine-Induced Neuronal Plasticity in the Hippocampus

    Science.gov (United States)

    Kobayashi, Katsunori; Ikeda, Yumiko; Asada, Minoru; Inagaki, Hirofumi; Kawada, Tomoyuki; Suzuki, Hidenori

    2013-01-01

    The hippocampal dentate gyrus has been implicated in a neuronal basis of antidepressant action. We have recently shown a distinct form of neuronal plasticity induced by the serotonergic antidepressant fluoxetine, that is, a reversal of maturation of the dentate granule cells in adult mice. This “dematuration” is induced in a large population of dentate neurons and maintained for at least one month after withdrawal of fluoxetine, suggesting long-lasting strong influence of dematuration on brain functioning. However, reliable induction of dematuration required doses of fluoxetine higher than suggested optimal doses for mice (10 to 18 mg/kg/day), which casts doubt on the clinical relevance of this effect. Since our previous studies were performed in naive mice, in the present study, we reexamined effects of fluoxetine using mice treated with chronic corticosterone that model neuroendocrine pathophysiology associated with depression. In corticosterone-treated mice, fluoxetine at 10 mg/kg/day downregulated expression of mature granule cell markers and attenuated strong frequency facilitation at the synapse formed by the granule cell axon mossy fiber, suggesting the induction of granule cell dematuration. In addition, fluoxetine caused marked enhancement of dopaminergic modulation at the mossy fiber synapse. In vehicle-treated mice, however, fluoxetine at this dose had no significant effects. The plasma level of fluoxetine was comparable to that in patients taking chronic fluoxetine, and corticosterone did not affect it. These results indicate that corticosterone facilitates fluoxetine-induced plastic changes in the dentate granule cells. Our finding may provide insight into neuronal mechanisms underlying enhanced responsiveness to antidepressant medication in certain pathological conditions. PMID:23675498

  18. Binding of tritiated corticosterone in brain sections of adrenalectomized rat

    International Nuclear Information System (INIS)

    Sarrieau, A.; Vial, M.; Dussaillant, M.; Rostene, W.; Philibert, P.

    1983-01-01

    A new technique which permits to study the specific binding of tritiated corticosterone in brain sections of adrenalectomized rats is described. Under these conditions, the specific binding of the glucocorticoid represents 60 to 70% of the initial binding. The apparent dissociation constant and the number of binding sites, determined by Scatchard analysis, are in the range of 10 -8 M and 100 fmoles/mg of protein respectively [fr

  19. Corticosterone suppresses immune activity in territorial Galápagos marine iguanas during reproduction.

    Science.gov (United States)

    Berger, Silke; Martin, Lynn B; Wikelski, Martin; Romero, L Michael; Kalko, Elisabeth K V; Vitousek, Maren N; Rödl, Thomas

    2005-04-01

    Individuals that display elaborate sexually selected characters often show reduced immune function. According to the immunocompetence handicap hypothesis, testosterone (T) is responsible for this result as it drives the development and maintenance of sexual characters and causes immunosuppression. But glucocorticoids also have strong influences on immune function and may also be elevated in reproductively active males. Here, we compared immune activity using the phytohemagglutinin (PHA) skin test in three discrete groups of male marine iguanas (Amblyrhynchus cristatus): territorials, satellites, and bachelors. Males of these three reproductive phenotypes had indistinguishable T concentrations during the height of the breeding season, but their corticosterone (cort) concentrations, body condition and hematocrit were significantly different. Territorial males, the animals with the most elaborate sexual ornaments and behaviors, had lower immune responses and body condition but higher cort concentrations and hematocrit than satellites or bachelors. To test directly cort's immunosuppressive role, we elevated cort by either restraining animals or additionally injecting cort and compared their PHA swelling response with the response of free-roaming animals. Such experimental elevation of cort significantly decreased immune activity in both restrained and cort-injected animals. Our data show that cort can induce immunosuppression, but they do not support the immunocompetence handicap hypothesis in its narrow sense because T concentrations were not related to immunosuppression.

  20. Patterns of stress responses shift during seasonal life-history transitions: An analysis comparing baseline, maximal and integrated corticosterone in female red-sided garter snakes (Thamnophis sirtalis parietalis).

    Science.gov (United States)

    Dayger, Catherine A; Lutterschmidt, Deborah I

    2017-05-15

    Glucocorticoids often rise and fall with a variety of external and internal cues and frequently vary among life-history stages. This suggests that changing glucocorticoids may coordinate life-history transitions. To explore this hypothesis, we asked if the time-course of stress-induced glucocorticoid levels differ between two life-history transitions (i.e., spring and fall migration) in female red-sided garter snakes (Thamnophis sirtalis parietalis). We collected non-migratory females from a communal den and migratory females from a road along the migration route and treated them with 4h of capture stress; plasma corticosterone was measured before, during and after capture stress. During the spring, den-collected females exhibited a stress-induced peak in corticosterone at an earlier sampling time than migrating, road-collected females. Because the pattern of corticosterone responses varied with migratory state, negative feedback on and/or sensitivity of the hypothalamus-pituitaryadrenal (HPA) axis may be linked to spring migration. During the fall, capture stress elicited an increase in corticosterone in den-collected females but not in migrating, road-collected females. Baseline corticosterone was higher and both maximal and integrated corticosterone responses were lower during the fall compared to spring, indicating that stress responses are smaller when baseline corticosterone is elevated, perhaps due to a "ceiling effect". These data suggest that HPA axis regulation changes during seasonal migration, possibly via altering negative feedback, HPA axis sensitivity, or some other mechanism. This study supports the hypothesis that glucocorticoids coordinate life-history events and suggests that examining a suite of stress response characteristics is most informative for understanding the function of HPA modulation. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Sex differences in reinstatement of alcohol seeking in response to cues and yohimbine in rats with and without a history of adolescent corticosterone exposure.

    Science.gov (United States)

    Bertholomey, M L; Nagarajan, V; Torregrossa, Mary M

    2016-06-01

    Women represent a vulnerable and growing population with respect to alcohol abuse. Elevated glucocorticoid exposure in adolescence increases addiction risk and stress sensitivity in adulthood. However, little is known about sex differences in ethanol craving-like behavior. This study characterized sex differences in ethanol-motivated behavior following ethanol-paired cues and/or acute stimulation of the HPA axis in male and female rats with or without exposure to chronically elevated glucocorticoids in adolescence. Adolescent corticosterone-treated (Experiment 1) or naïve (Experiment 2) male and female rats were trained as adults to self-administer ethanol paired with a cue, and tested for the effects of this cue, alone or in combination with yohimbine, on the reinstatement of ethanol seeking. Females showed elevated ethanol self-administration and seeking compared to males. In Experiment 1, corticosterone exposure in adolescence augmented cue-induced reinstatement of ethanol seeking in females only, and females were more sensitive to yohimbine in promoting reinstatement. Experiment 2 replicated these findings and showed that exposure to both yohimbine and alcohol-related cues enhanced the reinstatement of alcohol seeking, producing additive effects in females. Corticosterone levels were higher in females and in yohimbine-treated rats, and corticosterone and estradiol correlated with responding during reinstatement. Chronic manipulations in adolescence and acute manipulations in adulthood of the HPA axis increase cue-induced reinstatement of ethanol seeking to a greater degree in females than in males. Elucidating the mechanisms that underlie these effects may lead to the development of sex-specific interventions aimed at mitigating alcohol relapse risk in females.

  2. {sup 125}I-iomazenil - benzodiazepine receptor binding and serum corticosterone level during psychological stress in a rat model

    Energy Technology Data Exchange (ETDEWEB)

    Fukumitsu, Nobuyoshi E-mail: GZL13162@nifty.ne.jp; Ogi, Shigeyuki; Uchiyama, Mayuki; Mori, Yutaka

    2004-02-01

    To test the hypothesis that benzodiazepine receptor density decreases in response to stress, we correlated {sup 125}I-iomazenil ({sup 125}I-IMZ) binding with serum corticosterone levels in a rat model. Wistar male rats were divided into four groups; control group (CON, 10 rats), no physical or psychological stress; and one-, three-, and five-day stress groups of 12 rats each (1-DAY, 3-DAY, and 5-DAY, respectively), receiving psychological stress for the given number of days. Psychological stress were given to rats with a communication box. The standardized uptake value (SUV) of {sup 125}I-iomazenil of the 3-DAY and 5-DAY showed that {sup 125}I-iomazenil - benzodiazepine receptor binding was significantly reduced in the cortices, accumbens nuclei, amygdala and caudate putamen (p<0.05). Serum corticosterone level ratio appeared to be slightly elevated in 3-DAY and 5-DAY, although this elevation was not significant. These data suggest that {sup 125}I-IMZ is a useful radioligand to reflect received stress and its binding in the cortices, accumbens nuclei, amygdala and caudate putamen is strongly affected by psychological stress.

  3. Corticosterone profiles in northern cardinals (Cardinalis cardinalis): Do levels vary through life history stages?

    Science.gov (United States)

    Duckworth, Benjamin M; Jawor, Jodie M

    2018-04-17

    As animals move through life history stages, energy requirements for each stage will vary. Both daily and annual variation in the glucocoriticoid hormones (specifically corticosterone, or CORT, in birds) helps provide the variable energy needed through life history stages. In many bird species, CORT is higher in the breeding season when energy demands can be quite high and is often lower in the non-breeding season. Additionally, CORT has a role to play in the response to stressful stimuli and the level to which CORT is elevated following stressful events can vary through the annual cycle as well. Here we report on baseline and stress-induced CORT levels in both sexes of northern cardinals, Cardinalis cardinalis, a non-migrating, year-round territorial species across life history stages. Corticosterone is overall higher in the non-breeding season than the breeding season in both sexes. Males tend to have higher levels of stress-induced CORT than females, although the observed patterns are complex. Our findings differ from one of the more common profile reported in songbirds where breeding season CORT tends to be higher than non-breeding levels. A strong influence may be the prolonged breeding season seen in cardinals; lower levels of CORT during breeding may guard against adverse maternal effects, interruptions in breeding behaviors, or egg production. Additional investigation of species with similar ecologies to northern cardinals, and more populations of cardinals, may show that annual glucocorticoid profiles are more labile than previously appreciated. Copyright © 2018 Elsevier Inc. All rights reserved.

  4. A Small Decrease in Rubisco Content by Individual Suppression of RBCS Genes Leads to Improvement of Photosynthesis and Greater Biomass Production in Rice Under Conditions of Elevated CO2.

    Science.gov (United States)

    Kanno, Keiichi; Suzuki, Yuji; Makino, Amane

    2017-03-01

    Rubisco limits photosynthesis at low CO2 concentrations ([CO2]), but does not limit it at elevated [CO2]. This means that the amount of Rubisco is excessive for photosynthesis at elevated [CO2]. Therefore, we examined whether a small decrease in Rubisco content by individual suppression of the RBCS multigene family leads to increases in photosynthesis and biomass production at elevated [CO2] in rice (Oryza sativa L.). Our previous studies indicated that the individual suppression of RBCS decreased Rubisco content in rice by 10-25%. Three lines of BC2F2 progeny were selected from transgenic plants with individual suppression of OsRBCS2, 3 and 5. Rubisco content in the selected lines was 71-90% that of wild-type plants. These three transgenic lines showed lower rates of CO2 assimilation at low [CO2] (28 Pa) but higher rates of CO2 assimilation at elevated [CO2] (120 Pa). Similarly, the biomass production and relative growth rate (RGR) of the two lines were also smaller at low [CO2] but greater than that of wild-type plants at elevated [CO2]. This greater RGR was caused by the higher net assimilation rate (NAR). When the nitrogen use efficiency (NUE) for the NAR was estimated by dividing the NAR by whole-plant leaf N content, the NUE for NAR at elevated [CO2] was higher in these two lines. Thus, a small decrease in Rubisco content leads to improvements of photosynthesis and greater biomass production in rice under conditions of elevated CO2. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  5. Chemical modeling of groundwater in the Banat Plain, southwestern Romania, with elevated As content and co-occurring species by combining diagrams and unsupervised multivariate statistical approaches.

    Science.gov (United States)

    Butaciu, Sinziana; Senila, Marin; Sarbu, Costel; Ponta, Michaela; Tanaselia, Claudiu; Cadar, Oana; Roman, Marius; Radu, Emil; Sima, Mihaela; Frentiu, Tiberiu

    2017-04-01

    The study proposes a combined model based on diagrams (Gibbs, Piper, Stuyfzand Hydrogeochemical Classification System) and unsupervised statistical approaches (Cluster Analysis, Principal Component Analysis, Fuzzy Principal Component Analysis, Fuzzy Hierarchical Cross-Clustering) to describe natural enrichment of inorganic arsenic and co-occurring species in groundwater in the Banat Plain, southwestern Romania. Speciation of inorganic As (arsenite, arsenate), ion concentrations (Na + , K + , Ca 2+ , Mg 2+ , HCO 3 - , Cl - , F - , SO 4 2- , PO 4 3- , NO 3 - ), pH, redox potential, conductivity and total dissolved substances were performed. Classical diagrams provided the hydrochemical characterization, while statistical approaches were helpful to establish (i) the mechanism of naturally occurring of As and F - species and the anthropogenic one for NO 3 - , SO 4 2- , PO 4 3- and K + and (ii) classification of groundwater based on content of arsenic species. The HCO 3 - type of local groundwater and alkaline pH (8.31-8.49) were found to be responsible for the enrichment of arsenic species and occurrence of F - but by different paths. The PO 4 3- -AsO 4 3- ion exchange, water-rock interaction (silicates hydrolysis and desorption from clay) were associated to arsenate enrichment in the oxidizing aquifer. Fuzzy Hierarchical Cross-Clustering was the strongest tool for the rapid simultaneous classification of groundwaters as a function of arsenic content and hydrogeochemical characteristics. The approach indicated the Na + -F - -pH cluster as marker for groundwater with naturally elevated As and highlighted which parameters need to be monitored. A chemical conceptual model illustrating the natural and anthropogenic paths and enrichment of As and co-occurring species in the local groundwater supported by mineralogical analysis of rocks was established. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Circadian variation of corticosterone in adrenal vein blood in rats exposed to different light conditions

    International Nuclear Information System (INIS)

    Ostrowska, Z.; Zwirska-Korczala, K.; Buntner, B.; Kos-Kudla, B.

    1993-01-01

    The study was undertaken to examine the regulatory influence of a different light-dark cycle on 24-h rhythm of corticosterone in adrenal vein blood. The present findings suggest that exposure to 'short day' conditions has a suppressive effect on circadian secretion of corticosterone. In rats kept in 'long day' conditions the increase of the mean 24-h corticosterone levels in adrenal vein blood and the acrophase rhythm shift were observed. In rats kept in an inverted illumination cycle the phase reversal in the periodicity of corticosterone was found. (author). 27 refs, 1 fig., 1 tab

  7. Maternal condition but not corticosterone is linked to offspring sex ratio in a passerine bird.

    Directory of Open Access Journals (Sweden)

    Lindsay J Henderson

    Full Text Available There is evidence of offspring sex ratio adjustment in a range of species, but the potential mechanisms remain largely unknown. Elevated maternal corticosterone (CORT is associated with factors that can favour brood sex ratio adjustment, such as reduced maternal condition, food availability and partner attractiveness. Therefore, the steroid hormone has been suggested to play a key role in sex ratio manipulation. However, despite correlative and causal evidence CORT is linked to sex ratio manipulation in some avian species, the timing of adjustment varies between studies. Consequently, whether CORT is consistently involved in sex-ratio adjustment, and how the hormone acts as a mechanism for this adjustment remains unclear. Here we measured maternal baseline CORT and body condition in free-living blue tits (Cyanistes caeruleus over three years and related these factors to brood sex ratio and nestling quality. In addition, a non-invasive technique was employed to experimentally elevate maternal CORT during egg laying, and its effects upon sex ratio and nestling quality were measured. We found that maternal CORT was not correlated with brood sex ratio, but mothers with elevated CORT fledged lighter offspring. Also, experimental elevation of maternal CORT did not influence brood sex ratio or nestling quality. In one year, mothers in superior body condition produced male biased broods, and maternal condition was positively correlated with both nestling mass and growth rate in all years. Unlike previous studies maternal condition was not correlated with maternal CORT. This study provides evidence that maternal condition is linked to brood sex ratio manipulation in blue tits. However, maternal baseline CORT may not be the mechanistic link between the maternal condition and sex ratio adjustment. Overall, this study serves to highlight the complexity of sex ratio adjustment in birds and the difficulties associated with identifying sex biasing mechanisms.

  8. Experimental increase in baseline corticosterone level reduces oxidative damage and enhances innate immune response.

    Directory of Open Access Journals (Sweden)

    Csongor I Vágási

    Full Text Available Glucocorticoid (GC hormones are significant regulators of homeostasis. The physiological effects of GCs critically depend on the time of exposure (short vs. long as well as on their circulating levels (baseline vs. stress-induced. Previous experiments, in which chronic and high elevation of GC levels was induced, indicate that GCs impair both the activity of the immune system and the oxidative balance. Nonetheless, our knowledge on how mildly elevated GC levels, a situation much more common in nature, might influence homeostasis is limited. Therefore, we studied whether an increase in GC level within the baseline range suppresses or enhances condition (body mass, hematocrit and coccidian infestation and physiological state (humoral innate immune system activity and oxidative balance. We implanted captive house sparrows Passer domesticus with either 60 days release corticosterone (CORT or control pellets. CORT-treated birds had elevated baseline CORT levels one week after the implantation, but following this CORT returned to its pre-treatment level and the experimental groups had similar CORT levels one and two months following the implantation. The mass of tail feathers grown during the initial phase of treatment was smaller in treated than in control birds. CORT implantation had a transient negative effect on body mass and hematocrit, but both of these traits resumed the pre-treatment values by one month post-treatment. CORT treatment lowered oxidative damage to lipids (malondialdehyde and enhanced constitutive innate immunity at one week and one month post-implantation. Our findings suggest that a relatively short-term (i.e. few days elevation of baseline CORT might have a positive and stimulatory effect on animal physiology.

  9. Fructose increases corticosterone production in association with NADPH metabolism alterations in rat epididymal white adipose tissue.

    Science.gov (United States)

    Prince, Paula D; Santander, Yanina A; Gerez, Estefania M; Höcht, Christian; Polizio, Ariel H; Mayer, Marcos A; Taira, Carlos A; Fraga, Cesar G; Galleano, Monica; Carranza, Andrea

    2017-08-01

    Metabolic syndrome is an array of closely metabolic disorders that includes glucose intolerance/insulin resistance, central obesity, dyslipidemia, and hypertension. Fructose, a highly lipogenic sugar, has profound metabolic effects in adipose tissue, and has been associated with the etiopathology of many components of the metabolic syndrome. In adipocytes, the enzyme 11 β-HSD1 amplifies local glucocorticoid production, being a key player in the pathogenesis of central obesity and metabolic syndrome. 11 β-HSD1 reductase activity is dependent on NADPH, a cofactor generated by H6PD inside the endoplasmic reticulum. Our focus was to explore the effect of fructose overload on epididymal white adipose tissue (EWAT) machinery involved in glucocorticoid production and NADPH and oxidants metabolism. Male Sprague-Dawley rats fed with a fructose solution (10% (w/v) in tap water) during 9 weeks developed some characteristic features of metabolic syndrome, such as hypertriglyceridemia, and hypertension. In addition, high levels of plasma and EWAT corticosterone were detected. Activities and expressions of H6PD and 11 β-HSD1, NAPDH content, superoxide anion production, expression of NADPH oxidase 2 subunits, and indicators of oxidative metabolism were measured. Fructose overloaded rats showed an increased potential in oxidant production respect to control rats. In parallel, in EWAT from fructose overloaded rats we found higher expression/activity of H6PD and 11 β-HSD1, and NADPH/NADP + ratio. Our in vivo results support that fructose overload installs in EWAT conditions favoring glucocorticoid production through higher H6PD expression/activity supplying NADPH for enhanced 11 β-HSD1 expression/activity, becoming this tissue a potential extra-adrenal source of corticosterone under these experimental conditions. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Resveratrol Ameliorates the Depressive-Like Behaviors and Metabolic Abnormalities Induced by Chronic Corticosterone Injection

    Directory of Open Access Journals (Sweden)

    Yu-Cheng Li

    2016-10-01

    Full Text Available Chronic glucocorticoid exposure is known to cause depression and metabolic disorders. It is critical to improve abnormal metabolic status as well as depressive-like behaviors in patients with long-term glucocorticoid therapy. This study aimed to investigate the effects of resveratrol on the depressive-like behaviors and metabolic abnormalities induced by chronic corticosterone injection. Male ICR mice were administrated corticosterone (40 mg/kg by subcutaneous injection for three weeks. Resveratrol (50 and 100 mg/kg, fluoxetine (20 mg/kg and pioglitazone (10 mg/kg were given by oral gavage 30 min prior to corticosterone administration. The behavioral tests showed that resveratrol significantly reversed the depressive-like behaviors induced by corticosterone, including the reduced sucrose preference and increased immobility time in the forced swimming test. Moreover, resveratrol also increased the secretion of insulin, reduced serum level of glucose and improved blood lipid profiles in corticosterone-treated mice without affecting normal mice. However, fluoxetine only reverse depressive-like behaviors, and pioglitazone only prevent the dyslipidemia induced by corticosterone. Furthermore, resveratrol and pioglitazone decreased serum level of glucagon and corticosterone. The present results indicated that resveratrol can ameliorate depressive-like behaviors and metabolic abnormalities induced by corticosterone, which suggested that the multiple effects of resveratrol could be beneficial for patients with depression and/or metabolic syndrome associated with long-term glucocorticoid therapy.

  11. Localization of aldosterone and corticosterone in the central nervous system, assessed by quantitative autoradiography

    International Nuclear Information System (INIS)

    Birmingham, M.K.; Sar, M.; Stumpf, W.E.

    1984-01-01

    Nuclear localization of tritiated aldosterone in the CNS was studied in rats by numerical evaluation of silver grains, deposited over neuronal cell nuclei in thaw-mounted autoradiograms, and compared with the localization obtained after prior administration of a 100-fold excess of radioinert aldosterone, corticosterone or 18-hydroxy-11-deoxycorticosterone (18-OH-DOC). Corticosterone and 18-OH-DOC completely prevented nuclear localization in most regions examined. However, in contrast to pretreatment with aldosterone, pretreatment with corticosterone and 18-OH-DOC did not completely prevent the concentration of radioactivity in the cell nuclei of the indusium griseum. Traces of radioactivity were, furthermore, retained in areas CA1 and CA2 and the dentate gyrus in rats exposed to corticosterone, but not to 18-OH-DOC, prior to [ 3 H]aldosterone. A similar profile of silver grain distribution to that noted with aldosterone was found for corticosterone except that with tritiated corticosterone the most intense concentration of radioactivity occurred in hippocampal areas CA1 and CA2 and not in the indusium griseum. The authors conclude that (1) a receptor readily shared by aldosterone, corticosterone, 18-OH-DOC and DOC, but not by dihydrotestosterone, is widely distributed throughout the CNS, (2) a receptor shared by aldosterone and 18-OH-DOC, but not by corticosterone may be present in hippocampal areas CA1 and CA2, (3) that both these as well as the receptor accepting dihydrotestosterone can be located within the same cell

  12. Corticosterone and propranolol's role on taste recognition memory.

    Science.gov (United States)

    Ruetti, E; Justel, N; Mustaca, A; Boccia, M

    2014-12-01

    Taste recognition is a robust procedure to study learning and memory processes, as well as the different stages involved in them, i.e. encoding, storage and recall. Considerable evidence indicates that adrenal hormones and the noradrenergic system play an important role in aversive and appetitive memory formation in rats and humans. The present experiments were designed to characterize the effects of immediate post training corticosterone (Experiment 1) and propranolol administration (Experiment 2 and 3) on taste recognition memory. Administration of a high dose of corticosterone (5mg/kg, sc) impairs consolidation of taste memory, but the low and moderate doses (1 and 3mg/kg, sc) didn't affect it. On the other hand, immediate post-training administration of propranolol (1 and 2mg/kg, ip) impaired taste recognition memory. These effects were time-dependent since no effects were seen when drug administration was delayed 3h after training. These findings support the importance of stress hormones and noradrenergic system on the modulation of taste memory consolidation. Copyright © 2014. Published by Elsevier Inc.

  13. High plasma corticosterone levels persist during frequent automatic blood sampling in rats

    DEFF Research Database (Denmark)

    Abelson, Klas S P; Adem, Bashir; Royo, Felix

    2005-01-01

    Corticosterone levels in blood may be used as a marker of stress in rodents, provided that the blood sampling procedure itself is non-stressful. Automated blood sampling equipment (Accusampler) allows blood sampling without any interference with the animal and might be useful as a tool for an on......-line measurement of stress markers in blood. However, the impact of the blood sampling itself on the corticosterone levels in blood is unknown. The present study was designed to evaluate whether the frequency of blood sampling influences the plasma corticosterone levels in male and female rats. During anaesthesia...... the importance of considering the frequency of blood withdrawal during automated blood sampling. This parameter may have an impact on the experimental results when using blood corticosterone levels as a stress marker, but also during any in vivo study where blood is collected, since high corticosterone levels...

  14. Distribution and time course of corticosterone excretion in faeces and urine of female mice with varying systemic concentrations

    DEFF Research Database (Denmark)

    Kalliokoski, Otto; Hau, Jann; Jacobsen, Kirsten R

    2010-01-01

    distribution and time course of corticosterone excretion, after intravenous injection of varying corticosterone concentrations, was investigated in female mice. Female BALB/c mice excreted 60% of all corticosterone in the urine with an approximate delay of 5h from tail vein administration. The remaining 40......% were excreted in faeces, with an approximate delay of 9h from administration. The faecal/urinary excretion ratio, as well as time course of excretion, remained unaltered by administration of various doses of corticosterone covering the entire physiological range of serum corticosterone. Although...

  15. Corticosterone and time-activity budget: an experiment with Black-legged kittiwakes.

    Science.gov (United States)

    Angelier, Frédéric; Clément-Chastel, Céline; Gabrielsen, Geir Wing; Chastel, Olivier

    2007-11-01

    In vertebrates, the well established increase in plasma corticosterone in response to food shortage is thought to mediate adjustments of foraging behavior and energy allocation to environmental conditions. However, investigating the functional role of corticosterone is often constrained by the difficulty to track time-activity budget of free-ranging animals. To examine how an experimental increase in corticosterone affects the activity budget of male Black-legged kittiwakes (Rissa tridactyla), we used miniaturized activity loggers to record flying/foraging, presence on the sea surface and nest attendance. To investigate how corticosterone affects allocation processes between self-foraging and foraging devoted to the brood, we monitored body mass change of males from capture (day 0) to recapture (day 3). Among control birds, males in poor condition at day 0 spent significantly more time flying/foraging and less time attending the nest site than did males in good condition. Corticosterone treatment affected time spent flying/foraging in interaction with body condition at day 0: corticosterone-implanted males in good condition spent more time flying/foraging than control ones; this was not observed in poor condition males. In control birds, change in body mass was negatively correlated with body condition at day 0. This was reinforced by corticosterone treatment and, on average, corticosterone-implanted males gained much more mass than controls. These results suggest that in Black-legged kittiwakes, body condition and corticosterone levels can interact to mediate foraging decisions and possibly energy allocation: when facing stressful environmental conditions, birds in good body condition may afford to increase the time spent foraging probably to maintain brood provisioning, whereas poor body condition birds seemed rather to redirect available energy from reproduction to self-maintenance.

  16. Effects of Topical Anesthetics on Behavior, Plasma Corticosterone, and Blood Glucose Levels after Tail Biopsy of C57BL/6NHSD Mice (Mus musculus).

    Science.gov (United States)

    Dudley, Emily S; Johnson, Robert A; French, DeAnne C; Boivin, Gregory P

    2016-01-01

    Tail biopsy is a common procedure that is performed to obtain genetic material for determining genotype of transgenic mice. The use of anesthetics or analgesics is recommended, although identifying safe and effective drugs for this purpose has been challenging. We evaluated the effects of topical 2.5% lidocaine-2.5% prilocaine cream applied to the distal tail tip at 5 or 60 min before biopsy, immersion of the tail tip for 10 seconds in ice-cold 70% ethanol just prior to biopsy, and immersion of the tail tip in 0.5% bupivacaine for 30 s after biopsy. Mice were 7, 11, or 15 d old at the time of tail biopsy. Acute behavioral responses, plasma corticosterone, and blood glucose were measured after biopsy, and body weight and performance in elevated plus maze and open-field tests after weaning. Ice-cold ethanol prior to biopsy prevented acute behavioral responses to biopsy, and both ice-cold ethanol and bupivacaine prevented elevations in corticosterone and blood glucose after biopsy. Tail biopsy with or without anesthesia did not affect body weight or performance on elevated plus maze or open-field tests. We recommend the use of ice-cold ethanol for topical anesthesia prior to tail biopsy in mice 7 to 15 d old.

  17. Elevated CO2 induces substantial and persistent declines in forage digestibility and protein content irrespective of warming in mixed-grass prairie

    Science.gov (United States)

    Increasing atmospheric [CO2] and temperature are expected to affect the productivity, species composition, biogeochemistry, and therefore the quantity and quality of forage available to herbivores in rangeland ecosystems. Both elevated CO2 (eCO2) and warming affect plant tissue chemistry through mul...

  18. Adrenal and plasma corticosterone changes in continuously irradiated rats. II. Dependence on additional stress factors

    Energy Technology Data Exchange (ETDEWEB)

    Malatova, Z; Ahlers, I; Praslicka, M [Univerzita P.J. Safarika, Kosice (Czechoslovakia). Katedra Vseobecnej Biologie

    1978-01-01

    Adrenal and plasma corticosterone levels were followed in continuously irradiated rats in dependence on additional stress factors - transport of animals, handling and overnight fasting. Rats were gamma irradiated on an open experimental field with a daily dose rate of 15.48x10/sup -3/ C/kg (60 R) continuously up to a total exposure of 387.0x10/sup -3/ C/kg (1500 R) and analyzed after irradiation. The continuous irradiation increased the adrenal and plasma corticosterone concentrations in all groups of animals. The transport and weighing increased mainly adrenal corticosterone in all three groups, irradiated, non-irradiated controls from the field and intact laboratory controls. The scatter of the results made reproducibility difficult. Overnight fasting increased the absolute values in all groups. The radiation effect was evident especially in adrenal corticosterone values of non-handled animals.

  19. Quantitative autoradiography of [3H]corticosterone receptors in rat brain

    International Nuclear Information System (INIS)

    Sapolsky, R.M.; McEwen, B.S.; Rainbow, T.C.

    1983-01-01

    The authors have quantified corticosterone receptors in rat brain by optical density measurements of tritium-film autoradiograms. Rats were injected i.v. with 500 μCi [ 3 H]corticosterone to label brain receptors. Frozen sections of brain were cut with a cryostat and exposed for 2 months against tritium-sensitive sheet film (LKB Ultrofilm). Tritium standards were used to convert optical density readings into molar concentrations of receptor. High levels of corticosterone receptors were present throughout the pyramidal and granule cell layers of the hippocampus. Moderate levels of receptors were found in the neuropil of the hippocampus, the lateral septum, the cortical nucleus of the amygdala and the entorhinal cortex. All other brain regions had low levels of receptors. These results extend previous non-quantitative autoradigraphic studies of corticosterone receptors and provide a general procedure for the quantitative autoradiography of steroid hormone receptors in brain tissue. (Auth.)

  20. Dynamics of plasma catecholamine and corticosterone concentrations during reinforced and extinguished operant behavior in rats

    NARCIS (Netherlands)

    de Boer, S.F.; de Beun, R; Slangen, J L; van der Gugten, J

    Plasma noradrenaline (NA), adrenaline (A) and corticosterone (CS) concentrations were determined simultaneously in permanently heart-cannulated rats before and during the performance of reinforced and nonreinforced (extinguished) operant behavior. Shortly before the experimental food-reinforced (VI

  1. Corticosterone levels and behavioral changes induced by simultaneous exposure to chronic social stress and enriched environments in NMRI male mice.

    Science.gov (United States)

    Mesa-Gresa, Patricia; Ramos-Campos, Marta; Redolat, Rosa

    2016-05-01

    : animals allocated in EE during Phase I of the study showed higher corticosterone levels, lower body weight and higher fluid intake than SE mice. "Initial Stress" had significant long-term actions on food intake and exploratory behavior: animals initially reared under stress conditions displayed higher food intake and lower exploration levels on the hole-board test than non-stressed mice. In the elevated plus-maze, there were significant interactions between factors "Initial Housing" and "Initial Stress". These factors did not reach statistical significance for motor activity or learning task. We can conclude that both short- and long-term effects of housing conditions are evident for corticosterone levels, body weight and fluid intake. Social stress induced short-term effects on body weight, food and fluid intake and exploratory behavior whereas long-acting effects were reflected on food intake and exploratory behavior. Further studies are needed in order to explore more in depth behavioral and physiological consequences of social stress and environmental enrichment. Copyright © 2016. Published by Elsevier Inc.

  2. Magellanic penguin telomeres do not shorten with age with increased reproductive effort, investment, and basal corticosterone.

    Science.gov (United States)

    Cerchiara, Jack A; Risques, Rosa Ana; Prunkard, Donna; Smith, Jeffrey R; Kane, Olivia J; Boersma, P Dee

    2017-08-01

    All species should invest in systems that enhance longevity; however, a fundamental adult life-history trade-off exists between the metabolic resources allocated to maintenance and those allocated to reproduction. Long-lived species will invest more in reproduction than in somatic maintenance as they age. We investigated this trade-off by analyzing correlations among telomere length, reproductive effort and output, and basal corticosterone in Magellanic penguins ( Spheniscus magellanicus ). Telomeres shorten with age in most species studied to date, and may affect adult survival. High basal corticosterone is indicative of stressful conditions. Corticosterone, and stress, has been linked to telomere shortening in other species. Magellanic penguins are a particularly good model organism for this question as they are an unusually long-lived species, exceeding their mass-adjusted predicted lifespan by 26%. Contrary to our hypothesis, we found adults aged 5 years to over 24 years of age had similar telomere lengths. Telomeres of adults did not shorten over a 3-year period, regardless of the age of the individual. Neither telomere length, nor the rate at which the telomeres changed over these 3 years, correlated with breeding frequency or investment. Older females also produced larger volume clutches until approximately 15 years old and larger eggs produced heavier fledglings. Furthermore, reproductive success ( chicks fledged/eggs laid ) is maintained as females aged. Basal corticosterone, however, was not correlated with telomere length in adults and suggests that low basal corticosterone may play a role in the telomere maintenance we observed. Basal corticosterone also declined during the breeding season and was positively correlated with the age of adult penguins. This higher basal corticosterone in older individuals, and consistent reproductive success, supports the prediction that Magellanic penguins invest more in reproduction as they age. Our results

  3. Breakfast skippers display a disrupted cortisol rhythm and elevated blood pressure

    Science.gov (United States)

    Chronic stress and over-activity in the hypothalamic-pituitary-adrenal (HPA) axis may link breakfast skipping and poor cardiometabolic health. Missing the first major meal of the day in rodents prolongs elevated circulating corticosterone at a time when it’s normally decreasing. To extend these fi...

  4. Seasonal and daily plasma corticosterone rhythms in American toads, Bufo americanus

    International Nuclear Information System (INIS)

    Pancak, M.K.; Taylor, D.H.

    1983-01-01

    Concentrations of corticosterone were measured in the plasma of American toads, Bufo americanus, on a seasonal basis using a radioimmunoassay technique. Two populations of toads, maintained under different light conditions, were monitored to observe the effects of photoperiod on the seasonal rhythm of plasma corticosterone. Under a natural photoperiod toads demonstrated a rhythm consisting of a spring peak and a fall peak in corticosterone concentration. Toads maintained under a 12L:12D photoperiod all year round demonstrated a similar rhythm with peaks in the spring and fall. This suggests that an endogenous (circannual) rhythm of corticosterone may be playing an important role in the seasonal change of overt behavior and physiology of Bufo americanus. A daily rhythm of corticosterone was also detected in toads when blood samples were taken every 4 hr. When compared to a previously published circadian rhythm study of locomotor activity, the surge in corticosterone concentration for the day occurred at 1730 just prior to the peak in locomotor activity

  5. The effects of maternal corticosterone levels on offspring behavior in fast- and slow-growth garter snakes (Thamnophis elegans).

    Science.gov (United States)

    Robert, Kylie A; Vleck, Carol; Bronikowski, Anne M

    2009-01-01

    During embryonic development, viviparous offspring are exposed to maternally circulating hormones. Maternal stress increases offspring exposure to corticosterone and this hormonal exposure has the potential to influence developmental, morphological and behavioral traits of the resulting offspring. We treated pregnant female garter snakes (Thamnophis elegans) with low levels of corticosterone after determining both natural corticosterone levels in the field and pre-treatment levels upon arrival in the lab. Additional measurements of plasma corticosterone were taken at days 1, 5, and 10 during the 10-day exposure, which occurred during the last third of gestation (of 4-month gestation). These pregnant snakes were from replicate populations of fast- and slow-growth ecotypes occurring in Northern California, with concomitant short and long lifespans. Field corticosterone levels of pregnant females of the slow-growth ecotype were an order of magnitude higher than fast-growth dams. In the laboratory, corticosterone levels increased over the 10 days of corticosterone manipulation for animals of both ecotypes, and reached similar plateaus for both control and treated dams. Despite similar plasma corticosterone levels in treated and control mothers, corticosterone-treated dams produced more stillborn offspring and exhibited higher total reproductive failure than control dams. At one month of age, offspring from fast-growth females had higher plasma corticosterone levels than offspring from slow-growth females, which is opposite the maternal pattern. Offspring from corticosterone-treated mothers, although unaffected in their slither speed, exhibited changes in escape behaviors and morphology that were dependent upon maternal ecotype. Offspring from corticosterone-treated fast-growth females exhibited less anti-predator reversal behavior; offspring from corticosterone-treated slow-growth females exhibited less anti-predator tail lashing behavior.

  6. Dehydroepiandrosterone Attenuates Cocaine-Seeking Behaviour Independently of Corticosterone Fluctuations.

    Science.gov (United States)

    Maayan, R; Hirsh, L; Yadid, G; Weizman, A

    2015-11-01

    The neurosteroid dehydroepiandrosterone (DHEA) is involved in the pathophysiology of several psychiatric disorders, including cocaine addiction. We have previously shown that DHEA attenuates cocaine-seeking behaviour, and also that DHEA decreases corticosterone (CORT) levels in plasma and the prefrontal cortex. Previous studies have found that rats demonstrate cocaine-seeking behaviour only when the level of CORT reaches a minimum threshold. In the present study, we investigated whether the attenuating effect of DHEA on cocaine seeking is a result of it reducing CORT levels rather than a result of any unique neurosteroid properties. Rats received either daily DHEA injections (2 mg/kg, i.p.) alone, daily DHEA (2 mg/kg, i.p.) with CORT infusion (to maintain stable basal levels of CORT; 15 mg/kg, s.c.) or vehicle (i.p.) as control, throughout self-administration training and extinction sessions. We found that both DHEA-treated and DHEA + CORT-treated groups showed a significantly lower number of active lever presses compared to controls throughout training and extinction sessions, as well as at cocaine-primed reinstatement. DHEA-treated rats showed lower CORT levels throughout the experimental phases compared to DHEA + CORT-treated and control rats. Additionally, we show that DHEA administered to cocaine-trained rats throughout extinction sessions, or immediately before reinstatement, attenuated cocaine seeking. These findings indicate that DHEA attenuates cocaine-seeking behaviour independently of fluctuations in CORT levels. © 2015 British Society for Neuroendocrinology.

  7. Corticosterone-responsive and -unresponsive metabolic characteristics of adrenalectomized rats.

    Science.gov (United States)

    Hamelink, C R; Currie, P J; Chambers, J W; Castonguay, T W; Coscina, D V

    1994-09-01

    Glucocorticoids are important in influencing substrate flux through the metabolic pathways. This study was designed to answer the question "Does adrenalectomy (ADX) cause a shift toward fat metabolism as measured by a decrease in respiratory quotient (RQ)?" Male Sprague-Dawley rats were divided into four groups, ADX, ADX + 20% corticosterone (Cort) (ADX-20%), ADX + 40% Cort (ADX-40%), or sham-operated controls (Sham). ADX-20% received 50 mg and ADX-40% 100 mg Cort dissolved in 250-mg cholesterol pellets and placed subcutaneously. Each rat was monitored for 90 min four times both during a preoperative period and again after a 1-wk postsurgical recovery period in an indirect calorimeter. Cort prevented ADX-induced suppression of weight gain and food intake. ADX decreased motoric activity in both the light and dark periods. Cort restored activity to Sham levels. ADX decreased RQ only in the dark (0.858 ADX vs. 0.891 Sham) and was reversed only in the ADX-40% group. Energy expenditure (EE) was depressed in both the light and dark by ADX; Cort partially restored EE to Sham values in the light period.

  8. Transient elevation of element contents as a result of neuronal death in mutant-mice cerebellum studied by neutron activation analysis

    International Nuclear Information System (INIS)

    Kranda, K.; Kucera, J.; Baeurle, J.

    2006-01-01

    Accumulation of some metals, in particular iron or manganese, has long been considered to trigger or accentuate neurodegenerative processes in humans. The two most frequently cited examples are Parkinson's and Alzheimer diseases, where excitotoxic processes lead to neuronal death. However, these neuropathies are somewhat unsuitable for investigating the time course of the metal accumulation because the applied analytical methods such as neutron activation analysis (NAA) are invasive. Hence, only one measurement can be made after the patient's death. Animal models of Parkinson's type neurodegeneration, such as mice mutants, are more suitable as a larger number of animals can be investigated at various postnatal ages. In this study we used one type of mice mutants weaver, where primary neurodegeneration is principally confined to the cerebellum and centred in time around the postnatal age of six days. Elemental composition of brain segments with dry mass as low as 0.5 mg, which were isolated from weaver and wild type (normal) mice were investigated using a combination of INAA and RNAA. Elevated concentration of the following elements Fe, Zn, Cu, K, Na, Rb, and Br that were observed in the weaver's cerebella closely followed the time course of neurodegeneration documented for this type of mutant. The transient elevation of these elements never preceded the onset of neurodegeneration but closely mirrored its time course reaching its peak on the sixth day. The concentration of these elements in the weaver's cerebella declined afterwards to converge on the elemental time course observed in the wild type mice. In conclusion, metal and other elemental elevation observed in the cerebella of these mutants are an expression of neurodegenerative processes rather than its precondition. (author)

  9. Towards a better preclinical model of PTSD: characterizing animals with weak extinction, maladaptive stress responses and low plasma corticosterone.

    Science.gov (United States)

    Reznikov, Roman; Diwan, Mustansir; Nobrega, José N; Hamani, Clement

    2015-02-01

    Most of the available preclinical models of PTSD have focused on isolated behavioural aspects and have not considered individual variations in response to stress. We employed behavioural criteria to identify and characterize a subpopulation of rats that present several features analogous to PTSD-like states after exposure to classical fear conditioning. Outbred Sprague-Dawley rats were segregated into weak- and strong-extinction groups on the basis of behavioural scores during extinction of conditioned fear responses. Animals were subsequently tested for anxiety-like behaviour in the open-field test (OFT), novelty suppressed feeding (NSF) and elevated plus maze (EPM). Baseline plasma corticosterone was measured prior to any behavioural manipulation. In a second experiment, rats underwent OFT, NSF and EPM prior to being subjected to fear conditioning to ascertain whether or not pre-stress levels of anxiety-like behaviours could predict extinction scores. We found that 25% of rats exhibit low extinction rates of conditioned fear, a feature that was associated with increased anxiety-like behaviour across multiple tests in comparison to rats showing strong extinction. In addition, weak-extinction animals showed low levels of corticosterone prior to fear conditioning, a variable that seemed to predict extinction recall scores. In a separate experiment, anxiety measures taken prior to fear conditioning were not predictive of a weak-extinction phenotype, suggesting that weak-extinction animals do not show detectable traits of anxiety in the absence of a stressful experience. These findings suggest that extinction impairment may be used to identify stress-vulnerable rats, thus providing a useful model for elucidating mechanisms and investigating potential treatments for PTSD. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Comparisons among serum, egg albumin and yolk concentrations of corticosterone as biomarkers of basal and stimulated adrenocortical activity of laying hens.

    Science.gov (United States)

    Cook, N J; Renema, R; Wilkinson, C; Schaefer, A L

    2009-09-01

    1. Serial blood samples from individual birds were analysed for corticosterone concentrations under basal and stimulated conditions, and matched to eggs from the same birds for comparison to albumin and yolk concentrations of corticosterone. 2. Serum corticosterone exhibited increases in response to stimulation by ACTH and Handling stress. There were no significant increases in egg albumin or yolk concentrations of corticosterone following stimulation. 3. Several significant correlations were observed between the mean and area under the curve (AUC) measurements of serum corticosterone concentrations with albumin and yolk corticosterone concentrations in eggs laid from 1 to 2 d later. 4. The results demonstrated a relationship between endogenous concentrations of serum corticosterone that reflected daily adrenocortical output with albumin and yolk corticosterone concentrations in eggs laid the following day. 5. The results do not support the concept of albumin and yolk concentrations of corticosterone as biomarkers of acute adrenocortical responses to stimulation.

  11. Experimental relationships between levels of corticosterone in plasma and feathers in a free-living bird.

    Science.gov (United States)

    Fairhurst, Graham D; Marchant, Tracy A; Soos, Catherine; Machin, Karen L; Clark, Robert G

    2013-11-01

    Integrated measures of corticosterone (CORT), such as from feathers (CORTf), have intuitive appeal because they incorporate both the duration and amplitude of glucocorticoid secretion. An association between CORTf and plasma CORT has never been shown in wild birds, and it is unclear as to when and whether these measures should be correlated, given that they are fundamentally different yet related measures of physiology. We hypothesized that CORTf should correlate with instantaneous measurements of plasma CORT when the latter reflect sustained changes in the activity of the hypothalamic-pituitary-adrenal (HPA) axis. To test this, we experimentally manipulated levels of plasma CORT in wild nestling tree swallows (Tachycineta bicolor) using 5 day time-release CORT pellets, and measured plasma CORT and growth parameters before, during and at the end of hormone manipulation (days 7, 9 and 11 post-hatch, respectively). CORTf and plasma CORT were significantly positively related only when the latter was at its highest and most variable among individuals (day 9). A similar relationship was expected at day 11, but plasma CORT had returned to near-original levels. Nestlings with higher CORTf were smaller, lighter and less likely to fledge, but we did not detect seasonal effects on CORTf. Our results clearly demonstrate that CORTf from free-living birds can reflect plasma CORT, but correlations may not always be expected, especially if elevations in plasma CORT are relatively modest and of short duration. Our work suggests that CORTf is best used to study the activity of the HPA axis over relatively long time frames and can be used effectively to advance avian ecology.

  12. Benefits and costs of increased levels of corticosterone in seabird chicks

    Science.gov (United States)

    Kitaysky, A.S.; Kitaiskaia, E.V.; Piatt, John F.; Wingfield, J.C.

    2003-01-01

    Seabird chicks respond to food shortages by increasing corticosterone (cort) secretion, which is probably associated with fitness benefits and costs. To examine this, we experimentally increased levels of circulating cort in captive black-legged kittiwake chicks fed ad libitum. We found that cort-implanted chicks begged more frequently and were more aggressive compared to controls. These behavioral modifications must be beneficial to chicks as they facilitate acquisition of food from the parents and might trigger brood reduction and reduced competition for food. Cort-implanted chicks also increased food intake; however, their growth rates were similar to controls. To examine the costs of chronically increased circulating levels of cort, we removed cort implants and, after a 10-day recovery period, tested cognitive abilities of young kittiwakes. We found that the ability of kittiwakes to associate a visual cue with the presence of food in a choice situation was compromised by the experimental elevation of cort during development. To examine the long-term costs of increased levels of cort, 8 months later we tested the performance of the same individuals in a spatial task requiring them to make a detour around a barrier in order to escape from an enclosure. Individuals treated with cort during development took significantly more time to solve this task compared to controls. The results of this study suggest that the adrenocortical response of a developing bird to environmental stressors is associated with both benefits (increased food intake, foraging behavior, and aggression) and costs (low growth efficiency and compromised cognitive abilities later in life). This provides an evolutionary framework for relating juvenile physiological traits to fitness of birds in subsequent life-history stages. ?? 2003 Elsevier Science (USA). All rights reserved.

  13. Possible roles for corticosterone and critical size in the fledging of nestling pied flycatchers.

    Science.gov (United States)

    Kern, M; Bacon, W; Long, D; Cowie, R J

    2001-01-01

    Our study was designed to see whether corticosterone (B) rises abruptly in the blood of nestling pied flycatchers (Ficedula hypoleuca) at the time they fledge, as reported recently for kestrels, and if so, why. We measured the growth and blood levels of B and selected nutrients of nestlings in broods of five, seven, and nine chicks during 1998 and 1999. In half of the broods, we clipped selected wing and tail feathers of both parents with the intention of making it more difficult for them to provide their chicks with food. We collected blood samples when the chicks were six to 10 d old (period of rapid growth) and 15 d of age or older (0-5 d before fledging). B increased substantially several days before the chicks left the nest and then declined somewhat. We found no differences in rates of growth or blood levels of B, nutrients, and hematocrit as a function of either brood size or parental handicapping. Nestlings within a day of fledging appear to have been food deprived in 1998; their glucose was significantly reduced, and B, free fatty acids, and glycerol were significantly elevated compared to levels in chicks 1-4 d younger. Such changes did not occur in 1999. Blood levels of B were significantly correlated with brood size near the day of fledging, but not earlier, in both years of the study. It was possible to predict the day on which chicks would leave the nest, using their wing length when 12 d old. These results suggest that high blood levels of B associated with food restriction and sibling competition induce chicks to fledge, provided they have reached a critical size, and that the importance of fasting, sibling competition, and B may vary from year to year.

  14. Corticosterone, but not Glucose, Treatment Enables Fasted Adrenalectomized Rats to Survive Moderate Hemorrhage

    Science.gov (United States)

    Darlington, Daniel N.; Chew, Gordon; Ha, Taryn; Keil, Lanny C.; Dallman, Mary F.

    1990-01-01

    Fed adrenalectomized rats survive the stress of hemorrhage and hypovolemia, whereas fasted adrenalectomized rats become hypotensive and hypoglycemic after the first 90 min and die within 4 hours (h). We have studied the effects of glucose and corticosterone (B) infusions after hemorrhage as well as treatment with B at the time of adrenalectomy on the capacity of chronically prepared, conscious, fasted, adrenalectomized rats to survive hemorrhage. We have also measured the magnitudes of vasoactive hormone responses to hemorrhage. Maintenance of plasma glucose concentrations did not sustain life; however, treatment of rats at the time of adrenalectomy with B allowed 100 percent survival, and acute treatment of adrenalectomized rats at the time of hemorrhage allowed about 50 percent survival during the 5-h posthemorrhage observation period. Rats in the acute B infusion group that died exhibited significantly increased plasma B and significantly decreased plasma glucose concentrations by 2 h compared to the rats that lived. Plasma vasopressin, renin, and norepinephrine responses to hemorrhage were markedly augmented in the adrenalectomized rats not treated with B, and plasma vasopressin concentrations were significantly elevated at 1 and 2 h in all of the rats that subsequently died compared to values in those that lived. We conclude that: 1) death after hemorrhage in fasted adrenalectomized rats is not a result of lack of glucose; 2) chronic and, to an extent, acute treatment of fasted adrenalectomized rats with B enables survival; 3) fasted adrenalectomized rats exhibit strong evidence of hepatic insufficiency which is not apparent in either fed adrenalectomized rats or B-treated fasted adrenalectomized rats; 4) death after hemorrhage in fasted adrenalectomized rats may result from hepatic failure as a consequence of marked splanchnic vasoconstriction mediated bv the actions of extraordinarily high levels of vasoactive hormones after hemorrhage; and 5) B appears to

  15. Peripheral mechanisms contributing to the glucocorticoid hypersensitivity in proopiomelanocortin null mice treated with corticosterone

    Science.gov (United States)

    Michailidou, Zoi; Coll, Anthony P; Kenyon, Christopher J; Morton, Nicholas M; O'Rahilly, Stephen; Seckl, Jonathan R; Chapman, Karen E

    2007-01-01

    Proopiomelanocortin (POMC) deficiency causes severe obesity through hyperphagia of hypothalamic origin. However, low glucocorticoid levels caused by adrenal insufficiency mitigate against insulin resistance, hyperphagia and fat accretion in Pomc−/− mice. Upon exogenous glucocorticoid replacement, corticosterone-supplemented (CORT) Pomc−/− mice show exaggerated responses, including excessive fat accumulation, hyperleptinaemia and insulin resistance. To investigate the peripheral mechanisms underlying this glucocorticoid hypersensitivity, we examined the expression levels of key determinants and targets of glucocorticoid action in adipose tissue and liver. Despite lower basal expression of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1), which generates active glucocorticoids within cells, CORT-mediated induction of 11β-HSD1 mRNA levels was more pronounced in adipose tissues of Pomc−/− mice. Similarly, CORT treatment increased lipoprotein lipase mRNA levels in all fat depots in Pomc−/− mice, consistent with exaggerated fat accumulation. Glucocorticoid receptor (GR) mRNA levels were selectively elevated in liver and retroperitoneal fat of Pomc−/− mice but were corrected by CORT in the latter depot. In liver, CORT increased phosphoenolpyruvate carboxykinase mRNA levels specifically in Pomc−/− mice, consistent with their insulin-resistant phenotype. Furthermore, CORT induced hypertension in Pomc−/− mice, independently of adipose or liver renin–angiotensin system activation. These data suggest that CORT-inducible 11β-HSD1 expression in fat contributes to the adverse cardiometabolic effects of CORT in POMC deficiency, whereas higher GR levels may be more important in liver. PMID:17592030

  16. A Phenylurea Cytokinin, CPPU, Elevated Reducing Sugar and Correlated to Andrographolide Contents in Leaves of Andrographis paniculata (Burm. F.) Wall. Ex Nees.

    Science.gov (United States)

    Worakan, Phapawee; Karaket, Netiya; Maneejantra, Nuchada; Supaibulwatana, Kanyaratt

    2017-02-01

    Cytokinins are phytohormones that play multiple roles to control plant growth and development. In this study, leaf biomass and the production of andrographolide compounds in a medicinal plant Andrographis paniculata were significantly increased after exogenously treating with the synthetic cytokinin cytokinin-1-(2-chloro-4-pyridyl)-3-phenylurea (CPPU) at 0 (water), 5, or 10 mg L -1 and observed the results for 24 h, 48 h, and 7 days of treatment. It was found that CPPU could significantly enhance new axillary bud formation and further promote branching 4.6-5.6-fold higher, resulting in higher fresh weight (FW) and dry weight (DW) than the control. Application of CPPU at 5 mg L -1 significantly promoted the highest contents of total reducing sugar at 2.5-fold in leaves and at 1.5-fold in roots. Although treatments of CPPU significantly affected the increasing contents of chlorophyll and carotenoid (1.2-1.6-fold), CPPU at 10 mg L -1 slightly caused leaf stress and chlorophyll reduction. Interestingly, 5 mg L -1 CPPU could enhance andrographolide content, an active anti-infectious compound in Andrographis paniculata (2.2-fold higher than the control) that reached the highest content at 24 h after treatment. This study suggested that CPPU should be suitable for field application to promote leaf yields and induce the production of useful pharmaceutical compounds in Andrographis paniculata.

  17. Corticosterone release in oxytocin gene deletion mice following exposure to psychogenic versus non-psychogenic stress.

    Science.gov (United States)

    Amico, Janet A; Cai, Hou-ming; Vollmer, Regis R

    2008-09-19

    Both anxiety-related behavior [J.A. Amico, R.C. Mantella, R.R. Vollmer, X. Li, Anxiety and stress responses in female oxytocin deficient mice, J. Neuroendocrinol. 16 (2004) 1-6; R.C. Mantella, R.R. Vollmer, X. Li, J.A. Amico, Female oxytocin-deficient mice display enhanced anxiety-related behavior, Endocrinology 144 (2003) 2291-2296] and the release of corticosterone following a psychogenic stress such as exposure to platform shaker was greater in female [J.A. Amico, R.C. Mantella, R.R. Vollmer, X. Li, Anxiety and stress responses in female oxytocin deficient mice, J. Neuroendocrinol. 16 (2004) 1-6; R.C. Mantella, R.R. Vollmer, L. Rinaman, X. Li, J.A. Amico, Enhanced corticosterone concentrations and attenuated Fos expression in the medial amygdala of female oxytocin knockout mice exposed to psychogenic stress, Am. J. Physiol. Regul. Integr. Comp. Physiol. 287 (2004) R1494-R1504], but not male [R.C. Mantella, R.R. Vollmer, J.A. Amico, Corticosterone release is heightened in food or water deprived oxytocin deficient male mice, Brain Res. 1058 (2005) 56-61], oxytocin gene deletion (OTKO) mice compared to wild type (WT) cohorts. In the present study we exposed OTKO and WT female mice to another psychogenic stress, inserting a rectal probe to record body temperature followed by brief confinement in a metabolic cage, and measured plasma corticosterone following the stress. OTKO mice released more corticosterone than WT mice (Pstress. In contrast, if OTKO and WT female and male mice were administered insulin-induced hypoglycemia, an acute physical stress, corticosterone release was not different between genotypes. The absence of central OT signaling pathways in female mice heightens the neuroendocrine (e.g., corticosterone) response to psychogenic stress, but not to the physical stress of insulin-induced hypoglycemia.

  18. Stimulation of corticosterone secretion in vitro by brief ACTH exposure

    International Nuclear Information System (INIS)

    Keith, L.D.; Tam, B.; Greer, M.A.

    1986-01-01

    The authors examined the relationship between ACTH concentration and exposure duration on stimulation of corticosterone (B) secretion in vitro using perifused enzymatically dispersed rat adrenocortical cells. A modular perifusion apparatus was used that permitted evaluation of 20-24 cell chambers per experimental session. In expt 1,20-1000 pg/ml concentrations of synthetic ACTH-(1-24) were presented to cells for 1 min. In expt 2, 100 pg ACTH-(1-24) was presented to adrenal cells in five dose-duration regimens ranging from 5 pg/min for 20 min to 100 pg/min for 1 min. Perifusal rate was 1 ml/min in all sessions. B was determined by radioimmunoassay. In expt 1 (constant-duration paradigm), 1-min presentation of ACTH-(1-24) produced log-linear dose-response effects across these concentrations. In expt 2 (constant-mass paradigm), identical masses administered in different dose-duration regimens had different steroidogenic efficacies: low-dose long-duration regimens provoked greater total release than high-dose short-duration regimens. Overall, every dose-duration regimen was associated with stimulation of B secretion. These results indicate that 1) very brief exposure to physiological concentrations of ACTH-(1-24) is a significant stimulus for corticosteroid secretion; 2) variations in the dose-duration regimen over the physiological range modifies both the maximum rate of secretion and the duration of secretion, but not the response latency; and 3) ACTH-(1-24) presentation mass is not the sole determinant of B secretion

  19. Effects of long-time elevated temperature exposures on hot-isostatically-pressed power-metallurgy Udimet 700 alloys with reduced cobalt contents

    Science.gov (United States)

    Hart, F. H.

    1984-01-01

    Because almost the entire U.S. consumption of cobalt depends on imports, this metal has been designated "strategic'. The role and effectiveness of cobalt is being evaluated in commercial nickel-base superalloys. Udiment 700 type alloys in which the cobalt content was reduced from the normal 17% down to 12.7%, 8.5%, 4.3%, and 0% were prepared by standard powder metallurgy techniques and hot isostatically pressed into billets. Mechanical testing and microstructural investigations were performed. The mechanical properties of alloys with reduced cobalt contents which were heat-treated identically were equal or better than those of the standard alloy, except that creep rates tended to increase as cobalt was reduced. The effects of long time exposures at 760 C on mechanical properties and at 760 C and 845 C on microstructures were determined. Decreased tensile properties and shorter rupture lives with increased creep rates were observed in alloy modifications. The exposures caused gamma prime particle coarsening and formation of sigma phase in the alloys with higher cobalt contents. Exposure at 845 C also reduced the amount of MC carbides.

  20. Simultaneous radioimmunoassay for corticosterone and deoxycortisol in human serum: Sex differences in the mean serum concentrations

    International Nuclear Information System (INIS)

    Schoeneshoefer, M.; Harendt, H.; Vecsei, P.

    1977-01-01

    A specific radioimmunoassay is described which allows the simultaneous determination of serum corticosterone and deoxycortisol. The normal serum concentration of both steroids were found to be dependent on sex and menstrual cycle. Mean concentrations (+-S.D.) in males, females (follicular phase) and females (luteal phase) were 4210 +- 2170 ng/l, 2410 +- 1480 ng/l and 4390 +- 2320 ng/l for corticosterone and 499 +- 273 ng/l, 207 +- 152 ng/l and 335 +- 182 ng/l for deoxycortisol. After adrenal stimulation by corticotropin itself or by insulin induced hypoglycemia, the serum concentrations of corticosterone became significantly higher than those of deoxycortisol. After oral administration of dexamethasone serum concentrations of both steroids were suppressed to levels below the limit of the normal range. One hour after oral metyrapone administration at midnight, serum corticosterone decreased, while serum deoxycortisol increased by a factor of about five. After eight hours serum concentrations of both steroids were increased considerably. Corticosterone attained levels slightly higher than the normal range and deoxycortisol rose to levels which were higher than the normal mean concentrations by a factor of about 500. (orig./AS) [de

  1. Corticosterone and decision-making in male Wistar rats: the effect of corticosterone application in the infralimbic and orbitofrontal cortex.

    Science.gov (United States)

    Koot, Susanne; Koukou, Magdalini; Baars, Annemarie; Hesseling, Peter; van 't Klooster, José; Joëls, Marian; van den Bos, Ruud

    2014-01-01

    Corticosteroid hormones, released after stress, are known to influence neuronal activity and produce a wide range of effects upon the brain. They affect cognitive tasks including decision-making. Recently it was shown that systemic injections of corticosterone (CORT) disrupt reward-based decision-making in rats when tested in a rat model of the Iowa Gambling Task (rIGT), i.e., rats do not learn across trial blocks to avoid the long-term disadvantageous option. This effect was associated with a change in neuronal activity in prefrontal brain areas, i.e., the infralimbic (IL), lateral orbitofrontal (lOFC) and insular cortex, as assessed by changes in c-Fos expression. Here, we studied whether injections of CORT directly into the IL and lOFC lead to similar changes in decision-making. As in our earlier study, CORT was injected during the final 3 days of the behavioral paradigm, 25 min prior to behavioral testing. Infusions of vehicle into the IL led to a decreased number of visits to the disadvantageous arm across trial blocks, while infusion with CORT did not. Infusions into the lOFC did not lead to differences in the number of visits to the disadvantageous arm between vehicle treated and CORT treated rats. However, compared to vehicle treated rats of the IL group, performance of vehicle treated rats of the lOFC group was impaired, possibly due to cannulation/infusion-related damage of the lOFC affecting decision-making. Overall, these results show that infusions with CORT into the IL are sufficient to disrupt decision-making performance, pointing to a critical role of the IL in corticosteroid effects on reward-based decision-making. The data do not directly support that the same holds true for infusions into the lOFC.

  2. Changes in Plasma Corticosterone and Catecholamine Contents Induced by Low Doses of Deltamethrin in Rats

    NARCIS (Netherlands)

    Boer, Sietse F. de; Gugten, Jan van der; Slangen, Jef. L.; Hijzen, Theo H.

    1988-01-01

    The effects of low doses of (S)-α-cyano-3-phenoxybenzyl (1R)-cis-3-(2,2-dibromovinyl)-2,2-dimethylcyclopropanecarboxylate (Roussel UCLAF, Paris, France), (deltamethrin) upon sympathetic-adrenomedullary and pituitary-adrenocortical activity were investigated in rats by measuring plasma noradrenaline

  3. Data Elevator

    Energy Technology Data Exchange (ETDEWEB)

    2017-04-29

    Data Elevator: Efficient Asynchronous Data Movement in Hierarchical Storage Systems Multi-layer storage subsystems, including SSD-based burst buffers and disk-based parallel file systems (PFS), are becoming part of HPC systems. However, software for this storage hierarchy is still in its infancy. Applications may have to explicitly move data among the storage layers. We propose Data Elevator for transparently and efficiently moving data between a burst buffer and a PFS. Users specify the final destination for their data, typically on PFS, Data Elevator intercepts the I/O calls, stages data on burst buffer, and then asynchronously transfers the data to their final destination in the background. This system allows extensive optimizations, such as overlapping read and write operations, choosing I/O modes, and aligning buffer boundaries. In tests with large-scale scientific applications, Data Elevator is as much as 4.2X faster than Cray DataWarp, the start-of-art software for burst buffer, and 4X faster than directly writing to PFS. The Data Elevator library uses HDF5's Virtual Object Layer (VOL) for intercepting parallel I/O calls that write data to PFS. The intercepted calls are redirected to the Data Elevator, which provides a handle to write the file in a faster and intermediate burst buffer system. Once the application finishes writing the data to the burst buffer, the Data Elevator job uses HDF5 to move the data to final destination in an asynchronous manner. Hence, using the Data Elevator library is currently useful for applications that call HDF5 for writing data files. Also, the Data Elevator depends on the HDF5 VOL functionality.

  4. Anxiogenic-like effect of chronic corticosterone in the light-dark emergence task in mice.

    Science.gov (United States)

    Ardayfio, Paul; Kim, Kwang-Soo

    2006-04-01

    Chronic hypercortisolemia is a hallmark of neuroendocrine and psychiatric disorders, such as Cushing's disease and depression. Whether cortisol directly contributes to the altered mood and anxiety symptoms seen in these diseases remains unclear. To address this, the authors have modeled hypercortisolemia by administering corticosterone in the drinking water of female Swiss Webster mice for 17 or 18 days (13 mg/kg). Light-dark emergence, startle habituation, and startle reactivity were measured. Chronic but not acute treatment with corticosterone increased the latency to emerge into the light compartment, an anxiogenic-like effect. Chronic corticosterone treatment did not affect startle habituation, but did reduce startle reactivity. This study suggests that chronic hypercortisolemia may contribute to anxiety-related behavior in patients with Cushing's disease and depression. ((c) 2006 APA, all rights reserved).

  5. An elevator

    Energy Technology Data Exchange (ETDEWEB)

    Loginovskiy, V.I.; Medinger, N.V.; Rasskazov, V.A.; Solonitsyn, V.A.

    1983-01-01

    An elevator is proposed which includes a body, spring loaded cams and a shut-off ring. To increase the reliability of the elevator by eliminating the possibility of spontaneous shifting of the shut-off ring, the latter is equipped with handles hinged to it and is made with evolvent grooves. The cams are equipped with rollers installed in the evolvent grooves of the shut off ring, where the body is made with grooves for the handles.

  6. Elevated Carbon Dioxide Increases Contents of Flavonoids and Phenolic Compounds, and Antioxidant Activities in Malaysian Young Ginger (Zingiber officinale Roscoe. Varieties

    Directory of Open Access Journals (Sweden)

    Asmah Rahmat

    2010-11-01

    Full Text Available Zingiber officinale Roscoe. (Family Zingiberaceae is well known in Asia. The plant is widely cultivated in village gardens in the tropics for its medicinal properties and as a marketable spice in Malaysia. Ginger varieties are rich in physiologically active phenolics and flavonoids with a range of pharmacological activities. Experiments were conducted to determine the feasibility of increasing levels of flavonoids (quercetin, rutin, catechin, epicatechin, kaempferol, naringenin, fisetin and morin and phenolic acid (gallic acid, vanillic acid, ferulic acid, tannic acid, cinnamic acid and salicylic acid, and antioxidant activities in different parts of Malaysian young ginger varieties (Halia Bentong and Halia Bara with CO2 enrichment in a controlled environment system. Both varieties showed an increase in phenolic compounds and flavonoids in response to CO2 enrichment from 400 to 800 µmol mol-1 CO2. These increases were greater in rhizomes compared to leaves. High performance liquid chromatography (HPLC results showed that quercetin and gallic acid were the most abundant flavonoid and phenolic acid in Malaysian young ginger varieties. Under elevated CO2 conditions, kaempferol and fisetin were among the flavonoid compounds, and gallic acid and vanillic acid were among the phenolic compounds whose levels increased in both varieties. As CO2 concentration was increased from 400 to 800 µmol mol-1, free radical scavenging power (DPPH increased about 30% in Halia Bentong and 21.4% in Halia Bara; and the rhizomes exhibited more enhanced free radical scavenging power, with 44.9% in Halia Bentong and 46.2% in Halia Bara. Leaves of both varieties also displayed good levels of flavonoid compounds and antioxidant activities. These results indicate that the yield and pharmaceutical quality of Malaysian young ginger varieties can be enhanced by controlled environment production and CO2 enrichment.

  7. Plasma corticosterone and thyroxine concentrations during chronic ingestion of crude oil in mallard ducks (Anas platyrhynchos)

    Science.gov (United States)

    Rattner, B.A.; Eastin, W.C.

    1981-01-01

    1. Blood samples were collected from mallard ducks after 6, 12, and 18 weeks of dietary exposure to mash containing 0.015%, 0.150%, and 1.500% crude oil.2. Plasma corticosterone concentrations in ducks fed mash containing 0.150% or 1.500% Alaskan Prudhoe Bay crude oil were uniformly depressed when compared to values in untreated control birds.3. Plasma thyroxine concentration was not altered in ducks chronically exposed to crude oil.4. The observed alteration in corticosterone concentration could reduce tolerance to temperature and dietary fluctuations in the environment.

  8. Monocular Elevation Deficiency - Double Elevator Palsy

    Science.gov (United States)

    ... Español Condiciones Chinese Conditions Monocular Elevation Deficiency/ Double Elevator Palsy En Español Read in Chinese What is monocular elevation deficiency (Double Elevator Palsy)? Monocular Elevation Deficiency, also known by the ...

  9. Long-term corticosterone exposure decreases insulin sensitivity and induces depressive-like behaviour in the C57BL/6NCrl mouse.

    Directory of Open Access Journals (Sweden)

    Eva L van Donkelaar

    Full Text Available Chronic stress or long-term administration of glucocorticoids disrupts the hypothalamus-pituitary-adrenal system leading to continuous high levels of glucocorticoids and insulin resistance (IR. This pre-diabetic state can eventually develop into type 2 diabetes mellitus and has been associated with a higher risk to develop depressive disorders. The mechanisms underlying the link between chronic stress, IR and depression remains unclear. The present study aimed to establish a stress-depression model in mice to further study the effects of stress-induced changes upon insulin sensitivity and behavioural consequences. A pilot study was conducted to establish the optimal administration route and a pragmatic measurement of IR. Subsequently, 6-month-old C57BL/6NCrl mice were exposed to long-term oral corticosterone treatment via the drinking water. To evaluate insulin sensitivity changes, blood glucose and plasma insulin levels were measured at different time-points throughout treatment and mice were behaviourally assessed in the elevated zero maze (EZM, forced swimming test (FST and open field test to reveal behavioural changes. Long-term corticosterone treatment increased body weight and decreased insulin sensitivity. The latter was revealed by a higher IR index and increased insulin in the plasma, whereas blood glucose levels remained unchanged. Corticosterone treatment induced longer immobility times in the FST, reflecting depressive-like behaviour. No effects were observed upon anxiety as measured in the EZM. The effect of the higher body weight of the CORT treated animals at time of testing did not influence behaviour in the EZM or FST, as no differences were found in general locomotor activity. Long-term corticosterone treatment via the drinking water reduces insulin sensitivity and induces depressive-like behaviour in the C57BL/6 mouse. This mouse model could thus be used to further explore the underlying mechanisms of chronic stress-induced T2

  10. Individual differences in pavlovian autoshaping of lever pressing in rats predict stress-induced corticosterone release and mesolimbic levels of monoamines.

    Science.gov (United States)

    Tomie, A; Aguado, A S; Pohorecky, L A; Benjamin, D

    2000-03-01

    Pavlovian autoshaping CRs are directed and reflexive consummatory responses targeted at objects repeatedly paired with rewarding substances. To evaluate the hypothesis that autoshaping may provide an animal learning model of vulnerability to drug abuse, this study relates individual differences in lever-press autoshaping CR performance in rats to stress-induced corticosterone release and tissue monoamine levels in the mesolimbic dopamine tract. Long-Evans rats (n = 14) were given 20 sessions of Pavlovian autoshaping training wherein the insertion of a retractable lever CS was followed by the response-independent presentation of food US. Large between-subjects differences in lever-press autoshaping CR performance were observed, with group high CR frequency (n = 5) performing many more lever press CRs than group low CR frequency (n = 9). Tail-blood samples were obtained before and after the 20th autoshaping session, then 24 h later the rats were sacrificed and dissection yielded tissue samples of nucleus accumbens (NAC), prefrontal cortex (PFC), caudate putamen (CP), and ventral tegmental area (VTA). Serum levels of postsession corticosterone were elevated in group high CR frequency. HPLC revealed that group high CR frequency had higher tissue levels of dopamine and DOPAC in NAC, lower levels of DOPAC/DA turnover in CP, and lower levels of 5-HIAA and lower 5-HIAA/5-HT turnover in VTA. The neurochemical profile of rats that perform more autoshaping CRs share some features of vulnerability to drug abuse.

  11. Plasma catecholamine and corticosterone responses to predictable and unpredictable noise stress in rats

    NARCIS (Netherlands)

    Van der Gugten, J; Slangen, J L; de Boer, S.F.

    Plasma noradrenaline (NA), adrenaline (A) and corticosterone (CS) increases were determined in individual rats subjected to either 20 regularly or irregularly scheduled white-noise stimulations (4 min, 100 dBA). Blood was frequently sampled during the first and twentieth noise exposure, and during a

  12. Corticosterone infused into the dorsal striatum selectively enhances memory consolidation of cued water-maze training

    NARCIS (Netherlands)

    Quirarte, Gina L.; Sofia Ledesma de la Teja, I.; Casillas, Miriam; Serafin, Norma; Prado-Alcala, Roberto A.; Roozendaal, Benno

    2009-01-01

    Glucocorticoid hormones enhance memory consolidation of hippocampus-dependent spatial/contextual learning, but little is known about their possible influence on the consolidation of procedural/implicit memory. Therefore, in this study we examined the effect of corticosterone (2, 5, or 10 ng) infused

  13. Corticosterone binding to tissues of adrenalectomized lean and obese Zucker rats.

    Science.gov (United States)

    Grasa, M M; Cabot, C; Balada, F; Virgili, J; Sanchis, D; Monserrat, C; Fernández-López, J A; Remesar, X; Alemany, M

    1998-12-01

    The binding of corticosterone, dexamethasone and aldosterone was investigated in plasma and in homogenates of liver, kidney, brain, brown adipose tissue and visceral (periovaric) and subcutaneous white adipose tissues of Zucker lean and obese rats: intact controls, adrenalectomized and sham-operated. Corticosterone-binding globulin (CBG) accounted for most of the binding, whereas that of glucocorticoid and mineralocorticoid receptors was much lower. Plasma corticosterone levels increased in sham-operated and obviously decreased in the adrenalectomized animals. Sham-operated and adrenalectomized lean rats showed decreased plasma CBG; in the obese, CBG levels were lower than in controls and were not affected by either surgery. No variation with obesity or surgery was observed either in dexamethasone or aldosterone binding, the latter being practically zero in most samples. When expressed per unit of tissue protein, CBG activity was maximal in adipose tissues, with lowest values in brain and liver. In lean rats, tissue CBG activity decreased with either surgical treatment; no changes were observed in the obese, which also had lower CBG tissue levels. The relative lack of changes in CBG of obese rats suggests that they have lost -- at least in part -- the ability to counter-modulate the changes in glucocorticoid levels through CBG modulation, thus relying only on the control of corticosterone levels. This interpretation agrees with the postulated role of CBG modulating the availability of glucocorticoids to target cells.

  14. Vasopressin-related peptides increase the hippocampal corticosterone receptor capacity of diabetes insipidus (Brattleboro) rats

    NARCIS (Netherlands)

    Veldhuis, H D; de Kloet, E R

    The binding of [3H]corticosterone to receptors in cytosol of several brain regions and of [3H]dexamethasone to receptors in pituitary cytosol was measured after chronic treatment of homozygous diabetes insipidus rats (Ho-Di) with various neuropeptides. All rats were adrenalectomized 24 h before

  15. Does Environmental Enrichment Reduce Stress? An Integrated Measure of Corticosterone from Feathers Provides a Novel Perspective

    Science.gov (United States)

    Fairhurst, Graham D.; Frey, Matthew D.; Reichert, James F.; Szelest, Izabela; Kelly, Debbie M.; Bortolotti, Gary R.

    2011-01-01

    Enrichment is widely used as tool for managing fearfulness, undesirable behaviors, and stress in captive animals, and for studying exploration and personality. Inconsistencies in previous studies of physiological and behavioral responses to enrichment led us to hypothesize that enrichment and its removal are stressful environmental changes to which the hormone corticosterone and fearfulness, activity, and exploration behaviors ought to be sensitive. We conducted two experiments with a captive population of wild-caught Clark's nutcrackers (Nucifraga columbiana) to assess responses to short- (10-d) and long-term (3-mo) enrichment, their removal, and the influence of novelty, within the same animal. Variation in an integrated measure of corticosterone from feathers, combined with video recordings of behaviors, suggests that how individuals perceive enrichment and its removal depends on the duration of exposure. Short- and long-term enrichment elicited different physiological responses, with the former acting as a stressor and birds exhibiting acclimation to the latter. Non-novel enrichment evoked the strongest corticosterone responses of all the treatments, suggesting that the second exposure to the same objects acted as a physiological cue, and that acclimation was overridden by negative past experience. Birds showed weak behavioral responses that were not related to corticosterone. By demonstrating that an integrated measure of glucocorticoid physiology varies significantly with changes to enrichment in the absence of agonistic interactions, our study sheds light on potential mechanisms driving physiological and behavioral responses to environmental change. PMID:21412426

  16. Delayed behavioral effects of postnatal exposure to corticosterone in the zebra finch (Taeniopygia guttata)

    NARCIS (Netherlands)

    Spencer, K. A.; Verhulst, S.

    Early developmental conditions can significantly influence the growth and survival of many animal species. We studied the consequences of exposure to corticosterone (CORT), a stress hormone, during the nestling stage on two behavioral traits (neophobia, social dominance) measured when the birds had

  17. Corticosterone and thyroxine in cold-stunned Kemp's ridley sea turtles (Lepidochelys kempii).

    Science.gov (United States)

    Hunt, Kathleen E; Innis, Charles; Rolland, Rosalind M

    2012-09-01

    Kemp's ridley sea turtles (Lepidochelys kempii), a critically endangered species, frequently strand on the shores of Cape Cod (Massachusetts, USA) in late autumn in a state of "cold-stunning" exhibiting low body temperature and related clinical issues. Stranded turtles are transported to the New England Aquarium (Boston, Massachusetts, USA) for treatment and rehabilitation. This study tested the hypothesis that cold-stunned sea turtles might exhibit high corticosterone ("stress hormone") or low thyroxine (which is often affected by temperature), or both, and that monitoring of both hormones may be useful for assessing recovery. In a retrospective analysis, 87 archived plasma samples were assayed from 56 cold-stunned juvenile Kemp's ridley sea turtles for corticosterone and free thyroxine (fT4). Upon admission, mean corticosterone was the highest yet reported for a population of sea turtles (39.3 +/- 2.5 ng/ml; mean +/- standard error of the mean [SEM]) and fT4 was usually undetectable. On admission, corticosterone was negatively correlated with white blood cell count but was not correlated with blood glucose. There were no differences in either hormone between survivors and nonsurvivors on admission. After 18+ days in recovery, surviving turtles' corticosterone dropped significantly to levels typical of baseline in other species (0.9 +/- 1.0 ng/ml) while fT4 increased significantly (1.3 +/- 1.5 pg/ml). During recovery, corticosterone was positively correlated with blood glucose and was not correlated with white blood cell count. Turtles that showed persistent deficits in feeding, activity, or both during recovery had significantly lower fT4 than did turtles with no such deficits. The "high corticosterone, low fT4" endocrine profile seen on admission may be a useful marker of cold-stunning in this and other species. Further studies are necessary to determine whether low thyroid hormones play a causal role in deficits in feeding and activity during recovery

  18. Enduring neurobehavioral effects of early life trauma mediated through learning and corticosterone suppression

    Directory of Open Access Journals (Sweden)

    Stephanie Moriceau

    2009-09-01

    Full Text Available Early life trauma alters later life emotions, including fear. To better understand mediating mechanisms, we subjected pups to either predictable or unpredictable trauma, in the form of paired or unpaired odor-0.5mA shock conditioning which, during a sensitive period, produces an odor preference and no learning respectively. Fear conditioning and its neural correlates were then assessed after the sensitive period at postnatal day (PN13 or in adulthood, ages when amygdala-dependent fear occurs. Our results revealed that paired odor-shock conditioning starting during the sensitive period (PN8-12 blocked fear conditioning in older infants (PN13 and pups continued to express olfactory bulb-dependent odor preference learning. This PN13 fear learning inhibition was also associated with suppression of shock-induced corticosterone, although the age appropriate amygdala-dependent fear learning was reinstated with systemic corticosterone (3mg/kg during conditioning. On the other hand, sensitive period odor-shock conditioning did not prevent adult fear conditioning, although freezing, amygdala and hippocampal 2-DG uptake and corticosterone levels were attenuated compared to adult conditioning without infant conditioning. Normal levels of freezing, amygdala and hippocampal 2-DG uptake were induced with systemic corticosterone (5mg/kg during adult conditioning. These results suggest that the contingency of early life trauma mediates at least some effects of early life stress through learning and suppression of corticosterone levels. However, developmental differences between infants and adults are expressed with PN13 infants’ learning consistent with the original learned preference, while adult conditioning overrides the original learned preference with attenuated amygdala-dependent fear learning.

  19. Resveratrol ameliorates depressive-like behavior in repeated corticosterone-induced depression in mice.

    Science.gov (United States)

    Ali, Syed Hamid; Madhana, Rajaram Mohanrao; K V, Athira; Kasala, Eshvendar Reddy; Bodduluru, Lakshmi Narendra; Pitta, Sathish; Mahareddy, Jalandhar Reddy; Lahkar, Mangala

    2015-09-01

    A mouse model of depression has been recently developed by exogenous corticosterone (CORT) administration, which has shown to mimic HPA-axis induced depression-like state in animals. The present study aimed to examine the antidepressant-like effect and the possible mechanisms of resveratrol, a naturally occurring polyphenol of phytoalexin family, on depressive-like behavior induced by repeated corticosterone injections in mice. Mice were injected subcutaneously (s.c.) with 40mg/kg corticosterone (CORT) chronically for 21days. Resveratrol and fluoxetine were administered 30min prior to the CORT injection. After 21-days treatment with respective drugs, behavioral and biochemical parameters were estimated. Since brain derived neurotrophic factor (BDNF) has been implicated in antidepressant activity of many drugs, we also evaluated the effect of resveratrol on BDNF in the hippocampus. Three weeks of CORT injections in mice resulted in depressive-like behavior, as indicated by the significant decrease in sucrose consumption and increase in immobility time in the forced swim test and tail suspension test. Further, there was a significant increase in serum corticosterone level and a significant decrease in hippocampus BDNF level in CORT-treated mice. Treatment of mice with resveratrol significantly ameliorated all the behavioral and biochemical changes induced by corticosterone. These results suggest that resveratrol produces an antidepressant-like effect in CORT-induced depression in mice, which is possibly mediated by rectifying the stress-based hypothalamic-pituitary-adrenal (HPA) axis dysfunction paradigm and upregulation of hippocampal BDNF levels. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Response of testosterone and corticosterone plasma levels to the challenge of sibling competition: a study in common terns.

    Science.gov (United States)

    Braasch, Alexander; Becker, Peter H; Groothuis, Ton G G

    2014-08-01

    The hormonal response to social challenges has been widely studied, however, most work focused on adult behavior in a reproductive context although developing animals also encounter important social challenges early in life. We studied the relationship between acute sibling competition and plasma corticosterone (CORT) and testosterone (T) in common tern (Sterna hirundo) chicks, a species whose young compete for access to food by scramble interactions. Blood samples were taken in nests with two and only one single chick both immediately after a feeding bout and in non-challenged controls. We found that T levels were lower in siblings challenged by a feeding bout as compared to controls, which may be explained by the fact that T suppresses begging behavior and is only elevated in response to territorial intrusion but not sibling competition in a related species. Singletons had, corrected for body condition, generally lower CORT levels than siblings suggesting that growing up with siblings creates a competitive environment in which high CORT levels are sustained irrespective of a social challenge. CORT levels were also negatively correlated with body condition and were higher in males than in females. The latter may be related to sex-specific food requirements and susceptibility to stress. Our results suggest a possible suppressive effect of acute sibling competition on T secretion, and a positive effect on CORT levels by longer term sibling competition. The degree to which these dynamics are related to begging or aggression, or both, needs further experimental work. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Elevator wheel

    Energy Technology Data Exchange (ETDEWEB)

    Zhornik, V.I.; Cherkov, Ye.M.; Simonov, A.A.

    1982-01-01

    An elevator wheel is suggested for unloading a sunken product from a bath of a heavy-average separator including discs of a bucket with inner walls, and covering sheets hinged to the buckets. In order to improve the degree of dehydration of the removed product, the inner wall of each bucket is made of sheets installed in steps with gaps of one in relation to the other.

  2. HYPERPHAGIA INDUCED BY SUCROSE: RELATION TO CIRCULATING AND CSF GLUCOSE AND CORTICOSTERONE AND OREXIGENIC PEPTIDES IN THE ARCUATE NUCLEUS

    Science.gov (United States)

    Gaysinskaya, V. A.; Karatayev, O.; Shuluk, J.; Leibowitz, S. F.

    2010-01-01

    Sucrose-rich diets compared to starch-rich diets are known to stimulate overeating under chronic conditions. The present study in normal-weight rats established an acute “preload-to-test meal” paradigm for demonstrating sucrose-induced hyperphagia and investigating possible mechanisms that mediate this behavioral phenomenon. In this acute paradigm, the rats were first given a small (15 kcals) sucrose preload (30% sucrose) for 30 min compared to an equicaloric, starch preload (25% starch with 5% sucrose) and then allowed to freely consume a subsequent test meal of lab chow. The sucrose preload, when compared to a starch preload equal in energy density and palatability, consistently increased food intake in the subsequent test meal occurring between 60–120 min after the end of the preload. Measurements of hormones, metabolites and hypothalamic peptides immediately preceding this hyperphagia revealed marked differences between the sucrose vs starch groups that could contribute to the increase in food intake. Whereas the sucrose group compared to starch group immediately after the preload (at 10 min) had elevated levels of glucose in serum and cerebrospinal fluid (CSF) along with reduced expression of neuropeptide Y (NPY) and agouti-related protein (AgRP) in the arcuate nucleus (ARC), the subsequent effects (at 30–60 min) just preceding the test meal hyperphagia were the reverse. Along with lower levels of glucose, they included markedly elevated serum and CSF levels of corticosterone and mRNA levels of NPY and AgRP in the ARC. In addition to establishing an animal model for sucrose-induced hyperphagia, these results demonstrate peripheral and central mechanisms that may mediate this behavioral phenomenon. PMID:21036188

  3. An elevator

    Energy Technology Data Exchange (ETDEWEB)

    Gusev, A.S.; Peshkov, L.P.; Rozin, M.M.; Shestov, A.G.

    1983-01-01

    An elevator is proposed which includes a body, a flap, a lock with a catch and a spring-loaded shut-off clamp in the form of upper and lower horizontal levers which are connected by a handle and an axle and one end of which is made in the form of an eccentric cam. The size of the eccentricity of the cam of the levers is increased toward the handle of the clamp in order to increase the operational reliability and to extend the service life.

  4. An elevator

    Energy Technology Data Exchange (ETDEWEB)

    Rastorguyev, M.A.; Maloyarovslavtesv, D.A.; Prokopov, O.I.; Tukayev, Sh.V.; Zanilov, I.F.

    1983-01-01

    An elevator is proposed which includes a body with a turning collar locking device and a rod with longitudinal grooves, which are flexibly linked with jaws positioned in grooves in the body. To increase safety through ensuring automatic locking of the jaws in the closed position, the locking device is made in the form of head on wedges, spring loaded relative to the collar and made with cams and positioned with the capability of interacting with the grooves of the rod and through the cams with the collar.

  5. Bucket elevator

    OpenAIRE

    Chromek, Jiří

    2013-01-01

    Cílem této bakalářské práce je návrh svislého korečkového elevátoru, který má sloužit k dopravě obilovin s dopravní výškou 19 m a dopravovaným množstvím 100 t/hod. Práce se skládá z popisu korečkového elevátoru a jeho hlavních částí, zmiňující se v úvodní rešerši. Tato práce je zaměřena na funkční a kapacitní výpočet, určení pohonu a napínacího zařízení. Další výpočet je kontrolní, skládající se z pevnostní kontroly hnacího hřídele, výpočtu pera, životnosti ložisek a výpočtu napínacího zaříze...

  6. The effect of isoflurane anaesthesia and vasectomy on circulating corticosterone and ACTH in BALB/c mice

    DEFF Research Database (Denmark)

    Jacobsen, Kirsten Rosenmaj; Kalliokoski, Otto; Teilmann, Anne Charlotte

    2012-01-01

    compared to anaesthetised mice not treated with dexamethasone. Thus, dexamethasone effectively inhibited the corticosterone response in the anaesthetised-only mice, but not in the mice subjected to surgery. In conclusion, both isoflurane anaesthesia and vasectomy during isoflurane anaesthesia resulted...

  7. Seasonal changes in testosterone and corticosterone levels in four social classes of a desert dwelling sociable rodent.

    Science.gov (United States)

    Schradin, Carsten

    2008-04-01

    Animals have to adjust their physiology to seasonal changes, in response to variation in food availability, social tactics and reproduction. I compared basal corticosterone and testosterone levels in free ranging striped mouse from a desert habitat, comparing between the sexes, breeding and philopatric non-breeding individuals, and between the breeding and the non-breeding season. I expected differences between breeders and non-breeders and between seasons with high and low food availability. Basal serum corticosterone was measured from 132 different individuals and serum testosterone from 176 different individuals of free living striped mice. Corticosterone and testosterone levels were independent of age, body weight and not influenced by carrying a transmitter. The levels of corticosterone and testosterone declined by approximately 50% from the breeding to the non-breeding season in breeding females as well as non-breeding males and females. In contrast, breeding males showed much lower corticosterone levels during the breeding season than all other classes, and were the only class that showed an increase of corticosterone from the breeding to the non-breeding season. As a result, breeding males had similar corticosterone levels as other social classes during the non-breeding season. During the breeding season, breeding males had much higher testosterone levels than other classes, which decreased significantly from the breeding to the non-breeding season. My results support the prediction that corticosterone decreases during periods of low food abundance. Variation in the pattern of hormonal secretion in striped mice might assist them to cope with seasonal changes in energy demand in a desert habitat.

  8. Role of sex steroids in progesterone and corticosterone response to acute restraint stress in rats: sex differences.

    Science.gov (United States)

    Kalil, B; Leite, C M; Carvalho-Lima, M; Anselmo-Franci, J A

    2013-07-01

    Adrenal progesterone secretion increases along with corticosterone in response to stress in male and female rats to modulate some stress responses. Here we investigated the role of sex steroids in sex differences in the progesterone response to 60 min of restraint stress in adult male and female rats. Comparisons between males and females in the progesterone response were evaluated in parallel with corticosterone responses. From day 5 to 7 after gonadectomy, female and male rats were treated with estradiol or testosterone, respectively (OVX-E and ORCH-T groups), or oil (OVX and ORCH groups). Female rats in proestrus, intact and 7 d adrenalectomized (ADX) male rats were also studied. At 10:00 h, blood samples were withdrawn via an implanted jugular cannula before (-5 min), during (15, 30, 45, 60 min) and after (90 and 120 min) restraint stress to measure plasma progesterone and corticosterone concentrations by radioimmunoassay. Intact male and proestrus female rats exhibited similar progesterone responses to stress. Gonadectomy did not alter the amount of progesterone secreted during stress in female rats but decreased secretion in male rats. Unlike corticosterone, the progesterone response to stress in females was not influenced by estradiol. In males, testosterone replacement attenuated the progesterone and corticosterone responses to stress. Basal secretion of progesterone among intact, ORCH and ADX males was similar, but ADX-stressed rats secreted little progesterone. Hence, the gonads differently modulate adrenal progesterone and corticosterone responses to stress in female and male rats. The ovaries enhance corticosterone but not progesterone secretion, while the testes stimulate progesterone but not corticosterone secretion.

  9. Applicability of Commercially Available ELISA Kits for the Quantification of Faecal Immunoreactive Corticosterone Metabolites in Mice

    DEFF Research Database (Denmark)

    Abelson, Klas S P; Kalliokoski, Otto; Teilmann, Anne Charlotte

    2016-01-01

    Background: Commercially available ELISA kits are popular among investigators that quantify faecal corticosterone or cortisol metabolites (FCM) for stress assessment in animals. However, in faeces, these assays mainly detect immunoreactive glucocorticoid metabolites. Since different assays contain......: The present study was designed to investigate corticosterone (CORT) in serum and FCM levels in faeces of laboratory mice, as quantified in four different ELISA kits (DRG EIA-4164, Demeditec DEV9922, Enzo ADI-900-097 and Cayman EIA kit 500655). Assay kits were chosen based on the origin of the antibody...... assays, in both groups of mice. In faecal samples, there was no consistent positive correlation between the levels detected in the four assays and the measured concentration of FCM also differed between assays. Conclusion: Whereas commercially available CORT ELISAs are frequently successfully used...

  10. Tissue distribution of 3H-corticosterone in response to stress

    International Nuclear Information System (INIS)

    Kolta, M.G.; Soliman, K.F.A.

    1981-01-01

    The level and distribution of 3 H-corticosterone ( 3 H-B) was investigated in adult male Sprague-Dawley rats in response to diethyl ether stress, epinephrine (EP) and/or dexamethasone administration. Diethyl ether stress caused a significant increase in the 3 H-B counts by some of the body tissues and brain regions studied. Plasma 3 H-B counts in the stressed rats were found to be twice as much as in the control animals. When EP (1.0 mg/kg) was injected, the tissue-plasma ratios of 3 H-B were significantly lower (P 3 H-B count in the plasma in response to diethyl ether stress or EP may indicate a decline in rate of corticosterone metabolism. (author)

  11. Changes in the biogenic amine content of the prefrontal cortex, amygdala, dorsal hippocampus, and nucleus accumbens of rats submitted to single and repeated sessions of the elevated plus-maze test

    Directory of Open Access Journals (Sweden)

    Carvalho M.C.

    2005-01-01

    Full Text Available It has been demonstrated that exposure to a variety of stressful experiences enhances fearful reactions when behavior is tested in current animal models of anxiety. Until now, no study has examined the neurochemical changes during the test and retest sessions of rats submitted to the elevated plus maze (EPM. The present study uses a new approach (HPLC by looking at the changes in dopamine and serotonin levels in the prefrontal cortex, amygdala, dorsal hippocampus, and nucleus accumbens in animals upon single or double exposure to the EPM (one-trial tolerance. The study involved two experiments: i saline or midazolam (0.5 mg/kg before the first trial, and ii saline or midazolam before the second trial. For the biochemical analysis a control group injected with saline and not tested in the EPM was included. Stressful stimuli in the EPM were able to elicit one-trial tolerance to midazolam on re-exposure (61.01%. Significant decreases in serotonin contents occurred in the prefrontal cortex (38.74%, amygdala (78.96%, dorsal hippocampus (70.33%, and nucleus accumbens (73.58% of the animals tested in the EPM (P < 0.05 in all cases in relation to controls not exposed to the EPM. A significant decrease in dopamine content was also observed in the amygdala (54.74%, P < 0.05. These changes were maintained across trials. There was no change in the turnover rates of these monoamines. We suggest that exposure to the EPM causes reduced monoaminergic neurotransmission activity in limbic structures, which appears to underlie the "one-trial tolerance" phenomenon.

  12. Plasma catecholamine and corticosterone responses to predictable and unpredictable noise stress in rats

    OpenAIRE

    Van der Gugten, J; Slangen, J L; de Boer, S.F.

    1989-01-01

    Plasma noradrenaline (NA), adrenaline (A) and corticosterone (CS) increases were determined in individual rats subjected to either 20 regularly or irregularly scheduled white-noise stimulations (4 min, 100 dBA). Blood was frequently sampled during the first and twentieth noise exposure, and during a reexposure after 24 hr. During the sampling periods, behavioral activities of the rats were recorded. The initial noise-induced CS release was partially reduced following the regular noise present...

  13. Corticotropine-releasing hormone and/or corticosterone differentially affect behavior of rat

    Czech Academy of Sciences Publication Activity Database

    Valeš, Karel; Řezáčová, Lenka; Stuchlík, Aleš

    2008-01-01

    Roč. 11, Suppl.1 (2008), s. 118-118 ISSN 1461-1457. [CINP Congress /26./. 13.07.2008-17.07.2008, Munich] R&D Projects: GA MŠk(CZ) 1M0517; GA MZd NR9180; GA ČR(CZ) GA309/07/0341 Institutional research plan: CEZ:AV0Z50110509 Keywords : cpo1 * corticotropine-releasing hormone * corticosterone * behavior Subject RIV: FH - Neurology

  14. Differential abundance of egg white proteins in laying hens treated with corticosterone.

    Science.gov (United States)

    Kim, Jimin; Choi, Yang-Ho

    2014-12-24

    Stressful environments can affect not only egg production and quality but also gene and protein abundance in the ovary and oviduct in laying hens. The oviductal magnum of laying hens is the organ responsible for the synthesis and secretion of egg white proteins. The objective of this study was to investigate the effects of dietary corticosterone as a stress model on the abundance of proteins in the egg white and of mRNA and proteins in the magnum in laying hens. After a 14-day acclimation, 40 laying hens were divided into two groups which were provided for the next 14 days with either control (Control) or corticosterone (Stress) diet containing at 30 mg/kg. Corticosterone treatment resulted in increased feed intake (P ≤ 0.05) and decreased egg production. Two-dimensional electrophoresis (2DE) with MALDI-TOF/TOF MS/MS using eggs obtained on days 0 and 5 revealed differential abundance of egg white proteins by Stress: transiently expressed in neural precursors (TENP), hemopexin (HPX), IgY-Fcυ3-4, and extracellular fatty acid-binding protein (Ex-FABP) were decreased while ovoinhibitor and ovalbumin-related protein X (OVAX) were increased on days 5 vs 0 (P ≤ 0.05). Expression of mRNAs and proteins was also significantly modulated in the magnum of hens in Stress on day 14 (P ≤ 0.05). In conclusion, the current study provides the first evidence showing that dietary corticosterone modulates protein abundance in the egg white in laying hens, and it suggests that environmental stress can differentially modify expression of egg white proteins in laying hens.

  15. Conditioned taste aversion: modulation by 5-HT receptor activity and corticosterone

    DEFF Research Database (Denmark)

    Boris, Gorzalka; Hanson, Laura; Harrington, J

    2003-01-01

    Two experiments were designed to elucidate the involvement of the hypothalamic-pituitary-adrenal axis and the 5-hydroxytryptamine (5-HT) system in the acquisition of lithium chloride-conditioned taste aversion. In Experiment 1, rats were administered either vehicle or 50 mg/kg nefazodone daily fo......, corticosterone-treated animals required more trials to reach extinction. These results suggest the involvement of both the 5-HT system and the hypothalamic-pituitary-adrenal axis in lithium chloride-conditioned taste aversion....

  16. Effect of deafferentation of the rat tongue on plasma corticosterone, aldosterone, angiotensin and ACTH levels

    International Nuclear Information System (INIS)

    Polyntsev, Yu.V.; Serova, O.N.

    1987-01-01

    The effect of deafferentation of the tongue on the plasma level of hormones involved in regulation of the sodium ion level -- aldosterone, corticosterone, ACTH, and angiotensin -- was studied. Plasma hormone levels were determined by radioimmunoassay. The results indicate the important role of orosensory and taste perception in the processes of regulation of the sodium balance in the body. The experiments in this study were conducted on rats

  17. Maternal corticosterone elevation during egg formation in chickens (Gallus gallus domesticus) influences offspring traits, partly via prenatal undernutrition

    NARCIS (Netherlands)

    Henriksen, Rie; Rettenbacher, Sophie; Groothuis, Ton G. G.

    2013-01-01

    The relationship between maternal stress during pregnancy in humans and the subsequent physical and mental health disorders in their children has inspired a wide array of studies on animal models. Almost all of these studies have used mammalian species, but more recently oviparous species in which

  18. Elevated Plasma Corticosterone Decreases Yolk Testosterone and Progesterone in Chickens : Linking Maternal Stress and Hormone-Mediated Maternal Effects

    NARCIS (Netherlands)

    Henriksen, Rie; Groothuis, Ton G.; Rettenbacher, Sophie; Bartell, Paul A.

    2011-01-01

    Despite considerable research on hormone-mediated maternal effects in birds, the underlying physiology remains poorly understood. This study investigated a potential regulation mechanism for differential accumulation of gonadal hormones in bird eggs. Across vertebrates, glucocorticoids can suppress

  19. Offspring sex ratio is related to paternal train elaboration and yolk corticosterone in peafowl.

    Science.gov (United States)

    Pike, Thomas W; Petrie, Marion

    2005-06-22

    Several recent experimental studies have provided strong evidence for the ability of birds to manipulate the sex ratio of their offspring prior to laying. Using a captive population of peafowl (Pavo cristatus), we tested experimentally the effects of paternal attractiveness on offspring sex ratio, and related sex ratio deviations to egg-yolk concentrations of testosterone, 17beta-estradiol and corticosterone. When females were mated to males whose attractiveness had been experimentally reduced by removing prominent eyespot feathers from their trains, they produced significantly more female offspring, had significantly higher yolk corticosterone concentrations and tended to have lower levels of yolk testosterone than when mated to the same males with their full complement of feathers. Concentrations of 17beta-estradiol did not vary consistently with sex ratio biases. These findings add to the small number of studies providing experimental evidence that female birds can control the primary sex ratio of their offspring in response to paternal attractiveness, and highlight the possibility that corticosterone and perhaps testosterone are involved in the sex manipulation process in birds.

  20. Toxoplasma gondii infection induces dendritic retraction in basolateral amygdala accompanied by reduced corticosterone secretion

    Directory of Open Access Journals (Sweden)

    Rupshi Mitra

    2013-03-01

    Pathological anxiety is thought to reflect a maladaptive state characterized by exaggerated fear. Naturally occurring perturbations that reduce fear can be crucial in the search for new treatments. The protozoan parasite Toxoplasma gondii invades rat brain and removes the fear that rats have of cat odors, a change believed to be parasitic manipulation of host behavior aimed at increasing parasite transmission. It is likely that mechanisms employed by T. gondii can be used as a heuristic tool to understand possible means of fear reduction in clinical settings. Male Long-Evans rats were infected with T. gondii and compared with sham-infected animals 8 weeks after infection. The amount of circulating plasma corticosterone and dendritic arborization of basolateral amygdala principal neurons were quantified. Previous studies have shown that corticosterone, acting within the basolateral amygdala, enhances the fear response to environmental stimuli. Here we show that T. gondii infection causes a dendritic retraction in basolateral amygdala neurons. Such dendritic retraction is accompanied by lower amounts of circulating corticosterone, both at baseline and when induced by an aversive cat odor. The concerted effects of parasitism on two pivotal physiological nodes of the fear response provide an animal model relevant to interactions between stress hormones and amygdalar plasticity.

  1. Escitalopram or novel herbal mixture treatments during or following exposure to stress reduce anxiety-like behavior through corticosterone and BDNF modifications.

    Directory of Open Access Journals (Sweden)

    Ravid Doron

    Full Text Available Anxiety disorders are a major public health concern worldwide. Studies indicate that repeated exposure to adverse experiences early in life can lead to anxiety disorders in adulthood. Current treatments for anxiety disorders are characterized by a low success rate and are associated with a wide variety of side effects. The aim of the present study was to evaluate the anxiolytic effects of a novel herbal treatment, in comparison to treatment with the selective serotonin reuptake inhibitor escitalopram. We recently demonstrated the anxiolytic effects of these treatments in BALB mice previously exposed to one week of stress. In the present study, ICR mice were exposed to post natal maternal separation and to 4 weeks of unpredictable chronic mild stress in adolescence, and treated during or following exposure to stress with the novel herbal treatment or with escitalopram. Anxiety-like behavior was evaluated in the elevated plus maze. Blood corticosterone levels were evaluated using radioimmunoassay. Brain derived neurotrophic factor levels in the hippocampus were evaluated using enzyme-linked immunosorbent assay. We found that (1 exposure to stress in childhood and adolescence increased anxiety-like behavior in adulthood; (2 the herbal treatment reduced anxiety-like behavior, both when treated during or following exposure to stress; (3 blood corticosterone levels were reduced following treatment with the herbal treatment or escitalopram, when treated during or following exposure to stress; (4 brain derived neurotrophic factor levels in the hippocampus of mice treated with the herbal treatment or escitalopram were increased, when treated either during or following exposure to stress. This study expands our previous findings and further points to the proposed herbal compound's potential to be highly efficacious in treating anxiety disorders in humans.

  2. Effect of water deprivation on baseline and stress-induced corticosterone levels in the Children's python (Antaresia childreni).

    Science.gov (United States)

    Dupoué, Andréaz; Angelier, Frédéric; Lourdais, Olivier; Bonnet, Xavier; Brischoux, François

    2014-02-01

    Corticosterone (CORT) secretion is influenced by endogenous factors (e.g., physiological status) and environmental stressors (e.g., ambient temperature). Heretofore, the impact of water deprivation on CORT plasma levels has not been thoroughly investigated. However, both baseline CORT and stress-induced CORT are expected to respond to water deprivation not only because of hydric stress per se, but also because CORT is an important mineralocorticoid in vertebrates. We assessed the effects of water deprivation on baseline CORT and stress-induced CORT, in Children's pythons (Antaresia childreni), a species that experiences seasonal droughts in natural conditions. We imposed a 52-day water deprivation on a group of unfed Children's pythons (i.e., water-deprived treatment) and provided water ad libitum to another group (i.e., control treatment). We examined body mass variations throughout the experiment, and baseline CORT and stress-induced CORT at the end of the treatments. Relative body mass loss averaged ~10% in pythons without water, a value 2 to 4 times higher compared to control snakes. Following re-exposition to water, pythons from the water-deprived treatment drank readily and abundantly and attained a body mass similar to pythons from the control treatment. Together, these results suggest a substantial dehydration as a consequence of water deprivation. Interestingly, stress-induced but not baseline CORT level was significantly higher in water-deprived snakes, suggesting that baseline CORT might not respond to this degree of dehydration. Therefore, possible mineralocorticoid role of CORT needs to be clarified in snakes. Because dehydration usually induces adjustments (reduced movements, lowered body temperature) to limit water loss, and decreases locomotor performances, elevated stress-induced CORT in water-deprived snakes might therefore compensate for altered locomotor performances. Future studies should test this hypothesis. Copyright © 2013 Elsevier Inc

  3. Brain activation in response to visceral stimulation in rats with amygdala implants of corticosterone: an FMRI study.

    Directory of Open Access Journals (Sweden)

    Anthony C Johnson

    2010-01-01

    Full Text Available Although visceral pain of gastrointestinal (GI origin is the major complaint in patients with irritable bowel syndrome (IBS it remains poorly understood. Brain imaging studies suggest a defect in brain-gut communication in IBS with a greater activation of central arousal circuits including the amygdala. Previously, we found that stereotaxic implantation of corticosterone (CORT onto the amygdala in rats induced anxiety and colonic hypersensitivity. In the present study we used functional magnetic resonance imaging (fMRI to identify specific brain sites activated in a rat model characterized by anxiety and colonic hypersensitivity.Anesthetized male rats received micropellets (30 microg each of either CORT or cholesterol (CHOL, to serve as a control, implanted stereotaxically on the dorsal margin of each amygdala. Seven days later, rats were anesthetized and placed in the fMRI magnet (7T. A series of isobaric colorectal balloon distensions (CRD - 90s 'off', 30s 'on', 8 replicates at two pressures (40 and 60 mmHg were performed in a standard block-design. Cross correlation statistical analysis was used to determine significant differences between distended and non-distended states in CORT and CHOL-treated animals. Analysis of the imaging data demonstrated greater overall brain activation in response to CRD in rats with CORT implants compared to CHOL controls. Additionally, CORT implants produced significant positive bilateral increases in MRI signal in response to CRD in specific nuclei known as integration sites important in anxiety and pain perception.These data indicate that chronic exposure of the amygdala to elevated levels of CORT enhances overall brain activation in response to CRD, and identified other specific brain regions activated in response to mechanical distension of the colon. These results demonstrate the feasibility of performing fMRI imaging in a rodent model that supports clinical observations in IBS patients with enhanced

  4. Linking sex differences in corticosterone with individual reproductive behaviour and hatch success in two species of uniparental shorebirds.

    Science.gov (United States)

    Edwards, Darryl B; Chin, Eunice H; Burness, Gary; Gilchrist, H Grant; Schulte-Hostedde, Albrecht I

    2013-09-01

    In birds, corticosterone (CORT) appears to facilitate reproductive activity because baseline and stress-induced CORT levels are elevated in breeding individuals compared with other times of the year. In particular, CORT is lower in the sex providing most of the parental care (i.e., incubation), which could be an important adaptation to tolerate stressors that result in abandoning reproduction. Therefore, one explanation for sex differences in CORT is that lower levels are favoured during the incubation/parental phase of reproduction. Using two species of uniparental shorebird - polyandrous red phalaropes (Phalaropus fulicarius) and polygynous white-rumped sandpipers (Calidris fuscicollis) - we predicted that the incubating sex would have lower baseline and stress-induced CORT, and incubating individuals with lower CORT would more effectively defend nests against a simulated intrusion, would return more quickly afterwards, and would ultimately have higher hatch success. We found that phalaropes followed the predicted pattern: incubating individuals (males) had lower baseline and stress-induced CORT than females but for baseline CORT these differences existed prior to males commencing incubation. Incubating male phalaropes with lower baseline and stress-induced CORT returned to incubate more quickly after a disturbance and there was non-significant tendency for baseline CORT to be lower in successful nests. In sandpipers, we observed no sex differences and no significant relationships between individual CORT levels and nest defence behaviours or hatch success. Our results demonstrate that in phalaropes at least, selection favours lower baseline and stress-induced CORT during the nesting period. These results can explain sex differences in stress-induced levels of CORT, however sex differences in baseline CORT were present prior to incubation. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. The effects of irradiation on the cytosol glucocorticoid receptor and concentrations of corticosterone and cyclic nucleotides in the rat liver

    International Nuclear Information System (INIS)

    Teshima, Teruki; Mori, Masaki; Honke, Yoshifumi

    1983-01-01

    The effects of irradiation on both the cytosol glucocorticoid receptor and concentrations of corticosterone and cyclic nucleotides in the rat liver were investigated. The liver concentrations of corticosterone and cyclic nucleotides were measured by radioimmunoassay before and after the irradiation of 1,000 rad/l fraction. The glucocorticoid receptor in the liver cytosol was determined by the measurement of the cytosol binding to 3 H-dexamethasone. The cytosol and nuclear corticosterone levels reached a peak 1 day after the irradiation of the rat liver and declined to the control levels after 2 days. The increase in corticosterone levels may be due to the direct stimulation of the right adrenal gland and/ or the stress induced by the irradiation. The binding capacity of the glucocorticoid receptor in rat liver cytosol decreased to the minimum 1 day after the irradiation, and the recovery occurred at 4 days. The Kd value of the glucocorticoid receptor remained unchanged from 1 hour until 4 days but was high at 4 and 7 days. The distinctly increased levels of cyclic GMP in the rat liver were found from 1 hour through 7 days after the irradiation, while cyclic AMP did not change. The inversed relationship between the cytosol glucocorticoid receptor and corticosterone levels in cytosol and the nuclei indicates that the receptor-bound corticosterone in cytosol can be transferred to a nucleus and remain there in the presence of appropriate amounts of corticosterone in cytosol, after which the receptor is released from the nucleus into cytosol. The high Kd values observed 4 -- 7 days after the irradiation may be either due to the direct effect of irradiation or to the replenishment of the receptor with a low affinity. (author)

  6. Persistent effects of prior chronic exposure to corticosterone on reward-related learning and motivation in rodents.

    Science.gov (United States)

    Olausson, Peter; Kiraly, Drew D; Gourley, Shannon L; Taylor, Jane R

    2013-02-01

    Repeated or prolonged exposure to stress has profound effects on a wide spectrum of behavioral and neurobiological processes and has been associated with the pathophysiology of depression. The multifaceted nature of this disorder includes despair, anhedonia, diminished motivation, and disrupted cognition, and it has been proposed that depression is also associated with reduced reward-motivated learning. We have previously reported that prior chronic corticosterone exposure to mice produces a lasting depressive-like state that can be reversed by chronic antidepressant treatment. In the present study, we tested the effects of prior chronic exposure to corticosterone (50 μg/ml) administered to rats or to mice in drinking water for 14 days followed by dose-tapering over 9 days. The exposure to corticosterone produced lasting deficits in the acquisition of reward-related learning tested on a food-motivated instrumental task conducted 10-20 days after the last day of full dose corticosterone exposure. Rats exposed to corticosterone also displayed reduced responding on a progressive ratio schedule of reinforcement when tested on day 21 after exposure. Amitriptyline (200 mg/ml in drinking water) exposure for 14 days to mice produced the opposite effect, enhancing food-motivated instrumental acquisition and performance. Repeated treatment with amitriptyline (5 mg/kg, intraperitoneally; bid) subsequent to corticosterone exposure also prevented the corticosterone-induced deficits in rats. These results are consistent with aberrant reward-related learning and motivational processes in depressive states and provide new evidence that stress-induced neuroadaptive alterations in cortico-limbic-striatal brain circuits involved in learning and motivation may play a critical role in aspects of mood disorders.

  7. Leptin reverses corticosterone-induced inhibition of neural stem cell proliferation through activating the NR2B subunits of NMDA receptors

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Wen-Zhu [Anesthesia and Operation Center, Hainan Branch of Chinese PLA General Hospital, Hainan 572013 (China); Anesthesia and Operation Center, Chinese PLA General Hospital, Beijing 100853 (China); Miao, Yu-Liang [Department of Anesthesiology, PLA No. 306 Hospital, Beijing 100101 (China); Guo, Wen-Zhi [Department of Anesthesiology, Beijing Military General Hospital of Chinese People’s Liberation Army, Beijing 100700 (China); Wu, Wei, E-mail: wwzwgk@163.com [Department of Head and Neck Surgery of Otolaryngology, PLA No. 306 Hospital, Beijing 100101 (China); Li, Bao-Wei [Department of Head and Neck Surgery of Otolaryngology, PLA No. 306 Hospital, Beijing 100101 (China); An, Li-Na [Department of Anesthesiology, Armed Police General Hospital, Beijing 100039 (China); Fang, Wei-Wu [Department of Anesthesiology, PLA No. 306 Hospital, Beijing 100101 (China); Mi, Wei-Dong, E-mail: elite2005gg@163.com [Anesthesia and Operation Center, Chinese PLA General Hospital, Beijing 100853 (China)

    2014-04-25

    Highlights: • Leptin promotes the proliferation of neural stem cells isolated from embryonic mouse hippocampus. • Leptin reverses corticosterone-induced inhibition of neural stem cell proliferation. • The effects of leptin are partially mediated by upregulating NR2B subunits. - Abstract: Corticosterone inhibits the proliferation of hippocampal neural stem cells (NSCs). The removal of corticosterone-induced inhibition of NSCs proliferation has been reported to contribute to neural regeneration. Leptin has been shown to regulate brain development, improve angiogenesis, and promote neural regeneration; however, its effects on corticosterone-induced inhibition of NSCs proliferation remain unclear. Here we reported that leptin significantly promoted the proliferation of hippocampal NSCs in a concentration-dependent pattern. Also, leptin efficiently reversed the inhibition of NSCs proliferation induced by corticosterone. Interestingly, pre-treatment with non-specific NMDA antagonist MK-801, specific NR2B antagonist Ro 25-6981, or small interfering RNA (siRNA) targeting NR2B, significantly blocked the effect of leptin on corticosterone-induced inhibition of NSCs proliferation. Furthermore, corticosterone significantly reduced the protein expression of NR2B, whereas pre-treatment with leptin greatly reversed the attenuation of NR2B expression caused by corticosterone in cultured hippocampal NSCs. Our findings demonstrate that leptin reverses the corticosterone-induced inhibition of NSCs proliferation. This process is, at least partially mediated by increased expression of NR2B subunits of NMDA receptors.

  8. [Posttrial injections of corticosterone in dorsal hippocampus of the BALB/c mouse facilitate extinction of appetitive operant conditioning in the Skinner box].

    Science.gov (United States)

    Micheau, J; Destrade, C; Soumireu-Mourat, B

    1982-06-28

    Corticosterone was injected bilaterally into the dorsal hippocampus of BALB/c Mice immediately after the first extinction session of an operant conditioning in a Skinner box. Compared with the control animals the Mice that received 1 or 0.1 microgram corticosterone exhibited 24 hrs. later, faster extinction of this conditioning. With a 0.01 microgram dose of corticosterone in each hippocampus we obtained an accelerated extinction during the session. These data suggest that corticosterone modulates hippocampal mechanisms involved in memory processes.

  9. Short-term repeated corticosterone administration enhances glutamatergic but not GABAergic transmission in the rat motor cortex.

    Science.gov (United States)

    Kula, Joanna; Blasiak, Anna; Czerw, Anna; Tylko, Grzegorz; Sowa, Joanna; Hess, Grzegorz

    2016-04-01

    It has been demonstrated that stress impairs performance of skilled reaching and walking tasks in rats due to the action of glucocorticoids involved in the stress response. Skilled reaching and walking are controlled by the primary motor cortex (M1); however, it is not known whether stress-related impairments in skilled motor tasks are related to functional and/or structural alterations within the M1. We studied the effects of single and repeated injections of corticosterone (twice daily for 7 days) on spontaneous excitatory and inhibitory postsynaptic currents (sEPSCs and sIPSCs) recorded from layer II/III pyramidal neurons in ex vivo slices of the M1, prepared 2 days after the last administration of the hormone. We also measured the density of dendritic spines on pyramidal cells and the protein levels of selected subunits of AMPA, NMDA, and GABAA receptors after repeated corticosterone administration. Repeatedly administered corticosterone induced an increase in the frequency but not in the amplitude of sEPSCs, while a single administration had no effect on the recorded excitatory currents. The frequency and amplitude of sIPSCs as well as the excitability of pyramidal cells were changed neither after single nor after repeated corticosterone administration. Treatment with corticosterone for 7 days did not modify the density of dendritic spines on pyramidal neurons. Corticosterone influenced neither the protein levels of GluA1, GluA2, GluN1, GluN2A, and GluN2B subunits of glutamate receptors nor those of α1, β2, and γ2 subunits of the GABAA receptor. The increase in sEPSCs frequency induced by repeated corticosterone administration faded out within 7 days. These data indicate that prolonged administration of exogenous corticosterone selectively and reversibly enhances glutamatergic, but not GABAergic transmission in the rat motor cortex. Our results suggest that corticosterone treatment results in an enhancement of spontaneous glutamate release from presynaptic

  10. Effects of developmental manganese, stress, and the combination of both on monoamines, growth, and corticosterone

    Directory of Open Access Journals (Sweden)

    Charles V. Vorhees

    2014-01-01

    Full Text Available Developmental exposure to manganese (Mn or stress can each be detrimental to brain development. Here, Sprague-Dawley rats were exposed to two housing conditions and Mn from postnatal day (P4–28. Within each litter two males and two females were assigned to the following groups: 0 (vehicle, 50, or 100 mg/kg Mn by gavage every other day. Half the litters were reared in cages with standard bedding and half with no bedding. One pair/group in each litter had an acute shallow water stressor before tissue collection (i.e., standing in shallow water. Separate litters were assessed at P11, 19, or 29. Mn-treated rats raised in standard cages showed no change in baseline corticosterone but following acute stress increased more than controls on P19; no Mn effects were seen on P11 or P29. Mn increased neostriatal dopamine in females at P19 and norepinephrine at P11 and P29. Mn increased hippocampal dopamine at P11 and P29 and 5-HT at P29 regardless of housing or sex. Mn had no effect on hypothalamic dopamine, but increased norepinephrine in males at P29 and 5-HT in males at all ages irrespective of rearing condition. Barren reared rats showed no or opposite effects of Mn, i.e., barren rearing + Mn attenuated corticosterone increases to acute stress. Barren rearing also altered the Mn-induced changes in dopamine and norepinephrine in the neostriatum, but not in the hippocampus. Barren rearing caused a Mn-associated increase in hypothalamic dopamine at P19 and P29 not seen in standard reared Mn-treated groups. Developmental Mn alters monoamines and corticosterone as a function of age, stress (acute and chronic, and sex.

  11. Heightened aggression and winning contests increase corticosterone but decrease testosterone in male Australian water dragons.

    Science.gov (United States)

    Baird, Troy A; Lovern, Matthew B; Shine, Richard

    2014-07-01

    Water dragons (Intellegama [Physignathus] lesueurii) are large (to >1m) agamid lizards from eastern Australia. Males are fiercely combative; holding a territory requires incessant displays and aggression against other males. If a dominant male is absent, injured or fatigued, another male soon takes over his territory. Our sampling of blood from free-ranging adult males showed that baseline levels of both testosterone and corticosterone were not related to a male's social tactic (territorial versus non-territorial), or his frequency of advertisement display, aggression, or courtship behavior. Even when we elicited intense aggression by non-territorial males (by temporarily removing territory owners), testosterone did not increase with the higher levels of aggression that ensued. Indeed, testosterone levels decreased in males that won contests. In contrast, male corticosterone levels increased with the heightened aggression during unsettled conditions, and were higher in males that won contests. High chronic male-male competition in this dense population may favor high testosterone levels in all adult males to facilitate advertisement and patrol activities required for territory maintenance (by dominant animals), and to maintain readiness for territory take-overs (in non-territorial animals). Corticosterone levels increased in response to intense aggression during socially unstable conditions, and were higher in contest winners than losers. A positive correlation between the two hormones during socially unstable conditions suggests that the high stress of contests decreased androgen production. The persistent intense competition in this population appears to exact a high physiological cost, which together with our observation that males sometimes lose their territories to challengers may indicate cycling between these two tactics to manage long-term energetic costs. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Alternative reproductive tactics in female striped mice: Solitary breeders have lower corticosterone levels than communal breeders.

    Science.gov (United States)

    Hill, Davina L; Pillay, Neville; Schradin, Carsten

    2015-05-01

    Alternative reproductive tactics (ARTs), where members of the same sex and population show distinct reproductive phenotypes governed by decision-rules, have been well-documented in males of many species, but are less well understood in females. The relative plasticity hypothesis (RPH) predicts that switches between plastic ARTs are mediated by changes in steroid hormones. This has received much support in males, but little is known about the endocrine control of female ARTs. Here, using a free-living population of African striped mice (Rhabdomys pumilio) over five breeding seasons, we tested whether females following different tactics differed in corticosterone and testosterone levels, as reported for male striped mice using ARTs, and in progesterone and oestrogen, which are important in female reproduction. Female striped mice employ three ARTs: communal breeders give birth in a shared nest and provide alloparental care, returners leave the group temporarily to give birth, and solitary breeders leave to give birth and do not return. We expected communal breeders and returners to have higher corticosterone, owing to the social stress of group-living, and lower testosterone than solitary breeders, which must defend territories alone. Solitary breeders had lower corticosterone than returners and communal breeders, as predicted, but testosterone and progesterone did not differ between ARTs. Oestrogen levels were higher in returners (measured before leaving the group) than in communal and solitary breeders, consistent with a modulatory role. Our study demonstrates hormonal differences between females following (or about to follow) different tactics, and provides the first support for the RPH in females. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Effects of acrolein on the production of corticosterone in male rats.

    Science.gov (United States)

    Yeh, Yung-Hsing; Chou, Jou-Chun; Weng, Ting-Chun; Lieu, Fu-Kong; Lin, Jou-Yu; Yeh, Chii-Chang; Hu, Sindy; Wang, Paulus S; Idova, Galina; Wang, Shyi-Wu

    2016-07-01

    Acrolein, an α, β-unsaturated aldehyde, exists in a wide range of sources. Acrolein can be not only generated from all types of smoke but also produced endogenously from the metabolism by lipid peroxidation. The cellular influence of acrolein is due to its electrophilic character via binding to and depleting cellular nucleophiles. Although the toxicity of acrolein has been extensively studied, there is relatively little information about its impact on hormone release. This study aimed at the effect of acrolein on hypothalamic-pituitary-adrenal (H-P-A) axis. In an in vivo study, male rats were administrated with acrolein for 1 or 3days. The plasma corticosterone in response to a single injection of adrenocorticotropic hormone (ACTH) increased slowly in acrolein-pretreated rats than in control rats. Further investigating the steroidogenic pathway, the protein expressions of steroidogenic acute regulatory protein (StAR) and the upper receptor-melanocortin 2 receptor (MC2R) were attenuated in acrolein-treated groups. Another experiment using trilostane showed less activity of P450scc in zona fasciculata-reticularis (ZFR) cells in acrolein-treated groups. In addition to the suppressed ability of corticosterone production in ZFR cells, acrolein even had extended influence at higher concentrations. The lower ACTH was observed in the plasma from acrolein-pretreated rats. In an in vitro study, ZFR cells were incubated with acrolein and the results showed that corticosterone concentrations in media were decreased in a dose-dependent manner. Acrolein also desensitized the response of the ZFR cells to ACTH. These results suggested that acrolein decreased the releasing ability of corticosterone via an inhibition on the response of ZFR cells to ACTH and the reduction of protein expressions of StAR and MC2R as well as the activity of P450scc in rat ZFR cells. The present evidences showed that the H-P-A axis was affected by the administration of acrolein. Copyright © 2016

  14. ACTH, corticosterone, and beta-endorphin in rat blood plasma after prolonged immobilization stress

    Energy Technology Data Exchange (ETDEWEB)

    Kiyatkin, E.A.; Amiragova, M.G.; Kushlinskii, N.E.; Polyntsev, Yu. V.

    1986-01-01

    To assess functional relations between changes in ACTH, beta-endorphin (BE), and corticosterone (CS) levels, plasma concentrations of these hormones were studied in rats during the development of prolonged immobilization stress. Plasma hormone concentrations were determined by radioimmunoassay. The results were analyzed by standard statistical methods on a microcomputer. A particular feature about the kit used to determine BE was the presence of 50% cross-reactivity of the antiserum against beta-lipotrophin. To determine CS a highly specific antiserum produced by a laboratory was used.

  15. Separation and identification of corticosterone metabolites by liquid chromatography--electrospray ionization mass spectrometry.

    Science.gov (United States)

    Miksík, I; Vylitová, M; Pácha, J; Deyl, Z

    1999-04-16

    High-performance liquid chromatography coupled to atmospheric pressure ionization-electrospray ionization mass spectrometry (API-ESI-MS) was investigated for the analysis of corticosterone metabolites; their characterization was obtained by combining the separation on Zorbax Eclipse XDB C18 column (eluted with a methanol-water-acetic acid gradient) with identification using positive ion mode API-ESI-MS and selected ion analysis. The applicability of this method was verified by monitoring the activity of steroid converting enzymes (20beta-hydroxysteroid dehydrogenase and 11beta-hydroxysteroid dehydrogenase) in avian intestines.

  16. Role of 11. beta. -hydroxyprogesterone in biosynthesis of corticosterone from progesterone in guinea pig adrenals

    Energy Technology Data Exchange (ETDEWEB)

    Yudaev, N A; Afinogenova, S A [Institute of Experimental Endocrinology and Hormone Chemistry, Moscow (USSR)

    1975-06-01

    Slices of male guinea pig adrenals were incubated with a trace amount of /sup 3/H-7..cap alpha..-progesterone and the proportion of /sup 3/H incorporation various steroids at various intervals was measured. It was found that /sup 3/H accumulated predominantly in 11..beta..-hydroxyprogesterone as compared to DOC. This indicated that in guinea pig adrenals 11..beta..-hydroxyprogesterone plays a predominant role in the formation of corticosterone from progesterone. The observed sequence of changes in progesterone label accumulation in 17-hydroxycompounds indicated the pathway of cortisol synthesis through the intermediate formation of 17-hydroxyprogesterone and 11-deoxycortisol.

  17. Variations in maternal care alter corticosterone and 17beta-estradiol levels, estrous cycle and folliculogenesis and stimulate the expression of estrogen receptors alpha and beta in the ovaries of UCh rats

    Directory of Open Access Journals (Sweden)

    Amorim João PA

    2011-12-01

    Full Text Available Abstract Background Variations in maternal care are associated with neonatal stress, hormonal disturbances and reproductive injuries during adulthood. However, the effects of these variations on sex hormones and steroid receptors during ovary development remain undetermined. This study aimed to investigate whether variations in maternal care are able to influence the hormonal profile, follicular dynamics and expression of AR, ER-alpha and ER-beta in the ovaries of UCh rat offspring. Methods Twenty-four adult UCh rats, aged 120 days, were randomly divided into two groups (UChA and UChB and mated. Maternal care was assessed from birth (day 0 to the 10th postnatal day (PND. In adulthood, twenty adult female rats (UChA and UChB offspring; n = 10/group, aged 120 days, were euthanized by decapitation during the morning estrus. Results UChA females (providing high maternal care more frequently displayed the behaviors of carrying pups, as well as licking/grooming and arched back nursing cares. Also, mothers providing high care had elevated corticosterone levels. Additionally, offspring receiving low maternal care showed the highest estrous cycle duration, increased corticosterone and 17beta-estradiol levels, overexpression of receptors ER-alpha and ER-beta, increased numbers of primordial, antral and mature follicles and accentuated granulosa cell proliferation. Conclusions Our study suggests that low maternal care alters corticosterone and 17beta-estradiol levels, disrupting the estrous cycle and folliculogenesis and differentially regulating the expression of ER-alpha and ER-beta in the ovaries of adult rats.

  18. Altered Rhythm of Adrenal Clock Genes, StAR and Serum Corticosterone in VIP Receptor 2-Deficient Mice

    DEFF Research Database (Denmark)

    Fahrenkrug, Jan; Georg, Birgitte; Hannibal, Jens

    2012-01-01

    oscillator based on a group of clock genes and their protein products. Mice lacking the VPAC2 receptor display disrupted circadian rhythm of physiology and behaviour, and therefore, we using real-time RT-PCR quantified (1) the mRNAs for the clock genes Per1 and Bmal1 in the adrenal gland and SCN, (2......RNA expression and serum corticosterone concentration. Double immunohistochemistry showed that the PER1 protein and StAR were co-localised in the same steroidogenic cells. Circulating corticosterone plays a role in the circadian timing system and the misaligned corticosterone rhythm in the VPAC2 receptor......The circadian time-keeping system consists of clocks in the suprachiasmatic nucleus (SCN) and in peripheral organs including an adrenal clock linked to the rhythmic corticosteroid production by regulating steroidogenic acute regulatory protein (StAR). Clock cells contain an autonomous molecular...

  19. Stress induced a shift from dorsal hippocampus to prefrontal cortex-dependent memory retrieval: role of regional corticosterone.

    Directory of Open Access Journals (Sweden)

    Gaelle eDominguez

    2014-05-01

    Full Text Available Most of the deleterious effects of stress on memory retrieval are due to a dysfunction of the hippocampo-prefrontal cortex interplay. The role of the stress-induced regional corticosterone increase in such dysfunction remains however unclear, since there is no published study as yet dedicated to measuring corticosterone concentrations simultaneously in both the prefrontal cortex (mPFC and the hippocampus (dHPC in relation with memory impairments. To that aim, we first showed in Experiment 1 that an acute stress (3 electric footschocks; 0.9 mA each delivered before memory testing reversed the memory retrieval pattern (MRP in a serial discrimination task in which mice learned two successive discriminations. More precisely, whereas non-stressed animals remembered accurately the first learned discrimination and not the second one, stressed mice remembered more accurately the second discrimination but not the first one. We demonstrated that local inactivation of dHPC or mPFC with the anesthetic lidocaine recruited the dHPC activity in non-stress conditions whereas the stress-induced MRP inversion recruited the mPFC activity. In a second experiment, we showed that acute stress induced a very similar time-course evolution of corticosterone rises within both the mPFC and dHPC. In a 3rd experiment, we found however that in situ injections of corticosterone either within the mPFC or the dHPC before memory testing favored the emergence of the mPFC-dependent MRP but blocked the emergence of the dHPC-dependent one. Overall, our study evidences that the simultaneous increase of corticosterone after stress in both areas induces a shift from dHPC (non stress condition to mPFC-dependent memory retrieval pattern and that corticosterone is critically involved in mediating the deleterious effects of stress on cognitive functions involving the mPFC-HPC interplay.

  20. Effects of long-term corticosterone implants on growth and immune function in juvenile alligators, Alligator mississippiensis.

    Science.gov (United States)

    Morici, L A; Elsey, R M; Lance, V A

    1997-10-01

    Sixty juvenile alligators were implanted subcutaneously with slow release pellets of corticosterone or placebo. Alligators were divided into five different groups such that each group received a different dose. A blood sample was taken prior to and 4 days after the implants were in place to measure hormone levels. Additional blood samples were collected at 1 month and 3 months. At 4 days corticosterone levels ranged from 3,400 ng/ml in the group treated with the high dose to 40 ng/ml in the group implanted with the low dose. The extremely high dose caused 40% mortality within 4 weeks. It was evident that the pellets did not release the hormone for the expected 90 days. Circulating levels of corticosterone were back to baseline levels by 3 months. Hormone levels achieved at 4 days were a reliable predictor of subsequent growth. Rate of growth was negatively correlated with plasma corticosterone at 4 days (r2 = 0.711) and at 1 month (r2 = 0.544) posttreatment. Differential white blood cell counts performed after 1 month of treatment showed a clear effect of the implant. Alligators treated with corticosterone had decreased percentages of lymphocytes, eosinophils, and basophils and had a higher heterophil/lymphocyte (H/L) ratio than the placebo group. Furthermore, histological examination of the spleen revealed a significant depletion of lymphoid cells in alligators treated with the highest dose of hormone. The results from this study demonstrate that exogenous corticosterone can mimic the effects of prolonged stress in juvenile alligators.

  1. Agmatine, by Improving Neuroplasticity Markers and Inducing Nrf2, Prevents Corticosterone-Induced Depressive-Like Behavior in Mice.

    Science.gov (United States)

    Freitas, Andiara E; Egea, Javier; Buendia, Izaskun; Gómez-Rangel, Vanessa; Parada, Esther; Navarro, Elisa; Casas, Ana Isabel; Wojnicz, Aneta; Ortiz, José Avendaño; Cuadrado, Antonio; Ruiz-Nuño, Ana; Rodrigues, Ana Lúcia S; Lopez, Manuela G

    2016-07-01

    Agmatine, an endogenous neuromodulator, is a potential candidate to constitute an adjuvant/monotherapy for the management of depression. A recent study by our group demonstrated that agmatine induces Nrf2 and protects against corticosterone effects in a hippocampal neuronal cell line. The present study is an extension of this previous study by assessing the antidepressant-like effect of agmatine in an animal model of depression induced by corticosterone in mice. Swiss mice were treated simultaneously with agmatine or imipramine at a dose of 0.1 mg/kg/day (p.o.) and corticosterone for 21 days and the daily administrations of experimental drugs were given immediately prior to corticosterone (20 mg/kg/day, p.o.) administrations. Wild-type C57BL/6 mice (Nrf2 (+/+)) and Nrf2 KO (Nrf2 (-/-)) were treated during 21 days with agmatine (0.1 mg/kg/day, p.o.) or vehicle. Twenty-four hours after the last treatments, the behavioral tests and biochemical assays were performed. Agmatine treatment for 21 days was able to abolish the corticosterone-induced depressive-like behavior and the alterations in the immunocontent of mature BDNF and synaptotagmin I, and in the serotonin and glutamate levels. Agmatine also abolished the corticosterone-induced changes in the morphology of astrocytes and microglia in CA1 region of hippocampus. In addition, agmatine treatment in control mice increased noradrenaline, serotonin, and dopamine levels, CREB phosphorylation, mature BDNF and synaptotagmin I immunocontents, and reduced pro-BDNF immunocontent in the hippocampus. Agmatine's ability to produce an antidepressant-like effect was abolished in Nrf2 (-/-) mice. The present results reinforce the participation of Nrf2 in the antidepressant-like effect produced by agmatine and expand literature data concerning its mechanisms of action.

  2. Interaction between diazepam and hippocampal corticosterone after acute stress: impact on memory in middle-aged mice

    Directory of Open Access Journals (Sweden)

    Daniel eBeracochea

    2011-04-01

    Full Text Available Benzodiazepines (BDZ are widely prescribed in the treatment of anxiety disorders associated to aging. Interestingly, whereas a reciprocal interaction between the GABAergic system and HPA axis has been evidenced, there is to our knowledge no direct evaluation of the impact of BDZ on both hippocampus (HPC corticosterone concentrations and HPC-dependent memory in stressed middle-aged subjects. We showed previously that an acute stress induced in middle-aged mice severe memory impairments in a hippocampus-dependent task, and increased in parallel hippocampus corticosterone concentrations, as compared to non stressed middle-aged controls (Tronche et al., 2010. Based on these findings, the aims of the present study were to evidence the impact of diazepam (a positive allosteric modulator of the GABA-A receptor on HPC glucocorticoids concentrations and in parallel on HPC-dependent memory in acutely stressed middle-aged mice.Microdialysis experiments showed an interaction between diazepam doses and corticosterone concentrations into the HPC. From 0.25 mg/kg to 0.5 mg/kg, diazepam dose-dependently reduces intra-HPC corticosterone concentrations and in parallel, dose-dependently increased hippocampal-dependent memory performance. In contrast, the highest (1.0mg/kg diazepam dose induces a reduction in HPC corticosterone concentration, which was of greater magnitude as compared to the two other diazepam doses, but however decreased the hippocampal-dependent memory performance. In summary, our study provides first evidence that diazepam restores in stressed middle-aged animals the hippocampus-dependent response, in relation with HPC corticosterone concentrations. Overall, our data illustrate how stress and benzodiazepines could modulate cognitive functions depending on hippocampus activity.

  3. The number of insults and the cerebral damage after hypoxia/ischemia are altered after acute pretreatment with corticosterone and metyrapone.

    NARCIS (Netherlands)

    Knollema, S; Kemper, RHA; Korf, J; Wiersma, A; Ter Horst, GJ; Krugers, HJ

    1997-01-01

    The role of glucocorticoids in neuronal viability is controversial. Most studies which describe the effects of glucocorticoids on ischemic brain damage use surgical adrenalectomy to induce a reduction in plasma corticosterone levels. In the present study we used metyrapone, a corticosterone

  4. Effects of Endotoxin and Psychological Stress on Redox Physiology, Immunity and Feather Corticosterone in Greenfinches.

    Directory of Open Access Journals (Sweden)

    Richard Meitern

    Full Text Available Assessment of costs accompanying activation of immune system and related neuroendocrine pathways is essential for understanding the selective forces operating on these systems. Here we attempted to detect such costs in terms of disruption to redox balance and interference between different immune system components in captive wild-caught greenfinches (Carduelis chloris. Study birds were subjected to an endotoxin-induced inflammatory challenge and temporary exposure to a psychological stressor (an image of a predator in a 2*2 factorial experiment. Injection of bacterial endotoxin resulted in up-regulation of two markers of antioxidant protection - erythrocyte glutathione, and plasma oxygen radical absorbance (OXY. These findings suggest that inflammatory responses alter redox homeostasis. However, no effect on markers of oxidative damage to proteins or DNA in erythrocytes could be detected. We found no evidence that the endotoxin injection interfered with antibody production against Brucella abortus antigen or the intensity of chronic coccidiosis. The hypothesis of within-immune system trade-offs as a cost of immunity was thus not supported in our model system. We showed for the first time that administration of endotoxin can reduce the level of corticosterone deposited into feathers. This finding suggests a down-regulation of the corticosterone secretion cascade due to an endotoxin-induced immune response, a phenomenon that has not been reported previously. Exposure to the predator image did not affect any of the measured physiological parameters.

  5. Pasireotide treatment does not modify hyperglycemic and corticosterone acute restraint stress responses in rats.

    Science.gov (United States)

    Ribeiro-Oliveira, Antônio; Schweizer, Junia R O L; Amaral, Pedro H S; Bizzi, Mariana F; Silveira, Warley Cezar da; Espirito-Santo, Daniel T A; Zille, Giancarlo; Soares, Beatriz S; Schmid, Herbert A; Yuen, Kevin C J

    2018-04-17

    Pasireotide is a new-generation somatostatin analog that acts through binding to multiple somatostatin receptor subtypes. Studies have shown that pasireotide induces hyperglycemia, reduces glucocorticoid secretion, alters neurotransmission, and potentially affects stress responses typically manifested as hyperglycemia and increased corticosterone secretion. This study specifically aimed to evaluate whether pasireotide treatment modifies glucose and costicosterone secretion in response to acute restraint stress. Male Holtzman rats of 150-200 g were treated with pasireotide (10 µg/kg/day) twice-daily for two weeks or vehicle for the same period. Blood samples were collected at baseline and after 5, 10, 30, and 60 min of restraint stress. The three experimental groups comprised of vehicle + restraint (VEHR), pasireotide + restraint (PASR), and pasireotide + saline (PASNR). Following pasireotide treatment, no significant differences in baseline glucose and corticosterone levels were observed among the three groups. During restraint, hyperglycemia was observed at 10 min (p stressed groups when compared to the non-stressed PASNR group (p stressed groups at 5 min (p stressed PASNR group (p stress responses, thus preserving acute stress regulation.

  6. Polysaccharides from Wolfberry Prevents Corticosterone-Induced Inhibition of Sexual Behavior and Increases Neurogenesis

    Science.gov (United States)

    Lau, Benson Wui-Man; Lee, Jada Chia-Di; Li, Yue; Fung, Sophia Man-Yuk; Sang, Yan-Hua; Shen, Jiangang; Chang, Raymond Chuen-Chung; So, Kwok-Fai

    2012-01-01

    Lycium barbarum, commonly known as wolfberry, has been used as a traditional Chinese medicine for the treatment of infertility and sexual dysfunction. However, there is still a scarcity of experimental evidence to support the pro-sexual effect of wolfberry. The aim of this study is to determine the effect of Lycium barbarum polysaccharides (LBP) on male sexual behavior of rats. Here we report that oral feeding of LBP for 21 days significantly improved the male copulatory performance including increase of copulatory efficiency, increase of ejaculation frequency and shortening of ejaculation latency. Furthermore, sexual inhibition caused by chronic corticosterone was prevented by LBP. Simultaneously, corticosterone suppressed neurogenesis in subventricular zone and hippocampus in adult rats, which could be reversed by LBP. The neurogenic effect of LBP was also shown in vitro. Significant correlation was found between neurogenesis and sexual performance, suggesting that the newborn neurons are associated with reproductive successfulness. Blocking neurogenesis in male rats abolished the pro-sexual effect of LBP. Taken together, these results demonstrate the pro-sexual effect of LBP on normal and sexually-inhibited rats, and LBP may modulate sexual behavior by regulating neurogenesis. PMID:22523540

  7. Effects of sheltering on behavior and fecal corticosterone level of elderly dogs

    Directory of Open Access Journals (Sweden)

    Katsuji Uetake

    2016-11-01

    Full Text Available In Japan, the human population is aging rapidly, and the abandonment of dogs by the elderly people who have died or been hospitalized becomes a problem. It is hypothesized that elderly dogs have difficulty adapting to the novel circumstances when brought to an animal shelter. Therefore, the objective of this study was to assess stress levels and demonstrate stress responses of elderly dogs just after admission to an animal shelter. As stress indicators, fecal corticosterone levels and changes in the ethogram of the dogs were investigated during the first week of admittance. Fecal corticosterone levels (mean ± SE stayed high during the first week of residence, although they fell gently from the day after admittance (16650.1 ± 3769.7 ng/g to the seventh day (12178.4 ± 2524.4 ng/g (P <0.001. The proportions of behavioral expressions changed as the days passed (P < 0.001. In particular, stereotypies decreased from 35.7% on the first day to 2.6% on the sixth day, and time spent sleeping increased from 0.0% to 42.7%. These results indicate that elderly dogs admitted to an animal shelter seem to behaviorally adapt themselves to their novel circumstances, but might be stressed even on the seventh day of residence.

  8. Agmatine induces Nrf2 and protects against corticosterone effects in hippocampal neuronal cell line.

    Science.gov (United States)

    Freitas, Andiara E; Egea, Javier; Buendía, Izaskun; Navarro, Elisa; Rada, Patricia; Cuadrado, Antonio; Rodrigues, Ana Lúcia S; López, Manuela G

    2015-01-01

    Hyperactivation of the hypothalamic-pituitary-adrenal axis is a common finding in major depression; this may lead to increased levels of cortisol, which are known to cause oxidative stress imbalance and apoptotic neuronal cell death, particularly in the hippocampus, a key region implicated in mood regulation. Agmatine, an endogenous metabolite of L-arginine, has been proposed for the treatment of major depression. Corticosterone induced apoptotic cell death and increased ROS production in cultured hippocampal neuronal cells, effects that were abolished in a concentration- and time-dependent manner by agmatine. Interestingly, the combination of sub-effective concentrations of agmatine with fluoxetine or imipramine afforded synergic protection. The neuroprotective effect of agmatine was abolished by yohimbine (α2-adrenoceptor antagonist), ketanserin (5-HT2A receptor antagonist), LY294002 (PI3K inhibitor), PD98059 (MEK1/2 inhibitor), SnPP (HO-1 inhibitor), and cycloheximide (protein synthesis inhibitor). Agmatine increased Akt and ERK phosphorylation and induced the transcription factor Nrf2 and the proteins HO-1 and GCLc; induction of these proteins was prevented by yohimbine, ketanserin, LY294002, and PD98059. In conclusion, agmatine affords neuroprotection against corticosterone effects by a mechanism that implicates Nrf2 induction via α2-adrenergic and 5-HT2A receptors, Akt and ERK pathways, and HO-1 and GCLc expression.

  9. Snow cover and snowfall impact corticosterone and immunoglobulin a levels in a threatened steppe bird.

    Science.gov (United States)

    Liu, Gang; Hu, Xiaolong; Kessler, Aimee Elizabeth; Gong, Minghao; Wang, Yihua; Li, Huixin; Dong, Yuqiu; Yang, Yuhui; Li, Linhai

    2018-05-15

    Birds use both the corticosterone stress response and immune system to meet physiological challenges during exposure to adverse climatic conditions. To assess the stress level and immune response of the Asian Great Bustard during conditions of severe winter weather, we measured fecal corticosterone (CORT) and Immunoglobulin A (IgA) before and after snowfall in a low snow cover year (2014) and a high snow cover year (2015). A total of 239 fecal samples were gathered from individuals in Tumuji Nature Reserve, located in eastern Inner Mongolia, China. We observed high CORT levels that rose further after snowfall both in high and low snow cover years. IgA levels increased significantly after snowfall in the low snow cover year, but decreased after snowfall in the high snow cover year. These results suggest that overwintering Asian Great Bustards are subjected to climatic stress during severe winter weather, and the hypothalamic-pituitary-adrenal axis and immune system react to this challenge. Extreme levels of stress, such as snowfall in already prolonged and high snow cover conditions may decrease immune function. Supplemental feeding should be considered under severe winter weather conditions for this endangered subspecies. Copyright © 2018 Elsevier Inc. All rights reserved.

  10. Faecal corticosterone metabolite concentrations are not a good predictor of habitat suitability for common gartersnakes.

    Science.gov (United States)

    Halliday, William D; Gilmour, Kathleen M; Blouin-Demers, Gabriel

    2015-01-01

    Measuring habitat suitability is important in conservation and in wildlife management. Measuring the abundance or presence-absence of a species in various habitats is not sufficient to measure habitat suitability because these metrics can be poor predictors of population success. Therefore, having some measure of population success is essential in assessing habitat suitability, but estimating population success is difficult. Identifying suitable proxies for population success could thus be beneficial. We examined whether faecal corticosterone metabolite (fCM) concentrations could be used as a proxy for habitat suitability in common gartersnakes (Thamnophis sirtalis). We conducted a validation study and confirmed that fCM concentrations indeed reflect circulating corticosterone concentrations. We estimated abundance, reproductive output and growth rate of gartersnakes in field and in forest habitat and we also measured fCM concentrations of gartersnakes from these same habitats. Common gartersnakes were more abundant and had higher reproductive outputs and higher growth rates in field habitat than in forest habitat, but fCM concentrations did not differ between the same two habitats. Our results suggest either that fCM concentrations are not a useful metric of habitat suitability in common gartersnakes or that the difference in suitability between the two habitats was too small to induce changes in fCM concentrations. Incorporating fitness metrics in estimates of habitat suitability is important, but these metrics of fitness have to be sensitive enough to vary between habitats.

  11. Blood Biochemistry and Plasma Corticosterone Concentration in Broiler Chickens Under Heat Stress

    Directory of Open Access Journals (Sweden)

    Elvis Alexander Díaz López

    2014-07-01

    Full Text Available High ambient temperatures cause susceptibility to heat stress in broiler chickens, generating metabolic changes. This paper seeks to determine the changes in blood biochemistry and plasma corticosterone concentration, as well as in glucose, total protein, albumin, globulin, sodium, chlorine, potassium, magnesium, phosphorus, and calcium in broiler chickens under chronic heat stress and at ambient temperature conditions at the Colombian Amazonian piedmont. 21-days-old male chickens of two lines were studied, distributed in an unrestricted random design, in a two-factor scheme, with four treatments. Five repetitions per treatment were performed, and 25 animals per experimental unit examined. Broilers were fed a basic diet of corn and soybean meal with 3,100 kcal ME and 19.5% protein until they reached 42 days of age. The line factor had no effect on the evaluated variables (p ≥ 0.05. However, there was statistically significant difference (p ≤ 0.05 in all variables when concentrations of metabolites in broilers under chronic heat stress were compared to those of chickens exposed to ambient temperatures at the Colombian Amazon piedmont. In conclusion, blood biochemistry suffered significant changes under both experimental temperatures, with more physiological detriment in broilers under chronic heat stress. Concentration of corticosterone became the most sensitive and consistent indicator of the physiological condition of chronic heat stress.

  12. National Elevation Dataset (NED)

    Data.gov (United States)

    Kansas Data Access and Support Center — The U.S. Geological Survey has developed a National Elevation Database (NED). The NED is a seamless mosaic of best-available elevation data. The 7.5-minute elevation...

  13. Elevated Liver Enzymes

    Science.gov (United States)

    Symptoms Elevated liver enzymes By Mayo Clinic Staff Elevated liver enzymes may indicate inflammation or damage to cells in the liver. Inflamed or ... than normal amounts of certain chemicals, including liver enzymes, into the bloodstream, which can result in elevated ...

  14. Corticosterone facilitates extinction of fear memory in BALB/c mice but strengthens cue related fear in C57BL/6 mice.

    Science.gov (United States)

    Brinks, V; de Kloet, E R; Oitzl, M S

    2009-04-01

    Corticosterone, the naturally occurring glucocorticoid of rodents is secreted in response to stressors and is known for its facilitating and detrimental effects on emotional learning and memory. The large variability in the action of corticosterone on processing of emotional memories is postulated to depend on genetic background and the spatio-temporal domain in which the hormone operates. To address this hypothesis, mice of two strains with distinct corticosterone secretory patterns and behavioural phenotype (BALB/c and C57BL/6J) were treated with corticosterone (250 microg/kg, i.p.), either 5 min before or directly after acquisition in a fear conditioning task. As the paradigm allowed assessing in one experimental procedure both context- and cue-related fear behaviour, we were able to detect generalization and specificity of fear. BALB/c showed generalized strong fear memory, while C57BL/6J mice discriminated between freezing during context- and cue episodes. Corticosterone had opposite effects on fear memory depending on the strain and time of injection. Corticosterone after acquisition did not affect C57BL/6J mice, but destabilized consolidation and facilitated extinction in BALB/c. Corticosterone 5 min before acquisition strengthened stress-associated signals: BALB/c no longer showed lower fear memory, while C57BL/6J mice displayed increased fear memory and impaired extinction in cue episodes. We propose that corticosterone-induced facilitation of fear memory in C57BL/6J mice can be used to study the development of fear memories, corticosterone administration in BALB/c mice presents a model to examine treatment. We conclude that genetic background and time of corticosterone action are modifiers of fear memory with interesting translational implications for anxiety-related diseases.

  15. Corticosterone primes the neuroinflammatory response to DFP in mice: potential animal model of Gulf War Illness.

    Science.gov (United States)

    O'Callaghan, James P; Kelly, Kimberly A; Locker, Alicia R; Miller, Diane B; Lasley, Steve M

    2015-06-01

    Gulf War Illness (GWI) is a multi-symptom disorder with features characteristic of persistent sickness behavior. Among conditions encountered in the Gulf War (GW) theater were physiological stressors (e.g., heat/cold/physical activity/sleep deprivation), prophylactic treatment with the reversible AChE inhibitor, pyridostigmine bromide (PB), the insect repellent, N,N-diethyl-meta-toluamide (DEET), and potentially the nerve agent, sarin. Prior exposure to the anti-inflammatory glucocorticoid, corticosterone (CORT), at levels associated with high physiological stress, can paradoxically prime the CNS to produce a robust proinflammatory response to neurotoxicants and systemic inflammation; such neuroinflammatory effects can be associated with sickness behavior. Here, we examined whether CORT primed the CNS to mount neuroinflammatory responses to GW exposures as a potential model of GWI. Male C57BL/6 mice were treated with chronic (14 days) PB/ DEET, subchronic (7-14 days) CORT, and acute exposure (day 15) to diisopropyl fluorophosphate (DFP), a sarin surrogate and irreversible AChE inhibitor. DFP alone caused marked brain-wide neuroinflammation assessed by qPCR of tumor necrosis factor-α, IL6, chemokine (C-C motif) ligand 2, IL-1β, leukemia inhibitory factor, and oncostatin M. Pre-treatment with high physiological levels of CORT greatly augmented (up to 300-fold) the neuroinflammatory responses to DFP. Anti-inflammatory pre-treatment with minocycline suppressed many proinflammatory responses to CORT+DFP. Our findings are suggestive of a possible critical, yet unrecognized interaction between the stressor/environment of the GW theater and agent exposure(s) unique to this war. Such exposures may in fact prime the CNS to amplify future neuroinflammatory responses to pathogens, injury, or toxicity. Such occurrences could potentially result in the prolonged episodes of sickness behavior observed in GWI. Gulf War (GW) veterans were exposed to stressors, prophylactic

  16. Single, but not multiple pairings of sucrose and corticosterone enhance memory for sucrose drinking and amplify remote reward relativity effects

    NARCIS (Netherlands)

    Pecoraro, Norman; Gomez, Francisca; La Fleur, Susanne; Roy, Monica; Dallman, Mary F.

    2005-01-01

    This study tested whether pre-training pairings of ingestion of a 32% sucrose solution and injection(s) of corticosterone (B) would enhance later ingestion in the absence of B, and whether these effects would carry over into later contrast-like effects when animals were subsequently shifted to 4%

  17. Effects of chlordiazepoxide and buspirone on plasma catecholamine and corticosterone levels in rats under basal and stress conditions

    NARCIS (Netherlands)

    de Boer, S.F.; Slangen, J L; van der Gugten, J

    The effects of the classical benzodiazepine (BDZ) anxiolytic drug chlordiazepoxide (CDP) and the non-BDZ anxiolytic agent buspirone (BUSP) on basal and stress-induced plasma noradrenaline (NA), adrenaline (A) and corticosterone (CS) release were investigated. Male Wistar rats provided with a

  18. Acute endocrine correlates of attack by lactating females in male mice: effects on plasma prolactin, luteinizing hormone and corticosterone levels.

    Science.gov (United States)

    Broida, J; Michael, S D; Svare, B

    1984-05-01

    Immediately following defeat inflicted by lactating Rockland-Swiss (R-S) albino mice, adult R-S male mice exhibited significant reductions in circulating prolactin (PRL) and luteinizing hormone (LH), but not corticosterone (CORT). These results suggest that acute neuroendocrine responses to intersex competition may be as dramatic as those previously reported for intermale encounters.

  19. Significance of ACTH4-10 in the control of hippocampal corticosterone receptor capacity of hypophysectomized rats

    NARCIS (Netherlands)

    Veldhuis, H D; De Kloet, E R

    1982-01-01

    The effect of hypophysectomy on the number of corticosterone receptor sites was investigated in three rat brain regions and was compared with the effect of long-term adrenalectomy. Subsequently, the effect on receptor capacity was measured after the hypophysectomized rats had received as

  20. The effects of chronic corticosterone on hippocampal astrocyte numbers: A comparison of male and female Wistar rats

    Czech Academy of Sciences Publication Activity Database

    Bridges, N.; Šlais, Karel; Syková, Eva

    2008-01-01

    Roč. 68, č. 2 (2008), s. 131-138 ISSN 0065-1400 R&D Projects: GA MŠk 1M0538 Grant - others:GA ČR(CZ) GA309/04/0753 Institutional research plan: CEZ:AV0Z50390512 Keywords : Hippocampus * Astrocyte * Corticosterone Subject RIV: FH - Neurology Impact factor: 1.091, year: 2008

  1. Long-term decreases of corticosterone in captive migrant shorebirds that maintain seasonal mass and moult cycles

    NARCIS (Netherlands)

    Piersma, T; Ramenofsky, M

    Two flocks of Red Knots Calidris canutus, belonging to the temperate-wintering subspecies islandica and to the tropical-wintering subspecies canutus, were kept in outdoor cages at north-temperate latitudes over two annual cycles during which their plasma concentrations of corticosterone were

  2. Are birds stressed during long-term flights? A wind-tunnel study on circulating corticosterone in the red knot

    NARCIS (Netherlands)

    Jenni-Eiermann, Susanne; Hasselquist, Dennis; Lindstrom, Ake; Koolhaas, Anita; Piersma, Theunis; Lindström, Åke

    2009-01-01

    During endurance flight most birds do not feed and have to rely on their body reserves. Fat and protein is catabolised to meet the high energetic demands. Even though the hormonal regulation of migration is complex and not yet fully understood. the adrenocortical hormone corticosterone crystallizes

  3. Effects of fasting on plasma catecholamine, corticosterone and glucose concentrations under basal and stress conditions in individual rats

    NARCIS (Netherlands)

    de Boer, S.F.; Koopmans, S.J.; Slangen, J L; Van der Gugten, J

    Plasma noradrenaline (NA), adrenaline (A), corticosterone (CS) and glucose concentrations were determined in blood sampled via a cardiac catheter from freely moving male rats under ad lib fed and 24 hr food deprived conditions using a repeated measures within-subject design. Resting plasma NA and

  4. Corticosterone and pace of life in two life-history ecotypes of the garter snake Thamnophis elegans.

    Science.gov (United States)

    Palacios, Maria G; Sparkman, Amanda M; Bronikowski, Anne M

    2012-02-01

    Glucocorticoids are main candidates for mediating life-history trade-offs by regulating the balance between current reproduction and survival. It has been proposed that slow-living organisms should show higher stress-induced glucocorticoid levels that favor self-maintenance rather than current reproduction when compared to fast-living organisms. We tested this hypothesis in replicate populations of two ecotypes of the garter snake (Thamnophis elegans) that exhibit slow and fast pace of life strategies. We subjected free-ranging snakes to a capture-restraint protocol and compared the stress-induced corticosterone levels between slow- and fast-living snakes. We also used a five-year dataset to assess whether baseline corticosterone levels followed the same pattern as stress-induced levels in relation to pace of life. In accordance with the hypothesis, slow-living snakes showed higher stress-induced corticosterone levels than fast-living snakes. Baseline corticosterone levels showed a similar pattern with ecotype, although differences depended on the year of study. Overall, however, levels of glucocorticoids are higher in slow-living than fast-living snakes, which should favor self-maintenance and survival at the expense of current reproduction. The results of the present study are the first to relate glucocorticoid levels and pace of life in a reptilian system and contribute to our understanding of the physiological mechanisms involved in life-history evolution. Copyright © 2011 Elsevier Inc. All rights reserved.

  5. Determination of adrenaline, noradrenaline and corticosterone in rodent blood by ion pair reversed phase UHPLC-MS/MS.

    Science.gov (United States)

    Bergh, Marianne Skov-Skov; Bogen, Inger Lise; Andersen, Jannike Mørch; Øiestad, Åse Marit Leere; Berg, Thomas

    2018-01-01

    A novel ion pair reversed phase ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for simultaneous determination of the stress hormones adrenaline, noradrenaline and corticosterone in rodent blood was developed and fully validated. Separations were performed on an Acquity HSS T3 column (2.1mm i.d.×100mm, 1.8μm) with gradient elution and a runtime of 5.5min. The retention of adrenaline and noradrenaline was substantially increased by employing the ion pair reagent heptafluorobutyric acid (HFBA). Ion pair reagents are usually added to the mobile phase only, but we demonstrate for the first time that including HFBA to the sample reconstitution solvent as well, has a major impact on the chromatography of these compounds. The stability of adrenaline and corticosterone in rodent blood was investigated using the surrogate analytes adrenaline-d 3 and corticosterone-d 8 . The applicability of the described method was demonstrated by measuring the concentration of stress hormones in rodent blood samples. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Effects of different elevated CO2 concentrations on chlorophyll contents, gas exchange, water use efficiency, and PSII activity on C3 and C4 cereal crops in a closed artificial ecosystem.

    Science.gov (United States)

    Wang, Minjuan; Xie, Beizhen; Fu, Yuming; Dong, Chen; Hui, Liu; Guanghui, Liu; Liu, Hong

    2015-12-01

    Although terrestrial CO2 concentrations [CO2] are not expected to reach 1000 μmol mol(-1) (or ppm) for many decades, CO2 levels in closed systems such as growth chambers and greenhouses can easily exceed this concentration. CO2 levels in life support systems (LSS) in space can exceed 10,000 ppm (1 %). In order to understand how photosynthesis in C4 plants may respond to elevated CO2, it is necessary to determine if leaves of closed artificial ecosystem grown plants have a fully developed C4 photosynthetic apparatus, and whether or not photosynthesis in these leaves is more responsive to elevated [CO2] than leaves of C3 plants. To address this issue, we evaluated the response of gas exchange, water use efficiency, and photosynthetic efficiency of PSII by soybean (Glycine max (L.) Merr., 'Heihe35') of a typical C3 plant and maize (Zea mays L., 'Susheng') of C4 plant under four CO2 concentrations (500, 1000, 3000, and 5000 ppm), which were grown under controlled environmental conditions of Lunar Palace 1. The results showed that photosynthetic pigment by the C3 plants of soybean was more sensitive to elevated [CO2] below 3000 ppm than the C4 plants of maize. Elevated [CO2] to 1000 ppm induced a higher initial photosynthetic rate, while super-elevated [CO2] appeared to negate such initial growth promotion for C3 plants. The C4 plant had the highest ETR, φPSII, and qP under 500-3000 ppm [CO2], but then decreased substantially at 5000 ppm [CO2] for both species. Therefore, photosynthetic down-regulation and a decrease in photosynthetic electron transport occurred by both species in response to super-elevated [CO2] at 3000 and 5000 ppm. Accordingly, plants can be selected for and adapt to the efficient use of elevated CO2 concentration in LSS.

  7. Early social deprivation impairs pair bonding and alters serum corticosterone and the NAcc dopamine system in mandarin voles.

    Science.gov (United States)

    Yu, Peng; An, Shucheng; Tai, Fadao; Wang, Jianli; Wu, Ruiyong; Wang, Bo

    2013-12-01

    Early life stress has a long-term negative impact on emotion, learning, memory and adult sexual behavior, and these deficits most likely impair pair bonding. Here, we investigated whether early social deprivation (ED) affects the formation of pair bonds in socially monogamous mandarin voles (Microtus mandarinus). In a partner preference test (PPT), ED-reared adult females and males did not show a preference for their partner, spent more time exploring the cage of an unfamiliar animal and directed high levels of aggression toward unfamiliar animals. In social interaction test, ED increased exploring behavior only in females, but increased movement around the partner and reduced inactivity in both males and females. Three days of cohabitation did not alter serum corticosterone levels in ED-reared males, but increased corticosterone levels in males that received bi-parental care (PC). Interestingly, serum corticosterone levels in ED- and PC-reared females declined after cohabitation. ED significantly increased basal serum corticosterone levels in males, but had no effect on females. ED significantly up-regulated the levels of dopamine and the mRNA expression of dopamine 1-type receptor (D1R) in the nucleus accumbens (NAcc) in females and males. ED suppressed dopamine 2-type receptor mRNA (D2R) expression in females, but increased this in males. After three days of cohabitation, levels of D1R mRNA and D2R mRNA expression changed in opposite directions in PC-reared voles, but in the same direction in ED-reared males, and only the expression of D2R mRNA increased in ED-reared females. Our results indicate that early social deprivation inhibits pair bonding at adulthood. This inhibition is possibly associated with sex-specific alterations in serum corticosterone, levels of dopamine and mRNA expression of two types of dopamine receptors in the NAcc. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Application of a naturalistic psychogenic stressor in periadolescent mice: effect on serum corticosterone levels differs by strain but not sex

    Directory of Open Access Journals (Sweden)

    Klein Laura C

    2010-06-01

    Full Text Available Abstract Background As a first step in determining whether psychogenic stressors might be incorporated into periadolescent mouse models of stress, we evaluated whether a commonly used psychogenic stressor, exposure to red fox urine, alters serum corticosterone levels in periadolescent C57BL/6J and DBA/2J mice. Findings In a 1-day experiment, forty-eight 38-day-old C57BL/6J (N = 12 males; N = 12 females and DBA/2J (N = 12 males; N = 12 females mice were exposed to 10-min of red fox urine via cotton ball (N = 12 C57BL/6J mice; N = 12 DBA/2J mice or to a non-saturated cotton ball (N = 12 C57BL/6J mice; N = 12 DBA/2J mice. All mice were sacrificed 15-min after cotton ball exposure and serum was collected for corticosterone assessment. Overall, there was a main effect for strain such that C57BL/6J male and female mice displayed higher corticosterone levels than did male and female DBA/2J mice. There were no main effects for sex or odor exposure. However, there was a significant strain by odor exposure interaction, whereby, within odor-exposed mice, DBA/2J mice displayed lower corticosterone levels (ng/mL compared to C57BL/6J mice, regardless of sex. Further, among DBA/2J mice, predator odor exposure reduced corticosterone levels compared to no odor exposure. Conclusions Findings indicate that mouse strain, but not sex, may play an important role in the efficacy of a predator odor among periadolescent mice.

  9. Effects of intranasal and peripheral oxytocin or gastrin-releasing peptide administration on social interaction and corticosterone levels in rats.

    Science.gov (United States)

    Kent, Pamela; Awadia, Alisha; Zhao, Leah; Ensan, Donna; Silva, Dinuka; Cayer, Christian; James, Jonathan S; Anisman, Hymie; Merali, Zul

    2016-02-01

    The intranasal route of drug administration has gained increased popularity as it is thought to allow large molecules, such as peptide hormones, more direct access to the brain, while limiting systemic exposure. Several studies have investigated the effects of intranasal oxytocin administration in humans as this peptide is associated with prosocial behavior. There are, however, few preclinical studies investigating the effects of intranasal oxytocin administration in rodents. Oxytocin modulates hypothalamic-pituitary-adrenal (HPA) axis functioning and it has been suggested that oxytocin's ability to increase sociability may occur through a reduction in stress reactivity. Another peptide that appears to influence both social behavior and HPA axis activity is gastrin-releasing peptide (GRP), but it is not known if these GRP-induced effects are related. With this in mind, in the present study, we assessed the effects of intranasal and intraperitoneal oxytocin and GRP administration on social interaction and release of corticosterone in rats. Intranasal and intraperitoneal administration of 20, but not 5 μg, of oxytocin significantly increased social interaction, whereas intranasal and peripheral administration of GRP (20 but not 5 μg) significantly decreased levels of social interaction. In addition, while intranasal oxytocin (20 μg) had no effect on blood corticosterone levels, a marked increase in blood corticosterone levels was observed following intraperitoneal oxytocin administration. With GRP, intranasal (20 μg) but not peripheral administration increased corticosterone levels. These findings provide further evidence that intranasal peptide delivery can induce behavioral alterations in rodents which is consistent with findings from human studies. In addition, the peptide-induced changes in social interaction were not linked to fluctuations in corticosterone levels. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Corticosterone and the transition from courtship behavior to dispersal in male red-sided garter snakes (Thamnophis sirtalis parietalis).

    Science.gov (United States)

    Cease, Arianne J; Lutterschmidt, Deborah I; Mason, Robert T

    2007-01-01

    Seasonal modulation of baseline glucocorticoid concentrations as well as the sensitivity of the hypothalamic-pituitary-adrenal (HPA) axis plays an important role in supporting critical life-history events such as seasonal reproduction and migration. Despite numerous studies on adrenocortical modulation, little is known about the exact timing of this seasonal modulation with respect to critical life-history stages. We tested the hypothesis that seasonal modulation of the HPA axis during the spring mating season in male red-sided garter snakes (Thamnophis sirtalis parietalis) is temporally linked to the mechanisms regulating dispersal. We compared hormonal responses to capture stress in courting male red-sided garter snakes collected from the den site and den perimeter to those of dispersing snakes collected 0.6 km from the den. We also investigated possible changes in steroid hormones during the spring mating season. These studies support previous findings that plasma androgen and corticosterone concentrations significantly decline over the mating season. Our results demonstrate that males 0.6 km into a 15-20 km route to the feeding grounds have lower baseline corticosterone concentrations than male snakes actively courting at the den. Dispersing males also exhibit a typical stress response marked by a significant increase in corticosterone while actively courting males do not. Capture stress did not significantly influence androgen concentrations of either courting or dispersing male red-sided garter snakes. There were no significant differences in body composition indices among male snakes collected from the den, den perimeter, or 0.6 km away from the den. However, we did observe a significant negative correlation between baseline corticosterone levels and body composition indices. These data suggest that breeding is a distinct stage accompanied by specific physiological parameters that differ from those during dispersal to the feeding grounds. Our results

  11. Ozone modifies the metabolic and endocrine response to glucose: Reproduction of effects with the stress hormone corticosterone.

    Science.gov (United States)

    Thomson, Errol M; Pilon, Shinjini; Guénette, Josée; Williams, Andrew; Holloway, Alison C

    2018-03-01

    Air pollution is associated with increased incidence of metabolic disease (e.g. metabolic syndrome, obesity, diabetes); however, underlying mechanisms are poorly understood. Air pollutants increase the release of stress hormones (human cortisol, rodent corticosterone), which could contribute to metabolic dysregulation. We assessed acute effects of ozone, and stress axis involvement, on glucose tolerance and on the metabolic (triglyceride), endocrine/energy regulation (insulin, glucagon, GLP-1, leptin, ghrelin, corticosterone), and inflammatory/endothelial (TNF, IL-6, VEGF, PAI-1) response to exogenous glucose. Male Fischer-344 rats were exposed to clean air or 0.8 ppm ozone for 4 h in whole body chambers. Hypothalamic-pituitary-adrenal (HPA) axis involvement in ozone effects was tested through subcutaneous administration of the glucocorticoid synthesis inhibitor metyrapone (50 mg/kg body weight), corticosterone (10 mg/kg body weight), or vehicle (40% propylene glycol) prior to exposure. A glucose tolerance test (2 g/kg body weight glucose) was conducted immediately after exposure, with blood samples collected at 0, 30, 60, 90, and 120 min. Ozone exposure impaired glucose tolerance, an effect accompanied by increased plasma triglycerides but no impairment of insulin release. Ozone diminished glucagon, GLP-1, and ghrelin responses to glucose, but did not significantly impact inflammatory/endothelial analytes. Metyrapone reduced corticosterone but increased glucose and triglycerides, complicating evaluation of the impact of glucocorticoid inhibition. However, administration of corticosterone reproduced the profile of ozone effects, supporting a role for the HPA axis. The results show that ozone-dependent changes in glucose tolerance are accompanied by altered metabolic and endocrine responses to glucose challenge that are reproduced by exogenous stress hormone. Crown Copyright © 2018. Published by Elsevier Inc. All rights reserved.

  12. Plasma catecholamines and plasma corticosterone following restraint stress in juvenile alligators.

    Science.gov (United States)

    Lance, V A; Elsey, R M

    1999-05-01

    Ten juvenile alligators, mean body mass 793 g, hatched from artificially incubated eggs and raised under controlled conditions, were held out of water with their jaws held closed for 48 hr. An initial blood sample was taken and further samples collected at 1, 2, 4, 8, 24, and 48 hr. Epinephrine, norepinephrine, and dopamine were measured in plasma aliquots of 1.5 ml using high pressure liquid chromatography with electrochemical detection. Corticosterone was measured by radioimmunoassay. Plasma glucose was measured using the Trinder method and plasma calcium, cholesterol, and triglycerides were measured in an autoanalyzer. Epinephrine was about 4 ng/ml at the initial bleed, but declined steadily to blood cells showed changes indicating immune system suppression. By the end of the treatment the hetorophil/lymphocyte ratio increased to 4.7. These results suggest that handling alligators, taking multiple blood samples, and keeping them restrained for more than 8 hr is a severe stress to the animals.

  13. Pycnogenol Ameliorates Depression-Like Behavior in Repeated Corticosterone-Induced Depression Mice Model

    Directory of Open Access Journals (Sweden)

    Lin Mei

    2014-01-01

    Full Text Available Oxidative stress is considered to be a mechanism of major depression. Pycnogenol (PYC is a natural plant extract from the bark of Pinus pinaster Aiton and has potent antioxidant activities. We studied the ameliorative effect of PYC on depression-like behavior in chronic corticosterone- (CORT- treated mice for 20 days. After the end of the CORT treatment period, PYC (0.2 mg/mL was orally administered in normal drinking water. Depression-like behavior was investigated by the forced swimming test. Immobility time was significantly longer by CORT exposure. When the CORT-treated mice were supplemented with PYC, immobility time was significantly shortened. Our results indicate that orally administered PYC may serve to reduce CORT-induced stress by radical scavenging activity.

  14. Circadian variations of serum thyrotropin, thyroxine, triiodothyronine, reverse triiodothyronine, corticosterone and lipids in starved rats

    International Nuclear Information System (INIS)

    Zwirska-Korczala, K.; Ostrowska, Z.; Kucharzewski, M.; Marek, B.; Kos-Kudla, B.; Buntner, B.; Swietochowska, E.

    1993-01-01

    We investigated the circadian variation of serum thyrotropin (TSH), thyroxine (T 4 ), triiodothyronine (T 3 ), reverse triiodothyronine (rT 3 ), corticosterone (B) and lipids in male Wistar rats after one-week starvation. Starvation decreased the TSH level and eliminated its 24-h rhythm. The rhythmicity of oscillations of T 3 and B was maintained. Starvation led to a shift in the acrophase of 24-h T 3 and B oscillation and induced the circadian rhythm of T 4 . The T 3 , T 4 and mesor values were lower, while for rT 3 and B they increased. Lipid concentrations remained unchanged in both experimental and control rats. (author). 27 refs, 3 figs, 2 tabs

  15. Validation of a radioimmunoassay for the determination of total corticosterone in rat plasma

    DEFF Research Database (Denmark)

    Pedersen, Tine Karen Hjort

    2000-01-01

    Abstract A radioimmunoassay (RIA) for total corticosterone (CORT) in rat plasma requiring a plasma volume of 2 μl was established. The importance of inactivating plasma corticosteroid-binding globulin (CBG), denatured by heat, before measuring CORT was shown. The method was evaluated and shown...... the blood sampling procedure. The result showed that the method had a capacity to detect CORT concentrations comparable with previous reported basal concentrations. Finally, the possible stress inducing effect of the blood sampling procedure was examined using two groups of male rats housed under either...... conventional or enriched environmental conditions. The result indicated that conventional environment housing induces slightly stressed animals compared to enriched housing. Enriched housing may provide an environment that makes it possible for rats to compensate for a stressful situation, i.e., the blood...

  16. Feed contamination with Fusarium mycotoxins induces a corticosterone stress response in broiler chickens.

    Science.gov (United States)

    Antonissen, G; De Baere, S; Devreese, M; Van Immerseel, F; Martel, A; Croubels, S

    2017-01-01

    The aim of the present study was to evaluate the effect of the Fusarium mycotoxins deoxynivalenol (DON) and fumonisins (FBs) on the stress response in broiler chickens, using corticosterone (CORT) in plasma as a biomarker. Chickens were fed either a control diet, a DON contaminated diet, a FBs contaminated diet, or a DON and FBs contaminated diet for 15 d at concentrations close to the European Union maximum guidance levels for DON and FBs in poultry. Mean plasma CORT levels were significantly higher in broiler chickens fed a DON contaminated and a DON and FBs contaminated diet compared to birds fed a control diet. A similar trend was observed for animals fed a FBs contaminated diet. Consequently, feeding broilers a diet contaminated with DON and/or FBs induced a CORT stress response, which may indicate a negative effect on animal welfare. © 2016 Poultry Science Association Inc.

  17. Changes in eosinophil and corticosterone levels and catecholamine metabolism during emotionalpainful stress

    International Nuclear Information System (INIS)

    Malyshev, V.V.; Manukhin, B.N.; Petrova, V.A.

    1985-01-01

    The aim of this investigation was to study blood levels of eosinophils, corticosterone (CS), adrenalin, noradrenalin (NA), and dopamine (DA) during the development of the stress reaction, and also to study neuronal uptake and synthesis of catecholamines in the adrenals and heart. In some animal groups, the neuronal uptake of 3 H-NA and the intensity of 3 H-Na and 3 H-DA synthesis from 3 H-tyrosine were investigated by a method described previously, 2 h after the end of induction of emotional-painful stress (EPS). Radioactivity was measured on an SL-30 liquid scintillation counter. A regular relationship was found between changes in blood eosinophil level, the CH concentration, and catecholamine metabolism in the course of EPS

  18. Environmental temperature and stocking density effects on acute phase proteins, heat shock protein 70, circulating corticosterone and performance in broiler chickens

    Science.gov (United States)

    Najafi, Pardis; Zulkifli, Idrus; Amat Jajuli, Nurfarahin; Farjam, Abdoreza Soleimani; Ramiah, Suriya Kumari; Amir, Anna Aryani; O'Reily, Emily; Eckersall, David

    2015-11-01

    An experiment was conducted to determine the effect of different stocking densities on serum corticosterone (CORT), ovotransferrin (OVT), α1-acid glycoprotein (AGP) and ceruloplasmin (CP) concentrations, brain heat shock protein (HSP) 70 expression and performance in broiler chickens exposed to unheated and heated conditions. Day-old chicks were stocked at 0.100 m2/bird (low density (LD)) or 0.063 m2/bird (high density (HD)), in battery cages and housed in environmentally controlled rooms. From 21 to 35 days of age, birds from each stocking density group were exposed to either 24 or 32 °C. Growth performance was recorded during the heat treatment period, and blood and brain samples were collected to determine CORT, OVT, AGP, CP and HSP 70 levels on day 35. Heat treatment but not stocking density was detrimental to growth performance. There were significant temperature × density interactions for CORT, CP and OVT on day 35. Although HD elevated CORT, CP and OVT when compared to LD, the effects of the former were more obvious under heated condition. Both temperature and density had significant effect on AGP and HSP 70. In conclusion, irrespective of temperature, high stocking density was physiologically stressful to broiler chickens, as indicated by CORT, AGP, CP, OVT and HSP 70, but not detrimental to growth performance and survivability. As it was shown in the present study, AGP, CP and OVT could be useful biomarkers to determine the effect of overcrowding and high temperature on the welfare of broiler chickens.

  19. Metabolomic study of corticosterone-induced cytotoxicity in PC12 cells by ultra performance liquid chromatography-quadrupole/time-of-flight mass spectrometry.

    Science.gov (United States)

    Zhang, Hongye; Zheng, Hua; Zhao, Gan; Tang, Chaoling; Lu, Shiyin; Cheng, Bang; Wu, Fang; Wei, Jinbin; Liang, Yonghong; Ruan, Junxiang; Song, Hui; Su, Zhiheng

    2016-03-01

    Glucocorticoids (GCs) have been proved to be an important pathogenic factor of some neuropsychiatric disorders. Usually, a classical injury model based on corticosterone-induced cytotoxicity of differentiated rat pheochromocytoma (PC12) cells was used to stimulate the state of GC damage of hippocampal neurons and investigate its potential mechanisms involved. However, up to now, the mechanism of corticosterone-induced cytotoxicity in PC12 cells was still looking forward to further elucidation. In this work, the metabolomic study of the biochemical changes caused by corticosterone-induced cytotoxicity in differentiated PC12 cells with different corticosterone concentrations was performed for the first time, using the ultra performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q/TOF MS). Partial least squares-discriminate analysis (PLS-DA) indicated that metabolic profiles of different corticosterone treatment groups deviated from the control group. A total of fifteen metabolites were characterized as potential biomarkers involved in corticosterone-induced cytotoxicity, which were corresponding to the dysfunctions of five pathways including glycerophospholipid metabolism, sphingolipid metabolism, oxidation of fatty acids, glycerolipid metabolism and sterol lipid metabolism. This study indicated that the rapid and holistic cell metabolomics approach might be a powerful tool to further study the pathogenesis mechanism of corticosterone-induced cytotoxicity in PC12 cells.

  20. Effects of sex and time of day on metabolism and excretion of corticosterone in urine and feces of mice.

    Science.gov (United States)

    Touma, Chadi; Sachser, Norbert; Möstl, Erich; Palme, Rupert

    2003-02-15

    Non-invasive techniques to monitor stress hormones in small animals like mice offer several advantages and are highly demanded in laboratory as well as in field research. Since knowledge about the species-specific metabolism and excretion of glucocorticoids is essential to develop such a technique, we conducted radiometabolism studies in mice (Mus musculus f. domesticus, strain C57BL/6J). Each mouse was injected intraperitoneally with 740 kBq of 3H-labelled corticosterone and all voided urine and fecal samples were collected for five days. In a first experiment 16 animals (eight of each sex) received the injection at 9 a.m., while eight mice (four of each sex) were injected at 9 p.m. in a second experiment. In both experiments radioactive metabolites were recovered predominantly in the feces, although males excreted significantly higher proportions via the feces (about 73%) than females (about 53%). Peak radioactivity in the urine was detected within about 2h after injection, while in the feces peak concentrations were observed later (depending on the time of injection: about 10h postinjection in experiment 1 and about 4h postinjection in experiment 2, thus proving an effect of the time of day). The number and relative abundance of fecal [3H]corticosterone metabolites was determined by high performance liquid chromatography (HPLC). The HPLC separations revealed that corticosterone was extensively metabolized mainly to more polar substances. Regarding the types of metabolites formed, significant differences were found between males and females, but not between the experiments. Additionally, the immunoreactivity of these metabolites was assessed by screening the HPLC fractions with four enzyme immunoassays (EIA). However, only a newly established EIA for 5alpha-pregnane-3beta,11beta,21-triol-20-one (measuring corticosterone metabolites with a 5alpha-3beta,11beta-diol structure) detected several peaks of radioactive metabolites with high intensity in both sexes, while

  1. Iowa Bedrock Surface Elevation

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — This Digital Elevation Model (DEM) of the bedrock surface elevation in Iowa was compiled using all available data, principally information from GEOSAM, supplemented...

  2. Inactivation of basolateral amygdala prevents chronic immobilization stress-induced memory impairment and associated changes in corticosterone levels.

    Science.gov (United States)

    Tripathi, Sunil Jamuna; Chakraborty, Suwarna; Srikumar, B N; Raju, T R; Shankaranarayana Rao, B S

    2017-07-01

    Chronic stress causes detrimental effects on various forms of learning and memory. The basolateral amygdala (BLA) not only plays a crucial role in mediating certain forms of memory, but also in the modulation of the effects of stress. Chronic immobilization stress (CIS) results in hypertrophy of the BLA, which is believed to be one of the underlying causes for stress' effects on learning. Thus, it is plausible that preventing the effects of CIS on amygdala would preclude its deleterious cognitive effects. Accordingly, in the first part, we evaluated the effect of excitotoxic lesion of the BLA on chronic stress-induced hippocampal-dependent spatial learning using a partially baited radial arm maze task. The BLA was ablated bilaterally using ibotenic acid prior to CIS. Chronically stressed rats showed impairment in spatial learning with decreased percentage correct choice and increased reference memory errors. Excitotoxic lesion of the BLA prevented the impairment in spatial learning and reference memory. In the retention test, lesion of the BLA was able to rescue the chronic stress-induced impairment. Interestingly, stress-induced enhanced plasma corticosterone levels were partially prevented by the lesion of BLA. These results motivated us to evaluate if the same effects can be observed with temporary inactivation of BLA, only during stress. We found that chronic stress-induced spatial learning deficits were also prevented by temporary inactivation of the BLA. Additionally, temporary inactivation of BLA partially precluded the stress-induced increase in plasma corticosterone levels. Thus, inactivation of BLA precludes stress-induced spatial learning deficits, and enhanced plasma corticosterone levels. It is speculated that BLA inactivation-induced reduction in corticosterone levels during stress, might be crucial in restoring spatial learning impairments. Our study provides evidence that amygdalar modulation during stress might be beneficial for strategic

  3. Alteration in plasma corticosterone levels following long term oral administration of lead produces depression like symptoms in rats.

    Science.gov (United States)

    Haider, Saida; Saleem, Sadia; Tabassum, Saiqa; Khaliq, Saima; Shamim, Saima; Batool, Zehra; Parveen, Tahira; Inam, Qurat-ul-ain; Haleem, Darakhshan J

    2013-03-01

    Lead toxicity is known to induce a broad range of physiological, biochemical and behavioral dysfunctions that may result in adverse effects on several organs, including the central nervous system. Long-term exposure to low levels of lead (Pb(2+)) has been shown to produce behavioral deficits in rodents and humans by affecting hypothalamic-pituitary-adrenal (HPA) axis. These deficits are thought to be associated with altered brain monoamine neurotransmission and due to changes in glucocorticoids levels. This study was designed to investigate the effects of Pb(2+)exposure on growth rate, locomotor activity, anxiety, depression, plasma corticosterone and brain serotonin (5-HT) levels in rats. Rats were exposed to lead in drinking water (500 ppm; lead acetate) for 5 weeks. The assessment of depression was done using the forced swimming test (FST). Estimation of brain 5-HT was determined by high-performance liquid chromatography with electrochemical detection. Plasma corticosterone was determined by spectrofluorimetric method. The present study showed that long term exposure to Pb(2+) significantly decreased the food intake followed by the decrease in growth rate in Pb(2+)exposed rats as compared to control group. No significant changes in open field activity were observed following Pb(2+)exposure while significant increase in anxiogenic effect was observed. Increased plasma corticosterone and decreased 5-HT levels were exhibited by Pb(2+)exposed rats as compared to controls. A significant increase in depressive like symptoms was exhibited by Pb(2+)exposed rats as compared to control rats. The results are discussed in the context of Pb(2+) inducing a stress-like response in rats leading to changes in plasma corticosterone and brain 5-HT levels via altering tryptophan pyrrolase activity.

  4. EFFECT OF ROUTINE HANDLING AND TRANSPORTATION ON BLOOD LEUKOCYTE CONCENTRATIONS AND PLASMA CORTICOSTERONE IN CAPTIVE HISPANIOLAN AMAZON PARROTS ( AMAZONA VENTRALIS).

    Science.gov (United States)

    McRee, Anna Elizabeth; Tully, Thomas N; Nevarez, Javier G; Beaufrere, Hugues; Ammersbach, Melanie; Gaunt, Stephen D; Fuller, Rory G; Romero, L Michael

    2018-06-01

      Increased glucocorticoids cause a characteristic stress leukogram in mammalian taxa. It is assumed that avians exhibit a similar response, but to date, there have been no controlled studies to correlate serial endogenous corticosterone levels to hematologic values. An established flock of 18 Hispaniolan Amazon parrots ( Amazona ventralis) was used as a model in a crossover study. The treatment group was subjected to the stress of transport, restraint, and common clinical procedures with serial blood samples collected at 20-min intervals for hematology and corticosterone levels; the control group was sampled at the same intervals. Longitudinal data analysis was performed with linear mixed modeling. For all hematologic analytes, the baseline value had a significant positive effect on subsequent values (all P < 0.001). The white blood cell, heterophil, and eosinophil counts and heterophil to lymphocyte ratio increased over time in the treatment group, whereas it remained stable in the control group ( P = 0.016, P < 0.001, P < 0.001, P = 0.02, respectively, for the time*treatment effect). Lymphocyte absolute counts decreased over time, although not significantly; the decrease was significant for the relative lymphocyte count in the treatment group. Monocytes and basophils were not significantly altered. The treatment group had a higher mean corticosterone level overall than the control group by approximately 60% ( P = 0.008). The mean corticosterone level also increased over time in both groups by three- to fourfold ( P < 0.001) by 20 min then plateaued. These results demonstrate that some significant hematologic changes may arise with routine handling and transportation of birds and should be accounted for in hematologic interpretation of cell counts.

  5. A comparative evaluation of acute stress and corticosterone on the process of learning and emotional memory in rat

    Directory of Open Access Journals (Sweden)

    Vafaei AA

    2009-07-01

    Full Text Available "nBackground: Previous studies suggested that stressful events that release Glucocorticoid from adrenal cortex and also injection of agonists of glucocorticoids receptors probably affect emotional learning and memory process and modulate them. The aim of this study was to determine the effects of acute stress and systemic injection of Corticosterone (as agonist of glucocorticoid receptors on acquisition (ACQ, consolidation (CONS and retrieval (RET of emotional memory in rat. "nMethods: In this experimental study we used 180 male Wistar rats (220-250. At the first rats was training in one trial inhibitory avoidance task. On the retention test given 48 h after training, the latency to re-enter the dark compartment of the apparatus (Step-through latency, STL and the time spent in light chamber (TLC were recorded during 10 min test. Intraperitoneal corticosterone in doses of 0.5, 1 and 3mg/kg injected 30min before, immediately after instruction and 30min before retrieval test. Also some groups received 10min stressful stimulation by restrainer at the same time. At the end locomotor's activity was measured for all animals. "nResults: The data indicated that administration of corticosterone 30min before ACQ (1mg/kg, and immediately after CONS (1, 3mg/kg enhance and 30min before RET (1, 3mg/kg impair emotional memory (p<0.05. Acute stress impaired emotional memory in all phases (p<0.05. Also acute stress and injection of Corticosterone have not significantly affect motor activity.  "nConclusions: These findings show that Glucocorticoid receptors in activation dependently plays an important role in modulation of emotional spatial memory processes (ACQ, CONS and RET in new information for emotional events and these effects varies in different phases.

  6. Corticosterone manipulation reveals differences in hierarchical organization of multidimensional reproductive trade-offs in r-strategist and K-strategist females.

    Science.gov (United States)

    Lancaster, L T; Hazard, L C; Clobert, J; Sinervo, B R

    2008-03-01

    Life history trade-offs are often hierarchical with decisions at one level affecting lower level trade-offs. We investigated trade-off structure in female side-blotched lizards (Uta stansburiana), which exhibit two evolved strategies: yellow-throated females are K-strategists and orange-throated are r-strategists. Corticosterone treatment was predicted to differentially organize these females' reproductive decisions. Corticosterone-treated yellow females suppressed reproduction but survived well, and augmented egg mass without decreasing clutch size. Conversely, corticosterone enhanced mortality and reproductive rates in orange females, and increased egg mass only after lengthy exposure. Corticosterone did not affect post-laying condition, suggesting that corticosterone increased egg mass through enhanced energy acquisition (income breeding). Corticosterone enhanced survival of lightweight females, but decreased survival of heavy females, introducing a foraging vs. predation trade-off. We conclude that rather than being a direct, functional relationship, observed trade-offs between offspring size and number represent evolved differences in hierarchical organization of multidimensional trade-offs, particularly in response to stress.

  7. Impact of Diet Supplemented by Coconut Milk on Corticosterone and Acute Phase Protein Level under High Stocking Density

    Directory of Open Access Journals (Sweden)

    Majid SHAKERI

    2016-05-01

    Full Text Available The purpose of this study was to investigate effects of coconut milk supplementation on corticosterone and acute phase protein level under high stocking density. A total 300 Cobb 500 male chicks were placed in cages and stocked as 10 birds/cage (normal stocking density and 15 birds/cage (high stocking density. The treatments were as (i control diet and stocked at 10 and 15 birds/cage (ii control diet + 3% coconut milk from 1-42 day and stocked at 10 and 15 birds/cage (iii control diet + 5% coconut milk from 1-42 day and stocked at 10 and 15 birds/cage. On day 42, 20 birds per treatment were slaughtered to collect blood samples. The results showed higher level of corticosterone and acute phase protein level in control diet compare to other supplemented diets with coconut milk. In conclusion, coconut milk decreased the level of corticosterone and acute phase protein when chicks were subjected to high stocking density.

  8. Chronic Deep Brain Stimulation of the Hypothalamic Nucleus in Wistar Rats Alters Circulatory Levels of Corticosterone and Proinflammatory Cytokines

    Science.gov (United States)

    Calleja-Castillo, Juan Manuel; De La Cruz-Aguilera, Dora Luz; Manjarrez, Joaquín; Velasco-Velázquez, Marco Antonio; Morales-Espinoza, Gabriel; Moreno-Aguilar, Julia; Hernández, Maria Eugenia; Aguirre-Cruz, Lucinda

    2013-01-01

    Deep brain stimulation (DBS) is a therapeutic option for several diseases, but its effects on HPA axis activity and systemic inflammation are unknown. This study aimed to detect circulatory variations of corticosterone and cytokines levels in Wistar rats, after 21 days of DBS-at the ventrolateral part of the ventromedial hypothalamic nucleus (VMHvl), unilateral cervical vagotomy (UCVgX), or UCVgX plus DBS. We included the respective control (C) and sham (S) groups (n = 6 rats per group). DBS treated rats had higher levels of TNF-α (120%; P < 0.01) and IFN-γ (305%; P < 0.001) but lower corticosterone concentration (48%; P < 0.001) than C and S. UCVgX animals showed increased corticosterone levels (154%; P < 0.001) versus C and S. UCVgX plus DBS increased IL-1β (402%; P < 0.001), IL-6 (160%; P < 0.001), and corsticosterone (178%; P < 0.001 versus 48%; P < 0.001) compared with the C and S groups. Chronic DBS at VMHvl induced a systemic inflammatory response accompanied by a decrease of HPA axis function. UCVgX rats experienced HPA axis hyperactivity as result of vagus nerve injury; however, DBS was unable to block the HPA axis hyperactivity induced by unilateral cervical vagotomy. Further studies are necessary to explore these findings and their clinical implication. PMID:24235973

  9. Benzodiazepine effect of {sup 125}I-iomazenil-benzodiazepine receptor binding and serum corticosterone level in a rat model

    Energy Technology Data Exchange (ETDEWEB)

    Fukumitsu, Nobuyoshi [Proton Medical Research Center, University of Tsukuba, Ibaragi, 305-8575 (Japan)]. E-mail: gzl13162@nifty.ne.jp; Ogi, Shigeyuki [Department of Radiology, Jikei University School of Medicine, Tokyo, 105-8461 (Japan); Uchiyama, Mayuki [Department of Radiology, Jikei University School of Medicine, Tokyo, 105-8461 (Japan); Mori, Yutaka [Department of Radiology, Jikei University School of Medicine, Tokyo, 105-8461 (Japan)

    2005-01-01

    To test the change in free or unoccupied benzodiazepine receptor (BZR) density in response to diazepam, we investigated {sup 125}I-iomazenil ({sup 125}I-IMZ) binding and serum corticosterone levels in a rat model. Wistar male rats, which received psychological stress using a communication box for 5 days, were divided into two groups according to the amount of administered diazepam: no diazepam [D (0)] group and 10 mg/kg per day [D (10)] group of 12 rats each. The standardized uptake value (SUV) of {sup 125}I-IMZ of the D (10) group were significantly lower (P<.05) than those of the D (0) group in the frontal, parietal and temporal cortices, globus pallidus, hippocampus, amygdala and hypothalamus. The serum corticosterone level ratio in the D (10) group was significantly lower than that in the D (0) group (P<.05). From the change in serum corticosterone levels, diazepam attenuated the psychological stress produced by the physical stress to animals in adjacent compartments. From the reduced binding of {sup 125}I-IMZ, it is clear that diazepam competed with endogenous ligand for the free BZR sites, and the frontal, parietal and temporal cortices, globus pallidus, hippocampus, amygdala and hypothalamus are important areas in which {sup 125}I-IMZ binding is strongly affected by administration of diazepam.

  10. Corticosterone induces rapid spinogenesis via synaptic glucocorticoid receptors and kinase networks in hippocampus.

    Directory of Open Access Journals (Sweden)

    Yoshimasa Komatsuzaki

    Full Text Available BACKGROUND: Modulation of dendritic spines under acute stress is attracting much attention. Exposure to acute stress induces corticosterone (CORT secretion from the adrenal cortex, resulting in rapid increase of CORT levels in plasma and the hippocampus. METHODOLOGY/PRINCIPAL FINDINGS: Here we demonstrated the mechanisms of rapid effect (∼1 h of CORT on the density and morphology of spines by imaging neurons in adult male rat hippocampal slices. The application of CORT at 100-1000 nM induced a rapid increase in the density of spines of CA1 pyramidal neurons. The density of small-head spines (0.2-0.4 µm was increased even at low CORT levels (100-200 nM. The density of middle-head spines (0.4-0.5 µm was increased at high CORT levels between 400-1000 nM. The density of large-head spines (0.5-1.0 µm was increased only at 1000 nM CORT. Co-administration of RU486, an antagonist of glucocorticoid receptor (GR, abolished the effect of CORT. Blocking a single kinase, such as MAPK, PKA, PKC or PI3K, suppressed CORT-induced enhancement of spinogenesis. Blocking NMDA receptors suppressed the CORT effect. CONCLUSIONS/SIGNIFICANCE: These results imply that stress levels of CORT (100-1000 nM drive the spinogenesis via synaptic GR and multiple kinase pathways.

  11. Corticosterone regulates fear memory via Rac1 activity in the hippocampus.

    Science.gov (United States)

    Gan, Ping; Ding, Ze-Yang; Gan, Cheng; Mao, Rong-Rong; Zhou, Heng; Xu, Lin; Zhou, Qi-Xin

    2016-09-01

    Stressful events can generate enduring memories, which may induce certain psychiatric disorders such as post-traumatic stress disorder (PTSD). However, the underlying molecular mechanisms in these processes remain unclear. In this study, we examined whether the active form of the small G protein Rac1, Rac1-GTP, is involved in fear memory. Firstly, we detected the time course changes of Rac1-GTP after foot shocks (a strong stressor) and exogenous corticosterone (CORT) treatment. The data showed that stress and CORT induced the downregulation of Rac1-GTP in the hippocampus. Changes in the serum CORT level were negatively correlated with the level of Rac1-GTP. Additionally, a glucocorticoid receptor antagonist, RU38486, not only recovered the expression of Rac1-GTP but also impaired fear memory. Furthermore, systemic administration of NSC23766, an inhibitor of Rac1-GTP, improved fear memory at 1.5 and 24h. Therefore, Rac1 activity plays a critical role in stress-related cognition and may be a potential target in stress-related disorders. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Peony glycosides reverse the effects of corticosterone on behavior and brain BDNF expression in rats.

    Science.gov (United States)

    Mao, Qing-Qiu; Huang, Zhen; Ip, Siu-Po; Xian, Yan-Fang; Che, Chun-Tao

    2012-02-01

    Repeated injections of corticosterone (CORT) induce the dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, resulting in depressive-like behavior. This study aimed to examine the antidepressant-like effect and the possible mechanisms of total glycosides of peony (TGP) in the CORT-induced depression model in rats. The results showed that the 3-week CORT injections induced the significant increase in serum CORT levels in rats. Repeated CORT injections also caused depression-like behavior in rats, as indicated by the significant decrease in sucrose consumption and increase in immobility time in the forced swim test. Moreover, it was found that brain-derived neurotrophic factor (BDNF) protein levels in the hippocampus and frontal cortex were significantly decreased in CORT-treated rats. Treatment of the rats with TGP significantly suppressed the depression-like behavior and increased brain BDNF levels in CORT-treated rats. The results suggest that TGP produces an antidepressant-like effect in CORT-treated rats, which is possibly mediated by increasing BDNF expression in the hippocampus and frontal cortex. Copyright © 2011 Elsevier B.V. All rights reserved.

  13. The effects of testosterone on immune function in quail selected for divergent plasma corticosterone response.

    Science.gov (United States)

    Roberts, Mark L; Buchanan, Katherine L; Evans, Matthew R; Marin, Raul H; Satterlee, Daniel G

    2009-10-01

    The immunocompetence handicap hypothesis (ICHH) suggests that the male sex hormone testosterone has a dual effect; it controls the development and expression of male sexually selected signals, and it suppresses the immune system. Therefore only high quality males are able to fully express secondary sexual traits because only they can tolerate the immunosuppressive qualities of testosterone. A modified version of the ICHH suggests that testosterone causes immunosuppression indirectly by increasing the stress hormone corticosterone (CORT). Lines of Japanese quail (Coturnix japonica) selected for divergent responses in levels of plasma CORT were used to test these hypotheses. Within each CORT response line (as well as in a control stock) we manipulated levels of testosterone in castrated quail by treatment with zero (sham), low or high testosterone implants, before testing the birds' humoral immunity and phytohaemagglutinin (PHA)-induced immune response, as well as body condition. The PHA-induced response was not significantly affected by CORT selected line, testosterone treatment or their interaction. There was, however, a significant effect of CORT line on humoral immunity in that the control birds exhibited the greatest antibody production, but there was no significant effect of testosterone manipulation on humoral immunity. The males in the sham implant treatment group had significantly greater mass than the males in the high testosterone group, suggesting a negative effect of high testosterone on general body condition. We discuss these results in the context of current hypotheses in the field of sexual selection.

  14. Effect of corticosterone on gene expression of feed intake regulatory peptides in laying hens.

    Science.gov (United States)

    Liu, Lei; Song, Zhigang; Sheikhahmadi, Ardashir; Jiao, Hongchao; Lin, Hai

    2012-08-01

    The present study was conducted to explore the effects of corticosterone (CORT) on the regulation of appetite-associated genes in laying hens. Forty eight laying hens were randomly divided into two groups: one received subcutaneous injection of CORT (2mg/kg body weight, CORT-exposed) and the other received sham-treatment (Control). Treatment of hens with CORT stimulated an increase (P0.05) on the mRNA levels of neuropeptide Y (NPY), corticotropin-releasing hormone (CRH), melanocortin receptor 4 and 5 (MCR-4 and MCR-5) and cholecystokinin (CCK) in the hypothalamus when compared with control hens. However, the expression of pro-opiomelanocortin (POMC), agouti-related protein (AgRP) and melanocortin recepter 1 (MCR-1) were significantly (Phens. Treatment of laying hens with CORT had no significant (P>0.05) effect on the mRNA levels of CCK in the glandular stomach and the duodenum, and those of ghrelin in the glandular stomach, the duodenum and the jejunum. However, the mRNA levels of CCK in the jejunum and the ileum, and those of ghrelin in the ileum were significantly (Pfeeding status of CORT-exposed laying hens. Copyright © 2012 Elsevier Inc. All rights reserved.

  15. Chronic corticosterone exposure reduces hippocampal glycogen level and induces depression-like behavior in mice.

    Science.gov (United States)

    Zhang, Hui-yu; Zhao, Yu-nan; Wang, Zhong-li; Huang, Yu-fang

    2015-01-01

    Long-term exposure to stress or high glucocorticoid levels leads to depression-like behavior in rodents; however, the cause remains unknown. Increasing evidence shows that astrocytes, the most abundant cells in the central nervous system (CNS), are important to the nervous system. Astrocytes nourish and protect the neurons, and serve as glycogen repositories for the brain. The metabolic process of glycogen, which is closely linked to neuronal activity, can supply sufficient energy substrates for neurons. The research team probed into the effects of chronic corticosterone (CORT) exposure on the glycogen level of astrocytes in the hippocampal tissues of male C57BL/6N mice in this study. The results showed that chronic CORT injection reduced hippocampal neurofilament light protein (NF-L) and synaptophysin (SYP) levels, induced depression-like behavior in male mice, reduced hippocampal glycogen level and glycogen synthase activity, and increased glycogen phosphorylase activity. The results suggested that the reduction of the hippocampal glycogen level may be the mechanism by which chronic CORT treatment damages hippocampal neurons and induces depression-like behavior in male mice.

  16. The influence of short-time period of an adaptation to decreased ambient temperature on interleukin-6 and corticosterone levels in female Wistar strain rats in the proestrous phase of the reproductive cycle.

    Directory of Open Access Journals (Sweden)

    Grazyna Wójcik

    2008-04-01

    Full Text Available To date, there has been little research examining whether short-time changes of external environmental conditions exert any effects on immune responses. The activation of metabolic changes, release of hormones responsive for immunomodulation and the action of interleukins play an important role in interaction with hormones of an anterior pituitary gland in the proestrous phase of the reproductive cycle. The aim of our study was to determine the effects of a short-time change of ambient temperature (30 minutes on interleukin-6 (IL-6 and corticosterone plasma concentration of female rats in the proestrous phase of the reproductive cycle. The climatic chamber with automatically adjustable and monitored internal environmental parameters (temperature, oxygenation, humidity was used during the experiment. The estimation of the vaginal lavage using a microscope was done to determine the estrous cycle. On the day of the experiment, animals were divided into 2 groups: the control group (ambient temperature 21 degrees C +/- 1 degrees C; normoxia 21% O2 and the test group (ambient temperature 10 degrees C +/- 1 degrees C; normoxia 21% O2 stayed in the climatic chamber for 30 minutes. The blood samples were collected before the experiment and after 30, 60, 90, 150 and 210 minutes from the beginning of the experiment. The concentrations of IL-6 and corticosterone were measured in blood plasma samples using ELISA method. There was a significant elevation of IL-6 levels after staying in 10 degrees C during the first 150 minutes from the beginning of the experiment, with the highest value occurring after 60 minutes (426.6 pg/ml; SE - 146.1 with comparison to the value at first sampling (108.5 pg/ml; SE - 29.5; p<0.05 and with comparison to the control group at the same time from the beginning of the experiment (87.6 pg/ml; SE - 2.3; p<0.05. The changed level of corticosterone in the test group in comparison to control group was observed but the differences were

  17. Baseline and stress-induced levels of corticosterone in male and female Afrotropical and European temperate stonechats during breeding.

    Science.gov (United States)

    Apfelbeck, Beate; Helm, Barbara; Illera, Juan Carlos; Mortega, Kim G; Smiddy, Patrick; Evans, Neil P

    2017-05-22

    Latitudinal variation in avian life histories falls along a slow-fast pace of life continuum: tropical species produce small clutches, but have a high survival probability, while in temperate species the opposite pattern is found. This study investigated whether differential investment into reproduction and survival of tropical and temperate species is paralleled by differences in the secretion of the vertebrate hormone corticosterone (CORT). Depending on circulating concentrations, CORT can both act as a metabolic (low to medium levels) and a stress hormone (high levels) and, thereby, influence reproductive decisions. Baseline and stress-induced CORT was measured across sequential stages of the breeding season in males and females of closely related taxa of stonechats (Saxicola spp) from a wide distribution area. We compared stonechats from 13 sites, representing Canary Islands, European temperate and East African tropical areas. Stonechats are highly seasonal breeders at all these sites, but vary between tropical and temperate regions with regard to reproductive investment and presumably also survival. In accordance with life-history theory, during parental stages, post-capture (baseline) CORT was overall lower in tropical than in temperate stonechats. However, during mating stages, tropical males had elevated post-capture (baseline) CORT concentrations, which did not differ from those of temperate males. Female and male mates of a pair showed correlated levels of post-capture CORT when sampled after simulated territorial intrusions. In contrast to the hypothesis that species with low reproduction and high annual survival should be more risk-sensitive, tropical stonechats had lower stress-induced CORT concentrations than temperate stonechats. We also found relatively high post-capture (baseline) and stress-induced CORT concentrations, in slow-paced Canary Islands stonechats. Our data support and refine the view that baseline CORT facilitates energetically

  18. High post-partum levels of corticosterone given to dams influence postnatal hippocampal cell proliferation and behavior of offspring: A model of post-partum stress and possible depression.

    Science.gov (United States)

    Brummelte, Susanne; Pawluski, Jodi L; Galea, Liisa A M

    2006-09-01

    Post-partum stress and depression (PPD) have a significant effect on child development and behavior. Depression is associated with hypercortisolism in humans, and the fluctuating levels of hormones, including corticosterone, during pregnancy and the post-partum, may contribute to PPD. The present study was developed to investigate the effects of high-level corticosterone (CORT) post-partum in the mother on postnatal neurogenesis and behavior in the offspring. Sprague-Dawley dams were treated with either CORT (40 mg/kg) or sesame oil injections daily for 26 days beginning the day after giving birth. Dams were tested in the forced swim test (FST) and in the open field test (OFT) on days 24-26 post-partum. Results showed that the dams exposed to CORT expressed "depressive-like" behavior compared to controls, with decreased struggling behavior and increased immobility in the FST. To investigate the effects of treatment on hippocampal postnatal cell proliferation and survival in the offspring, males and females from treated dams were injected with BrdU (50 mg/kg) on postnatal day 21 and perfused either 24 h (cell proliferation) or 21 days (cell survival) later. Furthermore, male and female offspring from each litter were tested in adulthood on various behavioral tests, including the forced swim test, open field test, resistance to capture test and elevated plus maze. Intriguingly, male, but not female, offspring of CORT-treated dams exhibited decreased postnatal cell proliferation in the dentate gyrus. Both male and female offspring of CORT-treated dams showed higher resistance to capture and greater locomotor activity as assessed in the open field test. As high levels of CORT may be a characteristic of stress and/or depression, these findings support a model of 'CORT-induced' post-partum stress and possibly depression and demonstrate that the offspring of affected dams can exhibit changes in postnatal neurogenesis and behavior in adulthood.

  19. De stille elever

    DEFF Research Database (Denmark)

    Winther-Lindqvist, Ditte Alexandra

    2012-01-01

    Det er blevet en afgørende samværskompetence i uddannelsessystemet at stå aktivt frem og deltage verbalt i skoleklassens liv både fagligt og socialt. Men ikke alle elever deltager lige villigt verbalt i plenum. Artiklen handler om de stille elever og konsekvenserne af stillehed i skolen. Det...... foreslås at skolesystemet sanktionerer ældre elever hårdere for stillehed end yngre elever og det forklares med at skolelivet også er en kultivering henimod elevhed som social identitet og denne er der forventning om at eleverne mestrer i udskolingen....

  20. 大气CO2浓度升高和N沉降对南亚热带主要乡土树种叶片元素含量的影响%Effects of elevated CO2 concentration and N deposition on leaf element contents of major native tree species in southern subtropical China

    Institute of Scientific and Technical Information of China (English)

    李义勇; 黄文娟; 赵亮; 方熊; 刘菊秀

    2012-01-01

    大气CO2浓度升高和N沉降以及二者之间的耦合作用对陆地森林生态系统的影响是当前国际生态学界关注的热点之一.该实验运用大型开顶箱(open-top chamber,OTC)研究:1)高CO2浓度(700 μmol·mol-1)+高N沉降(100 kg N·hm-2·a-1) (CN);2)高CO2浓度(700 μmol·mol-1)和背景N沉降(CC);3)高N沉降(100 kg N·hm-2·a-1)和背景CO2浓度(NN);4)背景CO2和背景N沉降(CK)4种处理对南亚热带主要乡土树种木荷(Schima superba)、红锥(Castanopsis hystrix)、肖蒲桃(Acmena acuminatissima)、红鳞蒲桃(Syzygium hancei)、海南红豆(Ormosia pinnata)叶片元素含量的影响.研究结果表明,大气CO2浓度升高对5种乡土树种叶片元素含量有较大的影响,除海南红豆叶片的Ca含量外,其他树种的叶片元素含量在高CO2浓度处理下都显著升高(p<0.05);而在N沉降处理下,5个树种的叶片K和Ca含量都降低.大气CO2浓度升高与N沉降处理对5种乡土树种植物叶片元素含量影响的交互作用不是很明显,仅仅木荷和红鳞蒲桃的叶片Ca和Mn以及海南红豆的叶片Mn含量在大气CO2浓度上升和N沉降交互处理下显著下降,而肖蒲桃的叶片P含量在大气CO2浓度上升和N沉降交互处理下显著上升.%Aims The effects of elevated atmospheric CO2 concentration and N deposition on terrestrial ecosystems and plants are the focus of international ecological study. Changes of nutrient element content in plants induced by atmospheric CO2 concentration and/or N deposition directly affect the productivity of forest ecosystems; however, few studies have examined this in subtropical China. Our purpose is to study the effects of elevated CO2 and N deposition on leaf element contents of major native tree species in southern subtropical China. Methods Five tree species native in southern China were planted in model forest ecosystems. The species were exposed to elevated CO2 and N deposition in open top chambers in May 2005

  1. Maternal corticosterone exposure in the mouse programs sex-specific renal adaptations in the renin-angiotensin-aldosterone system in 6-month offspring.

    Science.gov (United States)

    Cuffe, James S M; Burgess, Danielle J; O'Sullivan, Lee; Singh, Reetu R; Moritz, Karen M

    2016-04-01

    Short-term maternal corticosterone (Cort) administration at mid-gestation in the mouse reduces nephron number in both sexes while programming renal and cardiovascular dysfunction in 12-month male but not female offspring. The renal renin-angiotensin-aldosterone system (RAAS), functions in a sexually dimorphic manner to regulate both renal and cardiovascular physiology. This study aimed to identify if there are sex-specific differences in basal levels of the intrarenal RAAS and to determine the impact of maternal Cort exposure on the RAAS in male and female offspring at 6 months of age. While intrarenal renin concentrations were higher in untreated females compared to untreated males, renal angiotensin II concentrations were higher in males than females. Furthermore, basal plasma aldosterone concentrations were greater in females than males. Cort exposed male but not female offspring had reduced water intake and urine excretion. Cort exposure increased renal renin concentrations and elevated mRNA expression of Ren1, Ace2, and Mas1 in male but not female offspring. In addition, male Cort exposed offspring had increased expression of the aldosterone receptor, Nr3c2 and renal sodium transporters. In contrast, Cort exposure increased Agtr1a mRNA levels in female offspring only. This study demonstrates that maternal Cort exposure alters key regulators of renal function in a sex-specific manner at 6 months of life. These finding likely contribute to the disease outcomes in male but not female offspring in later life and highlights the importance of renal factors other than nephron number in the programming of renal and cardiovascular disease. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

  2. Serotonin and corticosterone rhythms in mice exposed to cigarette smoke and in patients with COPD: implication for COPD-associated neuropathogenesis.

    Directory of Open Access Journals (Sweden)

    Isaac K Sundar

    Full Text Available The circadian timing system controls daily rhythms of physiology and behavior, and disruption of clock function can trigger stressful life events. Daily exposure to cigarette smoke (CS can lead to alteration in diverse biological and physiological processes. Smoking is associated with mood disorders, including depression and anxiety. Patients with chronic obstructive pulmonary disease (COPD have abnormal circadian rhythms, reflected by daily changes in respiratory symptoms and lung function. Corticosterone (CORT is an adrenal steroid that plays a considerable role in stress and anti-inflammatory responses. Serotonin (5-hydroxytryptamine; 5HT is a neurohormone, which plays a role in sleep/wake regulation and affective disorders. Secretion of stress hormones (CORT and 5HT is under the control of the circadian clock in the suprachiasmatic nucleus. Since smoking is a contributing factor in the development of COPD, we hypothesize that CS can affect circadian rhythms of CORT and 5HT secretion leading to sleep and mood disorders in smokers and patients with COPD. We measured the daily rhythms of plasma CORT and 5HT in mice following acute (3 d, sub-chronic (10 d or chronic (6 mo CS exposure and in plasma from non-smokers, smokers and patients with COPD. Acute and chronic CS exposure affected both the timing (peak phase and amplitude of the daily rhythm of plasma CORT and 5HT in mice. Acute CS appeared to have subtle time-dependent effects on CORT levels but more pronounced effects on 5HT. As compared with CORT, plasma 5HT was slightly elevated in smokers but was reduced in patients with COPD. Thus, the effects of CS on plasma 5HT were consistent between mice and patients with COPD. Together, these data reveal a significant impact of CS exposure on rhythms of stress hormone secretion and subsequent detrimental effects on cognitive function, depression-like behavior, mood/anxiety and sleep quality in smokers and patients with COPD.

  3. NREM sleep hypersomnia and reduced sleep/wake continuity in a neuroendocrine mouse model of anxiety/depression based on chronic corticosterone administration.

    Science.gov (United States)

    Le Dantec, Y; Hache, G; Guilloux, J P; Guiard, B P; David, D J; Adrien, J; Escourrou, P

    2014-08-22

    Sleep/wake disorders are frequently associated with anxiety and depression and to elevated levels of cortisol. Even though these alterations are increasingly sought in animal models, no study has investigated the specific effects of chronic corticosterone (CORT) administration on sleep. We characterized sleep/wake disorders in a neuroendocrine mouse model of anxiety/depression, based on chronic CORT administration in the drinking water (35 μg/ml for 4 weeks, "CORT model"). The CORT model was markedly affected during the dark phase by non-rapid eye movement sleep (NREM) increase without consistent alteration of rapid eye movement (REM) sleep. Total sleep duration (SD) and sleep efficiency (SE) increased concomitantly during both the 24h and the dark phase, due to the increase in the number of NREM sleep episodes without a change in their mean duration. Conversely, the total duration of wake decreased due to a decrease in the mean duration of wake episodes despite an increase in their number. These results reflect hypersomnia by intrusion of NREM sleep during the active period as well as a decrease in sleep/wake continuity. In addition, NREM sleep was lighter, with an increased electroencephalogram (EEG) theta activity. With regard to REM sleep, the number and the duration of episodes decreased, specifically during the first part of the light period. REM and NREM sleep changes correlated respectively with the anxiety and the anxiety/depressive-like phenotypes, supporting the notion that studying sleep could be of predictive value for altered emotional behavior. The chronic CORT model in mice that displays hallmark characteristics of anxiety and depression provides an insight into understanding the changes in overall sleep architecture that occur under pathological conditions. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

  4. Sources of variation in plasma corticosterone and dehydroepiandrosterone in the male northern cardinal (Cardinalis cardinalis): II. Effects of urbanization, food supplementation and social stress.

    Science.gov (United States)

    Wright, Sarah; Fokidis, H Bobby

    2016-09-01

    Perturbations in an organism's environment can induce significant shifts in hormone secretory patterns. In this context, the glucocorticoid (GC) steroids secreted by the adrenal cortex have received much attention from ecologists and behaviorists due to their role in the vertebrate stress response. Adrenal GCs, such as corticosterone (CORT), are highly responsive to instability in environmental and social conditions. However, little is understood about how adrenal dehydroepiandrosterone (DHEA) is influenced by changing conditions. We conducted field experiments to determine how circulating CORT and DHEA vary during restraint stress in the male northern cardinals (Cardinalis cardinalis). Specifically, we examined how four different changes in the physical (urbanization and food availability) and social (territorial conflict, distress of a mate) environment affect CORT and DHEA levels. The majority of cardinals responded to restraint stress by increasing and decreasing CORT and DHEA, respectively, however this depended on sampling context. Cardinals sampled from urban habitats had both lower initial and restraint stress CORT concentrations, but a comparable DHEA pattern to those sampled from a forest. Supplementing food to territorial males did not alter circulating initial DHEA or CORT concentrations nor did it change the response to restraint stress when compared to unsupplemented controls. Exposing cardinals to varying durations of song playback, which mimics a territorial intrusion, did not affect CORT levels, but did attenuate the DHEA response to restraint stress. Examining a larger dataset of males captured before, after or at the same time as their female mate, allowed us to address how the stress of a captured mate affected the male's CORT and DHEA response. Males showed elevated initial and restraint CORT and DHEA when their female mate was captured first. Taken together, these data demonstrate that both CORT and DHEA secretion patterns depends on

  5. Polychlorinated biphenyl exposure and corticosterone levels in seven polar seabird species

    International Nuclear Information System (INIS)

    Tartu, S.; Angelier, F.; Bustnes, J.O.; Moe, B.; Hanssen, S.A.; Herzke, D.; Gabrielsen, G.W.; Verboven, N.; Verreault, J.; Labadie, P.; Budzinski, H.; Wingfield, J.C.

    2015-01-01

    The role of polychlorinated biphenyls (PCBs) on exposure-related endocrine effects has been poorly investigated in wild birds. This is the case for stress hormones including corticosterone (CORT). Some studies have suggested that environmental exposure to PCBs and altered CORT secretion might be associated. Here we investigated the relationships between blood PCB concentrations and circulating CORT levels in seven free-ranging polar seabird species occupying different trophic positions, and hence covering a wide range of PCB exposure. Blood ∑ 7 PCB concentrations (range: 61–115,632 ng/g lw) were positively associated to baseline or stress-induced CORT levels in three species and negatively associated to stress-induced CORT levels in one species. Global analysis suggests that in males, baseline CORT levels generally increase with increasing blood ∑ 7 PCB concentrations, whereas stress-induced CORT levels decrease when reaching high blood ∑ 7 PCB concentrations. This study suggests that the nature of the PCB-CORT relationships may depend on the level of PCB exposure. - Highlights: • Relationships between PCBs and stress hormones (CORT) are not well known in birds. • We measured blood PCBs, baseline and stress-induced CORT in seven seabird species. • ∑PCB was positively associated to baseline or stress-induced CORT in three species. • ∑PCBs was negatively linked to stress-induced CORT in the most contaminated species. • The nature of the PCB-CORT relationships may depend on the level of PCB exposure. - In polar seabird species, the relationship between PCB and CORT concentrations may be related to the levels of contamination

  6. Does feather corticosterone reflect individual quality or external stress in arctic-nesting migratory birds?

    Directory of Open Access Journals (Sweden)

    Pierre Legagneux

    Full Text Available The effects of environmental perturbations or stressors on individual states can be carried over to subsequent life stages and ultimately affect survival and reproduction. The concentration of corticosterone (CORT in feathers is an integrated measure of hypothalamic-pituitary-adrenal activity during the molting period, providing information on the total baseline and stress-induced CORT secreted during the period of feather growth. Common eiders and greater snow geese replace all flight feathers once a year during the pre-basic molt, which occurs following breeding. Thus, CORT contained in feathers of pre-breeding individuals sampled in spring reflects the total CORT secreted during the previous molting event, which may provide insight into the magnitude or extent of stress experienced during this time period. We used data from multiple recaptures to disentangle the contribution of individual quality vs. external factors (i.e., breeding investment or environmental conditions on feather CORT in arctic-nesting waterfowl. Our results revealed no repeatability of feather CORT within individuals of either species. In common eiders, feather CORT was not affected by prior reproductive investment, nor by pre-breeding (spring body condition prior to the molting period. Individual feather CORT greatly varied according to the year, and August-September temperatures explained most of the annual variation in feather CORT. Understanding mechanisms that affect energetic costs and stress responses during molting will require further studies either using long-term data or experiments. Although our study period encompassed only five years, it nonetheless provides evidence that CORT measured in feathers likely reflects responses to environmental conditions experienced by birds during molt, and could be used as a metric to study carry-over effects.

  7. Continuous corticosterone delivery via the drinking water or pellet implantation: A comparative study in mice.

    Science.gov (United States)

    Gasparini, Sylvia J; Weber, Marie-Christin; Henneicke, Holger; Kim, Sarah; Zhou, Hong; Seibel, Markus J

    2016-12-01

    In order to investigate the effects of glucocorticoid excess in rodent models, reliable methods of continuous glucocorticoid delivery are essential. The current study compares two methods of corticosterone (CS) delivery in regards to their ability to induce typical adverse outcomes such as fat accrual, insulin resistance, sarcopenia and bone loss. Eight-week-old mice received CS for 4weeks either via the drinking water (25-100μgCS/mL) or through weekly surgical implantation of slow release pellets containing 1.5mg CS. Both methods induced abnormal fat mass accrual, inhibited lean mass accretion and bone expansion, suppressed serum osteocalcin levels and induced severe insulin resistance. There was a clear dose dependant relationship between the CS concentrations in the drinking water and the severity of the phenotype, with a concentration of 50μg CS/mL drinking water most closely matching the metabolic changes induced by weekly pellet implantations. In contrast to pellets, however, delivery of CS via the drinking water resulted in a consistent diurnal exposure pattern, closely mimicking the kinetics of clinical glucocorticoid therapy. In addition, the method is safe, inexpensive, easily adjustable, non-invasive and avoids operative stress to the animals. Our data demonstrate that delivery of CS via the drinking water has advantages over weekly implantations of slow-release pellets. A dose of 50μg CS/mL drinking water is appropriate for the investigation of chronic glucocorticoid excess in mice. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

  8. Dynamic regulation of NMDAR function in the adult brain by the stress hormone corticosterone

    Directory of Open Access Journals (Sweden)

    Yiu Chung eTse

    2012-03-01

    Full Text Available Stress and corticosteroids dynamically modulate the expression of synaptic plasticity at glutamatergic synapses in the developed brain. Together with alpha-amino-3-hydroxy-methyl-4-isoxazole propionic acid receptors (AMPAR, N-methyl-D-aspartate receptors (NMDAR are critical mediators of synaptic function and are essential for the induction of many forms of synaptic plasticity. Regulation of NMDAR function by cortisol/corticosterone (CORT may be fundamental to the effects of stress on synaptic plasticity. Recent reports of the efficacy of NMDAR antagonists in treating certain stress-associated psychopathologies further highlight the importance of understanding the regulation of NMDAR function by CORT. Knowledge of how corticosteroids regulate NMDAR function within the adult brain is relatively sparse, perhaps due to a common belief that NMDAR function is relatively stable in the adult brain. We review recent results from our laboratory and others demonstrating dynamic regulation of NMDAR function by CORT in the adult brain. In addition, we consider the issue of how differences in the early life environment may program differential sensitivity to modulation of NMDAR function by CORT and how this may influence synaptic function during stress. Findings from these studies demonstrate that NMDAR function in the adult hippocampus remains sensitive to even brief exposures to CORT and that the capacity for modulation of NMDAR may be programmed, in part, by the early life environment. Modulation of NMDAR function may contribute to dynamic regulation of synaptic plasticity and adaptation in the face of stress, however enhanced NMDAR function may be implicated in mechanisms of stress related psychopathologies including depression.

  9. Forced swimming-induced oxytocin release into blood and brain: Effects of adrenalectomy and corticosterone treatment.

    Science.gov (United States)

    Torner, Luz; Plotsky, Paul M; Neumann, Inga D; de Jong, Trynke R

    2017-03-01

    The oxytocin (OXT) system is functionally linked to the HPA axis in a reciprocal and complex manner. Certain stressors are known to cause the simultaneous release of OXT and adrenocorticotrophic hormone (ACTH) followed by corticosterone (CORT). Furthermore, brain OXT attenuates ACTH and CORT responses. Although there are some indications of CORT influencing OXT neurotransmission, specific effects of CORT on neurohypophyseal or intra-hypothalamic release of OXT have not been studied in detail. In the present set of experiments, adult male rats were adrenalectomized (ADX) or sham-operated and fitted with a jugular vein catheter and/or microdialysis probe targeting the hypothalamic paraventricular nucleus (PVN). Blood samples and dialysates were collected before and after forced swimming (FS) and analyzed for CORT, ACTH and AVP concentrations (in plasma) and OXT concentrations (in plasma and dialysates). Experimental treatments included acute infusion of CORT (70 or 175μg/kg i.v.) 5min prior to FS, or subcutaneous placement of 40% CORT pellets resulting in stable CORT levels in the normal basal range. Although ADX did not alter basal OXT concentrations either in plasma or in microdialysates from the PVN, it did cause an exaggerated peripheral secretion of OXT and a blunted intra-PVN release of OXT in response to FS. CORT pellets did not influence either of these ADX-induced effects, while acute infusion of 175μg/kg CORT rescued the stress-induced rise in OXT release within the PVN and modestly increased peripheral OXT secretion. In conclusion, these results indicate that CORT regulates both peripheral and intracerebral OXT release, but in an independent manner. Whereas the peripheral secretion of OXT occurs simultaneously to HPA axis activation in response to FS and is modestly influenced by CORT, HPA axis activation and circulating CORT strongly contribute to the stress-induced stimulation of OXT release within the PVN. Copyright © 2016 Elsevier Ltd. All rights

  10. Effects of acute corticosterone treatment on partner preferences in male and female zebra finches (Taeniopygia guttata).

    Science.gov (United States)

    LaPlante, Kimberly A; Huremovic, Enida; Tomaszycki, Michelle L

    2014-04-01

    Stress alters physiology and behavior across species. Most research on the effects of stress on behavior uses chronic stressors, and most are correlational. The effects of acute stressors on physiology and behavior have been mixed. Here, we use zebra finches, a highly gregarious species that forms long-term pair bonds, to test the effects of an acute corticosterone (CORT) on opposite-sex partner preferences over a same-sex individual or a group (the latter is a highly appealing option). We had two competing hypotheses. First, we predicted that acute CORT would alter preferences for the opposite sex bird in both conditions in both sexes. However, since there is a sex difference in the effects of CORT on partner preferences in voles, these effects may be more pronounced in males than in females. To test our hypotheses, we administered 2 doses of CORT (10μg and 20μg) or vehicle (control) using a repeated measures design. In the male vs. female test, there was a significant Sex by Treatment interaction, such that in males, 10μg CORT increased preferences for a female over the male compared to when these same males were treated with saline at baseline. There were no effects of treatment in females. In the opposite-sex vs. group condition, there was an overall effect of Treatment, such that the 10μg dose increased preference for the opposite-sex individual over both saline treatments, regardless of sex. These findings further our understanding of the effects of an acute stressor on sexual partner preferences. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Does feather corticosterone reflect individual quality or external stress in arctic-nesting migratory birds?

    Science.gov (United States)

    Legagneux, Pierre; Harms, N Jane; Gauthier, Gilles; Chastel, Olivier; Gilchrist, H Grant; Bortolotti, Gary; Bêty, Joël; Soos, Catherine

    2013-01-01

    The effects of environmental perturbations or stressors on individual states can be carried over to subsequent life stages and ultimately affect survival and reproduction. The concentration of corticosterone (CORT) in feathers is an integrated measure of hypothalamic-pituitary-adrenal activity during the molting period, providing information on the total baseline and stress-induced CORT secreted during the period of feather growth. Common eiders and greater snow geese replace all flight feathers once a year during the pre-basic molt, which occurs following breeding. Thus, CORT contained in feathers of pre-breeding individuals sampled in spring reflects the total CORT secreted during the previous molting event, which may provide insight into the magnitude or extent of stress experienced during this time period. We used data from multiple recaptures to disentangle the contribution of individual quality vs. external factors (i.e., breeding investment or environmental conditions) on feather CORT in arctic-nesting waterfowl. Our results revealed no repeatability of feather CORT within individuals of either species. In common eiders, feather CORT was not affected by prior reproductive investment, nor by pre-breeding (spring) body condition prior to the molting period. Individual feather CORT greatly varied according to the year, and August-September temperatures explained most of the annual variation in feather CORT. Understanding mechanisms that affect energetic costs and stress responses during molting will require further studies either using long-term data or experiments. Although our study period encompassed only five years, it nonetheless provides evidence that CORT measured in feathers likely reflects responses to environmental conditions experienced by birds during molt, and could be used as a metric to study carry-over effects.

  12. Influence of corticosterone treatment on nestling begging in Florida scrub-jays (Aphelocoma coerulescens).

    Science.gov (United States)

    Elderbrock, Emily K; Small, Thomas W; Schoech, Stephan J

    2018-04-01

    Altricial young are dependent on adults for protection and food, and they display nutritional need by begging to elicit feeding from parents. Begging at high levels can be energetically expensive and attract predators; thus, an individual must balance its nutritional needs with these potential costs. Further, because a parent is limited in the amount of food it can provide, begging can contribute to both parent-offspring conflict and sibling-sibling competition. Many extrinsic and intrinsic factors may contribute to begging behavior. One intrinsic factor of interest is corticosterone (CORT), a metabolic hormone hypothesized to play a role in regulating a nestling's begging behavior. We investigated the hypothesis that increased exposure to CORT influences nestling begging behavior in an altricial species, the Florida scrub-jay (Aphelocoma coerulescens). We treated one nestling per treatment nest with a twice-daily dose of exogenous hormone via a CORT-injected waxworm, whereas a second individual received a vehicle-injected waxworm. We monitored individual nestling and adult behavior at all nests with the use of high-definition video cameras on several days during treatment. We found no difference in begging rate between CORT fed and vehicle fed nestlings within a treatment nest. Further, to determine whether CORT treatment had indirect effects on the entire brood, we monitored additional nests, in which nestlings were not manipulated. When treatment and controls were compared, overall begging rates of nestlings in treatment nests were greater than those in control nests. This result suggests that CORT treatment of an individual altered its behavior, as well as that of its siblings. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Effects of different timing of stress on corticosterone, BDNF and memory in male rats.

    Science.gov (United States)

    Radahmadi, Maryam; Alaei, Hojjatallah; Sharifi, Mohammad Reza; Hosseini, Nasrin

    2015-02-01

    Learning and memory seem to be affected by chronic stress. Previous reports have considered chronic stress as a precipitating factor of different neuropsychological disorders, while others reported neurobiological adaptations following stress. The present study investigated the effects of chronic stress before, after, and during learning on the changes of learning and memory, on serum and hippocampal levels of corticosterone (CORT), brain-derived neurotrophic factor (BDNF) and body weight in rats. Male Wistar rats were randomly divided into four groups (n=10) including Control (Co), Stress-Learning-Rest (St-L-Re), Rest-Learning-Stress (Re-L-St), and Stress-Learning-Stress (St-L-St) groups. The chronic restraint stress was applied 6 h/day for 21 days. Moreover, the passive avoidance test was used to assess memory deficit, 1, 7, and 21 days after training. At the end of experiments, CORT and BDNF levels were measured. The findings did not support adaptation in chronic stress conditions. The acquisition time as well as the short and mid-term memories was significantly impaired in the St-L-Re group. Short, mid, and long-term memories were significantly impaired in the Re-L-St and St-L-St groups compared with the Co group, as a result of the enhancement of CORT and reduction of BDNF levels. In the St-L-St group, changes in memory functions were less pronounced than in the Re-L-St group. Also, body weight declined following the chronic stress, while recovery period enhanced the body weight gain in stressed rats. It can be concluded that a potential time-dependent involvement of stress and recovery period on the level of BDNF. Longer duration time of chronic stress might promote adaptive effects on memory and CORT level. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Effect of corticosterone on larval growth, antipredator behaviour and metamorphosis of Hylarana indica.

    Science.gov (United States)

    Kulkarni, P S; Gramapurohit, N P

    2017-09-15

    Corticosterone (CORT), a principal glucocorticoid in amphibians, is known to regulate diverse physiological processes including growth and metamorphosis of anuran tadpoles. Environmental stressors activate the neuroendocrine stress axis (hypothalamus-pituitary-interrenal axis, HPI) leading to an acute increase in CORT, which in turn, helps in coping with particular stress. However, chronic increase in CORT can negatively affect other physiological processes such as growth and metamorphosis. Herein, we studied the effect of exogenous CORT on larval growth, antipredator behaviour and metamorphic traits of Hylarana indica. Embryonic exposure to 5 or 20μg/L CORT did not affect their development, hatching duration as well as larval growth and metamorphosis. Exposure of tadpoles to 10 or 20μg/L CORT throughout larval development caused slower growth and development leading to increased body mass at stage 37. However, body and tail morphology of tadpoles was not affected. Interestingly, larval exposure to 5, 10 or 20μg/L CORT enhanced their antipredator response against kairomones in a concentration-dependent manner. Further, larval exposure to increasing concentrations of CORT resulted in the emergence of heavier froglets at 10 and 20μg/L while, delaying metamorphosis at all concentrations. Interestingly, the heavier froglets had shorter hindlimbs and consequently shorter jump distances. Tadpoles exposed to 20μg/L CORT during early, mid or late larval stages grew and developed slowly but tadpole morphology was not altered. Interestingly, exposure during early or mid-larval stages resulted in an enhanced antipredator response. These individuals metamorphosed later but at higher body mass while SVL was unaffected. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Temporal overlap and repeatability of feather corticosterone levels: practical considerations for use as a biomarker.

    Science.gov (United States)

    Harris, Christopher M; Madliger, Christine L; Love, Oliver P

    2016-01-01

    The measurement of corticosterone (CORT) levels in feathers has recently become an appealing tool for the conservation toolbox, potentially providing a non-invasive, integrated measure of stress activity throughout the time of feather growth. However, because the mechanism of CORT deposition, storage and stability in feathers is not fully understood, it is unclear how reliable this measure may be, especially when there is an extended interval between growth and feather collection. We compared CORT levels of naturally grown feathers from tree swallows ( Tachycineta bicolor ) that were moulted and regrown concurrently and therefore expected to have similar CORT levels. Specifically, we compared the same feather from the left and right wing (moulted symmetrically) and different types of feathers (wing, back and tail) expected to have been moulted within the same time period. We found that larger, heavier feathers held more CORT per unit length. In addition, we found a lack of concordance in CORT levels both within the same feather type and between different feather types, even after taking into account differences in feather density. Our results indicate that naturally grown feathers may not consistently provide an indication of stress status. Additionally, conflict in results may arise depending on the feather assayed, and total feather volume may be an important consideration when interpreting feather CORT levels. Future work is necessary to determine explicitly the mechanisms of CORT deposition, the effects of environmental exposure and feather wear on the permanence of the feather CORT signal, and the influence of responses to wild stressors on feather CORT levels, before feather CORT can be implemented effectively as a tool for ecological and conservation applications.

  16. Undervisning af tosprogede elever

    DEFF Research Database (Denmark)

    Horst, Christian

    2003-01-01

    Artiklen fremdrager hovedresultaterne fra Virginia P. Collier's og Wayne P. Thomas's længdeundersøgelser af tosprogede elever i USA, som formentlig er de mest omfattende undersøgelser af undervisningen af tosprogede elever overhovedet. Resultaterne diskuteres i relation til udviklingen af en...

  17. Effects of elevated CO

    NARCIS (Netherlands)

    Xue, Sha; Yang, Xiaomei; Liu, Guobin; Gai, Lingtong; Zhang, Changsheng; Ritsema, Coen J.; Geissen, Violette

    2017-01-01

    Elevated CO2 and drought are key consequences of climate change and affect soil processes and plant growth. This study investigated the effects of elevated CO2 and drought on the microbial biomass and enzymatic activities in the rhizospheres of Bothriochloa ischaemum and

  18. Elevator and hydraulics; Elevator to yuatsu

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, I. [Hitachi, Ltd., Tokyo (Japan)

    1994-07-15

    A hydraulic type elevator is installed in relatively lower buildings as compared with a rope type elevator, but the ratio in the number of installation of the former elevator is increasing. This paper explains from its construction and features to especially various control systems for the riding comfort and safety. A direct push-up system with hydraulic jacks arranged beneath a car, and an indirect push-up system that has hydraulic jacks arranged on flank of a car and transmits the movement of a plunger via a rope are available. The latter system eliminates the need of large holes to embed hydraulic jacks. While the speed is controlled by controlling flow rates of high-pressure oil, the speed, position, acceleration and even time differential calculus of the acceleration must be controlled severely. The system uses two-step control for the through-speed and the landing speed. Different systems that have been realized may include compensation for temperatures in flow rate control valves, load pressures, and oil viscosity, from learning control to fuzzy control for psychological effects, or control of inverters in motors. 13 refs., 12 figs., 1 tab.

  19. Effects of stress and corticosterone in two post-training periods, on spatial memory consolidation in adult male Wistar rats.

    Directory of Open Access Journals (Sweden)

    Jeimmy Marcela Cerón

    2015-04-01

    Full Text Available Memory consolidation is the process of gradual stabilization of long-term memory after learning (Alberini & Taubenfeld, 2008. This process involves the activation of intracellular signaling cascades that lead to the reorganization of synaptic proteins. Activation of these signaling pathways can regulate gene expression and protein synthesis (Brivanlou & Darnell, 2002. It is considered that the new proteins synthesized after learning are responsible for the changes in the neural architecture associated with memory consolidation (Mileusnic, 2004. In this sense, it has been shown that consolidation may be interrupted by inhibiting protein synthesis, leading to forgetfulness of the experience (Meeter & Murre, 2004. Although the dominant hypothesis is that memory consolidation requires a single molecular cascade, it has been suggested that multiple sets of synaptic modifications are required to reinforce changes after memory acquisition (Wittenber & Tsien, 2002. Consistently, recent studies have shown that protein synthesis associated with memory consolidation occurs in at least two post-training periods: immediately and 3-6 hours after training (Igaz et al., 2002; Bekinschtein et al., 2007. These memory consolidation periods share some molecular phenomena; however, each period is also associated with events that are different from the other (Igaz et al., 2002. To date, there is a substantial amount of evidence showing that stressful events may facilitate neuronal function and cognition. The term "stress" usually refers to a nonspecific response of the body to stimuli that threaten the physiological/psychological homeostasis (Selye, 1976; Chrousos et al., 1988. The stress response is associated with the activation of two physiological systems: the hypothalamic-pituitary-adrenal (HPA axis and the sympathetic adrenomedullary (SAM. Glucocorticoids (cortisol in humans and corticosterone in rodents are steroid hormones secreted by the adrenal glands as a

  20. Disruption of the HPA-axis through corticosterone-release pellets induces robust depressive-like behavior and reduced BDNF levels in mice.

    Science.gov (United States)

    Demuyser, Thomas; Bentea, Eduard; Deneyer, Lauren; Albertini, Giulia; Massie, Ann; Smolders, Ilse

    2016-07-28

    The corticosterone mouse model is widely used in preclinical research towards a better understanding of mechanisms of major depression. One particular administration procedure is the subcutaneous implantation of corticosterone slow-release pellets. In this report we want to provide basic evidence, regarding behavioral changes, neurotransmitter and -modulator levels and some other relevant biomolecules after hypothalamic-pituitary-adrenal-axis distortion. We show that three weeks of corticosterone pellet exposure robustly induces depressive-like but not anxiety-like behavior in mice, accompanied by a significant decrease in hippocampal brain-derived neurotrophic factor levels, at five weeks after the start of treatment. Furthermore there is an overall decrease in plasma corticosterone levels after three weeks of treatment that lasts up until the five weeks' time point. On the other hand, no differences are observed in total monoamine, glutamate or d-serine levels, nor in glucocorticoid receptor expression, in various depression-related brain areas. Altogether this characterization delivers vital information, supplementary to existing literature, regarding the phenotyping of pellet-induced hypothalamic-pituitary-adrenal-axis disruption in mice following three weeks of continuous corticosterone exposure. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  1. A combination of body condition measurements is more informative than conventional condition indices: temporal variation in body condition and corticosterone in brown tree snakes (Boiga irregularis).

    Science.gov (United States)

    Waye, Heather L; Mason, Robert T

    2008-02-01

    The body condition index is a common method for quantifying the energy reserves of individual animals. Because good body condition is necessary for reproduction in many species, body condition indices can indicate the potential reproductive output of a population. Body condition is related to glucocorticoid production, in that low body condition is correlated to high concentrations of corticosterone in reptiles. We compared the body condition index and plasma corticosterone levels of brown tree snakes on Guam in 2003 to those collected in 1992/1993 to determine whether that population still showed the chronic stress and poor condition apparent in the earlier study. We also examined the relationship between fat mass, body condition and plasma corticosterone concentrations as indicators of physiological condition of individuals in the population. Body condition was significantly higher in 2003 than in the earlier sample for mature male and female snakes, but not for juveniles. The significantly lower levels of corticosterone in all three groups in 2003 suggests that although juveniles did not have significantly improved energy stores they, along with the mature males and females, were no longer under chronic levels of stress. Although the wet season of 2002 was unusually rainy, low baseline levels of corticosterone measured in 2000 indicate that the improved body condition of snakes in 2003 is likely the result of long-term changes in prey populations rather than annual variation in response to environmental conditions.

  2. Corticosterone metabolite concentrations in greater sage-grouse are positively associated with the presence of cattle grazing

    Science.gov (United States)

    Jankowski, M.D.; Russell, Robin E.; Franson, J. Christian; Dusek, Robert J.; Hines, M.K.; Gregg, M.; Hofmeister, Erik K.

    2014-01-01

    The sagebrush biome in the western United States is home to the imperiled greater sage-grouse (Centrocercus urophasianus) and encompasses rangelands used for cattle production. Cattle grazing activities have been implicated in the range-wide decline of the sage-grouse, but no studies have investigated the relationship between the physiological condition of sage-grouse and the presence of grazing cattle. We sampled 329 sage-grouse across four sites (two grazed and two ungrazed) encompassing 13 600 km2 during the spring and late summer–early autumn of 2005 to evaluate whether demographic factors, breeding status, plasma protein levels, and residence in a cattle-grazed habitat were associated with the stress hormone corticosterone. Corticosterone was measured in feces as immunoreactive corticosterone metabolites (ICM). Males captured during the lekking season exhibited higher ICM levels than all others. Prenesting female sage-grouse captured in a grazed site had higher ICM levels than those in ungrazed sites and prenesting female plasma protein levels were negatively correlated with ICM concentrations. With the use of a small-scale spatial model, we identified a positive correlation between cattle pat count and sage-grouse ICM levels. Our model indicated that ICM levels increased by 2.60 ng · g-1 dry feces for every increase in the number of cow pats found in the vicinity. Management practices will benefit from future research regarding the consistency and mechanism(s) responsible for this association and, importantly, how ICM levels and demographic rates are related in this species of conservation concern.

  3. Elevators or stairs?

    Science.gov (United States)

    Shah, Sachin; O’Byrne, Michael; Wilson, Merne; Wilson, Thomas

    2011-01-01

    Background: Staff in hospitals frequently travel between floors and choose between taking the stairs or elevator. We compared the time savings with these two options. Methods: Four people aged 26–67 years completed 14 trips ranging from one to six floors, both ascending and descending. We compared the amount of time per floor travelled by stairs and by two banks of elevators. Participants reported their fatigue levels using a modified Borg scale. We performed two-way analysis of variance to compare the log-transformed data, with participant and time of day as independent variables. Results: The mean time taken to travel between each floor was 13.1 (standard deviation [SD] 1.7) seconds by stairs and 37.5 (SD 19.0) and 35.6 (SD 23.1) seconds by the two elevators (F = 8.61, p elevator equaled about 15 minutes a day. Self-reported fatigue was less than 13 (out of 20) on the Borg scale for all participants, and they all stated that they were able to continue their duties without resting. The extra time associated with elevator use was because of waiting for its arrival. There was a difference in the amount of time taken to travel by elevator depending on the time of day and day of the week. Interpretation: Taking the stairs rather than the elevator saved about 15 minutes each workday. This 3% savings per workday could translate into improved productivity as well as increased fitness. PMID:22159365

  4. Elevated temperature fracture mechanics

    International Nuclear Information System (INIS)

    Tomkins, B.

    1979-01-01

    The application of fracture mechanics concepts to cracks at elevated temperatures is examined. Particular consideration is given to the characterisation of crack tip stress-strain fields and parameters controlling crack extension under static and cyclic loads. (author)

  5. Antidepressant activity of vorinostat is associated with amelioration of oxidative stress and inflammation in a corticosterone-induced chronic stress model in mice.

    Science.gov (United States)

    Kv, Athira; Madhana, Rajaram Mohanrao; Js, Indu Chandran; Lahkar, Mangala; Sinha, Swapnil; Naidu, V G M

    2018-05-15

    Major depressive disorder (MDD) is a multifactorial neuropsychiatric disorder. Chronic administration of corticosterone (CORT) to rodents is used to mimic the stress associated dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, a well-established feature found in depressive patients. Recently, preclinical studies have demonstrated the antidepressant potential of histone deacetylase (HDAC) inhibitors. So, we examined the antidepressant potential of vorinostat (VOR), a HDAC inhibitor against CORT injections in male mice. VOR (25 mg/kg; intraperitoneal) and fluoxetine (FLX) (15 mg/kg; oral) treatments were provided to CORT administered mice. At the end of dosing schedule, neurobehavioral tests were conducted; followed by mechanistic evaluation through biochemical analysis, RTPCR and western blot in serum and hippocampus. Neurobehavioral tests revealed the development of anxiety/depressive-like behavior in CORT mice as compared to the vehicle control. Depressive-mice showed concomitant HPA axis dysregulation as observed from the significant increase in serum CORT and ACTH. Chronic CORT administration was found to significantly increase hippocampal malondialdehyde (MDA) and iNOS levels while lowering glutathione (GSH) content, as compared to vehicle control. VOR treatment, in a similar manner to the classical antidepressant FLX, significantly ameliorated anxiety/depressive-like behavior along with HPA axis alterations induced by CORT. The antidepressant-like ability of drug treatments against chronic CORT induced stress model, as revealed in our study, may be due to their potential to mitigate inflammatory damage and oxidative stress via modulation of hippocampal NF-κB p65, COX-2, HDAC2 and phosphorylated JNK levels. Copyright © 2018 Elsevier B.V. All rights reserved.

  6. Indsatser for tosprogede elever

    DEFF Research Database (Denmark)

    Andersen, Dines; Jakobsen, Vibeke; Jensen, Vibeke Myrup

    Fagligt set klarer tosprogede elever sig dårligere i skolen og det videre uddannelsessystem end ’danske’ elever. Kommuner og folkeskoler har derfor sat en række tiltag i værk, som sigter mod at forbedre de tosprogede elevers skole- og uddannelsessituation. Rapporten kortlægger og analyserer...... af klasseundervisningen. Analysen viser, at de elever, der bliver taget ud af klassen for at få ekstra undervisning i dansk som andetsprog, klarer sig dårligere end elever, der modtager ekstraundervisningen i klassen eller uden for skoletid. Undersøgelsen er baseret på spørgeskemaundersøgelser blandt...... kommunale forvaltningschefer, skoleledere, lærere og forældre til børn i 2. klasse samt lærere til og elever i 9. klasse, SFI’s forløbsundersøgelse af årgang 1995 og registerdata. Undersøgelsen er via Ministeriet for Børn og Undervisning betalt med midler fra satspuljeaftalen 2009 om integration....

  7. Seasonal variation of the impact of a stressful procedure on open field behaviour and blood corticosterone in laboratory mice.

    Science.gov (United States)

    Meyer, L; Caston, J; Mensah-Nyagan, A G

    2006-02-28

    Behavioural and hormonal seasonal changes are well documented in various vertebrate species living in their natural environment but circannual variations that may occur in laboratory animals reared in standard conditions are poorly investigated. This study shows that, in laboratory mice, the effects of stress on behavioural inhibition, investigatory behaviour and blood concentration of corticosterone are seasonally dependent. No consistency was observed between the reactivity of biological structures controlling the hormonal response to stress and the behavioural activities investigated at every period of the year. During the spring time, stress, which elicited a decrease of investigatory behaviour (estimated by the walking time in an open field), increased behavioural inhibition (estimated by the percentage of walking in the central area of the open field) as well as the blood corticosterone concentration in laboratory mice. In autumn, stress had no significant effect on behaviour despite the great hormonal concentration increase. The results reveal that, at certain period of the year, a stressful procedure is unable to affect behavioural parameters in laboratory mice which were maintained in constant 12-h dark/12-h light cycle. The report constitutes a novel piece of information suggesting a potential role of the endogenous biological clock in the modulation of stress response in mammals.

  8. High corticosterone, not high energy cost, correlates with reproductive success in the burrow-nesting ancient murrelet.

    Directory of Open Access Journals (Sweden)

    Akiko Shoji

    Full Text Available Theory and observations suggest that offspring abandonment in animals may occur when the costs to future reproductive output of current reproductive effort outweigh the fitness benefits of rearing the current brood. While hormonal cues (i.e. corticosterone or energy reserves are believed to be involved, few studies have directly focused on the proximate cues influencing behaviours directly related to reproductive success. To address this information gap, we determined the incubation metabolic rates and corticosterone (CORT levels of naturally fasting and freely incubating ancient murrelets (Synthliboramphus antiquus. Respiratory quotient (RQ increased with date, suggesting that incubating ancient murrelets shifted from strictly lipid-based metabolism towards more protein-based metabolism as incubation progressed. Birds that hatched only one nestling had higher levels of circulating CORT than those which hatched two, suggesting that birds which laid only a single egg found incubation more stressful than those which laid two. However, CORT levels and incubation shift lengths were not correlated, suggesting that birds that undertook prolonged incubation shifts did so only when their energy stores were not jeopardized.

  9. [The influence of application of a low-frequency magnetic field on the serum corticosterone level (an experimental study)].

    Science.gov (United States)

    Alabovskiĭ, V V; Gotovskiĭ, M Iu; Vinokurov, A A; Maslov, O V

    2013-01-01

    The results of analysis of the literature publications suggest the necessity of experimental studies aimed at investigation of modulating effect of low-frequency magnetic fields on endocrine organs. The present study was carried out using 200 outbred white male rats (body weight 200-220 g). Corticosterone was measured in blood sera following the application of a low-frequency magnetic field (20 and 53 Hz with induction from 0.4 to 6 mT) generated by a Mini-Expert-T apparatus for induction magnetic therapy during 30 minutes. It was shown that the application of the alternating magnetic field to the adrenal region of the rats in the selected frequency and induction ranges caused a significant increase in the serum corticosterone levels. The results of the present study on the hormonal activity of rat adrenals give reason to consider the influence of the alternating magnetic fields as being modulatory. Analysis of the data thus obtained has demonstrated the non-linear dependence of glucocorticoid activity of the rat adrenal glands on the induction strength of the alternating magnetic field.

  10. Neonatal corticosterone administration in rodents as a tool to investigate the maternal programming of emotional and immune domains

    Directory of Open Access Journals (Sweden)

    Simone Macrì

    2017-02-01

    Full Text Available Neonatal experiences exert persistent influences on individual development. These influences encompass numerous domains including emotion, cognition, reactivity to external stressors and immunity. The comprehensive nature of the neonatal programming of individual phenotype is reverberated in the large amount of experimental data collected by many authors in several scientific fields: biomedicine, evolutionary and molecular biology. These data support the view that variations in precocious environmental conditions may calibrate the individual phenotype at many different levels. Environmental influences have been traditionally addressed through experimental paradigms entailing the modification of the neonatal environment and the multifactorial (e.g. behaviour, endocrinology, cellular and molecular biology analysis of the developing individual's phenotype. These protocols suggested that the role of the mother in mediating the offspring's phenotype is often associated with the short-term effects of environmental manipulations on dam's physiology. Specifically, environmental manipulations may induce fluctuations in maternal corticosteroids (corticosterone in rodents which, in turn, are translated to the offspring through lactation. Herein, I propose that this mother-offspring transfer mechanism can be leveraged to devise experimental protocols based on the exogenous administration of corticosterone during lactation. To support this proposition, I refer to a series of studies in which these protocols have been adopted to investigate the neonatal programming of individual phenotype at the level of emotional and immune regulations. While these paradigms cannot replace traditional studies, I suggest that they can be considered a valid complement.

  11. National Elevation Dataset

    Science.gov (United States)

    ,

    2002-01-01

    The National Elevation Dataset (NED) is a new raster product assembled by the U.S. Geological Survey. NED is designed to provide National elevation data in a seamless form with a consistent datum, elevation unit, and projection. Data corrections were made in the NED assembly process to minimize artifacts, perform edge matching, and fill sliver areas of missing data. NED has a resolution of one arc-second (approximately 30 meters) for the conterminous United States, Hawaii, Puerto Rico and the island territories and a resolution of two arc-seconds for Alaska. NED data sources have a variety of elevation units, horizontal datums, and map projections. In the NED assembly process the elevation values are converted to decimal meters as a consistent unit of measure, NAD83 is consistently used as horizontal datum, and all the data are recast in a geographic projection. Older DEM's produced by methods that are now obsolete have been filtered during the NED assembly process to minimize artifacts that are commonly found in data produced by these methods. Artifact removal greatly improves the quality of the slope, shaded-relief, and synthetic drainage information that can be derived from the elevation data. Figure 2 illustrates the results of this artifact removal filtering. NED processing also includes steps to adjust values where adjacent DEM's do not match well, and to fill sliver areas of missing data between DEM's. These processing steps ensure that NED has no void areas and artificial discontinuities have been minimized. The artifact removal filtering process does not eliminate all of the artifacts. In areas where the only available DEM is produced by older methods, then "striping" may still occur.

  12. Upshot of Elevated Temperature on Performance Facet of Fly Ash ...

    African Journals Online (AJOL)

    This study investigates the effects of elevated temperature variation on the compressive strength of Fly Ash/Ordinary Portland Cement (OPC) Laterized concrete ... and 10% Fly ash content at 2500C. This is an indication that the strength of Fly ash/OPC Laterized concrete is generally sufficient for use at elevated temperature ...

  13. High-Contention Mutual Exclusion by Elevator Algorithms

    NARCIS (Netherlands)

    Buhr, Peter A.; Dice, Dave; Hesselink, Wim H.

    2018-01-01

    This paper presents new starvation-free hardware-assisted and software-only algorithms for the N-thread mutual-exclusion problem. The hardware-assisted versions use a single atomic-CAS instruction and no fences. The software-only algorithms simulate the CAS instruction using a variation of

  14. Interaktive tavler - interaktive elever

    DEFF Research Database (Denmark)

    Reusch, Charlotte F.; Otzen, Elsebeth

    Abstract, Poster-præsentation 13.-14. juni 2012, Pilotprojekt: Interaktive tavler – interaktive elever Lektor, cand. pæd., Elsebeth Otzen og Lektor, cand. mag., Charlotte Reusch, Institut for Skole og Læring, Læreruddannelsen, Professionshøjskolen Metropol, København Hvordan motiverer en interaktiv...... tavle lærere og elever? Hvad sker der mellem elev, stof og lærer, når læreren bliver i stand til at billedliggøre og dynamisere sine oplæg på tavlen? Bliver læreroplæg prioriteret? Bliver eleverne aktive, eller ender den interaktive tavle med blot at understøtte lærerens envejskommunikation til klassen......? Og hvad sker der mellem eleverne? Disse spørgsmål var igangsættende for arbejdet med pilotprojektet Interaktive tavler – interaktive elever, som blev afviklet i skoleåret 2010-2011. Projektet blev udført af en tværfaglig gruppe, bestående af lektorer i matematik, biologi og dansk i læreruddannelsen...

  15. Udeskole og elevers handlekompetence

    DEFF Research Database (Denmark)

    Breiting, Søren

    2011-01-01

    Elever elsker at komme væk fra undervisningen i skolen. Er det positivt eller negativt? Og hvad har betydning for, at eleverne får mest muligt ud af oplevelserne uden for skolen? Forskellige former for udeskole giver nogle oplagte muligheder, så eleverne udvikler sig som engagerede borgere i et...

  16. Interaktive tavler - interaktive elever

    DEFF Research Database (Denmark)

    Reusch, Charlotte; Otzen, Elsebeth

    Abstract, Poster-præsentation 13.-14. juni 2012, Pilotprojekt: Interaktive tavler ? interaktive elever Lektor, cand. pæd., Elsebeth Otzen og Lektor, cand. mag., Charlotte Reusch, Institut for Skole og Læring, Læreruddannelsen, Professionshøjskolen Metropol, København Hvordan motiverer en interaktiv...... tavle lærere og elever? Hvad sker der mellem elev, stof og lærer, når læreren bliver i stand til at billedliggøre og dynamisere sine oplæg på tavlen? Bliver læreroplæg prioriteret? Bliver eleverne aktive, eller ender den interaktive tavle med blot at understøtte lærerens envejskommunikation til klassen......? Og hvad sker der mellem eleverne? Disse spørgsmål var igangsættende for arbejdet med pilotprojektet Interaktive tavler ? interaktive elever, som blev afviklet i skoleåret 2010-2011. Projektet blev udført af en tværfaglig gruppe, bestående af lektorer i matematik, biologi og dansk i læreruddannelsen...

  17. The utility of fecal corticosterone metabolites and animal welfare assessment protocols as predictive parameters of tumor development and animal welfare in a murine xenograft model

    DEFF Research Database (Denmark)

    Jacobsen, Kirsten Rosenmaj; Jørgensen, Pernille Schønning; Pipper, Christian Bressen

    2013-01-01

    consumption, and an animal welfare assessment (AWA) protocol revealed marked differences between control and cancer lines as the size of the tumor increased. However, only the AWA protocol was effective in predicting the tumor size and the level of fecal corticosterone metabolites (FCM). FCM levels were...

  18. Antidepressant-like activity of red wine phenolic extracts in repeated corticosterone-induced depression mice via BDNF/TrkB/CREB signaling pathway

    Directory of Open Access Journals (Sweden)

    Jia Ying

    2016-01-01

    Full Text Available The aim of this study was to investigate the antidepressant-like effect of red wine phenolic extracts in mouse model exposed to exogenous corticosterone. The results showed that 3-week corticosterone injections caused depression-like behavior in mice, as indicated by the significant decrease in sucrose consumption and increase immobility time in the forced swim test. Red wine phenolic extracts treatment significantly reduced serum corticosterone levels. Moreover, it was found that red wine phenolic extract increased the brain-derived neurotrophic factor protein (BNDF and Tropomyosin-related kinase B (TrkB phosphorylation and cAMP-responsive element binding protein (CREB phosphorylation levels in the hippocampus and prefrontal cortex. However, K252a, an inhibitor of TrkB, completely abolished those antidepressant-like effects. These results suggested that the red wine phenolic extracts produce an antidepressant-like effect in corticosterone-treated mice, at least in part, which is possibly mediated by modulating hypothalamic-pituitary-adrenal (HPA axis, BDNF, TrkB and CREB phosphorylation levels in the brain region of mice.

  19. Schisandra chinensis produces the antidepressant-like effects in repeated corticosterone-induced mice via the BDNF/TrkB/CREB signaling pathway.

    Science.gov (United States)

    Yan, Tingxu; Xu, Mengjie; Wan, Shutong; Wang, Mengshi; Wu, Bo; Xiao, Feng; Bi, Kaishun; Jia, Ying

    2016-09-30

    The present study aimed to examine the antidepressant-like effects and the possible mechanisms of Schisandra chinensis on depressive-like behavior induced by repeated corticosterone injections in mice. Here we evaluated the effect of an ethanol extract of the dried fruit of S. chinensis (EESC) on BDNF/TrkB/CREB signaling in the hippocampus and the prefrontal cortex. Three weeks of corticosterone injections in mice resulted in depressive-like behavior, as indicated by the significant decrease in sucrose consumption and increase the immobility time in the forced swim test, but without any influence on the locomotor activity. Further, there was a significant increase in serum corticosterone level and a significant downregulation of BDNF/TrkB/CREB signaling pathway in the hippocampus and prefrontal cortex in CORT-treated mice. Treatment of mice with EESC (600mg/kg) significantly ameliorated all the behavioral and biochemical changes induced by corticosterone. Moreover, pharmacological inhibition of BDNF signaling by K252a abolished entirely the antidepressant-like effect triggered by chronic EESC treatment. These results suggest that EESC produces an antidepressant-like effect in CORT-induced depression in mice, which is possibly mediated, at least in part, by rectifying the stress-based hypothalamic-pituitary-adrenal (HPA) axis dysfunction paradigm and upregulation of BDNF/TrkB/CREB signaling pathway. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  20. Validation of the long-term assessment of hypothalamic-pituitary-adrenal activity in rats using hair corticosterone as a biomarker.

    Science.gov (United States)

    Scorrano, Fabrizio; Carrasco, Javier; Pastor-Ciurana, Jordi; Belda, Xavier; Rami-Bastante, Alicia; Bacci, Maria Laura; Armario, Antonio

    2015-03-01

    The evaluation of chronic activity of the hypothalamic-pituitary-adrenal (HPA) axis is critical for determining the impact of chronic stressful situations. However, current methods have important limitations. The potential use of hair glucocorticoids as a noninvasive retrospective biomarker of long-term HPA activity is gaining acceptance in humans and wild animals. However, there is no study examining hair corticosterone (HC) in laboratory animals. The present study validates a method for measuring HC in rats and demonstrates that it properly reflects chronic HPA activity. The HC concentration was similar in male and female rats, despite higher total plasma corticosterone levels in females, tentatively suggesting that it reflects free rather than total plasma corticosterone. Exposure of male rats to 2 different chronic stress protocols (chronic immobilization and chronic unpredictable stress) resulted in similarly higher HC levels compared to controls (1.8-fold). HC also increased after a mild chronic stressor (30 min daily restraint). Chronic administration of 2 different doses of a long-acting ACTH preparation dramatically increased HC (3.1- and 21.5-fold, respectively), demonstrating that a ceiling effect in HC accumulation is unlikely under other more natural conditions. Finally, adrenalectomy significantly reduced HC. In conclusion, HC measurement in rats appears appropriate to evaluate integrated chronic changes in circulating corticosterone. © FASEB.

  1. Regulation of breeding behavior: do energy-demanding periods induce a change in prolactin or corticosterone baseline levels in the common tern (Sterna hirundo)?

    Science.gov (United States)

    Riechert, Juliane; Chastel, Olivier; Becker, Peter H

    2014-01-01

    Hormones are involved in reproductive decisions, linking environmental cues and body condition and adapting behavior. Mass loss is often accompanied by decreased prolactin and increased corticosterone concentrations, influencing incubation and brooding behavior and ultimately triggering nest desertion. Using blood-sucking bugs (Dipetalogaster maxima), we measured baseline prolactin, corticosterone, and ketone body values in incubating common terns (Sterna hirundo) between 2006 and 2009 during energy-demanding periods: 50 pairs were sampled hungry (after an incubation bout) and again fed (after foraging). In a second approach, we sampled 57 other pairs (experienced and inexperienced birds) three times over their individual breeding period, because reproduction, especially chick rearing, is a very energy-demanding process. In line with the common physiological pattern of fasting, we found significantly lower baseline prolactin values in hungry terns, which were negatively related to mass loss over the incubation bout, whereas corticosterone and ketone body levels were marginally increased. Compared to that in the incubation phase, the prolactin level dropped after hatching of chicks in inexperienced birds, perhaps indicating lower parental expenditure. Corticosterone, on the other hand, increased after hatching in males, probably linked to higher foraging activity, as males mainly deliver food during the first days. These energy-demanding periods clearly influenced hormones and ketone bodies, maybe reinforced by the low energy margin of this small seabird species, but energy reserves were not depleted to a level affecting behavior or reproductive success.

  2. Baseline corticosterone peaks in shorebirds with maximal energy stores for migration : A general preparatory mechanism for rapid behavioral and metabolic transitions?

    NARCIS (Netherlands)

    Piersma, T; Reneerkens, J; Ramenofsky, M

    2000-01-01

    In captive red knots (Calidris canutus, Scolopacidae) showing a regulated body mass increase of 50% related to their migration from temperate staging sites to tundra:breeding grounds, plasma corticosterone concentrations increased from less than 10 ng.ml(-1) to levels as high-as 30 ng.ml(-1) when

  3. Effects of parasitic infection and reproduction on corticosterone plasma levels in Galápagos land iguanas, Conolophus marthae and C. subcristatus.

    Science.gov (United States)

    Onorati, Michela; Sancesario, Giulia; Pastore, Donatella; Bernardini, Sergio; Cruz, Marilyn; Carrión, Jorge E; Carosi, Monica; Vignoli, Leonardo; Lauro, Davide; Gentile, Gabriele

    2017-08-01

    In vertebrates, one main feature of stress response is the release of glucocorticoids (corticosterone in reptiles), steroid hormones whose synthesis is regulated by the hypothalamic-pituitary-adrenal axis (HPA). In the Galápagos Islands, populations of land iguanas are differentially impacted by a tick-transmitted apicomplexan hemoparasite of genus Hepatozoon , which could cause diseases and ultimately reduce fitness. Using competitive enzyme-linked immunosorbent assays (ELISA), we examined baseline plasma corticosterone levels of two syntopic and highly parasitized populations of the land iguana species Conolophus marthae and C. subcristatus in Wolf volcano (Isabela Island). We also used a poorly parasitized population of C. subcristatus from the same island (Bahia Urbina) as a reference. To better interpret the observed glucocorticoids patterns, we simultaneously performed the count of white blood cells (WBCs) in all individuals and investigated the reproductive status of females. We did not find evidence in support of either a positive or negative relationship between the tick load, hemoparasite infection, and glucocorticoid plasma concentration in C. marthae and C. subcristatus at Wolf volcano. The comparison between parasitized and non-parasitized sites (V. Wolf and Bahia Urbina) would instead suggest an inverse relationship between corticosterone and parasites. Our findings support association between corticosterone plasma levels and reproduction.

  4. Sex and migratory strategy influence corticosterone levels in winter-grown feathers, with positive breeding effects in a migratory pelagic seabird.

    Science.gov (United States)

    Pérez, Cristóbal; Granadeiro, José Pedro; Dias, Maria P; Catry, Paulo

    2016-08-01

    To overcome unpredictable stressful transitory events, animals trigger an allostatic response involving the hypothalamic-pituitary-adrenal cortex. This hormonal response, which involves the release of glucocorticoids which in turn mediate between the main physiological mechanisms that regulate the energetic demands and resource allocation trade-off with behavioural responses to environmental perturbations and may ultimately lead to variation in fitness. We have used the Cory's shearwater Calonectris borealis, a sexually dimorphic pelagic seabird with a partial migratory strategy, as a model bird species to analyse a number of traits related to the stress response. We investigated whether the activation of a stressful response, mediated by corticosterone, during the wintering period (1) correlated with the previous breeding success, (2) was affected by the migratory behaviour of male birds and (3) had consequences in the fitness of the birds. Corticosterone levels in feathers grown overwinter were analysed in 61 adult birds during three consecutive migratory periods (2009-2012) and in 14 immature birds in the wintering period 2010-2011. Moreover, the levels of corticosterone were analysed in experimental birds which were freed from their reproductive duties and compared with control birds which raised fledglings to the end of the breeding period. The results show that the levels of corticosterone were sex dependent, differed between years and were affected by the migratory strategy performed by the birds. The activation of the stressful response over the wintering period generated residual carry-over effects that positively affected the reproductive output in the subsequent breeding stage, a phenomenon previously undescribed in a long-lived pelagic seabird. Our study provides evidence that the analysis of corticosterone from feathers is a useful tool to evaluate carry-over effects in birds far away from breeding sites, opening new possibilities for future studies in

  5. 125I-iomazenil - benzodiazepine receptor binding and serum corticosterone level during psychological stress in a rat model

    International Nuclear Information System (INIS)

    Fukumitsu, Nobuyoshi; Ogi, Shigeyuki; Uchiyama, Mayuki; Mori, Yutaka

    2004-01-01

    To test the hypothesis that benzodiazepine receptor density decreases in response to stress, we correlated 125 I-iomazenil ( 125 I-IMZ) binding with serum corticosterone levels in a rat model. Wistar male rats were divided into four groups; control group (CON, 10 rats), no physical or psychological stress; and one-, three-, and five-day stress groups of 12 rats each (1-DAY, 3-DAY, and 5-DAY, respectively), receiving psychological stress for the given number of days. Psychological stress were given to rats with a communication box. The standardized uptake value (SUV) of 125 I-iomazenil of the 3-DAY and 5-DAY showed that 125 I-iomazenil - benzodiazepine receptor binding was significantly reduced in the cortices, accumbens nuclei, amygdala and caudate putamen (p 125 I-IMZ is a useful radioligand to reflect received stress and its binding in the cortices, accumbens nuclei, amygdala and caudate putamen is strongly affected by psychological stress

  6. Functional characterization of neotropical snakes peripheral blood leukocytes subsets: Linking flow cytometry cell features, microscopy images and serum corticosterone levels.

    Science.gov (United States)

    de Carvalho, Marcelo Pires Nogueira; Queiroz-Hazarbassanov, Nicolle Gilda Teixeira; de Oliveira Massoco, Cristina; Sant'Anna, Sávio Stefanini; Lourenço, Mariana Mathias; Levin, Gabriel; Sogayar, Mari Cleide; Grego, Kathleen Fernandes; Catão-Dias, José Luiz

    2017-09-01

    Reptiles are the unique ectothermic amniotes, providing the key link between ectothermic anamniotes fish and amphibians, and endothermic birds and mammals; becoming an important group to study with the aim of providing significant knowledge into the evolutionary history of vertebrate immunity. Classification systems for reptiles' leukocytes have been described by their appearance rather than function, being still inconsistent. With the advent of modern techniques and the establishment of analytical protocols for snakes' blood by flow cytometry, we bring a qualitative and quantitative assessment of innate activities presented by snakes' peripheral blood leukocytes, thereby linking flow cytometric features with fluorescent and light microscopy images. Moreover, since corticosterone is an important immunomodulator in reptiles, hormone levels of all blood samples were measured. We provide novel and additional information which should contribute to better understanding of the development of the immune system of reptiles and vertebrates. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Benzodiazepine effect of 125I-iomazenil-benzodiazepine receptor binding and serum corticosterone level in a rat model

    International Nuclear Information System (INIS)

    Fukumitsu, Nobuyoshi; Ogi, Shigeyuki; Uchiyama, Mayuki; Mori, Yutaka

    2005-01-01

    To test the change in free or unoccupied benzodiazepine receptor (BZR) density in response to diazepam, we investigated 125 I-iomazenil ( 125 I-IMZ) binding and serum corticosterone levels in a rat model. Wistar male rats, which received psychological stress using a communication box for 5 days, were divided into two groups according to the amount of administered diazepam: no diazepam [D (0)] group and 10 mg/kg per day [D (10)] group of 12 rats each. The standardized uptake value (SUV) of 125 I-IMZ of the D (10) group were significantly lower (P 125 I-IMZ, it is clear that diazepam competed with endogenous ligand for the free BZR sites, and the frontal, parietal and temporal cortices, globus pallidus, hippocampus, amygdala and hypothalamus are important areas in which 125 I-IMZ binding is strongly affected by administration of diazepam

  8. Local Content

    CSIR Research Space (South Africa)

    Gibberd, Jeremy

    2016-10-01

    Full Text Available Local content refers to materials and products made in a country as opposed those that are imported. There is an increasing interest in the concept of local content as a means of supporting local economies and providing jobs (Belderbos & Sleuwaegen...

  9. Skuldertesten "Kombineret Elevation"

    DEFF Research Database (Denmark)

    Clausen, Mikkel Bek; Overkær, Brian

    2010-01-01

    Formål: At udarbejde en testprotokol for testen Kombineret Elevation (KE) og undersøge test-retest variationen ved test af elite svømmere, samt diskutere testens relevans og validitet. Materiale og Metode: 9 elite og 10 sub-elite svømmere, heraf var 11 mænd og 8 kvinder, gennemførte testen KE 2...

  10. Plants with elevated levels of glucan

    Energy Technology Data Exchange (ETDEWEB)

    Pauly, Markus; Kraemer, Florian J.; Hake, Sarah

    2018-03-20

    The present disclosure relates to mutations in licheninase genes encoding polypeptides with decreased licheninase activity, which when expressed in plants results in elevated levels of glucan in the plants. In particular, the disclosure relates to licheninase nucleic acids and polypeptides related to glucan accumulation in plants, plants with reduced expression of a licheninase nucleic acid, and methods related to the generation of plants with increased glucan content in the cell walls of leaf tissue.

  11. Influence of postnatal glucocorticoids on hippocampal-dependent learning varies with elevation patterns and administration methods.

    Science.gov (United States)

    Claflin, Dragana I; Schmidt, Kevin D; Vallandingham, Zachary D; Kraszpulski, Michal; Hennessy, Michael B

    2017-09-01

    Recent interest in the lasting effects of early-life stress has expanded to include effects on cognitive performance. An increase in circulating glucocorticoids is induced by stress exposure and glucocorticoid effects on the hippocampus likely underlie many of the cognitive consequences. Here we review studies showing that corticosterone administered to young rats at the conclusion of the stress-hyporesponsiveness period affects later performance in hippocampally-mediated trace eyeblink conditioning. The nature and even direction of these effects varies with the elevation patterns (level, duration, temporal fluctuation) achieved by different administration methods. We present new time course data indicating that constant glucocorticoid elevations generally corresponded with hippocampus-mediated learning deficits, whereas acute, cyclical elevations corresponded with improved initial acquisition. Sensitivity was greater for males than for females. Further, changes in hippocampal neurogenesis paralleled some but not all effects. The findings demonstrate that specific patterns of glucocorticoid elevation produced by different drug administration procedures can have markedly different, sex-specific consequences on basic cognitive performance and underlying hippocampal physiology. Implications of these findings for glucocorticoid medications prescribed in childhood are discussed. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Adrenergic blockade does not abolish elevated glucose turnover during bacterial infection

    International Nuclear Information System (INIS)

    Hargrove, D.M.; Bagby, G.J.; Lang, C.H.; Spitzer, J.J.

    1988-01-01

    Infusions of adrenergic antagonists were used to investigate the role of catecholamines in infection-induced elevations of glucose kinetics. Infection was produced in conscious catheterized rats by repeated subcutaneous injections of live Escherichia coli over 24 h. Glucose kinetics were measured by the constant intravenous infusion of [6- 3 H]- and [U- 14 C]glucose. Compared with noninfected rats, infected animals were hyperthermic and showed increased rates of glucose appearance, clearance, and recycling as well as mild hyperlacticacidemia. Plasma catecholamine concentrations were increased by 50-70% in the infected rats, but there were no differences in plasma glucagon, corticosterone, and insulin levels. Adrenergic blockade was produced by primed constant infusion of both propranolol (β-blocker) and phentolamine (α-blocker). A 2-h administration of adrenergic antagonists did not attenuate the elevated glucose kinetics or plasma lactate concentration in the infected rats, although it abolished the hyperthermia. In a second experiment, animals were infused with propranolol and phentolamine beginning 1 h before the first injection of E. coli and throughout the course of infection. Continuous adrenergic blockade failed to attenuate infection-induced elevations in glucose kinetics and plasma lactate. These results indicate that the adrenergic system does not mediate the elevated glucose metabolism observed in this mild model of infection

  13. A spider elevator

    Energy Technology Data Exchange (ETDEWEB)

    Butylkin, A.V.; Butylkin, V.A.; Izosimov, A.M.

    1983-01-01

    A spider elevator is proposed which contains a body, a wedge clamp with wedges hinged to each other, a subassembly for holding the wedge clamp in the open and closed positions and a mechanism for changing the wedge clamp, which is made in the form of levers with ears for cleats and installed in the body with the capability of turning. To increase reliability in the operational mode through using the external force for clamping the pipe, the free ends of the levers are hinged with the body by a power cylinder.

  14. Elevator Control Strategies

    OpenAIRE

    Ceder, Frederick; Nordin, Alexandra

    2013-01-01

    The purpose of this essay is to investigate if it is eective to switch strategies for elevators during one day in an oce building. This essay describes some of the strategies in use today, followed by a comparison and analysis of two of the strategies described. We have also implemented optimizations to one of these strategies. From our test results we can conclude that our optimized strategy worked and produced better results on average waiting time and total traveling time than the two stra...

  15. Automatic pipe elevator

    Energy Technology Data Exchange (ETDEWEB)

    Haney, K.M.; Willis, C.A.

    1987-03-17

    This patent describes an elevator adapted for use with a power swivel for supporting a drilling or production tubular, the elevator comprising: at least two jaws, each jaw having a clamping surface; a connector member for supporting the jaws, the connector member comprising an upper end, a lower end, means for coupling the upper end to the power swivel, means for coupling the lower end to a tubular. The member also comprises means for defining a passageway extending from the upper end to the lower end through the connector member to allow drilling mud to be passed from the power swivel through the bore, into the tubular; and linkage means mounted between the connector member and the jaws for coupling the jaws to the connector member and for maintaining the clamping surfaces of the jaws in clamping engagement with the tubular when the connector member and the tubular are urged apart relative to one another. The linkage means is configured such that the force by which the clamping surfaces clamp the tubular increases as the force urging the connector member and the tubular apart increases.

  16. Elevation data for floodplain mapping

    National Research Council Canada - National Science Library

    Committee on Floodplain Mapping Technologies; National Research Council; Division on Earth and Life Studies; National Research Council

    2007-01-01

    .... Elevation Data for Floodplain Mapping shows that there is sufficient two-dimensional base map imagery to meet FEMA's flood map modernization goals, but that the three-dimensional base elevation data...

  17. An association between feather damaging behavior and corticosterone metabolite excretion in captive African grey parrots (Psittacus erithacus

    Directory of Open Access Journals (Sweden)

    Pierluca Costa

    2016-09-01

    Full Text Available Background African grey parrots (Psittacus erithacus are kept as pets and are frequently hand-reared. It has been observed that hand-reared African grey parrots may develop behavioral disorders such as feather damaging behavior (FDB. It is well known that chronic stress is involved in behavioral disorders in captive parrots. The main glucocorticoid in birds is corticosterone; its quantification provides information about adrenocortical activity and is considered to be a reliable indicator of stress levels in birds. We analyzed the differences in the excretion of corticosterone metabolites (CM in the droppings of African grey parrots characterized by: 1. different rearing histories (parent rearing vs. hand rearing; and 2. the presence or absence of FDB in hand-reared parrots. Methods A total of 82 African grey parrots that were kept in captivity were considered. According to breeding methods, three groups of birds were defined: 1. The parent-reared (PR parrots included birds kept in pairs (n = 30 pairs with a conspecific partner of the opposite sex. All of these birds were healthy and never showed FDB signs; 2. The healthy hand-reared parrots (H-HR included pet parrots individually kept, that were hand-reared and did not display any sign of FDB (n = 11, 7 males and 4 females; 3. The FDB hand-reared parrot (FDB-HR included pet parrots individually kept, that were hand-reared and displayed FDB (n = 11, 7 males and 4 females. Droppings were collected in the morning over three alternating days in autumn 2014 and spring 2015. The CM were determined using a multi-species corticosterone enzyme immunoassay kit. Split-plot repeated-measure ANOVA was used to examine any differences using group, season and group × season as the main factors. Results Different quantities of CM in droppings were found for the three groups. The mean CM value was 587 ng/g in the PR parrots, 494 ng/g in the H-HR parrots and 1,744 ng/g in the FDB-HR parrots, irrespective of the

  18. Sex-specific differences in corticosterone secretion, behavioral phenotypes and expression of TrkB.T1 and TrkB.FL receptor isoforms: Impact of systemic TrkB inhibition and combinatory stress exposure in adolescence.

    Science.gov (United States)

    Azogu, Idu; Liang, Jacky; Plamondon, Helene

    2018-05-09

    Stress exposure has been implicated in the development of mood disorders, although little is known about the lasting effects of repeated stress during the adolescent period on sex-specific differences in endocrine and plasticity-signaling responses in adulthood. Using a 10-day combinatory stress paradigm (postnatal day (PND) 26 to 35), we examined sex-specific impact of adolescent stress and inhibition of tyrosine-related kinase B (TrkB) receptor (ANA-12; 0.5 mg/kg, i.p.) on 1) adolescent blood corticosterone levels, 2) adult locomotion and anxiety-like behavior, and 3) region-specific differences in endogenous TrkB full-length (TrkB.FL) and truncated (TrkB.T1) receptor isoforms. Blood collected on days 1, 5 and 10 revealed elevated basal and stress-induced CORT secretion in females compared to males, while ANA-12 attenuated CORT elevations post stress in both sexes. As adults, all females exhibited higher locomotor and exploratory activity than males in the open field test and elevated plus maze, and differences were comparable in the forced swim within stress-naïve and stress groups. Biochemically, vehicle-treated males showed elevated TrkB.T1 and TrkB.FL compared to vehicle-treated females in the PFC, hippocampus and NAc, and levels were consistently attenuated by ANA-12 treatment in non-stress males. With regards to stress exposure, expression of both isoforms was strongly down-regulated in the NAc of males only and was associated with increased TrkB.T1 in the PFC. ANA-12 enhanced expression in females, independent of stress exposure, compared to vehicle-treated counterparts, expression being increased for TrkB.T1 versus TrkB.FL and magnitude of the changes being region-specific. In contrast, ANA-12 effects in stressed males were restricted to inhibition of both isoforms in the hippocampus. Together, our findings support that TrkB activation, contingent on stress exposure, differentially affects TrkB isoform regulation during adulthood. Sex

  19. Fear memory for cue and context: opposite and time-dependent effects of a physiological dose of corticosterone in male BALB/c and C57BL/6J mice.

    Science.gov (United States)

    Diamantopoulou, Anastasia; Oitzl, Melly S; Grauer, Ettie

    2012-07-23

    Highly emotional, stress reactive BALB/c mice secrete more corticosterone in response to fear conditioning than the low stress reactive C57BL/6J mice. Fear memory to cue and context differs between the strains. We injected corticosterone at physiological concentrations (250 μg/kg i.p.) 30 min before fear conditioning. Fear memory was tested 48 and 72 h later. Although corticosterone had little effect on acquisition, it differentially affected fear memories in strain dependent manner: while BALB/c mice decreased freezing during cue and context episodes, C57BL/6J mice showed an overall increase in freezing. BALB/c mice showed extinction over days while no such extinction was seen in C57BL/6J mice. Evaluation of these data in the perspective of previous studies using the same fear conditioning paradigm with corticosterone injections 5 min before or immediately after acquisition, revealed the impact of corticosterone during conditioning on the strength of fear memories. In C57BL/6J mice the overall increase in fear memories was higher if corticosterone was injected 30 min pre acquisition than if injected 5 min pre. In contrast, BALB/c mice showed reduced fear memories when injected 30 min pre compared to that seen 5 min pre acquisition. Both strains showed decreased fear memories compared to vehicle if corticosterone was administered immediately after acquisition. We conclude that the timing of physiologically relevant, stress levels increase in corticosterone is essential for the processing of aversive events and the formation of fear memories. However, the quality of the effect depends on the genetic background. These findings contribute to the understanding of the etiology of stress-related disorders. Copyright © 2012 Elsevier B.V. All rights reserved.

  20. Chronic restraint stress in rats causes sustained increase in urinary corticosterone excretion without affecting cerebral or systemic oxidatively generated DNA/RNA damage

    DEFF Research Database (Denmark)

    Jorgensen, Anders; Maigaard, Katrine; Wörtwein, Gitta

    2013-01-01

    acids, 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) and 8-oxo-7,8-dihydroguanosine (8-oxoGuo), respectively, in rats subjected to chronic restraint stress. To reliably collect 24h urine samples, the full 3-week restraint stress paradigm was performed in metabolism cages. We further determined frontal...... and Tnf). The metabolism cage housing in itself did not significantly influence a range of biological stress markers. In the restraint stress group, there was a sustained 2.5 fold increase in 24h corticosterone excretion from day 2 after stress initiation. However, neither whole-body nor cerebral measures......Increased oxidatively generated damage to nucleic acids (DNA/RNA) may be a common mechanism underlying accelerated aging in psychological stress states and mental disorders. In the present study, we measured the urinary excretion of corticosterone and markers of systemic oxidative stress on nucleic...

  1. An elevator wheel

    Energy Technology Data Exchange (ETDEWEB)

    Zhornik, V.I.; Cherkov, Ye.M.; Simonov, A.A.

    1982-01-01

    This invention deals with mineral enrichment and is primarily for unloading submerged products of enrichment during separation in heavy mediums. An elevator wheel is proposed for unloading the submerged product from the bath of a heavy to medium separator which includes ladle disks with internal walls and overlapping sheets hinged to the ends. In order to increase the degree of dehydration of the unloaded product, the internal wall of each ladle is made of sheets installed in stages with clearances relative to each other. The advantages of the proposed device include an improvement in the degree of dehydration of the submerged product in the ladles and a reduction in the carry away of the heavy medium with the enrichment products.

  2. Effects of co-administration of fluoxetine or tianeptine with metyrapone on immobility time and plasma corticosterone concentration in rats subjected to the forced swim test.

    Science.gov (United States)

    Rogóz, Zofia; Skuza, Grazyna; Leśkiewicz, Monika; Budziszewska, Bogusława

    2008-01-01

    Major depression is frequently associated with hyperactivity of the hypothalamic-pituitary-adrenocortical axis, and glucocorticoid synthesis inhibitors have been shown to exert antidepressant action. The aim of the present study was to examine the effect of co-administration of fluoxetine or tianeptine with metyrapone on immobility time and plasma corticosterone concentration in male Wistar rats subjected to the forced swim test. Metyrapone alone (50 mg/kg, but not 25 mg/kg) reduced the immobility time of rats in the forced swim test; moreover, both doses tested (25 and 50 mg/kg), dose-dependently decreased the stress-induced plasma corticosterone concentration. Joint administration of fluoxetine or tianeptine (10 mg/kg) and metyrapone (25 mg/kg - a dose inactive per se) exhibited antidepressant-like activity in the forced swim test in rats. WAY 100636 (a 5-HT(1A) antagonist), but not prazosin (an alpha(1)-adrenergic antagonist), used in doses ineffective in the forced swim test, inhibited the antidepressant-like effect induced by co-administration of fluoxetine or tianeptine with metyrapone (25 mg/kg). Combined treatment of fluoxetine or tianeptine and metyrapone inhibited stress-induced corticosterone secretion to a similar extent as metyrapone alone. The obtained results indicate that metyrapone potentiates the antidepressant-like activity of fluoxetine or tianeptine and that, among other mechanisms, 5-HT(1A) receptors may play some role in this effect. Moreover, metyrapone exerts a beneficial effect on the stress-induced increase in plasma corticosterone concentration. These findings suggest that the co-administration of metyrapone and an antidepressant drug may be useful for the treatment of drug-resistant depression and/or depression associated with a high cortisol level.

  3. Effects of methamphetamine exposure on anxiety-like behavior in the open field test, corticosterone, and hippocampal tyrosine hydroxylase in adolescent and adult mice.

    Science.gov (United States)

    Struntz, Katelyn H; Siegel, Jessica A

    2018-08-01

    Methamphetamine (MA) is a psychomotor stimulant drug that can alter behavior, the stress response system, and the dopaminergic system. The effects of MA can be modulated by age, however relatively little research has examined the acute effects of MA in adolescents and how the effects compare to those found in adults. The hippocampal dopamine system is altered by MA exposure and can modulate anxiety-like behavior, but the effects of MA on the hippocampal dopamine system have not been well studied, especially in adolescent animals. In order to assess potential age differences in the effects of MA exposure, this research examined the effects of acute MA exposure on locomotor and anxiety-like behavior in the open field test, plasma corticosterone levels, and hippocampal total tyrosine hydroxylase and phosphorylated tyrosine hydroxylase levels in adolescent and adult male C57BL/6 J mice. Tyrosine hydroxylase is the rate limiting enzyme in the synthesis of dopamine and was used as a marker of the hippocampal dopaminergic system. Mice were exposed to saline or 4 mg/kg MA and locomotor and anxiety-like behavior were measured in the open field test. Serum and brains were collected immediately after testing and plasma corticosterone and hippocampal total tyrosine hydroxylase and phosphorylated tyrosine hydroxylase levels measured. MA-exposed mice showed increased locomotor activity and anxiety-like behavior in the open field test compared with saline controls, regardless of age. There was no effect of MA on plasma corticosterone levels or hippocampal total tyrosine hydroxylase or phosphorylated tyrosine hydroxylase levels in either adolescent or adult mice. These data suggest that acute MA exposure during adolescence and adulthood increases locomotor activity and anxiety-like behavior but does not alter plasma corticosterone levels or hippocampal total tyrosine hydroxylase or phosphorylated tyrosine hydroxylase levels, and that these effects are not modulated by age

  4. The effects of prolonged exposure to elevated temperatures and elevated CO2 levels on the growth, yield and dry matter partitioning of field-sown meadow fescue

    Directory of Open Access Journals (Sweden)

    Kaija Hakala

    1996-05-01

    Full Text Available Field-sown meadow fescue (Festuca pratensis, cv. Kalevi stands were exposed to elevated temperatures (+3°C and elevated CO2, (700 ppm levels in two experiments conducted in 1992-1993 (experiment 1 and in 1994-1995 (experiment 2. Total aboveground yield was, on average, 38% higher at elevated than at ambient temperatures. At ambient temperatures elevated CO2 increased the number of tillers by 63% in 1992, 24% in 1993, 90% in 1994 and 14% in 1995. At elevated temperatures, the increase in tiller number in elevated CO2 was seen only in the first growing seasons after sowing. The total yield in a growing season was about 10% higher in elevated CO2 in experiment 1. In experiment 2 the yield was more than 20% higher in elevated CO2 at elevated temperatures, whereas at ambient temperatures the rise in CO2 level had no effect on the yield; the root biomass, however, increased by more than 30%. In elevated CO2 at ambient temperatures the root biomass also increased in experiment I, but at elevated temperatures there was no consistent change. The soluble carbohydrate content of above-ground biomass was 5-48% higher in elevated CO2 at most of the measuring times during the growing season, but the nitrogen content did not show a clear decrease. The reasons for the lack of a marked increase in biomass in elevated CO2 despite a 40-60% increase in photosynthesis are discussed.

  5. Social instigation and repeated aggressive confrontations in male Swiss mice: analysis of plasma corticosterone, CRF and BDNF levels in limbic brain areas

    Directory of Open Access Journals (Sweden)

    Paula Madeira Fortes

    2017-06-01

    Full Text Available Abstract Introduction: Agonistic behaviors help to ensure survival, provide advantage in competition, and communicate social status. The resident-intruder paradigm, an animal model based on male intraspecific confrontations, can be an ethologically relevant tool to investigate the neurobiology of aggressive behavior. Objectives: To examine behavioral and neurobiological mechanisms of aggressive behavior in male Swiss mice exposed to repeated confrontations in the resident intruder paradigm. Methods: Behavioral analysis was performed in association with measurements of plasma corticosterone of mice repeatedly exposed to a potential rival nearby, but inaccessible (social instigation, or to 10 sessions of social instigation followed by direct aggressive encounters. Moreover, corticotropin-releasing factor (CRF and brain-derived neurotrophic factor (BNDF were measured in the brain of these animals. Control mice were exposed to neither social instigation nor aggressive confrontations. Results: Mice exposed to aggressive confrontations exhibited a similar pattern of species-typical aggressive and non-aggressive behaviors on the first and the last session. Moreover, in contrast to social instigation only, repeated aggressive confrontations promoted an increase in plasma corticosterone. After 10 aggressive confrontation sessions, mice presented a non-significant trend toward reducing hippocampal levels of CRF, which inversely correlated with plasma corticosterone levels. Conversely, repeated sessions of social instigation or aggressive confrontation did not alter BDNF concentrations at the prefrontal cortex and hippocampus. Conclusion: Exposure to repeated episodes of aggressive encounters did not promote habituation over time. Additionally, CRF seems to be involved in physiological responses to social stressors.

  6. Cysteamine attenuates the decreases in TrkB protein levels and the anxiety/depression-like behaviors in mice induced by corticosterone treatment.

    Directory of Open Access Journals (Sweden)

    Ammar Kutiyanawalla

    Full Text Available OBJECTIVE: Stress and glucocorticoid hormones, which are released into the circulation following stressful experiences, have been shown to contribute significantly to the manifestation of anxiety-like behaviors observed in many neuropsychiatric disorders. Brain-derived neurotrophic factor (BDNF signaling through its receptor TrkB plays an important role in stress-mediated changes in structural as well as functional neuroplasticity. Studies designed to elucidate the mechanisms whereby TrkB signaling is regulated in chronic stress might provide valuable information for the development of new therapeutic strategies for several stress-related psychiatric disorders. MATERIALS AND METHODS: We examined the potential of cysteamine, a neuroprotective compound to attenuate anxiety and depression like behaviors in a mouse model of anxiety/depression induced by chronic corticosterone exposure. RESULTS: Cysteamine administration (150 mg/kg/day, through drinking water for 21 days significantly ameliorated chronic corticosterone-induced decreases in TrkB protein levels in frontal cortex and hippocampus. Furthermore, cysteamine treatment reversed the anxiety and depression like behavioral abnormalities induced by chronic corticosterone treatment. Finally, mice deficient in TrkB, showed a reduced response to cysteamine in behavioral tests, suggesting that TrkB signaling plays an important role in the antidepressant effects of cysteamine. CONCLUSIONS: The animal studies described here highlight the potential use of cysteamine as a novel therapeutic strategy for glucocorticoid-related symptoms of psychiatric disorders.

  7. Chronic Stress Induces Structural Alterations in Splenic Lymphoid Tissue That Are Associated with Changes in Corticosterone Levels in Wistar-Kyoto Rats

    Directory of Open Access Journals (Sweden)

    María Eugenia Hernandez

    2013-01-01

    Full Text Available Major depressive disorder patients present chronic stress and decreased immunity. The Wistar-Kyoto rat (WKY is a strain in which the hypothalamic-pituitary-adrenal axis is overactivated. To determine whether chronic stress induces changes in corticosterone levels and splenic lymphoid tissue, 9-week-old male rats were subject to restraint stress (3 h daily, chemical stress (hydrocortisone treatment, 50 mg/Kg weight, mixed stress (restraint plus hydrocortisone, or control treatment (without stress for 1, 4, and 7 weeks. The serum corticosterone levels by RIA and spleens morphology were analyzed. Corticosterone levels as did the structure, size of the follicles and morphology of the parenchyma (increase in red pulp in the spleen, varied depending on time and type of stressor. These changes indicate that chronic stress alters the immune response in the spleen in WKY rats by inducing morphological changes, explaining in part the impaired immunity that develops in organisms that are exposed to chronic stress.

  8. Levels of central oxytocin and glucocorticoid receptor and serum adrenocorticotropic hormone and corticosterone in mandarin voles with different levels of sociability.

    Science.gov (United States)

    Qiao, Xufeng; Yan, Yating; Tai, Fadao; Wu, Ruiyong; Hao, Ping; Fang, Qianqian; Zhang, Shuwei

    2014-11-01

    Sociability is the prerequisite to social living. Oxytocin and the hypothalamo-pituitary-adrenocortical axis mediate various social behaviors across different social contexts in different rodents. We hypothesized that they also mediate levels of non-reproductive social behavior. Here we explored naturally occurring variation in sociability through a social preference test and compared central oxytocin, glucocorticoid receptors, serum adrenocorticotropic hormone and corticosterone in mandarin voles with different levels of sociability. We found that low-social voles showed higher levels of anxiety-like behavior in open field tests, and had more serum adrenocorticotropic hormone and corticosterone than high-social voles. High-social individuals had more glucocorticoid receptor positive neurons in the hippocampus and more oxytocin positive neurons in the paraventricular nuclei and supraoptic nuclei of the hypothalamus than low-social individuals. Within the same level of sociability, females had more oxytocin positive neurons in the paraventricular nuclei and supraoptic nuclei of the hypothalamus than males. These results indicate that naturally occurring social preferences are associated with higher levels of central oxytocin and hippocampus glucocorticoid receptor and lower levels of anxiety and serum adrenocorticotropic hormone and corticosterone. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Variation in immune function, body condition, and feather corticosterone in nestling Tree Swallows (Tachycineta bicolor) on reclaimed wetlands in the Athabasca oil sands, Alberta, Canada

    International Nuclear Information System (INIS)

    Jane Harms, N.; Fairhurst, Graham D.; Bortolotti, Gary R.; Smits, Judit E.G.

    2010-01-01

    In the Athabasca oil sands region of northern Alberta, mining companies are evaluating reclamation using constructed wetlands for integration of tailings. From May to July 2008, reproductive performance of 40 breeding pairs of tree swallows (Tachycineta bicolor), plus growth and survival of nestlings, was measured on three reclaimed wetlands on two oil sands leases. A subset of nestlings was examined for i) feather corticosterone levels, ii) delayed-type hypersensitivity response, and iii) innate immune function. Nestlings on one of two wetlands created with oil sands process affected material (OSPM) were heavier and had greater wing-lengths, and mounted a stronger delayed-type hypersensitivity response compared those on the reference wetland. Corticosterone was significantly higher in male nestlings on one of two OSPM-containing wetland compared to the reference wetland. Body condition of 12-day-old female nestlings was inversely related to feather corticosterone. Under ideal weather conditions, reclaimed wetlands can support healthy populations of aerially-insectivorous birds. - Under ideal weather conditions, tree swallow nestlings on reclaimed OSPM-affected wetlands are in good body condition and mount strong cell-mediated immune responses.

  10. Effect of tidal cycle and food intake on the baseline plasma corticosterone rhythm in intertidally foraging marine iguanas.

    Science.gov (United States)

    Woodley, Sarah K; Painter, Danika L; Moore, Michael C; Wikelski, Martin; Romero, L Michael

    2003-06-15

    In most species, plasma levels of baseline glucocorticoids such as corticosterone (B) have a circadian rhythm. This rhythm can be entrained by both photoperiod and food intake and is related to aspects of energy intake and metabolism. Marine iguanas (Amblyrhynchus cristatus) offer a unique opportunity to better understand the relative importance of the light:dark cycle versus food intake in influencing the rhythm in baseline B in a natural system. Compared to other species, food intake is not as strictly determined by the phase of the light:dark cycle. Animals feed in the intertidal zone so feeding activity is heavily influenced by the tidal cycle. We measured baseline plasma B levels in free-living iguanas over several 24-h periods that varied in the timing of low tide/foraging activity. We found that baseline B levels were higher during the day relative to night. However, when low tide occurred during the day, baseline B levels dropped coincident with the timing of low tide. Whether the baseline B rhythm (including the drop during foraging) is an endogenous rhythm with a circatidal component, or is simply a result of feeding and associated physiological changes needs to be tested. Together, these data suggest that the baseline B rhythm in marine iguanas is influenced by the tidal cycle/food intake as well as the light:dark cycle.

  11. Effects of stress, circadian rhythms, and dietary sodium on brain cell-nuclear uptake of aldosterone and corticosterone

    International Nuclear Information System (INIS)

    Yongue, B.G.

    1985-01-01

    The binding of the adrenal steroid hormones aldosterone (ALD) and corticosterone (CORT) in brain cell-nuclei has been implicated as a necessary step in the behavioral and physiological actions of these hormones. In vivo uptake of radioactively labeled ALD and CORT in adrenalectomized (ADX) rats indicates a strong cell-nuclear localization of both of these hormones in limbic brain regions (such as hippocampus, septum and amygdala). Research using sub-cellular fractionation and radioimmunoassay (RIA), has confirmed both the presence of endogenously secreted CORT in cell-nuclei and its limbic localization in the brains of adrenal-intact rats. In this study, environmental and dietary factors were manipulated to induce variation in serum ALD and CORT. A series of experiments employing sub-cellular fractionation and RIA were performed, which reveal that: (1) endogenously secreted ALD and CORT, are concentrated by cell-nuclei of the brain in adrenal-intact rats, (2) the majority of the corticosteroids measured in ethanol extracts of brain cell-nuclei are associated with receptor molecules, and (3) the regional distribution of endogenously secreted ALD differs markedly from the predominantly limbic pattern predicted from in vivo uptake of labeled ALD in ADX rats. Instead, brain cell-nuclear ALD is heavily concentrated in the hypothalamus, which supports the hypothesized relationship between the interaction of ALD and angiotensin in the brain and the behavioral regulation of fluid/electrolyte balance

  12. Corticosterone rapidly increases thorns of CA3 neurons via synaptic/extranuclear glucocorticoid receptor in rat hippocampus

    Directory of Open Access Journals (Sweden)

    Miyuki eYoshiya

    2013-11-01

    Full Text Available Modulation of synapses under acute stress is attracting much attention. Exposure to acute stress induces corticosterone (CORT secretion from the adrenal cortex, resulting in rapid increase of CORT levels in plasma and the hippocampus. We tried to test whether rapid CORT effects involve activation of essential kinases as non-genomic processes.We demonstrated rapid effects (~ 1 h of CORT on the density of thorns, by imaging Lucifer Yellow-injected neurons in adult male rat hippocampal slices. Thorns of thorny excrescences of CA3 hippocampal neurons are post-synaptic regions whose presynaptic partners are mossy fiber terminals. The application of CORT at 100, 500 and 1000 nM induced a rapid increase in the density of thorns in the stratum lucidum of CA3 pyramidal neurons. Co-administration of RU486, an antagonist of glucocorticoid receptor (GR, abolished the effect of CORT. Blocking a single kinase, including MAPK, PKA or PKC, suppressed CORT-induced enhancement of thorn-genesis. On the other hand, GSK-3β was not involved in the signaling of thorn-genesis. Blocking AMPA receptors suppressed the CORT effect. Expression of CA3 synaptic/extranuclear GR was demonstrated by immunogold electron microscopic analysis. From these results, stress levels of CORT (100-1000 nM might drive the rapid thorn-genesis via synaptic/extranuclear GR and multiple kinase pathways, although a role of nuclear GRs cannot be completely excluded.

  13. Adolescent Corticosterone and TrkB Pharmaco-Manipulations Sex-Dependently Impact Instrumental Reversal Learning Later in Life

    Directory of Open Access Journals (Sweden)

    Elizabeth T. Barfield

    2017-12-01

    Full Text Available Early-life trauma can increase the risk for, and severity of, several psychiatric illnesses. These include drug use disorders, and some correlations appear to be stronger in women. Understanding the long-term consequences of developmental stressor or stress hormone exposure and possible sex differences is critically important. So-called “reversal learning” tasks are commonly used in rodents to model cognitive deficits in stress- and addiction-related illnesses in humans. Here, we exposed mice to the primary stress hormone corticosterone (CORT during early adolescence (postnatal days 31–42, then tested behavioral flexibility in adulthood using an instrumental reversal learning task. CORT-exposed female, but not male, mice developed perseverative errors. Despite resilience to subchronic CORT exposure, males developed reversal performance impairments following exposure to physical stressors. Administration of a putative tyrosine kinase receptor B (trkB agonist, 7,8-dihydroxyflavone (7,8-DHF, during adolescence blocked CORT-induced errors in females and improved performance in males. Conversely, blockade of trkB by ANA-12 impaired performance. These data suggest that trkB-based interventions could have certain protective benefits in the context of early-life stressor exposure. We consider the implications of our findings in an extended “Discussion” section.

  14. Inhibiting corticosterone synthesis during fear memory formation exacerbates cued fear extinction memory deficits within the single prolonged stress model.

    Science.gov (United States)

    Keller, Samantha M; Schreiber, William B; Stanfield, Briana R; Knox, Dayan

    2015-01-01

    Using the single prolonged stress (SPS) animal model of post-traumatic stress disorder (PTSD), previous studies suggest that enhanced glucocorticoid receptor (GR) expression leads to cued fear extinction retention deficits. However, it is unknown how the endogenous ligand of GRs, corticosterone (CORT), may contribute to extinction retention deficits in the SPS model. Given that CORT synthesis during fear learning is critical for fear memory consolidation and SPS enhances GR expression, CORT synthesis during fear memory formation could strengthen fear memory in SPS rats by enhancing GR activation during fear learning. In turn, this could lead to cued fear extinction retention deficits. We tested the hypothesis that CORT synthesis during fear learning leads to cued fear extinction retention deficits in SPS rats by administering the CORT synthesis inhibitor metyrapone to SPS and control rats prior to fear conditioning, and observed the effect this had on extinction memory. Inhibiting CORT synthesis during fear memory formation in control rats tended to decrease cued freezing, though this effect never reached statistical significance. Contrary to our hypothesis, inhibiting CORT synthesis during fear memory formation disrupted extinction retention in SPS rats. This finding suggests that even though SPS exposure leads to cued fear extinction memory deficits, CORT synthesis during fear memory formation enhances extinction retention in SPS rats. This suggests that stress-induced CORT synthesis in previously stressed rats can be beneficial. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Influence of temperature on the corticosterone stress-response: an experiment in the Children's python (Antaresia childreni).

    Science.gov (United States)

    Dupoué, Andréaz; Brischoux, François; Lourdais, Olivier; Angelier, Frédéric

    2013-11-01

    To cope with environmental challenges, organisms have to adjust their behaviours and their physiology to the environmental conditions they face (i.e. allostasis). In vertebrates, such adjustments are often mediated through the secretion of glucocorticoids (GCs) that are well-known to activate and/or inhibit specific physiological and behavioural traits. In ectothermic species, most processes are temperature-dependent and according to previous studies, low external temperatures should be associated with low GC concentrations (both baseline and stress-induced concentrations). In this study, we experimentally tested this hypothesis by investigating the short term influence of temperature on the GC stress response in a squamate reptile, the Children's python (Antaresia childreni). Snakes were maintained in contrasting conditions (warm and cold groups), and their corticosterone (CORT) stress response was measured (baseline and stress-induced CORT concentrations), within 48h of treatment. Contrary to our prediction, baseline and stress-induced CORT concentrations were higher in the cold versus the warm treatment. In addition, we found a strong negative relationship between CORT concentrations (baseline and stress-induced) and temperature within the cold treatment. Although it remains unclear how cold temperatures can mechanistically result in increased CORT concentrations, we suggest that, at suboptimal temperature, high CORT concentrations may help the organism to maintain an alert state. Copyright © 2013 Elsevier Inc. All rights reserved.

  16. Impact of elevated CO2 and elevated O3 on Beta vulgaris L.: Pigments, metabolites, antioxidants, growth and yield

    International Nuclear Information System (INIS)

    Kumari, Sumita; Agrawal, Madhoolika; Tiwari, Supriya

    2013-01-01

    The present study was conducted to assess morphological, biochemical and yield responses of palak (Beta vulgaris L. cv Allgreen) to ambient and elevated levels of CO 2 and O 3 , alone and in combination. As compared to the plants grown in charcoal filtered air (ACO 2 ), growth and yield of the plants increased under elevated CO 2 (ECO 2 ) and decreased under combination of ECO 2 with elevated O 3 (ECO 2 + EO 3 ), ambient O 3 (ACO 2 + AO 3 ) and elevated O 3 (EO 3 ). Lipid peroxidation, ascorbic acid, catalase and glutathione reductase activities enhanced under all treatments and were highest in EO 3. Foliar starch and organic carbon contents increased under ECO 2 and ECO 2 + EO 3 and reduced under EO 3 and ACO 2 + AO 3. Foliar N content declined in all treatments compared to ACO 2 resulting in alteration of C/N ratio. This study concludes that ambient level of CO 2 is not enough to counteract O 3 impact, but elevated CO 2 has potential to counteract the negative effects of future O 3 level. -- Highlights: ► Elevated CO 2 enhanced the growth and yield of palak. ► Ambient and elevated ozone reduced the growth and yield of the test plant. ► Elevated CO 2 reduced negative effects of elevated O 3 by reducing oxidative stress. ► Higher amelioration was recorded at elevated CO 2 + O 3 compared to ambient CO 2 + O 3 . -- Predicted levels of CO 2 have greater ameliorative potential against negative effects of elevated ozone compared to present day CO 2 against ambient ozone

  17. Elevated stress hormone diminishes the strength of female preferences for acoustic signals in the green treefrog.

    Science.gov (United States)

    Davis, A Gabriell; Leary, Christopher J

    2015-03-01

    Mate selection can be stressful; time spent searching for mates can increase predation risk and/or decrease food consumption, resulting in elevated stress hormone levels. Both high predation risk and low food availability are often associated with increased variation in mate choice by females, but it is not clear whether stress hormone levels contribute to such variation in female behavior. We examined how the stress hormone corticosterone (CORT) affects female preferences for acoustic signals in the green treefrog, Hyla cinerea. Specifically, we assessed whether CORT administration affects female preferences for call rate - an acoustic feature that is typically under directional selection via mate choice by females in most anurans and other species that communicate using acoustic signals. Using a dual speaker playback paradigm, we show that females that were administered higher doses of CORT were less likely to choose male advertisement calls broadcast at high rates. Neither CORT dose nor level was related to the latency of female phonotactic responses, suggesting that elevated CORT does not influence the motivation to mate. Results were also not related to circulating sex steroids (i.e., progesterone, androgens or estradiol) that have traditionally been the focus of studies examining the hormonal basis for variation in female mate choice. Our results thus indicate that elevated CORT levels decrease the strength of female preferences for acoustic signals. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Advertising Content

    OpenAIRE

    Simon P. Anderson; Régis Renault

    2002-01-01

    Empirical evidence suggests that most advertisements contain little direct informa- tion. Many do not mention prices. We analyze a firm'ss choice of advertising content and the information disclosed to consumers. A firm advertises only product informa- tion, price information, or both; and prefers to convey only limited product information if possible. Extending the "persuasion" game, we show that quality information takes precedence over price information and horizontal product information.T...

  19. Group control of elevators

    Energy Technology Data Exchange (ETDEWEB)

    Umeda, Yasukazu; Hikita, Shiro; Tuji, Sintaro (Mitsubishi Electric Corp., Tokyo (Japan))

    1988-09-05

    Items to be evaluated in the group control of elevators, and a typical control system are described. A new system in which the fuzzy rule base is employed is introduced together with the configuration. The items to be evaluated are waiting time, riding time, accuracy of forecasting, energy saving, and ease of usage. The everage waiting time of less than 20 seconds with less than 3% waiting rate of more than 60 seconds is accepted as a satisfactory service condition. There are many conflicting matters in group-controlling, and the study for the controlling must deal with the optimization of multi-purpose problems. The standards for group-control evaluation differ according to building structures and the tastes of users, and an important problem is where to give emphasis of the evaluation. The TRAFFIC PATTERN LEARNING METHOD has been applied in the system for careful control to accommodate the traffic. No specific function is provided for the evaluation, but the call allocation is made by fuzzy rule-base. The configuration of a new group-control system is introduced. 7 references, 7 figures, 1 table.

  20. Lærer-elev-relationer

    DEFF Research Database (Denmark)

    Laursen, Per Fibæk; Nielsen, Anne Maj

    2015-01-01

    I kapitlet belyser vi relationskompetence i forholdet mellem lærer og elever og hvordan læreren kan arbejde med forhold til elever og med sin opmærksomhed på relationsarbejdet. Afslutningsvis ser vi på hvordan lærere fortsat kan udvikle deres relationskompetence.......I kapitlet belyser vi relationskompetence i forholdet mellem lærer og elever og hvordan læreren kan arbejde med forhold til elever og med sin opmærksomhed på relationsarbejdet. Afslutningsvis ser vi på hvordan lærere fortsat kan udvikle deres relationskompetence....

  1. Tanzania Elevation and Surface Characteristics

    Data.gov (United States)

    US Agency for International Development — The dataset displays Elevation, Slope, Aspect, Topographic Position Index, Terrain Ruggedness, and Roughness based on Shuttle Radar Topography Mission (SRTM) (3...

  2. Different patterns of amygdala priming differentially affect dentate gyrus plasticity and corticosterone, but not CA1 plasticity.

    Directory of Open Access Journals (Sweden)

    Rose-Marie eVouimba

    2013-05-01

    Full Text Available Stress-induced activation of the amygdala is involved in the modulation of memory processes in the hippocampus. However, stress effects on amygdala and memory remain complex. The activation of the basolateral amygdala (BLA was found to modulate plasticity in other brain areas, including the hippocampus. We previously demonstrated a differential effect of BLA priming on LTP in the CA1 and the dentate gyrus (DG. While BLA priming suppressed long term potentiation (LTP in CA1, it was found to enhance it in the DG. However, since the amygdala itself is amenable to experience-induced plasticity it is thus conceivable that when activity within the amygdala is modified this will have impact on the way the amygdala modulates activity and plasticity in other brain areas. In the current study we examined the effects of different patterns of BLA activation on the modulation of LTP in the DG and CA1, as well as on serum corticosterone (CORT. In CA1, BLA priming impaired LTP induction as was reported before. In contrast, in the DG, varying BLA stimulation intensity and frequency resulted in differential effects on LTP, ranging from no effect to strong impairment or enhancement. Varying BLA stimulation patterns resulted in also differential alterations in Serum CORT, leading to higher CORT levels being positively correlated with LTP magnitude in DG but not in CA1.The results support the notion of a differential role for the DG in aspects of memory, and add to this view the possibility that DG-associated aspects of memory will be enhanced under more emotional or stressful conditions. It is interesting to think of BLA patterns of activation and the differential levels of circulating CORT as two arms of the emotional and stress response that attempt to synchronize brain activity to best meet the challenge. It is foreseeable to think of abnormal such synchronization under extreme conditions, which would lead to the development of maladaptive behavior.

  3. Brain aromatase and circulating corticosterone are rapidly regulated by combined acute stress and sexual interaction in a sex specific manner

    Science.gov (United States)

    Dickens, M.J.; Balthazart, J.; Cornil, C. A.

    2012-01-01

    Neural production of 17β-oestradiol via aromatisation of testosterone may play a critical role in rapid, non-genomic regulation of physiological and behavioural processes. In brain nuclei implicated in the control of sexual behaviour, sexual or stressfull stimuli induce respectively a rapid inhibition or increase in preoptic aromatase activity (AA). Here, we tested quail that were either non-stressed or acutely stressed (15 min restraint) immediately prior to sexual interaction (5 min) with stressed or non-stressed partners. We measured nuclei-specific AA changes, corresponding behavioural output, fertilisation rates and corticosterone (CORT) concentrations. In males, sexual interaction rapidly reversed stress-induced increases of AA in the medial preoptic nucleus (POM). This time scale (behaviour suggesting that the input from the sexual stimuli on POM AA may actively preserve sexual behaviour despite stress exposure. We also found distinct sex differences in contextual physiological responses: while males did not show any effect of partner status, females responded to both their stress exposure and the male partner’s stress exposure at the level of circulating CORT and AA. In addition, fertilisation rates and female CORT correlated with the male partner’s exhibition of sexually aggressive behaviour suggesting that female perception of the male can affect their physiology as much as direct stress. Overall, male reproduction appears relatively simple – sexual stimuli, irrespective of stress, drives major neural changes including rapid reversal of stress-induced changes of AA. In contrast, female reproduction appears more nuanced and context specific, with subjects responding physiologically and behaviourally to stress, the male partner’s stress exposure, and female-directed male behaviour. PMID:22612582

  4. Corticosterone stress response shows long-term repeatability and links to personality in free-living Nazca boobies.

    Science.gov (United States)

    Grace, Jacquelyn K; Anderson, David J

    2014-11-01

    The concept of "coping styles", or consistently different responses to stressors, is of broad interest in behavioral ecology and biomedicine. Two critical predictions of this concept are individual consistency of neurophysiological and behavioral responses (relative to population variability) and a negative relationship between aggression/proactivity and hypothalamic-pituitary-adrenal axis reactivity. Recent studies failed to provide strong support for these predictions, especially outside of strictly controlled conditions, and long-term measures to test the first prediction are rare. Here, we demonstrate individual repeatability across 2-3years of maximum circulating corticosterone concentration [CORT] and area under the [CORT] response curve (AUCI) during a standard capture-restraint test in wild, free-living adult Nazca boobies (Sula granti). We also show that the stress response predicts the personality traits aggression and anxiety in these birds (measured in the wild); however, the strength of these results was weak. Maximum [CORT] and AUCI showed higher repeatability between years than baseline [CORT]. After controlling breeding status, sex, mass, date sampled, and their interactions, baseline [CORT] was most closely related to personality traits, followed by AUCI, and then maximum [CORT]. The direction of these relationships depended on whether the testing context was social or non-social. [CORT] parameters had little to no relationship with cross-context plasticity in personality traits. Our results generally affirm two critical predictions of coping styles, but match the emerging trend that these relationships are weak in the wild, and may depend on testing context. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Individual variation in baseline and stress-induced corticosterone and prolactin levels predicts parental effort by nesting mourning doves

    Science.gov (United States)

    Miller, David A.; Vleck, Carol M.; Otis, David L.

    2009-01-01

    Endocrine systems have an important mechanistic role in structuring life-history trade-offs. During breeding, individual variation in prolactin (PRL) and corticosterone (CORT) levels affects behavioral and physiological processes that drive trade-offs between reproduction and self-maintenance. We examined patterns in baseline (BL) and stress induced (SI; level following a standard capture-restraint protocol) levels of PRL and CORT for breeding mourning doves (Zenaida macroura). We determined whether the relationship of adult condition and parental effort to hormone levels in wild birds was consistent with life-history predictions. Both BL PRL and BL CORT level in adults were positively related to nestling weight at early nestling ages, consistent with the prediction of a positive relationship of hormone levels to current parental effort of adults and associated increased energy demand. Results are consistent with the two hormones acting together at baseline levels to limit negative effects of CORT on reproduction while maintaining beneficial effects such as increased foraging for nestling feeding. Our data did not support predictions that SI responses would vary in response to nestling or adult condition. The magnitude of CORT response in the parents to our capture-restraint protocol was negatively correlated with subsequent parental effort. Average nestling weights for adults with the highest SI CORT response were on average 10–15% lighter than expected for their age in follow-up visits after the stress event. Our results demonstrated a relationship between individual hormone levels and within population variation in parental effort and suggested that hormonal control plays an important role in structuring reproductive decisions for mourning doves.

  6. Exogenous corticosterone and nest abandonment: a study in a long-lived bird, the Adélie penguin.

    Science.gov (United States)

    Spée, Marion; Marchal, Lorène; Lazin, David; Le Maho, Yvon; Chastel, Olivier; Beaulieu, Michaël; Raclot, Thierry

    2011-09-01

    Breeding individuals enter an emergency life-history stage when their body reserves reach a minimum threshold. Consequently, they redirect current activity toward survival, leading to egg abandonment in birds. Corticosterone (CORT) is known to promote this stage. How and to what extent CORT triggers egg abandonment when breeding is associated with prolonged fasting, however, requires further investigation. We manipulated free-living male Adélie penguins with CORT-pellets before their laying period. We then examined their behavioral response with respect to nest abandonment in parallel with their prolactin levels (regulating parental care), and the subsequent effects of treatment on breeding success in relieved birds. Exogenous CORT triggered nest abandonment in 60% of the treated penguins ~14 days after treatment and induced a concomitant decline in prolactin levels. Interestingly, prolactin levels in treated penguins that did not abandon their nest were higher at the point of implantation and also after being relieved by females, when compared with abandoning penguins. Among successful birds, the treatment did not affect the number of chicks, nor the brood mass. Our results show the involvement of CORT in the decision-making process regarding egg abandonment in Adélie penguins when incubation is associated with a natural long fast. However, we suggest that CORT alone is not sufficient to trigger nest abandonment but that 1) prolactin levels need to reach a low threshold value, and 2) a rise in proteolysis (i.e. utilization of protein as main energy substrate) seems also to be required. Copyright © 2011 Elsevier Inc. All rights reserved.

  7. Chronic stress alters concentrations of corticosterone receptors in a tissue-specific manner in wild house sparrows (Passer domesticus).

    Science.gov (United States)

    Lattin, Christine R; Romero, L Michael

    2014-07-15

    The physiological stress response results in release of glucocorticoid hormones such as corticosterone (CORT). Whereas short-term activation of this response helps animals cope with environmental stressors, chronic activation can result in negative effects including metabolic dysregulation and reproductive failure. However, there is no consensus hormonal profile of a chronically stressed animal, suggesting that researchers may need to look beyond hormone titers to interpret the impacts of chronic stress. In this study, we brought wild house sparrows (Passer domesticus) into captivity. We then compared glucocorticoid and mineralocorticoid receptor concentrations in sparrows exposed either to a standardized chronic stress protocol (n=26) or to standard husbandry conditions (controls; n=20). We used radioligand binding assays to quantify receptors in whole brain, liver, kidneys, spleen, gonads, gastrocnemius and pectoralis muscle, omental and subcutaneous fat, and bib and back skin. In most tissues, CORT receptors did not differ between controls and stressed animals, although we found marginal increases in receptor density in kidney and testes in stressed birds at some time points. Only in pectoralis muscle was there a robust effect of chronic stress, with both receptor types higher in stressed animals. Increased pectoralis sensitivity to CORT with chronic stress may be part of the underlying mechanism for muscle wasting in animals administered exogenous CORT. Furthermore, the change in pectoralis was not paralleled by gastrocnemius receptors. This difference may help explain previous reports of a greater effect of CORT on pectoralis than on other muscle types, and indicate that birds use this muscle as a protein reserve. © 2014. Published by The Company of Biologists Ltd.

  8. Elevation of the diaphragmatic cupola

    International Nuclear Information System (INIS)

    Semenov, V.M.; Talesnik, M.R.

    1988-01-01

    Altogether 45 patients with elevation of the diaphragmatic cupola were examined. A high frequency of erroneous initial interpretation of examination results was noted in inflammatory and tumorous lesions and congenital conditions. Routine and contrast methods (pneumoperitoneum, bronchography, pleurography and fistulography) were used. Disease-related methods of X-ray investigation were proposed. A variety of causes of diaphragm elevation was indicated

  9. Space Station tethered elevator system

    Science.gov (United States)

    Haddock, Michael H.; Anderson, Loren A.; Hosterman, K.; Decresie, E.; Miranda, P.; Hamilton, R.

    1989-01-01

    The optimized conceptual engineering design of a space station tethered elevator is presented. The tethered elevator is an unmanned, mobile structure which operates on a ten-kilometer tether spanning the distance between Space Station Freedom and a platform. Its capabilities include providing access to residual gravity levels, remote servicing, and transportation to any point along a tether. The report discusses the potential uses, parameters, and evolution of the spacecraft design. Emphasis is placed on the elevator's structural configuration and three major subsystem designs. First, the design of elevator robotics used to aid in elevator operations and tethered experimentation is presented. Second, the design of drive mechanisms used to propel the vehicle is discussed. Third, the design of an onboard self-sufficient power generation and transmission system is addressed.

  10. Effect of co-treatment with fluoxetine or mirtazapine and risperidone on the active behaviors and plasma corticosterone concentration in rats subjected to the forced swim test.

    Science.gov (United States)

    Rogóż, Zofia; Kabziński, Marcin; Sadaj, Witold; Rachwalska, Paulina; Gądek-Michalska, Anna

    2012-01-01

    Several clinical reports have postulated a beneficial effect of the addition of a low dose of risperidone to the ongoing treatment with antidepressants in treatment-resistant depression. The present study aimed to examine the effect of treatment with fluoxetine or mirtazapine, given separately or jointly with risperidone, on active behavior and plasma corticosterone level in male Wistar rats subjected to the forced swim test (FST). The obtained results showed that fluoxetine (5 mg/kg), mirtazapine (5 and 10 mg/kg) or risperidone (0.05 and 0.1 mg/kg) did not change the active behavior of rats in the FST. However, co-treatment with fluoxetine (10 mg/kg) and risperidone (0.1 mg/kg) induced an antidepressant-like effect in that test because it significantly increased the swimming time and decreased the immobility time, while combined treatment with mirtazapine at 5 and 10 mg/kg and risperidone at 0.05 and 0.1 mg/kg evoked a significant increase in the swimming time and also climbing, and decreased the immobility time. WAY 100635 (a 5-HT(1A) receptor antagonist) at a dose of 0.1 mg/kg inhibited the antidepressant-like effect induced by co-administration of fluoxetine or mirtazapine and risperidone. Active behavior in that test did not reflect an increase in general activity, since combined treatment with fluoxetine or mirtazapine and risperidone failed to enhance the exploratory activity of rats. Co-treatment with fluoxetine or mirtazapine and risperidone did not reduce the stress-induced increase in plasma corticosterone concentration in animals subjected to the FST. The obtained results indicate that risperidone applied in a low dose enhances the antidepressant-like activity of fluoxetine and mirtazapine in the FST (but does not normalize the stress-induced increase in corticosterone level in these rats), and that 5-HT(1A) receptors may play some role in these effects.

  11. Context-Aware Elevator Scheduling

    OpenAIRE

    Strang, Thomas; Bauer, Christian

    2007-01-01

    Research on context-aware systems is usually user-centric and thus focussed on the context of a specific user to serve his or her needs in an optimized way. In this paper, we want to apply core concepts developed in research on context-awareness in a system-centric way, namely to elevator systems. We show with three different examples that the performance of an elevator system can be significantly improved if the elevator control has access to contextual knowledge. The first example demons...

  12. Creatine, Similar to Ketamine, Counteracts Depressive-Like Behavior Induced by Corticosterone via PI3K/Akt/mTOR Pathway.

    Science.gov (United States)

    Pazini, Francis L; Cunha, Mauricio P; Rosa, Julia M; Colla, André R S; Lieberknecht, Vicente; Oliveira, Ágatha; Rodrigues, Ana Lúcia S

    2016-12-01

    Ketamine has emerged as a novel strategy to treat refractory depression, producing rapid remission, but elicits some side effects that limit its use. In an attempt to investigate a safer compound that may afford an antidepressant effect similar to ketamine, this study examined the effects of the ergogenic compound creatine in a model of depression, and the involvement of phosphatidylinositol-3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR) pathway in its effect. In order to induce a depressive-like behavior, mice were administered with corticosterone (20 mg/kg, per os (p.o.)) for 21 days. This treatment increased immobility time in the tail suspension test (TST), an effect abolished by a single administration of creatine (10 mg/kg, p.o.) or ketamine (1 mg/kg, i.p.), but not by fluoxetine (10 mg/kg, p.o., conventional antidepressant). Treatment of mice with wortmannin (PI3K inhibitor, 0.1 μg/site, intracerebroventricular (i.c.v.)) or rapamycin (mTOR inhibitor, 0.2 nmol/site, i.c.v.) abolished the anti-immobility effect of creatine and ketamine. None of the treatments affected locomotor activity of mice. The immunocontents of p-mTOR, p-p70S6 kinase (p70S6K), and postsynaptic density-95 protein (PSD95) were increased by creatine and ketamine in corticosterone or vehicle-treated mice. Moreover, corticosterone-treated mice presented a decreased hippocampal brain-derived neurotrophic factor (BDNF) level, an effect abolished by creatine or ketamine. Altogether, the results indicate that creatine shares with ketamine the ability to acutely reverse the corticosterone-induced depressive-like behavior by a mechanism dependent on PI3K/AKT/mTOR pathway, and modulation of the synaptic protein PSD95 as well as BDNF in the hippocampus, indicating the relevance of targeting these proteins for the management of depressive disorders. Moreover, we suggest that creatine should be further investigated as a possible fast-acting antidepressant.

  13. FEMA DFIRM Base Flood Elevations

    Data.gov (United States)

    Minnesota Department of Natural Resources — The Base Flood Elevation (BFE) table is required for any digital data where BFE lines will be shown on the corresponding Flood Insurance Rate Map (FIRM). Normally,...

  14. Advanced energy saving hydraulic elevator

    Energy Technology Data Exchange (ETDEWEB)

    Garrido, A.; Sevilleja, J.; Servia, A.

    1993-08-24

    An hydraulic elevator is described comprising: a counterweighted elevator comprising a car, a counterweight, and a rope connecting the car and the counterweight; a ram having a first reaction surface for driving one of the car or the counterweight upwardly and a second reaction surface for driving one of the car or the counterweight downwardly; multiplier means for moving the car a distance greater than a stroke of the ram, the multiplier means connecting the ram to the counterweighted elevator, the multiplier means comprising: a first pulley; a second pulley; means for rigidly connecting the first and second pulley, the means having a length corresponding to a rise of the hydraulic elevator, the means attaching to the ram; and a pulley rope which: has a first end attaching to a first fixed point, extends about the first pulley, extends about the second pulley, and has a second end attaching to a second fixed point.

  15. Space Elevators Preliminary Architectural View

    Science.gov (United States)

    Pullum, L.; Swan, P. A.

    Space Systems Architecture has been expanded into a process by the US Department of Defense for their large scale systems of systems development programs. This paper uses the steps in the process to establishes a framework for Space Elevator systems to be developed and provides a methodology to manage complexity. This new approach to developing a family of systems is based upon three architectural views: Operational View OV), Systems View (SV), and Technical Standards View (TV). The top level view of the process establishes the stages for the development of the first Space Elevator and is called Architectural View - 1, Overview and Summary. This paper will show the guidelines and steps of the process while focusing upon components of the Space Elevator Preliminary Architecture View. This Preliminary Architecture View is presented as a draft starting point for the Space Elevator Project.

  16. Coastal Digital Elevation Models (DEMs)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Digital elevation models (DEMs) of U.S. and other coasts that typically integrate ocean bathymetry and land topography. The DEMs support NOAA's mission to understand...

  17. Base Flood Elevation (BFE) Lines

    Data.gov (United States)

    Department of Homeland Security — The Base Flood Elevation (BFE) table is required for any digital data where BFE lines will be shown on the corresponding Flood Insurance Rate Map (FIRM). Normally if...

  18. Elevated Fixed Platform Test Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Elevated Fixed Platform (EFP) is a helicopter recovery test facility located at Lakehurst, NJ. It consists of a 60 by 85 foot steel and concrete deck built atop...

  19. Energy efficient elevators and escalators

    Energy Technology Data Exchange (ETDEWEB)

    Patrao, Carlos; Fong, Joao; Almeida, Anibal de (Dep. Electrical Engineering, Univ. of Coimbra, Coimbra (Portugal)); Rivet, Luc

    2009-07-01

    Elevators and escalators are the crucial element that makes it practical to live and work several floors above ground - more than 4,3 million units are installed in Europe. Due to ageing of the European population the installation of elevators in single family houses is experiencing a significant growth, as well as equipping existing buildings. Elevators use about 4% of the electricity in tertiary sector buildings. High untapped saving potentials exist with respect to energy-efficient technologies, investment decisions and behavioural approaches, in these sectors. This paper presents preliminary results from the IEE project E4, whose overall objective is the improvement of the energy performance of elevators and escalators, in tertiary sector buildings and in multi family residential buildings. The project is characterizing people conveyors electricity consumption in the tertiary sector and in residential buildings in the EU. The installed park is characterised by a survey among elevators national associations in each country. An assessment of the barriers has been made in the first phase of the project and will be presented. Monitoring campaigns in elevators and escalators are being conducted in each country according to a common developed methodology. More than fifty elevators and escalators will be audited. This will allow the collection of load curves (start up, travel up and down, travel full and empty), including the characterization of standby consumption. Standby consumption of an elevator can represent up to 80% of the total energy consumed per year, and can be drastically reduced. This paper presents the preliminary results of the first ten audits performed in Portugal by Isr-UC.

  20. Sensitization of restraint-induced corticosterone secretion after chronic restraint in rats: Involvement of 5-HT7 receptors

    Science.gov (United States)

    García-Iglesias, Brenda B.; Mendoza-Garrido, María E.; Gutiérrez-Ospina, Gabriel; Rangel-Barajas, Claudia; Noyola-Díaz, Martha; Terrón, José A.

    2013-01-01

    Serotonin (5-HT) modulates the hypothalamic-pituitary-adrenal (HPA) axis response to stress. We examined the effect of chronic restraint stress (CRS; 20 min/day) as compared to control (CTRL) conditions for 14 days, on: 1) restraint-induced ACTH and corticosterone (CORT) secretion in rats pretreated with vehicle or SB-656104 (a 5-HT7 receptor antagonist); 2) 5-HT7 receptor-like immunoreactivity (5-HT7-LI) and protein in the hypothalamic paraventricular nucleus (PVN) and adrenal glands (AG); 3) baseline levels of 5-HT and 5-hydroxyindolacetic acid (5-HIAA), and 5-HIAA/5-HT ratio in PVN and AG; and 4) 5-HT-like immunoreactivity (5-HT-LI) in AG and tryptophan hydroxylase (TPH) protein in PVN and AG. On day 15, animals were subdivided into Treatment and No treatment groups. Treatment animals received an i.p. injection of vehicle or SB-656104; No Treatment animals received no injection. Sixty min later, Treatment animals were either decapitated with no further stress (0 min) or submitted to acute restraint (10, 30, 60 or 120 min); hormone serum levels were measured. No Treatment animals were employed for the rest of measurements. CRS decreased body weight gain and increased adrenal weight. In CTRL animals, acute restraint increased ACTH and CORT secretion in a time of restraint-dependent manner; both responses were inhibited by SB-656104. Exposure to CRS abolished ACTH but magnified CORT responses to restraint as compared to CTRL conditions; SB-656104 had no effect on ACTH levels but significantly inhibited sensitized CORT responses. In CTRL animals, 5-HT7-LI was detected in magnocellular and parvocellular subdivisions of PVN and sparsely in adrenal cortex. Exposure to CRS decreased 5-HT7-LI and protein in the PVN, but increased 5-HT7-LI in the adrenal cortex and protein in whole AG. Higher 5-HT and 5-HIAA levels were detected in PVN and AG from CRS animals but 5-HIAA/5-HT ratio increased in AG only. Finally, whereas 5-HT-LI was sparsely observed in the adrenal cortex

  1. The effect of chronic corticosterone on fear learning and memory depends on dose and the testing protocol.

    Science.gov (United States)

    Marks, W N; Fenton, E Y; Guskjolen, A J; Kalynchuk, L E

    2015-03-19

    Chronic exposure to the stress hormone corticosterone (CORT) is known to alter plasticity within hippocampal and amygdalar circuits that mediate fear learning and memory. The purpose of this experiment was to clarify the effects of chronic CORT on Pavlovian fear conditioning, which is dependent on intact hippocampal and amygdalar activity. In particular, we assessed whether the effect of chronic CORT on fear learning and memory is influenced by two factors-the dose of CORT and the order in which rats are tested for freezing to context versus tone cues. Male Long-Evans rats received low-dose CORT (5mg/kg), high-dose CORT (40mg/kg), or vehicle injections once daily for 21days. On day 22, the rats were trained in a fear-conditioning paradigm. On days 23 and 24, the rats were tested for the retrieval of fear memories to context and tone cues in a counterbalanced way-half the rats received context testing on day 23 and then tone testing on day 24 and half the rats received tone testing on day 23 followed by context testing on day 24. Our results revealed dose-dependent effects of CORT on memory retrieval: Rats injected with high-dose CORT froze significantly more than control rats to both context and tone cues regardless of what testing day these cues were presented. However, rats injected with low-dose CORT froze significantly more than control rats to tone cues only. We also found an order effect in that the effects of CORT on freezing were greater on the second day of testing, regardless of whether that testing was to context or tones cues. This order effect may be due to a lack of extinction in the CORT rats. Overall, these results suggest a relationship between stress intensity and testing conditions that should be taken into account when assessing the effect of stress on fear memories. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

  2. 5,7-DHT lesion of the dorsal raphe nuclei impairs object recognition but not affective behavior and corticosterone response to stressor in the rat.

    Science.gov (United States)

    Lieben, Cindy K J; Steinbusch, Harry W M; Blokland, Arjan

    2006-04-03

    Previous studies with acute tryptophan depletion, leading to transient central 5-HT reductions, showed no effects on affective behavior but impaired object memory. In the present study, the behavioral effects of a 5,7-dihydroxytryptamine (5,7-DHT) lesion in the dorsal raphe were evaluated in animal models of anxiety (open field test), depression (forced swimming test), behavioral inhibition (discrete fixed interval test) and cognition (object recognition task). The corticosterone response to a stress condition was examined at several intervals after 5,7-DHT treatment. The substantial reduction in neuronal 5-HT markers in the dorsal raphe did not affect anxiety-related, depressive-like or impulsive behavior. Compared to the SHAM group, the lesioned rats showed a lower response latency to obtain a reward, indicating a quick and accurate reaction to a stimulus. No differences were found in the progressive ratio test for food motivation. A marked impairment in object recognition was found. The 5,7-DHT treatment did not affect the corticosterone response to a stressful situation. Overall, these results corroborate studies with acute tryptophan depletion suggesting a role of 5-HT in object memory, but not affective behavior.

  3. Complex behavior of elevators in peak traffic

    Science.gov (United States)

    Nagatani, Takashi

    2003-08-01

    We study the dynamical behavior of elevators in the morning peak traffic. We present a stochastic model of the elevators to take into account the interactions between elevators through passengers. The dynamics of the elevators is expressed in terms of a coupled nonlinear map with noises. The number of passengers carried by an elevator and the time-headway between elevators exhibit the complex behavior with varying elevator trips. It is found that the behavior of elevators exhibits a deterministic chaos even if there are no noises. The chaotic motion depends on the loading parameter, the maximum capacity of an elevator, and the number of elevators. When the loading parameter is superior to the threshold, each elevator carries a full load of passengers throughout its trip. The dependence of the threshold (transition point) on the elevator capacity is clarified.

  4. Vessels for elevated temperature service

    International Nuclear Information System (INIS)

    O'Donnell, W.J.; Porowski, J.S.

    1983-01-01

    The subject is covered in chapters, entitled: introduction (background; elevated temperature concerns; design tools); design of pressure vessels for elevated temperature per ASME code; basic elevated temperature failure modes; allowable stresses and strains per ASME code (basic allowable stress limits; ASME code limits for bending; time-fraction summations; strain limits; buckling and instability; negligible creep and stress-rupture effects); combined membrane and bending stresses in creep regime; thermal stress cycles; bounding methods based on elastic core concept (bounds on accumulated strains; more accurate bounds; strain ranges; maximum stresses; strains at discontinuities); elastic follow-up; creep strain concentrations; time-dependent fatigue (combined creep rupture and fatigue damage; limits for inelastic design analyses; limits for elastic design analyses); flaw evaluation techniques; type 316 stainless steel; type 304 stainless steel; steel 2 1/4Cr1Mo; Inconel 718; Incolloy 800; Hastelloy X; detailed inelastic design analyses. (U.K.)

  5. Troponin elevation in subarachnoid hemorrhage

    Directory of Open Access Journals (Sweden)

    Ioannis N. Mavridis

    2015-03-01

    Full Text Available Troponin (tr elevation in aneurysmal subarachnoid hemorrhage (SAH patients is often difficult to be appropriately assessed by clinicians, causing even disagreements regarding its management between neurosurgeons and cardiologists. The purpose of this article was to review the literature regarding the clinical interpretation of tr elevation in SAH. We searched for articles in PubMed using the key words: “troponin elevation” and “subarachnoid hemorrhage”. All of them, as well as relative neurosurgical books, were used for this review. Some type of cardiovascular abnormality develops in most SAH patients. Neurogenic stunned myocardium is a frequent SAH complication, due to catecholamine surge which induces cardiac injury, as evidenced by increased serum tr levels, electrocardiographic (ECG changes and cardiac wall motion abnormalities. Tr elevation, usually modest, is an early and specific marker for cardiac involvement after SAH and its levels peak about two days after SAH. Cardiac tr elevation predictors include poor clinical grade, intraventricular hemorrhage, loss of consciousness at ictus, global cerebral edema, female sex, large body surface area, lower systolic blood pressure, higher heart rate and prolonged Q-Tc interval. Elevated tr levels are associated with disability and death (especially tr >1 μg/L, worse neurological grade, systolic and diastolic cardiac dysfunction, pulmonary congestion, longer intensive care unit stay and incidence of vasospasm. Tr elevation is a common finding in SAH patients and constitutes a rightful cause of worry about the patients' cardiac function and prognosis. It should be therefore early detected, carefully monitored and appropriately managed by clinicians.

  6. California gull chicks raised near colony edges have elevated stress levels

    Science.gov (United States)

    Herring, Garth; Ackerman, Joshua T.

    2011-01-01

    Coloniality in nesting birds represents an important life history strategy for maximizing reproductive success. Birds nesting near the edge of colonies tend to have lower reproductive success than individuals nesting near colony centers, and offspring of edge-nesting parents may be impaired relative to those of central-nesting parents. We used fecal corticosterone metabolites in California gull chicks (Larus californicus) to examine whether colony size or location within the colony influenced a chick's physiological condition. We found that chicks being raised near colony edges had higher fecal corticosterone metabolite concentrations than chicks raised near colony centers, but that colony size (ranging from 150 to 11,554 nests) had no influence on fecal corticosterone levels. Fecal corticosterone metabolite concentrations also increased with chick age. Our results suggest that similarly aged California gull chicks raised near colony edges may be more physiologically stressed, as indicated by corticosterone metabolites, than chicks raised near colony centers.

  7. Historie i spillefilm - for elever

    DEFF Research Database (Denmark)

    Tønnesen, Lone Guldbrandt

    2016-01-01

    MOOC om historiebrug i spillefilm, hvor elever kan lære om, hvordan spillefilm bruger fortiden, og om hvordan vores opfattelse af historien både sætter sig spor i filmene og bliver påvirket af dem.......MOOC om historiebrug i spillefilm, hvor elever kan lære om, hvordan spillefilm bruger fortiden, og om hvordan vores opfattelse af historien både sætter sig spor i filmene og bliver påvirket af dem....

  8. Tether Elevator Crawler Systems (TECS)

    Science.gov (United States)

    Swenson, Frank R.

    1987-01-01

    One of the needs of the experimenters on the space station is access to steady and controlled-variation microgravity environments. A method of providing these environments is to place the experiment on a tether attached to the space station. This provides a high degree of isolation from structural oscillations and vibrations. Crawlers can move these experiments along the tethers to preferred locations, much like an elevator. This report describes the motion control laws developed for these crawlers and the testing of laboratory models of these tether elevator crawlers.

  9. Trace mineral interactions during elevated calcium consumption

    International Nuclear Information System (INIS)

    Smith, K.T.; Luhrsen, K.R.

    1986-01-01

    Elevated calcium consumption is reported to affect trace mineral bioavailability. The authors examined this phenomenon in both single dose radio-label test meals and an eight week feeding trial in rats. In the single dose studies, human milk, cows milk, and various calcium sources were examined in relation to radio-iron and radio-zinc retention. 59 Fe retention was greater from human milk than cows milk. However, when the calcium content of human milk was adjusted (with CaHPO 4 or CaCO 3 ) to equal the level in cows milk, iron retention was depressed. Similarly, when calcium sources (CaCO 3 , CaHPO 4 , hydroxy-apatite, bone meal) were examined at different calcium:metal molar ratios, the degree of inhibition on metal retention varied. In general, phosphate salts were more inhibiting than carbonates. In the feeding trial, calcium was fed in diets at normal (0.5%) or elevated (1.5%) levels. Serum, liver, kidney, and bone trace mineral profiles were obtained. In general, most trace elements showed decreased levels in the tissues. Zinc and iron were most striking, followed by magnesium with minor changes in copper. A high calcium:high mineral supplemented group was also fed. Mixed mineral supplementation prevented all calcium interactions. These data indicate the importance of calcium mineral interactions in bioavailability considerations in both milk sources and in mineral supplementation

  10. Adaptive population divergence and directional gene flow across steep elevational gradients in a climate‐sensitive mammal

    Science.gov (United States)

    Waterhouse, Matthew D.; Erb, Liesl P.; Beever, Erik; Russello, Michael A.

    2018-01-01

    The American pika is a thermally sensitive, alpine lagomorph species. Recent climate-associated population extirpations and genetic signatures of reduced population sizes range-wide indicate the viability of this species is sensitive to climate change. To test for potential adaptive responses to climate stress, we sampled pikas along two elevational gradients (each ~470 to 1640 m) and employed three outlier detection methods, BAYESCAN, LFMM, and BAYPASS, to scan for genotype-environment associations in samples genotyped at 30,763 SNP loci. We resolved 173 loci with robust evidence of natural selection detected by either two independent analyses or replicated in both transects. A BLASTN search of these outlier loci revealed several genes associated with metabolic function and oxygen transport, indicating natural selection from thermal stress and hypoxia. We also found evidence of directional gene flow primarily downslope from large high-elevation populations and reduced gene flow at outlier loci, a pattern suggesting potential impediments to the upward elevational movement of adaptive alleles in response to contemporary climate change. Finally, we documented evidence of reduced genetic diversity associated the south-facing transect and an increase in corticosterone stress levels associated with inbreeding. This study suggests the American pika is already undergoing climate-associated natural selection at multiple genomic regions. Further analysis is needed to determine if the rate of climate adaptation in the American pika and other thermally sensitive species will be able to keep pace with rapidly changing climate conditions.

  11. Dannelsen af den ansvarlige elev

    DEFF Research Database (Denmark)

    Larsen, Jesper

    2010-01-01

    Denne artikel handler om den del af lærergerningen, der har at gøre med udarbejdelse af elevplaner. Der tages udgangspunkt i en foucaultsk forståelse, hvor beskrivelsen af den enkelte elev udtrykker et særligt normativt ideal om, hvilke former for elevhed der er de ønskværdige i den danske...

  12. Methylphenidatinduceret ST-elevations-myokardieinfarkt

    DEFF Research Database (Denmark)

    Ruwald, Martin Huth; Ruwald, Anne-Christine Huth; Tønder, Niels

    2012-01-01

    Adult attention deficit and hyperkinetic disorder (ADHD) is increasingly diagnosed and treated with methylphenidate. We present the case of an 20 year-old man, who was diagnosed with ADHD and suffered a ST elevation acute myocardial infarction due to coronary vasospasm related to an overdose...

  13. Elevated lactate during psychogenic hyperventilation

    NARCIS (Netherlands)

    ter Avest, E.; Patist, F. M.; ter Maaten, J. C.; Nijsten, M. W. N.

    Study objective Elevated arterial lactate levels are closely related to morbidity and mortality in various patient categories. In the present retrospective study, the relation between arterial lactate, partial pressure of carbon dioxide (Pco(2)) and pH was systematically investigated in patients who

  14. Study on the chemical components of shoots and leaves of Camellia oleifera from different elevations

    International Nuclear Information System (INIS)

    Wu, W.; Shu, Q.; Duan, W.

    2015-01-01

    The correlation between chemical components of shoot and leaf of Camellia oleifera and elevations were discussed, to provide theoretical basis for taking effective cultivation measures to promote the cold resistance of C. oleifera in the future Northward Movement of C. oleifera. The ratio of bound water to free water of the leaf, as well as the contents of holocellulose, cellulose, lignin and benzene-ethanol extracts were determined. The results showed that: In different elevations, the ratio of bound water to free water of the leaf varied from 0.11-0.22, the contents of holocellulose, cellulose, lignin and benzene-ethanol extracts varied from 25.08%-62.72%, 7.72%-36.61%, 11.80%-30.29% and 7.66%-8.57% respectively. In the same elevation, the content of benzene-ethanol extracts of leaf was higher than that of shoot, and the contents of other materials were quite the contrary. The elevation was positively correlated with the ratio of bound water to free water and the contents of holocellulose, cellulose, lignin and benzene-ethanol extracs. The chemical components of shoot and leaf represented extremely significant difference (p<0.01) among different elevations. In the future northward movement of C. oleifera, for the climate characteristics of cooler regions and higher elevation, a serious of cultivation measures, improving the contents of holocellulose, cellulose, lignin, benzene-ethanol extracts and the ratio of water to free water, were taken to improve the cold resistance of C. oleifera. (author)

  15. Effects of growth pattern and dietary protein level during rearing on feed intake, eating time, eating rate, behavior, plasma corticosterone concentration, and feather cover in broiler breeder females during the rearing and laying period

    NARCIS (Netherlands)

    Emous, van R.A.; Kwakkel, R.P.; Krimpen, van M.M.; Hendriks, W.H.

    2014-01-01

    An experiment was conducted to evaluate the effect of growth patterns (GP) and dietary crude protein levels (CP) during rearing (2–22 weeks of age) on feed intake, eating time, eating rate, behavior, plasma corticosterone concentration, and feather cover in broiler breeder females during the rearing

  16. Distinct soil bacterial communities along a small-scale elevational gradient in alpine tundra

    Directory of Open Access Journals (Sweden)

    Congcong eShen

    2015-06-01

    Full Text Available The elevational diversity pattern for microorganisms has received great attention recently but is still understudied, and phylogenetic relatedness is rarely studied for microbial elevational distributions. Using a bar-coded pyrosequencing technique, we examined the biodiversity patterns for soil bacterial communities of tundra ecosystem along 2000–2500 m elevations on Changbai Mountain in China. Bacterial taxonomic richness displayed a linear decreasing trend with increasing elevation. Phylogenetic diversity and mean nearest taxon distance (MNTD exhibited a unimodal pattern with elevation. Bacterial communities were more phylogenetically clustered than expected by chance at all elevations based on the standardized effect size of MNTD metric. The bacterial communities differed dramatically among elevations, and the community composition was significantly correlated with soil total carbon, total nitrogen, C:N ratio, and dissolved organic carbon. Multiple ordinary least squares regression analysis showed that the observed biodiversity patterns strongly correlated with soil total carbon and C:N ratio. Taken together, this is the first time that a significant bacterial diversity pattern has been observed across a small-scale elevational gradient. Our results indicated that soil carbon and nitrogen contents were the critical environmental factors affecting bacterial elevational distribution in Changbai Mountain tundra. This suggested that ecological niche-based environmental filtering processes related to soil carbon and nitrogen contents could play a dominant role in structuring bacterial communities along the elevational gradient.

  17. Multimedia content classification metrics for content adaptation

    OpenAIRE

    Fernandes, Rui; Andrade, M.T.

    2015-01-01

    Multimedia content consumption is very popular nowadays. However, not every content can be consumed in its original format: the combination of content, transport and access networks, consumption device and usage environment characteristics may all pose restrictions to that purpose. One way to provide the best possible quality to the user is to adapt the content according to these restrictions as well as user preferences. This adaptation stage can be best executed if knowledge about the conten...

  18. Multimedia content classification metrics for content adaptation

    OpenAIRE

    Fernandes, Rui; Andrade, M.T.

    2016-01-01

    Multimedia content consumption is very popular nowadays. However, not every content can be consumed in its original format: the combination of content, transport and access networks, consumption device and usage environment characteristics may all pose restrictions to that purpose. One way to provide the best possible quality to the user is to adapt the content according to these restrictions as well as user preferences. This adaptation stage can be best executed if knowledge about the conten...

  19. Elevated Steroid Hormone Production in the db/db Mouse Model of Obesity and Type 2 Diabetes.

    Science.gov (United States)

    Hofmann, Anja; Peitzsch, Mirko; Brunssen, Coy; Mittag, Jennifer; Jannasch, Annett; Frenzel, Annika; Brown, Nicholas; Weldon, Steven M; Eisenhofer, Graeme; Bornstein, Stefan R; Morawietz, Henning

    2017-01-01

    Obesity and type 2 diabetes have become a major public health problem worldwide. Steroid hormone dysfunction appears to be linked to development of obesity and type 2 diabetes and correction of steroid abnormalities may offer new approaches to therapy. We therefore analyzed plasma steroids in 15-16 week old obese and diabetic db/db mice using liquid chromatography-tandem mass spectrometry. Lean db/+ served as controls. Db/db mice developed obesity, hyperglycemia, hyperleptinemia, and hyperlipidemia. Hepatic triglyceride storage was increased and adiponectin and pancreatic insulin were lowered. Aldosterone, corticosterone, 11-deoxycorticosterone, and progesterone were respectively increased by 3.6-, 2.9-, 3.4, and 1.7-fold in db/db mice compared to controls. Ratios of aldosterone-to-progesterone and corticosterone-to-progesterone were respectively 2.0- and 1.5-fold higher in db/db mice. Genes associated with steroidogenesis were quantified in the adrenal glands and gonadal adipose tissues. In adrenals, Cyp11b2 , Cyp11b1 , Cyp21a1 , Hsd3b1 , Cyp11a1 , and StAR were all significantly increased in db/db mice compared with db/+ controls. In adipose tissue, no Cyp11b2 or Cyp11b1 transcripts were detected and no differences in Cyp21a1 , Hsd3b1 , Cyp11a1 , or StAR expression were found between db/+ and db/db mice. In conclusion, the present study showed an elevated steroid hormone production and adrenal steroidogenesis in the db/db model of obesity and type 2 diabetes. © Georg Thieme Verlag KG Stuttgart · New York.

  20. An acute injection of corticosterone increases thyrotrophin-releasing hormone expression in the paraventricular nucleus of the hypothalamus but interferes with the rapid hypothalamus pituitary thyroid axis response to cold in male rats.

    Science.gov (United States)

    Sotelo-Rivera, I; Jaimes-Hoy, L; Cote-Vélez, A; Espinoza-Ayala, C; Charli, J-L; Joseph-Bravo, P

    2014-12-01

    The activity of the hypothalamic-pituitary-thyroid (HPT) axis is rapidly adjusted by energy balance alterations. Glucocorticoids can interfere with this activity, although the timing of this interaction is unknown. In vitro studies indicate that, albeit incubation with either glucocorticoid receptor (GR) agonists or protein kinase A (PKA) activators enhances pro-thyrotrophin-releasing hormone (pro-TRH) transcription, co-incubation with both stimuli reduces this enhancement. In the present study, we used primary cultures of hypothalamic cells to test whether the order of these stimuli alters the cross-talk. We observed that a simultaneous or 1-h prior (but not later) activation of GR is necessary to inhibit the stimulatory effect of PKA activation on pro-TRH expression. We tested these in vitro results in the context of a physiological stimulus on the HPT axis in adult male rats. Cold exposure for 1 h enhanced pro-TRH mRNA expression in neurones of the hypophysiotrophic and rostral subdivisions of the paraventricular nucleus (PVN) of the hypothalamus, thyrotrophin (TSH) serum levels and deiodinase 2 (D2) activity in brown adipose tissue (BAT). An i.p. injection of corticosterone stimulated pro-TRH expression in the PVN of rats kept at ambient temperature, more pronouncedly in hypophysiotrophic neurones that no longer responded to cold exposure. In corticosterone-pretreated rats, the cold-induced increase in pro-TRH expression was detected only in the rostral PVN. Corticosterone blunted the increase in serum TSH levels and D2 activity in BAT produced by cold in vehicle-injected animals. Thus, increased serum corticosterone levels rapidly restrain cold stress-induced activation of TRH hypophysiotrophic neurones, which may contribute to changing energy expenditure. Interestingly, TRH neurones of the rostral PVN responded to both corticosterone and cold exposure with an amplified expression of pro-TRH mRNA, suggesting that these neurones integrate stress and temperature

  1. Paroxetine blunts the corticosterone response to swim-induced stress and increases depressive-like behavior in a rat model of postpartum depression

    DEFF Research Database (Denmark)

    Overgaard, Agnete; Lieblich, Stephanie E; Richardson, Robin

    2018-01-01

    Perinatal depression (PND) affects 15% of women. During the perinatal period both stress- and gonadal hormones fluctuate widely. Putatively, these fluctuations are involved in PND disease mechanisms. The serotonin system is sensitive to such hormone fluctuations, and serotonin reuptake inhibitors...... depression. In the rat model corticosterone (CORT; 40mg/kgs.c.) was administered in Sprague Dawley rats across postpartum day (PD)2 to PD14. Stress response was measured during the first exposure to the forced swim test (FST1), and depressive-like behavior was measured in both FST1 and FST2. We found...... that paroxetine completely blunted the swim stress-induced CORT response and increased depressive-like behavior in both FST1 and FST2. Our findings suggest that in the postpartum context, SSRIs compromise stress axis dynamics, which are needed for a healthy stress response. This is likely unfavorable...

  2. Effects of stock density on the laying performance, blood parameter, corticosterone, litter quality, gas emission and bone mineral density of laying hens in floor pens

    Science.gov (United States)

    Kang, H. K.; Park, S. B.; Kim, S. H.; Kim, C. H.

    2016-01-01

    The effects of stocking density on the performance, egg quality, leukocyte concentration, blood biochemistry, corticosterone levels, bone mineral density, and noxious gas emission of laying hens were investigated. Eight hundred 34-week-old Hy-Line Brown laying hens (Gallus gallus domesticus) were randomly assigned to one of 4 treatments, each of which was replicated 4 times. Four stocking densities, including 5, 6, 7, and 10 birds/m2, were compared. A commercial-type basal diet was formulated to meet or exceed nutrient recommendations for laying hens from the National Research Council. The diet was fed to the hens ad libitum for 8 wk. Results indicated that hen-day egg production, egg mass, and feed intake were less for (P hens. PMID:27578881

  3. Effects of air transportation cause physiological and biochemical changes indicative of stress leading to regulation of chaperone expression levels and corticosterone concentration.

    Science.gov (United States)

    Shim, SunBo; Lee, SeHyun; Kim, ChuelKyu; Kim, ByoungGuk; Jee, SeungWan; Lee, SuHae; Sin, JiSoon; Bae, ChangJoon; Woo, Jong-Min; Cho, JungSik; Lee, EonPil; Choi, HaeWook; Kim, HongSung; Lee, JaeHo; Jung, YoungJin; Cho, ByungWook; Chae, KabRyong; Hwang, DaeYoun

    2009-01-01

    Laboratory animals generally experience numerous unfamiliar environmental and psychological influences such as noises, temperatures, handling, shaking, and smells during the process of air transportation. To investigate whether stress induced by air transportation affects stress-related factors in animals, the levels of hormone and chaperone protein were measured in several tissues of F344 rats transported for 13 h and not transported. Herein, we conclude that the levels of corticosterone, HSP70, and GRP78 were significantly increased in the transported group compare to not transported group, but they were rapidly restored to the not transported group level after a recovery period of one week. However, the magnitude of induction and restoration levels of these factors varied depending on the tissue type. Thus, these results suggest that air transportation should be considered for the improvement of laboratory animal health and to reduce the incidence of laboratory animal stress.

  4. Effect of fish oil and coconut fat supplementation on depressive-type behavior and corticosterone levels of prenatally stressed male rats.

    Science.gov (United States)

    Borsonelo, Elizabethe Cristina; Suchecki, Deborah; Galduróz, José Carlos Fernandes

    2011-04-18

    Prenatal stress (PNS) during critical periods of brain development has been associated with numerous behavioral and/or mood disorders in later life. These outcomes may result from changes in the hypothalamic-pituitary-adrenal (HPA) axis activity, which, in turn, can be modulated by environmental factors, such as nutritional status. In this study, the adult male offspring of dams exposed to restraint stress during the last semester of pregnancy and fed different diets were evaluated for depressive-like behavior in the forced swimming test and for the corticosterone response to the test. Female Wistar rats were allocated to one of three groups: regular diet, diet supplemented with coconut fat or with fish oil, offered during pregnancy and lactation. When pregnancy was confirmed, they were distributed into control or stress groups. Stress consisted of restraint and bright light for 45 min, three times per day, in the last week of pregnancy. The body weight of the adult offspring submitted to PNS was lower than that of controls. In the forced swimming test, time of immobility was reduced and swimming was increased in PNS rats fed fish oil and plasma corticosterone levels immediately after the forced swimming test were lower in PNS rats fed regular diet than their control counterparts; this response was reduced in control rats whose mothers were fed fish oil and coconut fat. The present results indicate that coconut fat and fish oil influenced behavioral and hormonal responses to the forced swimming test in both control and PNS adult male rats. Copyright © 2011 Elsevier B.V. All rights reserved.

  5. Corticosterone stress response and plasma metabolite levels during breeding and molt in a free-living migratory songbird, the wood thrush (Hylocichla mustelina).

    Science.gov (United States)

    Done, Tyler; Gow, Elizabeth A; Stutchbury, Bridget J M

    2011-04-01

    Many birds face energetic trade-offs between different life history stages, such as reproductive effort, feather molt and the non-breeding period. Little is known about how physiological measures of condition (corticosterone, plasma metabolites) in free-living birds change from nesting stages to the post-breeding molt period or whether this is influenced by prior reproductive effort. We evaluated whether corticosterone (CORT) and plasma metabolite levels vary with date, nest stage and sex in a free-living migratory songbird, the wood thrush (Hylocichla mustelina). We also tested whether (1) baseline CORT levels early in the season were predictive of subsequent reproductive success and (2) whether prior reproductive effort influenced CORT levels and blood metabolites during molt. Baseline CORT levels decreased with date during both the incubation stage and nestling stage, but did not vary significantly across stage of breeding season. Stress-induced CORT declined with date during incubation and varied significantly across breeding stage, with lower levels during feather molt. Profiles of the metabolites of β-hydroxybutyrate, glycerol, and triglyceride did not vary significantly with date or breeding stage. Only triglycerides varied significantly with sex, with females having higher levels than males. Reproductive output was highly variable (0-10 fledglings per season) but baseline CORT levels in females during the first incubation period of the season was not related to subsequent reproductive output. Prior reproductive effort, measured as the cumulative number of young hatched during the breeding season, was positively related to stress-induced CORT during molt. High reproductive effort in wood thrush appears to have physiological carry-over effects into the molt period which could potentially affect rate of molt and preparation for fall migration. Copyright © 2011. Published by Elsevier Inc.

  6. Elevated carboxyhemoglobin in a marine mammal, the northern elephant seal.

    Science.gov (United States)

    Tift, Michael S; Ponganis, Paul J; Crocker, Daniel E

    2014-05-15

    Low concentrations of endogenous carbon monoxide (CO), generated primarily through degradation of heme from heme-proteins, have been shown to maintain physiological function of organs and to exert cytoprotective effects. However, high concentrations of carboxyhemoglobin (COHb), formed by CO binding to hemoglobin, potentially prevent adequate O2 delivery to tissues by lowering arterial O2 content. Elevated heme-protein concentrations, as found in marine mammals, are likely associated with greater heme degradation, more endogenous CO production and, consequently, elevated COHb concentrations. Therefore, we measured COHb in elephant seals, a species with large blood volumes and elevated hemoglobin and myoglobin concentrations. The levels of COHb were positively related to the total hemoglobin concentration. The maximum COHb value was 10.4% of total hemoglobin concentration. The mean (± s.e.m.) value in adult seals was 8.7 ± 0.3% (N=6), while juveniles and pups (with lower heme-protein contents) had lower mean COHb values of 7.6 ± 0.2% and 7.1 ± 0.3%, respectively (N=9 and N=9, respectively). Serial samples over several hours revealed little to no fluctuation in COHb values. This consistent elevation in COHb suggests that the magnitude and/or rate of heme-protein turnover is much higher than in terrestrial mammals. The maximum COHb values from this study decrease total body O2 stores by 7%, thereby reducing the calculated aerobic dive limit for this species. However, the constant presence of elevated CO in blood may also protect against potential ischemia-reperfusion injury associated with the extreme breath-holds of elephant seals. We suggest the elephant seal represents an ideal model for understanding the potential cytoprotective effects, mechanisms of action and evolutionary adaptation associated with chronically elevated concentrations of endogenously produced CO. © 2014. Published by The Company of Biologists Ltd.

  7. Elevator deflections on the icing process

    Science.gov (United States)

    Britton, Randall K.

    1990-01-01

    The effect of elevator deflection of the horizontal stabilizer for certain icing parameters is investigated. Elevator deflection can severely change the lower and upper leading-edge impingement limits, and ice can accrete on the elevator itself. Also, elevator deflection had practically no effect on the maximum local collection efficiency. It is shown that for severe icing conditions (large water droplets), elevator deflections that increase the projected height of the airfoil can significantly increase the total collection efficiency of the airfoil.

  8. Når elever producerer

    DEFF Research Database (Denmark)

    Bremholm, Jesper; Hansen, Rune; Slot, Marie Falkesgaard

    2017-01-01

    Dette kapitel præsenterer centrale resultater fra studiet Elevopgaver og elevproduktion i det 21. århundrede der blandt andet rummer den første større kvantitative undersøgelse af opgavedidaktik og elevers produktive arbejde i den danske grundskole. Studiet omfatter også en kvalitativ del, og i...... undersøgelsen præsenteres og diskuteres gennem en række konkrete eksempler fra de berørte fag. I forhold til elevers produktive arbejde peger undersøgelsens resultater både på potentialer og særlige barrierer i forbindelse med at udvikle en kompetenceorienteret undervisning. I kapitlet argumenteres desuden...

  9. Læring mellem elever

    DEFF Research Database (Denmark)

    Georgsen, Marianne; Davidsen, Jacob

    2010-01-01

    I denne rapport præsenteres resultater fra følgeforskningen til projektet Læring gennem Bevægelse, som er gennemført på Søndervangskolen i Hammel i perioden august 2009 - maj 2010. Projektet er gennemført i samspil mellem lærere, it-vejleder, elever og skolens ledelse. Projektets overordnede formål...

  10. Science on a space elevator

    Energy Technology Data Exchange (ETDEWEB)

    Laubscher, B. E. (Bryan E.); Jorgensen, A. M. (Anders M.)

    2004-01-01

    The Space Elevator (SE) represents a major paradigm shift in space access. If the SE's promise of low cost access can be realized, everything becomes economically more feasible to accomplish in space. In this paper we describe in-situ science stations mounted on a science-dedicated space elevator tether. The concept presented here involves a carbon nanotube ribbon that is constructed by an existing space elevator and then science sensors are stationed along the ribbon at differing altitudes. The finished ribbon can be moved across the earth to the position at which its scientific measurements are to be taken. The ability to station scientific, in-situ instrumentation at different altitudes for round-the-clock observations is a unique capability of the SE. The environments that the science packages sense range from the troposphere out beyond the magnetopause of the magnetosphere on the solar side of the earth. Therefore, the very end of the SE can sense the solar wind. The measurements at various points along its length include temperature, pressure, density, sampling, chemical analyses, wind speed, turbulence, free oxygen, electromagnetic radiation, cosmic rays, energetic particles and plasmas in the earth's magnetosphere and the solar wind. There exist some altitudes that are difficult to access with aircraft or balloons or rockets and so remain relatively unexplored. The space elevator solves these problems and opens these regions up to in-situ measurements. Without the need for propulsion, the SE provides a more benign and pristine environment for atmospheric measurements than available with powered aircraft. Moreover, replacing and upgrading instrumentation is expected to be very cost effective with the SE. Moving and stationing the science SE affords the opportunity to sense multiple regions of the atmosphere. The SE's geosynchronous, orbital motion through the magnetosphere, albeit nominally with Earth's magnetic field, will trace a plane

  11. Elevation alters ecosystem properties across temperate treelines globally

    Science.gov (United States)

    Mayor, Jordan R.; Sanders, Nathan J.; Classen, Aimée T.; Bardgett, Richard D.; Clément, Jean-Christophe; Fajardo, Alex; Lavorel, Sandra; Sundqvist, Maja K.; Bahn, Michael; Chisholm, Chelsea; Cieraad, Ellen; Gedalof, Ze'Ev; Grigulis, Karl; Kudo, Gaku; Oberski, Daniel L.; Wardle, David A.

    2017-01-01

    Temperature is a primary driver of the distribution of biodiversity as well as of ecosystem boundaries. Declining temperature with increasing elevation in montane systems has long been recognized as a major factor shaping plant community biodiversity, metabolic processes, and ecosystem dynamics. Elevational gradients, as thermoclines, also enable prediction of long-term ecological responses to climate warming. One of the most striking manifestations of increasing elevation is the abrupt transitions from forest to treeless alpine tundra. However, whether there are globally consistent above- and belowground responses to these transitions remains an open question. To disentangle the direct and indirect effects of temperature on ecosystem properties, here we evaluate replicate treeline ecotones in seven temperate regions of the world. We find that declining temperatures with increasing elevation did not affect tree leaf nutrient concentrations, but did reduce ground-layer community-weighted plant nitrogen, leading to the strong stoichiometric convergence of ground-layer plant community nitrogen to phosphorus ratios across all regions. Further, elevation-driven changes in plant nutrients were associated with changes in soil organic matter content and quality (carbon to nitrogen ratios) and microbial properties. Combined, our identification of direct and indirect temperature controls over plant communities and soil properties in seven contrasting regions suggests that future warming may disrupt the functional properties of montane ecosystems, particularly where plant community reorganization outpaces treeline advance.

  12. Plasma catecholamine content using radioenzymatic assay

    International Nuclear Information System (INIS)

    Minami, Masaru; Togashi, Hiroko; Koike, Yuichi; Shimamura, Keiichi; Yamazaki, Noriko

    1980-01-01

    Catecholamine (CA) contents in blood plasma of spontaneously hypertensive rats (SHR) and human blood plasma were measured by radioenzymatic assay (REA) and trihydroxyindol (THI) fluorescent method using high performance liquid chromatography (HPLC), and both measurement methods were compared. The standard curve of REA showed a good linear relationship between total CA contents and separated CA contents. Though there was a danger of exposure to β-ray when REA was performed, this method was useful for measurement of CA contents in blood of small animals and small quantity of blood because CA content of only 50 μg of blood plasma could be measured by this method. Norepinephrine (NE) and epinephrine (E) contents in men with normal blood pressure measured by REA was 250 +- 61 pg/ml and 37 +- 22 pg/ml, respectively. NE and E contents in patients with mild hypertension were 460 +- 128 pg/ml and 50 +- 20 pg/ml, respectively. There was not a significant difference between NE and E contents in men with normal blood pressure and those in patients with mild hypertension. Total CA content in blood plasma of SHR killed by decapitation was 5,000 +- 1,131 pg/ml, which was 5 times NE and E contents in blood plasma obtained from femoral vein of anesthetized SHR (816 +- 215 pg/ml and 209 +- 44 pg/ml). Total CA content in the same sample was measured by REA and HPLC. As a result, total CA content measured by REA was higher than that measured by HPLC, but there was a good relationship between total CA content measured by REA and that measured by HPLC. NE content in men with normal blood pressure measured by HPLC was elevated significantly according to an increase in their age, but this tendency was not observed in patients with hypertension. (Tsunoda, M.)

  13. Mechanism for elevated temperature leaching

    International Nuclear Information System (INIS)

    Kenna, B.T.; Murphy, K.D.

    1979-01-01

    Long-term, elevated temperature leaching and subsequent electron microprobe analysis of simulated waste glass and ceramic materials have been completed. A cyclic leaching pattern was found in all systems over a 20-month period. It appears that the leaching of mobile ions by simple diffusional processes is modified by more complex chemical interactions. The release of immobile ions is primarily a function of their chemical interactions in the matrix which suggests that these ions may be complex species when released into solution. A mechanism is proposed which incorporates these ideas and the cyclic phenomenon observed

  14. PLC VVVF Elevator Control System

    OpenAIRE

    Tang, Yujian; Gui, Tianyu

    2016-01-01

    The aim of the thesis is to introduce the PLC VVVF elevator and its control system. The thesis can be divided into three parts. The first part is about the overview of the lift: the kinds of the lift and the structure of the lift, it shows the knowledge about the components and the operating systems of the lift. The second part is about the PLC control system, it’s about the operations of the lift from the introduction about the hardware and software of the PLC control system. And the thi...

  15. Amorphisation during elevated temperature implantation

    International Nuclear Information System (INIS)

    Carter, G.; Nobes, M.J.; Elliman, R.G.

    1994-01-01

    Transition state theory is employed to predict the rates of amorphous zone recrystallization by direct thermal and radiation mediated thermal annealing processes. These rates are functions of zone radius and are employed to describe the competition between amorphous zone generation and annealing during elevated temperature heavy ion implantation of, particularly, Si and the accumulation of amorphousness with increasing ion fluence. This analysis predicts a change from monotonic to sigmoidal to biexponential accumulation functions with increasing annealing rate or substrate temperature in agreement with experiments. A logarithmic dependence of ion flux density upon substrate temperature for the achievement of defined fractional amorphisation is predicted and is also in agreement with the experiment. (author)

  16. Effects of periadolescent fluoxetine and paroxetine on elevated plus-maze, acoustic startle, and swimming immobility in rats while on and off-drug.

    Science.gov (United States)

    Vorhees, Charles V; Morford, LaRonda R; Graham, Devon L; Skelton, Matthew R; Williams, Michael T

    2011-10-05

    Whether selective serotonin reuptake inhibitors (SSRIs) exposure during adolescent brain development causes lasting effects remains unresolved. Assess the effects of fluoxetine and paroxetine 60 days after adolescent exposure compared with when on-drug. Male Sprague-Dawley littermates (41 litters) were gavaged on postnatal days 33-53 with fluoxetine (3 or 10 mg/kg/day), paroxetine (3, 10 or, 17 mg/kg/day), or water; half were tested while on-drug (21 litters) and half after 60 days off-drug (20 litters). The highest dose of the drugs reduced body weight gain during treatment that rebounded 1 week post-treatment. On-drug, no significant group differences were found on elevated plus maze time-in-open, zone entries, or latency to first open entry; however, the high dose of paroxetine significantly reduced head-dips (N=20/group). No significant effects were found on-drug for acoustic startle response/prepulse inhibition (ASR/PPI) although a trend (pfluoxetine and paroxetine (N=20-21/group). No differences on immobility time were seen in the Porsolt forced swim test or in plasma corticosterone at the end of forced swim (N-19-21/group). Off-drug, no effects were seen in the elevated plus maze (N=16/group), ASR/PPI (N=20/group), forced swim (N=19-20/group), or plasma corticosterone (N=19/group). At the doses tested, fluoxetine and paroxetine induced minor effects with drug on-board but no residual, long-term adverse effects in rats 60 days after drug discontinuation. The data provide no evidence that fluoxetine or paroxetine have long-term adverse effects on the behaviors measured here after adolescent to young adult exposure.

  17. Carbon and nutrient contents in soils from the Kings River Experimental Watersheds, Sierra Nevada Mountains, California

    Science.gov (United States)

    D.W. Johnson; C.T. Hunsaker; D.W. Glass; B.M. Rau; B.A. Roath

    2011-01-01

    Soil C and nutrient contents were estimated for eight watersheds in two sites (one high elevation, Bull, and one low elevation, Providence) in the Kings River Experimental Watersheds in the western Sierra Nevada Mountains of California. Eighty-seven quantitative pits were dug to measure soil bulk density and total rock content, while three replicate surface samples...

  18. Age-dependent effect of high cholesterol diets on anxiety-like behavior in elevated plus maze test in rats.

    Science.gov (United States)

    Hu, Xu; Wang, Tao; Luo, Jia; Liang, Shan; Li, Wei; Wu, Xiaoli; Jin, Feng; Wang, Li

    2014-09-01

    Cholesterol is an essential component of brain and nerve cells and is essential for maintaining the function of the nervous system. Epidemiological studies showed that patients suffering from anxiety disorders have higher serum cholesterol levels. In this study, we investigated the influence of high cholesterol diet on anxiety-like behavior in elevated plus maze in animal model and explored the relationship between cholesterol and anxiety-like behavior from the aspect of central neurochemical changes. Young (3 weeks old) and adult (20 weeks old) rats were given a high cholesterol diet for 8 weeks. The anxiety-like behavior in elevated plus maze test and changes of central neurochemical implicated in anxiety were measured. In young rats, high cholesterol diet induced anxiolytic-like behavior, decreased serum corticosterone (CORT), increased hippocampal brain-derived neurotrophic factor (BDNF), increased hippocampal mineralocorticoid receptor (MR) and decreased glucocorticoid receptor (GR). In adult rats, high cholesterol diet induced anxiety-like behavior and increase of serum CORT and decrease of hippocampal BDNF comparing with their respective control group that fed the regular diet. High cholesterol diet induced age-dependent effects on anxiety-like behavior and central neurochemical changes. High cholesterol diet might affect the central nervous system (CNS) function differently, and resulting in different behavior performance of anxiety in different age period.

  19. Age-dependent effect of high cholesterol diets on anxiety-like behavior in elevated plus maze test in rats

    Science.gov (United States)

    2014-01-01

    Background Cholesterol is an essential component of brain and nerve cells and is essential for maintaining the function of the nervous system. Epidemiological studies showed that patients suffering from anxiety disorders have higher serum cholesterol levels. In this study, we investigated the influence of high cholesterol diet on anxiety-like behavior in elevated plus maze in animal model and explored the relationship between cholesterol and anxiety-like behavior from the aspect of central neurochemical changes. Methods Young (3 weeks old) and adult (20 weeks old) rats were given a high cholesterol diet for 8 weeks. The anxiety-like behavior in elevated plus maze test and changes of central neurochemical implicated in anxiety were measured. Results In young rats, high cholesterol diet induced anxiolytic-like behavior, decreased serum corticosterone (CORT), increased hippocampal brain-derived neurotrophic factor (BDNF), increased hippocampal mineralocorticoid receptor (MR) and decreased glucocorticoid receptor (GR). In adult rats, high cholesterol diet induced anxiety-like behavior and increase of serum CORT and decrease of hippocampal BDNF comparing with their respective control group that fed the regular diet. Discussion High cholesterol diet induced age-dependent effects on anxiety-like behavior and central neurochemical changes. High cholesterol diet might affect the central nervous system (CNS) function differently, and resulting in different behavior performance of anxiety in different age period. PMID:25179125

  20. Elevated Hypothalamic Glucocorticoid Levels Are Associated With Obesity and Hyperphagia in Male Mice.

    Science.gov (United States)

    Sefton, Charlotte; Harno, Erika; Davies, Alison; Small, Helen; Allen, Tiffany-Jayne; Wray, Jonathan R; Lawrence, Catherine B; Coll, Anthony P; White, Anne

    2016-11-01

    Glucocorticoid (Gc) excess, from endogenous overproduction in disorders of the hypothalamic-pituitary-adrenal axis or exogenous medical therapy, is recognized to cause adverse metabolic side effects. The Gc receptor (GR) is widely expressed throughout the body, including brain regions such as the hypothalamus. However, the extent to which chronic Gcs affect Gc concentrations in the hypothalamus and impact on GR and target genes is unknown. To investigate this, we used a murine model of corticosterone (Cort)-induced obesity and analyzed Cort levels in the hypothalamus and expression of genes relevant to Gc action. Mice were administered Cort (75 μg/mL) or ethanol (1%, vehicle) in drinking water for 4 weeks. Cort-treated mice had increased body weight, food intake, and adiposity. As expected, Cort increased plasma Cort levels at both zeitgeber time 1 and zeitgeber time 13, ablating the diurnal rhythm. Liquid chromatography dual tandem mass spectrometry revealed a 4-fold increase in hypothalamic Cort, which correlated with circulating levels and concentrations of Cort in other brain regions. This occurred despite decreased 11β-hydroxysteroid dehydrogenase (Hsd11b1) expression, the gene encoding the enzyme that regenerates active Gcs, whereas efflux transporter Abcb1 mRNA was unaltered. In addition, although Cort decreased hypothalamic GR (Nr3c1) expression 2-fold, the Gc-induced leucine zipper (Tsc22d3) mRNA increased, which indicated elevated GR activation. In keeping with the development of hyperphagia and obesity, Cort increased Agrp, but there were no changes in Pomc, Npy, or Cart mRNA in the hypothalamus. In summary, chronic Cort treatment causes chronic increases in hypothalamic Cort levels and a persistent elevation in Agrp, a mediator in the development of metabolic disturbances.

  1. Diffusion rates for elevated releases

    International Nuclear Information System (INIS)

    Ramsdell, J.V.

    1983-11-01

    A search of the literature related to diffusion from elevated sources has determined that an adequate data base exists for use in developing parameterizations for estimating diffusion rates for material released from free standing stacks at nuclear power plants. A review of published data analyses indicates that a new parameterization of horizontal diffusion rates specifically for elevated releases is not likely to significantly change the magnitudes of horizontal diffusion coefficients on the average. However, the uncertainties associated with horizontal diffusion coefficient estimates under any given set of atmospheric conditions could be reduced by a new parameterization. Similarly, a new parameterization of vertical diffusion rates would be unlikely to significantly alter the magnitudes of diffusion coefficients for unstable atmospheric conditons. However, for neutral and stable atmospheric conditions, a new parameterization of vertical diffusion rates might increase vertical diffusion coefficients significantly. The increase would move ground-level time-integrated concentration maxima closer to the plant and would increase the maxima. 55 references, 2 figures, 4 tables

  2. Operation experience with elevated ammonia

    International Nuclear Information System (INIS)

    Vankova, Katerina; Kysela, Jan; Malac, Miroslav; Petrecky, Igor; Svarc, Vladimir

    2011-01-01

    The 10 VVER units in the Czech and Slovak Republics are all in very good water chemistry and radiation condition, yet questions have arisen regarding the optimization of cycle chemistry and improved operation in these units. To address these issues, a comprehensive experimental program for different water chemistries of the primary circuit was carried out at the Rez Nuclear Research Institute, Czech Republic, with the goal of judging the influence of various water chemistries on radiation build-up. Four types of water chemistries were compared: standard VVER water chemistry (in common use), direct hydrogen dosing without ammonia, standard VVER water chemistry with elevated ammonia levels, and zinc dosing to standard VVER water chemistry. The test results showed that the types of water chemistry other than the common one have benefits for the operation of the nuclear power plant (NPP) primary circuit. Operation experience with elevated ammonia at NPP Dukovany Units 3 and 4 is presented which validates the experimental results, demonstrating improved corrosion product volume activity. (orig.)

  3. Digitial Elevation Model (DEM) 100K

    Data.gov (United States)

    Kansas Data Access and Support Center — Digital Elevation Model (DEM) is the terminology adopted by the USG to describe terrain elevation data sets in a digital raster form. The standard DEM consists of a...

  4. Digtial Elevation Model (DEM) 250K

    Data.gov (United States)

    Kansas Data Access and Support Center — Digital Elevation Model (DEM) is the terminology adopted by the USGS to describe terrain elevation data sets in a digital raster form. The standard DEM consists of a...

  5. Digital Elevation Model (DEM) 24K

    Data.gov (United States)

    Kansas Data Access and Support Center — Digital Elevation Model (DEM) is the terminology adopted by the USGS to describe terrain elevation data sets in a digital raster form. The standard DEM consists of a...

  6. Bucket elevator type continuous unloader; Basket elevator gata renzokushiki anroda

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-04-20

    This unloader was delivered to Wakayama branch of Sumikin Butsuryu in the site of Wakayama steel plant of Sumitomo Metal Industries Ltd. for landing sub-materials for ironworks. Main specifications: (1) Capacity: 400t/h for limestone, 280t/h for gypsum, (2) Kinds of ships: 5,000DWT maximum, (3) Boom swing radius: 20m. Features: (1) Simple light-weight unloader for not large ships for main materials but small coastal service ships which works with not swing motion but only traveling and normal-directional motion of the under structure of a bucket elevator unit, (2) Various useful functions such as ground conveyance, truck loading, back yard stacking and back yard shipment for handling of various sub-materials. (translated by NEDO)

  7. History of Elevators and Related Research

    Science.gov (United States)

    Abe, Shigeru; Watanabe, Eiki

    The history of traction drive elevators in Japan is described. The electrical technologies such as the microprocessor car control and the VVVF motor control made remarkable progress leading to higher reliability and energy savings. Then, the various machine-room-less elevators have been developed and the space saving technology, such as the shuttle and the double-deck elevators become important, too. The elevators used for evacuation in case of emergencies are also discussed.

  8. Digital Content Strategies

    OpenAIRE

    Halbheer, Daniel; Stahl, Florian; Koenigsberg, Oded; Lehmann, Donald R

    2013-01-01

    This paper studies content strategies for online publishers of digital information goods. It examines sampling strategies and compares their performance to paid content and free content strategies. A sampling strategy, where some of the content is offered for free and consumers are charged for access to the rest, is known as a "metered model" in the newspaper industry. We analyze optimal decisions concerning the size of the sample and the price of the paid content when sampling serves the dua...

  9. 21 CFR 890.3930 - Wheelchair elevator.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Wheelchair elevator. 890.3930 Section 890.3930 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... elevator. (a) Identification. A wheelchair elevator is a motorized lift device intended for medical...

  10. 46 CFR 183.540 - Elevators.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Elevators. 183.540 Section 183.540 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER 100 GROSS TONS) ELECTRICAL INSTALLATION Miscellaneous Systems and Requirements § 183.540 Elevators. Each elevator on a vessel must meet the requirements of ANSI A 17.1 ...

  11. Global variation in elevational diversity patterns

    Science.gov (United States)

    Qinfeng Guo; Douglas A. Kelt; Zhongyu Sun; Hongxiao Liu; Liangjun Hu; Hai Ren; Jun We

    2013-01-01

    While horizontal gradients of biodiversity have been examined extensively in the past, vertical diversity gradients (elevation, water depth) are attracting increasing attention. We compiled data from 443 elevational gradients involving diverse organisms worldwide to investigate how elevational diversity patterns may vary between the Northern and Southern hemispheres...

  12. Falsely elevated triiodothyronine values in radioimmunoassay

    International Nuclear Information System (INIS)

    Skovsted, L.; Moelholm Hansen, J.E.; Nygaard, B.

    1995-01-01

    Five patients with falsely elevated serum triiodothyronine (T 3 ) concentrations (>9 nmol/l) in a radioimmunoassay are reported. The high T 3 -values disagreed with the other thyroid variables investigated as well as with the clinical observations. In sera from all patients a normal non-specific binding of T 3 was found, thus excluding abnormal serum-protein-binding of the hormone. An ethanol extraction of T 3 from serum before RIA reduced the T 3 content in serum from all patients to normal levels (2.0-2.4 nmol/l). These findings indicate the presence in the sera of substances, probably of protein nature, that were interfering with the assay by binding the reagent-antibody and not the antigen. Addition of non-immune rabbit serum prevented this interference and normalized the T 3 -values (1.8-2.4 nmol/l). Thus the interfering substance in T 3 -RIA could be an anti-rabbit antibody, the interaction of which can be eliminated by a minor modification of the assay making it possible to differentiate true from false T 3 -values. (au) 16 refs

  13. Myocarditis with ST elevation and elevated cardiac enzymes misdiagnosed as an ST-elevation myocardial infarction.

    Science.gov (United States)

    Sheldon, Seth H; Crandall, Mark A; Jaffe, Allan S

    2012-12-01

    Acute myocarditis can mimic ST-elevation myocardial infarction (STEMI). Quickly determining the correct diagnosis is critical given the "time is muscle" implication with a STEMI and the potential adverse effects associated with use of fibrinolytic therapy. A 46-year-old man presented to a rural emergency department with chest pain, and an electrocardiogram (ECG) read as showing 0.1 mV of ST-segment elevation in leads III and aVF. His initial cardiac troponin T was 0.44 ng/mL. He received fibrinolytic therapy for presumed STEMI. Cardiac magnetic resonance imaging was later performed and showed epicardial delayed enhancement consistent with myocarditis. Upon further questioning, he acknowledged 3 days of stuttering chest discomfort and a recent upper respiratory infection, as well as similar chest pain in his wife. A systematic evaluation is essential for acute chest pain, including a focused history, identification of cardiac risk factors, and ECG interpretation. A history of recent viral illness, absence of cardiac risk factors, or ECG findings inconsistent with a single anatomic lesion would suggest a potential alternate diagnosis to STEMI. This case emphasizes the importance of a focused history in the initial evaluation of chest pain. Copyright © 2012 Elsevier Inc. All rights reserved.

  14. The effects of seeds with hot and cold temperaments on serum thyroid hormones, corticosterone and urine vanillylmandelic acid concentrations of healthy rats.

    Science.gov (United States)

    Parvinroo, Shirin; Naghibi, Farzaneh; Zahediasl, Saleh; Kamalinejad, Mohammad; Sabetkasaei, Masoumeh

    2014-10-28

    Hot and cold temperaments are the basic concepts of Iranian traditional medicine (ITM). Nevertheless, studies on the functional mechanisms of medicinal herbs based on hot and cold temperaments are not very extensive. This study aimed to evaluate the effects of diets containing hot or cold temperament seeds according to ITM on some hormonal and neuromediator parameters with a regulatory role in thermogenesis and energy metabolism in acute (24 hr) and subacute (7-day) experiments that were performed on rats. Each experiment was performed on 42 male Wistar rats, which were randomly divided into 7 groups. while 1 group received usual diet (controls), 6 other groups were fed with a diet containing 10% seeds, namely, anise, fennel, or ajowan (hot temperament groups) or cucumber, pumpkin, or watermelon (cold temperament groups), respectively. The levels of the rats׳ serum free thyroxin (FT4), free triiodothyronin (FT3), triiodothyronin (T3), thyroxin (T4), corticosterone and urine vanillylmandelic acid (VMA) were analyzed. After 24 hours, a significant decrease in FT3 was observed in groups that were fed anise or fennel seeds. However, a significant increase in T3 was observed in the ajowan seed-fed group, and no changes in other parameters were observed in this group. On the 7th day, FT4 was significantly increased in fennel seed-fed group; T3 was significantly increased in the anise, fennel, ajowan and watermelon seed-fed groups; corticosterone was significantly increased in the watermelon and pumpkin seed-fed groups; and VMA was significantly increased in the fennel seed-fed group and significantly decreased in the cucumber seed-fed group. Alterations induced by hot and cold temperament seeds in measured hormonal and neuromediator levels that have a regulatory role in thermogenesis and the body׳s energy metabolism revealed that hot and cold temperament characteristics of studied seeds may most likely be related to their intervention in the body׳s energy metabolism

  15. Community and ecosystem responses to elevational gradients

    DEFF Research Database (Denmark)

    Sundqvist, Maja K.; Sanders, Nate; Wardle, David A.

    2013-01-01

    Community structure and ecosystem processes often vary along elevational gradients. Their responses to elevation are commonly driven by changes in temperature, and many community- and ecosystem-level variables therefore frequently respond similarly to elevation across contrasting gradients...... elevational gradients for understanding community and ecosystem responses to global climate change at much larger spatial and temporal scales than is possible through conventional ecological experiments. However, future studies that integrate elevational gradient approaches with experimental manipulations...... will provide powerful information that can improve predictions of climate change impacts within and across ecosystems....

  16. Ginseng Total Saponins Reverse Corticosterone-Induced Changes in Depression-Like Behavior and Hippocampal Plasticity-Related Proteins by Interfering with GSK-3β-CREB Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Lin Chen

    2014-01-01

    Full Text Available This study aimed to explore the antidepressant mechanisms of ginseng total saponins (GTS in the corticosterone-induced mouse depression model. In Experiment 1, GTS (50, 25, and 12.5 mg kg−1 d−1, intragastrically were given for 3 weeks. In Experiment 2, the same doses of GTS were administrated after each corticosterone (20 mg kg−1 d−1, subcutaneously injection for 22 days. In both experiments, mice underwent a forced swimming test and a tail suspension test on day 20 and day 21, respectively, and were sacrificed on day 22. Results of Experiment 1 revealed that GTS (50 and 25 mg kg−1 d−1 exhibited antidepressant activity and not statistically altered hippocampal protein levels of brain-derived neurotrophic factor (BDNF and neurofilament light chain (NF-L. Results of Experiment 2 showed that GTS (50 and 25 mg kg−1 d−1 ameliorated depression-like behavior without normalizing hypercortisolism. The GTS treatments reversed the corticosterone-induced changes in mRNA levels of BDNF and NF-L, and protein levels of BDNF NF-L, phosphor-cAMP response element-binding protein (Ser133, and phosphor-glycogen synthase kinase-3β (Ser9 in the hippocampus. These findings imply that the effect of GTS on corticosterone-induced depression-like behavior may be mediated partly through interfering with hippocampal GSK-3β-CREB signaling pathway and reversing decrease of some plasticity-related proteins.

  17. Bilateral lesions of suprachiasmatic nuclei affect circadian rhythms in [3H]-thymidine incorporation into deoxyribonucleic acid in mouse intestinal tract, mitotic index of corneal epithelium, and serum corticosterone

    International Nuclear Information System (INIS)

    Scheving, L.E.; Tsai, T.H.; Powell, E.W.; Pasley, J.N.; Halberg, F.; Dunn, J.

    1983-01-01

    Investigations into the role of the suprachiasmatic nuclei (SCN) in the coordination of circadian rhythms have presented differing results. Several reports have shown that ablation of the suprachiasmatic nuclei (SCNA) alters the phase and amplitude of rhythms but does not abolish them. The present study investigates the effect of SCNA on the rhythms in cell proliferation in various regions of the intestinal tract as measured by the incorporation of [ 3 H]-thymidine into deoxyribonucleic acid, in the mitotic activity of the corneal epithelium, and in serum corticosterone levels. The study involved mice with verified lesions of the SCN (six to 13 mice per time point) and control groups of both sham-operated and unoperated mice (seven of each per time point). The mice were killed in groups that represented seven time points over a single 24 hr span (3 hr intervals with the 0800 hr sampled both at start and end of the series). The tissues examined were the tongue, esophagus, gastric stomach, and colon for DNA synthesis, the corneal epithelium for mitotic index, and blood serum for corticosterone level. The most consistent result of SCNA was a phase advance in the rhythms in cell proliferation in the tongue, esophagus, gastric stomach, colon, and corneal epithelium. A reduction in rhythm amplitude occurred in the tongue, esophagus, and corneal epithelium; however, there was an amplitude increase for the stomach, colon, and serum corticosterone. The mesor (rhythm-adjusted mean) was increased by SCNA in all tissues except the corneal epithelium. These findings further support the role of the suprachiasmatic nuclear area in the control of rhythms in cell proliferation and corticosterone production, by acting as a ''phase-resetter'' and as a modulator of rhythm amplitude

  18. Slc7a11 (xCT) protein expression is not altered in the depressed brain and system xc- deficiency does not affect depression-associated behaviour in the corticosterone mouse model.

    Science.gov (United States)

    Demuyser, Thomas; Deneyer, Lauren; Bentea, Eduard; Albertini, Giulia; Femenia, Teresa; Walrave, Laura; Sato, Hideyo; Danbolt, Niels C; De Bundel, Dimitri; Michotte, Alex; Lindskog, Maria; Massie, Ann; Smolders, Ilse

    2017-09-27

    The cystine/glutamate antiporter (system xc-) is believed to contribute to nonvesicular glutamate release from glial cells in various brain areas. Although recent investigations implicate system xc- in mood disorders, unambiguous evidence has not yet been established. Therefore, we evaluated the possible role of system xc- in the depressive state. We conducted a protein expression analysis of the specific subunit of system xc- (xCT) in brain regions of the corticosterone mouse model, Flinders Sensitive Line rat model and post-mortem tissue of depressed patients. We next subjected system xc- deficient mice to the corticosterone model and analysed their behaviour in several tests. Lastly, we subjected additional cohorts of xCT-deficient and wild-type mice to N-acetylcysteine treatment to unveil whether the previously reported antidepressant-like effects are dependent upon system xc-. We did not detect any changes in xCT expression levels in the animal models or patients compared to proper controls. Furthermore, loss of system xc- had no effect on depression- and anxiety-like behaviour. Finally, the antidepressant-like effects of N-acetylcysteine are not mediated via system xc-. xCT protein expression is not altered in the depressed brain and system xc- deficiency does not affect depression-associated behaviour in the corticosterone mouse model.

  19. The alleviating effect of elevated CO2 on heat stress susceptibility of two wheat (Triticum aestivum L.) cultivars

    DEFF Research Database (Denmark)

    Kjær, Katrine Heinsvig; Ottosen, Carl-Otto; Rosenqvist, Eva S. K.

    2013-01-01

    efficiency of photosystem II (PSII) photochemistry (Fv/Fm) and contents of pigments and carbohydrates in leaves were analysed before and during the stress treatments as well as after one day of recovery. Heat stress reduced PN and Fv/Fm in both wheat cultivars, but plants grown in elevated CO2 maintained...... higher PN and Fv/Fm in comparison to plants grown in ambient CO2. Heat stress reduced leaf chlorophyll contents and increased leaf sucrose contents in both cultivars grown at ambient and elevated CO2. The content of hexoses in the leaves increased mainly in the tolerant cultivar in response...... to the combination of elevated CO2 and heat stress. The results show that heat stress tolerance in wheat is related to cultivar origin, the phenological stage of the plants and can be alleviated by elevated CO2. This confirms the complex interrelation between environmental factors and genotypic traits that influence...

  20. Publishing and Revising Content

    Science.gov (United States)

    Editors and Webmasters can publish content without going through a workflow. Publishing times and dates can be set, and multiple pages can be published in bulk. Making an edit to published content created a revision.

  1. Effects of Crocin on Learning and Memory in Rats Under Chronic Restraint Stress with Special Focus on the Hippocampal and Frontal Cortex Corticosterone Levels.

    Science.gov (United States)

    Dastgerdi, Azadehalsadat Hosseini; Radahmadi, Maryam; Pourshanazari, Ali Asghar; Dastgerdi, Hajaralsadat Hosseini

    2017-01-01

    Chronic stress adversely influences brain functions while crocin, as an effective component of saffron, exhibits positive effects on memory processes. This study investigated the effects of different doses of crocin on the improvement of learning and memory as well as corticosterone (CORT) levels in the hippocampus and frontal cortex of rats subjected to chronic stress. Forty male rats were randomly allocated to five different groups ( n = 8): Control, sham; stress (6 h/day for 21 days) groups, and two groups receiving daily intraperitoneal injections of one of two doses (30 and 60 mg/kg) of crocin accompanied by 21 days of restraint stress. Latency was evaluated as a brain function using the passive avoidance test before and one-day after a foot shock. CORT levels were measured in the homogenized hippocampus and frontal cortex. Results revealed that chronic stress had a significantly ( P effect on memory. Crocin (30 and 60 mg/kg), however, gave increase to significantly ( P effects than its higher (60 mg/kg) dose on learning and memory under chronic stress conditions. Moreover, it was speculated that different doses of crocin act on different neurotransmitters and biochemical factors in the brain.

  2. Repeated exposure to corticosterone increases depression-like behavior in two different versions of the forced swim test without altering nonspecific locomotor activity or muscle strength.

    Science.gov (United States)

    Marks, Wendie; Fournier, Neil M; Kalynchuk, Lisa E

    2009-08-04

    We have recently shown that repeated high dose injections of corticosterone (CORT) reliably increase depression-like behavior on a modified one-day version of the forced swim test. The main purpose of this experiment was to compare the effect of these CORT injections on our one-day version of the forced swim test and the more traditional two-day version of the test. A second purpose was to determine whether altered behavior in the forced swim test could be due to nonspecific changes in locomotor activity or muscle strength. Separate groups of rats received a high dose CORT injection (40 mg/kg) or a vehicle injection once per day for 21 consecutive days. Then, half the rats from each group were exposed to the traditional two-day forced swim test and the other half were exposed to our one-day forced swim test. After the forced swim testing, all the rats were tested in an open field and in a wire suspension grip strength test. The CORT injections significantly increased the time spent immobile and decreased the time spent swimming in both versions of the forced swim test. However, they had no significant effect on activity in the open field or grip strength in the wire suspension test. These results show that repeated CORT injections increase depression-like behavior regardless of the specific parameters of forced swim testing, and that these effects are independent of changes in locomotor activity or muscle strength.

  3. Depression-like behaviors in mice subjected to co-treatment of high-fat diet and corticosterone are ameliorated by AICAR and exercise.

    Science.gov (United States)

    Liu, Weina; Zhai, Xiaofeng; Li, Haipeng; Ji, Liu

    2014-03-01

    Major depressive disorder (MDD) and type II diabetes mellitus (T2DM) are highly co-morbid, and there may be a bi-directional connection between the two. Herein, we have described a mouse model of a depression-like and insulin-resistant (DIR) state induced by the co-treatment of high-fat diet (HFD) and corticosterone (CORT). 5-Aminoimidazole-4-carboxamide-1-β-d- ribofuranoside (AICAR), a pharmacological activator of AMP-activated protein kinase (AMPK), was originally used to improve insulin resistance (IR). Interestingly, our results show a clear potential for AICAR as a putative antidepressant with a chronic action on the DIR mice. In contrast to the traditional antidepressants, AICAR as a promising antidepressant avoids reducing insulin actions of skeletal muscle in the context of long-term HFD. Exercise also produced antidepressant effects. Our data suggest that the effects of AICAR and exercise on DIR may further increase our understanding on the link between depression and diabetes. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Elevated CO2 as a driver of global dryland greening

    KAUST Repository

    Lu, Xuefei; Wang, Lixin; McCabe, Matthew

    2016-01-01

    While recent findings based on satellite records indicate a positive trend in vegetation greenness over global drylands, the reasons remain elusive. We hypothesize that enhanced levels of atmospheric CO2 play an important role in the observed greening through the CO2 effect on plant water savings and consequent available soil water increases. Meta-analytic techniques were used to compare soil water content under ambient and elevated CO2 treatments across a range of climate regimes, vegetation types, soil textures and land management practices. Based on 1705 field measurements from 21 distinct sites, a consistent and statistically significant increase in the availability of soil water (11%) was observed under elevated CO2 treatments in both drylands and non-drylands, with a statistically stronger response over drylands (17% vs. 9%). Given the inherent water limitation in drylands, it is suggested that the additional soil water availability is a likely driver of observed increases in vegetation greenness.

  5. Elevated CO2 as a driver of global dryland greening

    KAUST Repository

    Lu, Xuefei

    2016-02-12

    While recent findings based on satellite records indicate a positive trend in vegetation greenness over global drylands, the reasons remain elusive. We hypothesize that enhanced levels of atmospheric CO2 play an important role in the observed greening through the CO2 effect on plant water savings and consequent available soil water increases. Meta-analytic techniques were used to compare soil water content under ambient and elevated CO2 treatments across a range of climate regimes, vegetation types, soil textures and land management practices. Based on 1705 field measurements from 21 distinct sites, a consistent and statistically significant increase in the availability of soil water (11%) was observed under elevated CO2 treatments in both drylands and non-drylands, with a statistically stronger response over drylands (17% vs. 9%). Given the inherent water limitation in drylands, it is suggested that the additional soil water availability is a likely driver of observed increases in vegetation greenness.

  6. Dynamic multibody modeling for tethered space elevators

    Science.gov (United States)

    Williams, Paul

    2009-08-01

    This paper presents a fundamental modeling strategy for dealing with powered and propelled bodies moving along space tethers. The tether is divided into a large number of discrete masses, which are connected by viscoelastic springs. The tether is subject to the full range of forces expected in Earth orbit in a relatively simple manner. Two different models of the elevator dynamics are presented. In order to capture the effect of the elevator moving along the tether, the elevator dynamics are included as a separate body in both models. One model treats the elevator's motion dynamically, where propulsive and friction forces are applied to the elevator body. The second model treats the elevator's motion kinematically, where the distance along the tether is determined by adjusting the lengths of tether on either side of the elevator. The tether model is used to determine optimal configurations for the space elevator. A modal analysis of two different configurations is presented which show that the fundamental mode of oscillation is a pendular one around the anchor point with a period on the order of 160 h for the in-plane motion, and 24 h for the out-of-plane motion. Numerical simulation results of the effects of the elevator moving along the cable are presented for different travel velocities and different elevator masses.

  7. Predictors of backrest elevation in critical care.

    Science.gov (United States)

    Grap, Mary Jo; Munro, Cindy L; Bryant, Sandra; Ashtiani, Brooke

    2003-04-01

    Low backrest and supine positions are associated with increased mortality and ventilator associated pneumonia (VAP). Data are not available across ICU settings about the level of backrest position used and its relationship to enteral feeding and hemodynamic status. The purpose of this descriptive study was to document the level of backrest elevation and position and identify factors associated with and predict positioning in a medical, surgical and neuroscience intensive care unit. Data were collected randomly in each unit over a 6-week period, resulting in 506 observations for170 patients. Backrest elevation was determined by electronic bed read-out or bed frame elevation gauge. BP, HR and enteral feeding status were retrieved from the medical record. Results showed that mean backrest elevation was 19.2 degrees and 70% of subjects were supine. No difference in backrest elevation among units was found. Significant correlations between backrest elevation and systolic BP (r=0.15, P=0.006); and backrest and diastolic BP (r=0.13, P=0.02) were found. There was no difference in backrest elevation between patients being fed and not being fed. Differences in backrest elevation for intubated versus nonintubated patients approached significance (P=0.07) with intubated patients at lower backrest elevations. In summary, use of higher backrest elevations (>30 degrees ) is minimal, is not related to feeding and minimally related to hemodynamic status. Strategies to meet published recommendations for backrest elevation (30-45 degrees ) must include repeated feedback about nurse's use of backrest elevation and estimates of elevation.

  8. The space station tethered elevator system

    Science.gov (United States)

    Anderson, Loren A.

    1989-01-01

    The optimized conceptual engineering design of a space station tethered elevator is presented. The elevator is an unmanned mobile structure which operates on a ten kilometer tether spanning the distance between the Space Station and a tethered platform. Elevator capabilities include providing access to residual gravity levels, remote servicing, and transportation to any point along a tether. The potential uses, parameters, and evolution of the spacecraft design are discussed. Engineering development of the tethered elevator is the result of work conducted in the following areas: structural configurations; robotics, drive mechanisms; and power generation and transmission systems. The structural configuration of the elevator is presented. The structure supports, houses, and protects all systems on board the elevator. The implementation of robotics on board the elevator is discussed. Elevator robotics allow for the deployment, retrieval, and manipulation of tethered objects. Robotic manipulators also aid in hooking the elevator on a tether. Critical to the operation of the tethered elevator is the design of its drive mechanisms, which are discussed. Two drivers, located internal to the elevator, propel the vehicle along a tether. These modular components consist of endless toothed belts, shunt-wound motors, regenerative power braking, and computer controlled linear actuators. The designs of self-sufficient power generation and transmission systems are reviewed. Thorough research indicates all components of the elevator will operate under power provided by fuel cells. The fuel cell systems will power the vehicle at seven kilowatts continuously and twelve kilowatts maximally. A set of secondary fuel cells provides redundancy in the unlikely event of a primary system failure. Power storage exists in the form of Nickel-Hydrogen batteries capable of powering the elevator under maximum loads.

  9. Plasmaspheric electron content

    International Nuclear Information System (INIS)

    Hartmann, G.K.

    1978-01-01

    Measurements of the plasmaspheric electron content are reviewed with particular reference to the ATS-6 radio beacon experiment. From the review, it appears likely that measurement of the plasmaspheric electron content is the only one capable of monitoring electron fluxes continuously between L 1 and L 2. Some recent important results deduced from plasmaspheric electron content measurements are discussed

  10. Space elevator systems level analysis

    Energy Technology Data Exchange (ETDEWEB)

    Laubscher, B. E. (Bryan E.)

    2004-01-01

    The Space Elevator (SE) represents a major paradigm shift in space access. It involves new, untried technologies in most of its subsystems. Thus the successful construction of the SE requires a significant amount of development, This in turn implies a high level of risk for the SE. This paper will present a systems level analysis of the SE by subdividing its components into their subsystems to determine their level of technological maturity. such a high-risk endeavor is to follow a disciplined approach to the challenges. A systems level analysis informs this process and is the guide to where resources should be applied in the development processes. It is an efficient path that, if followed, minimizes the overall risk of the system's development. systems level analysis is that the overall system is divided naturally into its subsystems, and those subsystems are further subdivided as appropriate for the analysis. By dealing with the complex system in layers, the parameter space of decisions is kept manageable. Moreover, A rational way to manage One key aspect of a resources are not expended capriciously; rather, resources are put toward the biggest challenges and most promising solutions. This overall graded approach is a proven road to success. The analysis includes topics such as nanotube technology, deployment scenario, power beaming technology, ground-based hardware and operations, ribbon maintenance and repair and climber technology.

  11. Phase-preserved optical elevator.

    Science.gov (United States)

    Luo, Yuan; Zhang, Baile; Han, Tiancheng; Chen, Zhi; Duan, Yubo; Chu, Chia-Wei; Barbastathis, George; Qiu, Cheng Wei

    2013-03-25

    The unique superiority of transformation optics devices designed from coordinate transformation is their capability of recovering both ray trajectory and optical path length in light manipulation. However, very few experiments have been done so far to verify this dual-recovery property from viewpoints of both ray trajectory and optical path length simultaneously. The experimental difficulties arise from the fact that most previous optical transformation optics devices only work at the nano-scale; the lack of intercomparison between data from both optical path length and ray trajectory measurement in these experiments obscured the fact that the ray path was subject to a subwavelength lateral shift that was otherwise not easily perceivable and, instead, was pointed out theoretically [B. Zhang et al. Phys. Rev. Lett. 104, 233903, 2010]. Here, we use a simple macroscopic transformation optics device of phase-preserved optical elevator, which is a typical birefringent optical phenomenon that can virtually lift an optical image by a macroscopic distance, to demonstrate decisively the unique optical path length preservation property of transformation optics. The recovery of ray trajectory is first determined with no lateral shift in the reflected ray. The phase preservation is then verified with incoherent white-light interferometry without ambiguity and phase unwrapping.

  12. Defense of a space elevator

    Energy Technology Data Exchange (ETDEWEB)

    Laubscher, B. E. (Bryan E.)

    2004-01-01

    The Space Elevator (SE) represents a major paradigm shift in space access. If the SE's promise of low-cost access is to be realized, everything becomes economically more feasible to accomplish in space. In this paper we describe a defensive system of the SE. The primary scenario adopted for this analysis is the SE based on a floating platform in the ocean along the equator. A second possible scenario is the SE stationed on land (island or continent) on or near the equator. The SE will capture the imaginations of people around the world. It will become a symbol of power, capability, wealth and prestige for the country that builds it. As such, it will become a prime terrorist target. Moreover, the tremendous economic leverage afforded by the SE might motivate rogue nations to plot its destruction. Therefore, it is necessary to consider the requirements for defense of the SE. For the purposes of this paper it is assumed that the SE is to be deployed by the United States or one of its companies, and the resources of the US are available for its defense.

  13. Naturalising Representational Content

    Science.gov (United States)

    Shea, Nicholas

    2014-01-01

    This paper sets out a view about the explanatory role of representational content and advocates one approach to naturalising content – to giving a naturalistic account of what makes an entity a representation and in virtue of what it has the content it does. It argues for pluralism about the metaphysics of content and suggests that a good strategy is to ask the content question with respect to a variety of predictively successful information processing models in experimental psychology and cognitive neuroscience; and hence that data from psychology and cognitive neuroscience should play a greater role in theorising about the nature of content. Finally, the contours of the view are illustrated by drawing out and defending a surprising consequence: that individuation of vehicles of content is partly externalist. PMID:24563661

  14. Broadband phase-preserved optical elevator

    OpenAIRE

    Luo, Yuan; Han, Tiancheng; Zhang, Baile; Qiu, Cheng-Wei; Barbastathis, George

    2011-01-01

    Phase-preserved optical elevator is an optical device to lift up an entire plane virtually without distortion in light path or phase. Using transformation optics, we have predicted and observed the realization of such a broadband phase-preserved optical elevator, made of a natural homogeneous birefringent crystal without resorting to absorptive and narrowband metamaterials involving time-consuming nano-fabrication. In our demonstration, the optical elevator is designed to lift a sheet upwards...

  15. International Digital Elevation Model Service (IDEMS): A Revived IAG Service

    Science.gov (United States)

    Kelly, K. M.; Hirt, C., , Dr; Kuhn, M.; Barzaghi, R.

    2017-12-01

    A newly developed International Digital Elevation Model Service (IDEMS) is now available under the umbrella of the International Gravity Field Service of the International Association of Geodesy. Hosted and operated by Environmental Systems Research Institute (Esri) (http://www.esri.com/), the new IDEMS website is available at: https://idems.maps.arcgis.com/home/index.html. IDEMS provides a focus for distribution of data and information about various digital elevation models, including spherical-harmonic models of Earth's global topography and lunar and planetary DEM. Related datasets, such as representation of inland water within DEMs, and relevant software which are available in the public domain are also provided. Currently, IDEMS serves as repository of links to providers of global terrain and bathymetry, terrain related Earth models and datasets such as digital elevation data services managed and maintained by Esri (Terrain and TopoBathy), Bedmap2-Ice thickness and subglacial topographic model of Antarctica and Ice, Cloud, and Land Elevation ICESat/GLAS Data, as well as planetary terrain data provided by PDS Geosciences Node at Washington University, St. Louis. These services provide online access to a collection of multi-resolution and multi-source elevation and bathymetry data, including metadata and source information. In addition to IDEMS current holdings of terrestrial and planetary DEMs, some topography related products IDEMS may include in future are: dynamic ocean topography, 3D crustal density models, Earth's dynamic topography, etc. IDEMS may also consider terrain related products such as quality assessments, global terrain corrections, global height anomaly-to-geoid height corrections and other geodesy-relevant studies and products. IDEMS encourages contributions to the site from the geodetic community in any of the product types listed above. Please contact the authors if you would like to contribute or recommend content you think appropriate for

  16. Soil nematodes show a mid-elevation diversity maximum and elevational zonation on Mt. Norikura, Japan.

    Science.gov (United States)

    Dong, Ke; Moroenyane, Itumeleng; Tripathi, Binu; Kerfahi, Dorsaf; Takahashi, Koichi; Yamamoto, Naomichi; An, Choa; Cho, Hyunjun; Adams, Jonathan

    2017-06-08

    Little is known about how nematode ecology differs across elevational gradients. We investigated the soil nematode community along a ~2,200 m elevational range on Mt. Norikura, Japan, by sequencing the 18S rRNA gene. As with many other groups of organisms, nematode diversity showed a high correlation with elevation, and a maximum in mid-elevations. While elevation itself, in the context of the mid domain effect, could predict the observed unimodal pattern of soil nematode communities along the elevational gradient, mean annual temperature and soil total nitrogen concentration were the best predictors of diversity. We also found nematode community composition showed strong elevational zonation, indicating that a high degree of ecological specialization that may exist in nematodes in relation to elevation-related environmental gradients and certain nematode OTUs had ranges extending across all elevations, and these generalized OTUs made up a greater proportion of the community at high elevations - such that high elevation nematode OTUs had broader elevational ranges on average, providing an example consistent to Rapoport's elevational hypothesis. This study reveals the potential for using sequencing methods to investigate elevational gradients of small soil organisms, providing a method for rapid investigation of patterns without specialized knowledge in taxonomic identification.

  17. On a lunar space elevator

    Science.gov (United States)

    Lemke, E. H.

    We consider a space elevator system for lunar surface access that consists of a space station in circumlunar orbit, a cable reaching down to some meters above the surface and a magnetically levitated vehicle driven by a linear motor. It accelerates the load to be lifted to the speed of the cable end. Loads to be delivered are either put on the vehicle and slowed down by it or they are slowed down by a sand braking technique in a mare terrain. It is technically possible to operate this transport system nearly without fuel supply from Earth. We calculate various steel cable dimensions for a static stress maximum of 1/5th of the tensile strength. The process of takeover is considered in detail. Five ways of eliminating the adverse large cable elongation due to the load are described. The touchdown process and behaviour of the cable after disconnection are analysed. The positive difference between the speed of the load at takeover and cable end can excite a large inplane swing motion. We propose to damp it by a dissipative pulley that hangs in a loop of wire leading to the ends of two beams mounted on the space station tangentially to the orbit, the pulley's core being connected with the load. Roll librations are damped by energy losses in the elastic beams; damping can be reinforced by viscous beam elements and/or controlled out-of-plane motions of the beams. We argue in favour of the possibility of fast deployment. The problems of vehicle vibrations and agglutination at sand braking blades are underlined and their combined experimental investigation is suggested.

  18. An Automatic System for Elevator Monitoring

    OpenAIRE

    Md. Haidar Sharif; Ibrahim Furkan Ince

    2015-01-01

    An elevator is a conveyor device or transport equipment that moves people or goods between floors or levels or decks of a building, vessel, or other structures. It has become a part and parcel of modern life in developed countries. The number of floors in high buildings, skyscrapers, and towers generate the usage of elevators. If it is simply assumed that each floor has at least two elevators in a thirty-floor building, people call the elevators in each floor even they are already occupied in...

  19. Rats with differential self-grooming expression in the elevated plus-maze do not differ in anxiety-related behaviors.

    Science.gov (United States)

    Reimer, Adriano Edgar; de Oliveira, Amanda Ribeiro; Diniz, Juliana Belo; Hoexter, Marcelo Queiroz; Chiavegatto, Silvana; Brandão, Marcus Lira

    2015-10-01

    Individual differences are important biological predictors for reactivity to stressful stimulation. The extent to which trait differences underlie animal's reactions to conditioned and unconditioned fear stimuli, for example, is still to be clarified. Although grooming behavior has been associated with some aspects of the obsessive-compulsive disorder in humans, its relation with other anxiety disorders is still unknown. Given that grooming behavior could be a component of the whole spectrum of these disorders, in the present study we allocated male Wistar rats in low, intermediate and high self-grooming groups according to the duration of such behavior in the elevated plus-maze (EPM). These groups were then evaluated in unconditioned fear tests, such as the EPM and the open-field, and in conditioned fear tests, such as fear-potentiated startle and fear extinction retention. Additionally, we studied the expression of unconditioned behaviors in marble burying test and the sensorimotor gate function with prepulse inhibition test. Neurochemicals and neuroendocrine parameters were also evaluated, with the quantification of basal corticosterone in the plasma, and dopamine, serotonin and their metabolites in brain structures involved with fear processing. In general, rats classified according to grooming expression showed similar performance in all behavioral tests. Accordingly, corticosterone and monoamine concentrations were similar among groups. Thus, despite grooming expression elicited by different approaches--especially pharmacological ones--has been related with some aspects of anxiety disorders, rats with different expression of spontaneous self-grooming in the EPM do not differ in anxiety-like behaviors nor in neurochemical and neuroendocrine parameters generally associated with anxiety disorders. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. National requirements for improved elevation data

    Science.gov (United States)

    Snyder, Gregory I.; Sugarbaker, Larry J.; Jason, Allyson L.; Maune, David F.

    2014-01-01

    This report presents the results of surveys, structured interviews, and workshops conducted to identify key national requirements for improved elevation data for the United States and its territories, including coastlines. Organizations also identified and reported the expected economic benefits that would be realized if their requirements for improved elevation were met (appendixes 1–3). This report describes the data collection methodology and summarizes the findings. Participating organizations included 34 Federal agencies, 50 States and two territories, and a sampling of local governments, tribes, and nongovernmental orgnizations. The nongovernmental organizations included The Nature Conservancy and a sampling of private sector businesses. These data were collected in 2010-2011 as part of the National Enhanced Elevation Assessment (NEEA), a study to identify program alternatives for better meeting the Nation’s elevation data needs. NEEA tasks included the collection of national elevation requirements; analysis of the benefits and costs of meeting these requirements; assessment of emerging elevation technologies, lifecycle data management needs, and costs for managing and distributing a national-scale dataset and derived products; and candidate national elevation program alternatives that balance costs and benefits in meeting the Nation’s elevation requirements. The NEEA was sponsored by the National Digital Elevation Program (NDEP), a government coordination body with the U.S. Geological Survey (USGS) as managing partner that includes the National Geospatial-Intelligence Agency (NGA), the Federal Emergency Management Agency (FEMA), the Natural Resources Conservation Service (NRCS), the U.S. Army Corps of Engineers (USACE), and the National Oceanic and Atmospheric Administration (NOAA), among the more than a dozen agencies and organizations. The term enhanced elevation data as used in this report refers broadly to three-dimensional measurements of land or

  1. Qualitative Content Analysis

    OpenAIRE

    Philipp Mayring

    2000-01-01

    The article describes an approach of systematic, rule guided qualitative text analysis, which tries to preserve some methodological strengths of quantitative content analysis and widen them to a concept of qualitative procedure. First the development of content analysis is delineated and the basic principles are explained (units of analysis, step models, working with categories, validity and reliability). Then the central procedures of qualitative content analysis, inductive development of ca...

  2. Comprehensive growth performance, immune function, plasma biochemistry, gene expressions and cell death morphology responses to a daily corticosterone injection course in broiler chickens.

    Science.gov (United States)

    Mehaisen, Gamal M K; Eshak, Mariam G; Elkaiaty, Ahmed M; Atta, Abdel-Rahman M M; Mashaly, Magdi M; Abass, Ahmed O

    2017-01-01

    The massive meat production of broiler chickens make them continuously exposed to potential stressors that stimulate releasing of stress-related hormones like corticosterone (CORT) which is responsible for specific pathways in biological mechanisms and physiological activities. Therefore, this research was conducted to evaluate a wide range of responses related to broiler performance, immune function, plasma biochemistry, related gene expressions and cell death morphology during and after a 7-day course of CORT injection. A total number of 200 one-day-old commercial Cobb broiler chicks were used in this study. From 21 to 28 d of age, broilers were randomly assigned to one of 2 groups with 5 replicates of 20 birds each; the first group received a daily intramuscular injection of 5 mg/kg BW corticosterone dissolved in 0.5 ml ethanol:saline solution (CORT group), while the second group received a daily intramuscular injection of 0.5 ml ethanol:saline only (CONT group). Growth performance, including body weight (BW), daily weight gain (DG), feed intake (FI) and feed conversion ratio (FC), were calculated at 0, 3 and 7 d after the start of the CORT injections. At the same times, blood samples were collected in each group for hematological (TWBC's and H/L ratio), T- and B-lymphocytes proliferation and plasma biochemical assays (total protein, TP; free triiodothyronine hormone, fT3; aspartate amino transaminase, AST; and alanine amino transaminase, ALT). The liver, thymus, bursa of Fabricius and spleen were dissected and weighed, and the mRNA expression of insulin-like growth factor 1 gene (IGF-1) in liver and cell-death-program gene (caspase-9) in bursa were analyzed for each group and time; while the apoptotic/necrotic cells were morphologically detected in the spleen. From 28 to 35 d of age, broilers were kept for recovery period without CORT injection and the same sampling and parameters were repeated at the end (at 14 d after initiation of the CORT injection). In

  3. 78 FR 14697 - Final Flood Elevation Determinations

    Science.gov (United States)

    2013-03-07

    ... Communities affected elevation above ground [caret] Elevation in meters (MSL) Modified Cecil County, Maryland... 1 to Stone Run At the Stone Run +271 Town of Rising Sun, confluence. Unincorporated Areas of Cecil County. Approximately 460 feet +359 downstream of Pierce Road. Tributary 2 to Stone Run At the Stone Run...

  4. 75 FR 31361 - Proposed Flood Elevation Determinations

    Science.gov (United States)

    2010-06-03

    ... source(s) elevation ground [caret] Elevation Communities affected in meters (MSL) Effective Modified... American Vertical Datum. Depth in feet above ground. [caret] Mean Sea Level, rounded to the nearest 0.1.... Stone County, Mississippi, and Incorporated Areas Church House Branch Approximately 0.5 mile None +211...

  5. High elevation white pines educational website

    Science.gov (United States)

    Anna W. Schoettle; Michele Laskowski

    2011-01-01

    The high elevation five-needle white pines are facing numerous challenges ranging from climate change to invasion by a non-native pathogen to escalation of pest outbreaks. This website (http://www.fs.fed.us/rm/highelevationwhitepines/) serves as a primer for managers and the public on the high elevation North American five-needle pines. It presents information on each...

  6. 46 CFR 120.540 - Elevators.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Elevators. 120.540 Section 120.540 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS CARRYING MORE THAN 150 PASSENGERS OR WITH OVERNIGHT ACCOMMODATIONS FOR MORE THAN 49 PASSENGERS ELECTRICAL INSTALLATION Miscellaneous Systems and Requirements § 120.540 Elevators....

  7. Insect Population Dynamics in Commercial Grain Elevators

    Science.gov (United States)

    Data were collected in 1998-2002 from wheat stored in commercial grain elevators in south-central Kansas. Storage bins at these elevators had concrete walls and were typically 6-9 m in diameter and 30-35 m tall. A vacuum-probe sampler was used to collect ten 3-kg grain samples in the top 12 m of the...

  8. 75 FR 69892 - Final Flood Elevation Determinations

    Science.gov (United States)

    2010-11-16

    ...: * Elevation in feet (NGVD) + Elevation in feet (NAVD) State City/town/county Source of flooding Location Depth... county +899 City of Norwich, Town boundary. of Greene, Town of North Norwich, Town of Oxford, Town of...). Susquehanna River At the downstream county +965 Town of Afton, Town of boundary. Bainbridge, Village of Afton...

  9. 77 FR 6980 - Final Flood Elevation Determinations

    Science.gov (United States)

    2012-02-10

    ... in feet (NGVD) + Elevation in feet (NAVD) State City/town/county Source of flooding Location Depth in feet above ground [caret] Elevation in meters (MSL) Modified Unincorporated Areas of Nowata County... Bayou An area bounded by the +100 Town of Mayersville, county boundary to the Unincorporated Areas of...

  10. 76 FR 1535 - Final Flood Elevation Determinations

    Science.gov (United States)

    2011-01-11

    ... in feet (NGVD) + Elevation in feet (NAVD) State City/town/county Source of flooding Location Depth in feet above ground [caret] Elevation in meters (MSL) Modified Unincorporated Areas of Poinsett County... with the St. Francis River...... +212 Areas of Poinsett County. Approximately 0.45 mile downstream of...

  11. 75 FR 29253 - Proposed Flood Elevation Determinations

    Science.gov (United States)

    2010-05-25

    ...: * Elevation in feet (NGVD) + Elevation in feet (NAVD) Depth in feet above State City/town/county Source of... +21 Town of Ebro, upstream of the Unincorporated Areas confluence with the of Washington County. East... County, Colorado, and Incorporated Areas Willow Creek At the confluence with None +8,154 Unincorporated...

  12. 75 FR 68710 - Final Flood Elevation Determinations

    Science.gov (United States)

    2010-11-09

    ...: * Elevation in feet (NGVD) + Elevation in feet (NAVD) State City/town/county Source of flooding Location Depth... County, California Docket Nos.: FEMA-B-7762, FEMA-B-7795, and FEMA-B-1053 California Unincorporated Oregon Slough..... City of Montague +2503 Areas of Siskiyou and County. Unincorporated Siskiyou County...

  13. 76 FR 50918 - Final Flood Elevation Determinations

    Science.gov (United States)

    2011-08-17

    ... in feet (NGVD) + Elevation in feet (NAVD) Depth in feet State City/town/county Source of flooding... affected [caret] Elevation in meters (MSL) Modified Jones County, Texas, and Incorporated Areas Docket No.: FEMA-B-1122 Lake Fort Phantom Hill Just downstream of County +1642 City of Abilene, Highway 1082...

  14. 78 FR 10066 - Final Flood Elevation Determinations

    Science.gov (United States)

    2013-02-13

    ... follows: * Elevation in feet (NGVD) + Elevation in feet (NAVD) Depth in feet State City/town/county Source...). Scriba Creek Approximately 0.90 mile +546 Town of Amboy. upstream of County Route 23 (Potter Road.... Town of Palermo Maps are available for inspection at the Palermo Town Municipal Offices, 53 County...

  15. 77 FR 49379 - Final Flood Elevation Determinations

    Science.gov (United States)

    2012-08-16

    ... in feet (NGVD) + Elevation in feet (NAVD) State City/town/county Source of flooding Location Depth in feet above ground [caret] Elevation in meters (MSL) Modified Unincorporated Areas of Washington County... of the +35 Areas of railroad. Washington County. Approximately 2.1 miles upstream of the railroad...

  16. 75 FR 43418 - Final Flood Elevation Determinations

    Science.gov (United States)

    2010-07-26

    ... follows: * Elevation in feet (NGVD) + Elevation in feet (NAVD) State City/town/county Source of flooding... +869 Town of Peoria, upstream of Main Street. Unincorporated Areas of Ottawa County. Approximately 1.... Town of Peoria Maps are available for inspection at the Ottawa County Courthouse, 102 East Central...

  17. 78 FR 21272 - Final Flood Elevation Determinations

    Science.gov (United States)

    2013-04-10

    ... below for the modified BFEs for each community listed. These modified elevations have been published in... [Amended] 0 2. The tables published under the authority of Sec. 67.11 are amended as follows: * Elevation... Austin. upstream of 29th Avenue Southwest (County Highway 28). At the downstream side of +1205 I and M...

  18. Elevated temperatures are associated with stress in rooftop-nesting Common Nighthawk (Chordeiles minor) chicks.

    Science.gov (United States)

    Newberry, Gretchen N; Swanson, David L

    2018-01-01

    Grasslands and riparian forests in southeastern South Dakota have been greatly reduced since historical times, primarily due to conversion to row-crop agriculture. Common Nighthawk ( Chordeiles minor ) nesting habitat includes grasslands, open woodlands and urban rooftops, but nesting sites in southeastern South Dakota are confined to rooftops, as natural nesting habitat is limited. Nighthawks nesting on exposed rooftop habitats may encounter thermal conditions that increase operative temperatures relative to vegetated land cover types. Mean humidity has increased and mean wind speed and cloud cover have decreased during the nighthawk breeding season from 1948 to 2016 in southeastern South Dakota. These changes might contribute to increasing operative temperatures at exposed rooftop nest sites and this could influence chick condition. We studied nest micro-climate and the plasma stress response for 24 rooftop-nesting nighthawk chicks from 17 nests during 2015 and 2016. High humidity prior to blood collection reduced both baseline and stress-induced plasma corticosterone (CORT). In contrast, high maximum temperatures during the day before sampling increased stress-induced CORT. The magnitude of the chick stress response was significantly negatively related to maximum wind speed for the week prior to CORT measurement. Other weather and micro-climate variables were not significant effectors of CORT metrics. Most chicks had low baseline CORT and were able to mount a stress response, but a subset of chicks ( n = 4) showed elevated baseline CORT and a negative association between the magnitude of stress response and ambient temperature. For this subset, mean ambient temperature for the day before sampling was significantly higher (2.3°C) than for chicks with typical baseline CORT levels. These data suggest that regional climate change trends could affect the ability of nighthawk chicks to mount a stress response, which, in turn, might influence the susceptibility of

  19. Effects of elevated temperature postharvest on color aspect, physiochemical characteristics, and aroma components of pineapple fruits.

    Science.gov (United States)

    Liu, Chuanhe; Liu, Yan

    2014-12-01

    In this work, 2 separate experiments were performed to describe the influence of elevated temperature treatments postharvest on the color, physiochemical characteristics and aroma components of pineapple fruits during low-temperature seasons. The L* (lightness) values of the skin and pulp of pineapple fruits were decreased. The a* (greenness-redness) and b* (blueness-yellowness) values of the skin and pulp were all markedly increased. The elevated temperature significantly increased the contents of total soluble solids (TSS) and slightly affected contents of vitamin C (nonsignificant). Titratable acidity (TA) of pineapple fruits were notably decreased, whereas the values of TSS/TA of pineapple fruits were significantly increased. The firmness of the pineapple fruits decreased and more esters and alkenes were identified. The total relative contents of esters were increased, and the total relative contents of alkenes were decreased. © 2014 Institute of Food Technologists®

  20. Maternal postpartum corticosterone and fluoxetine differentially affect adult male and female offspring on anxiety-like behavior, stress reactivity, and hippocampal neurogenesis.

    Science.gov (United States)

    Gobinath, Aarthi R; Workman, Joanna L; Chow, Carmen; Lieblich, Stephanie E; Galea, Liisa A M

    2016-02-01

    Postpartum depression (PPD) affects approximately 15% of mothers, disrupts maternal care, and can represent a form of early life adversity for the developing offspring. Intriguingly, male and female offspring are differentially vulnerable to the effects of PPD. Antidepressants, such as fluoxetine, are commonly prescribed for treating PPD. However, fluoxetine can reach offspring via breast milk, raising serious concerns regarding the long-term consequences of infant exposure to fluoxetine. The goal of this study was to examine the long-term effects of maternal postpartum corticosterone (CORT, a model of postpartum stress/depression) and concurrent maternal postpartum fluoxetine on behavioral, endocrine, and neural measures in adult male and female offspring. Female Sprague-Dawley dams were treated daily with either CORT or oil and fluoxetine or saline from postnatal days 2-23, and offspring were weaned and left undisturbed until adulthood. Here we show that maternal postpartum fluoxetine increased anxiety-like behavior and impaired hypothalamic-pituitary-adrenal (HPA) axis negative feedback in adult male, but not female, offspring. Furthermore, maternal postpartum fluoxetine increased the density of immature neurons (doublecortin-expressing) in the hippocampus of adult male offspring but decreased the density of immature neurons in adult female offspring. Maternal postpartum CORT blunted HPA axis negative feedback in males and tended to increase density of immature neurons in males but decreased it in females. These results indicate that maternal postpartum CORT and fluoxetine can have long-lasting effects on anxiety-like behavior, HPA axis negative feedback, and adult hippocampal neurogenesis and that adult male and female offspring are differentially affected by these maternal manipulations. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Brain antioxidant effect of mirtazapine and reversal of sedation by its combination with alpha-lipoic acid in a model of depression induced by corticosterone.

    Science.gov (United States)

    Oliveira, Tatiana de Queiroz; de Sousa, Caren Nádia Soares; Vasconcelos, Germana Silva; de Sousa, Luciene Costa; de Oliveira, Anneheydi Araújo; Patrocínio, Cláudio Felipe Vasconcelos; Medeiros, Ingridy da Silva; Honório Júnior, José Eduardo Ribeiro; Maes, Michael; Macedo, Danielle; Vasconcelos, Silvânia Maria Mendes

    2017-09-01

    Depression is accompanied by activated neuro-oxidative and neuro-nitrosative pathways, while targeting these pathways has clinical efficacy in depression. This study aimed to investigate the effects of mirtazapine (MIRT) alone and combined with alpha-lipoic acid (ALA) against corticosterone (CORT) induced behavioral and oxidative alterations. Male mice received vehicle or CORT 20mg/kg during 14 days. From the 15th to 21st days they were divided in groups administered: vehicle, MIRT 3mg/kg or the combinations MIRT+ALA100 or MIRT+ALA200. On the 21st day of treatment, the animals were subjected to behavioral tests. Twenty-four hours after the last drug administration hippocampus (HC) and striatum (ST) were dissected for the determination reduced glutathione (GSH), lipid peroxidation (LP) and nitrite levels. CORT induced anxiety- and depressive-like behaviors as observed by increased immobility time in the tail suspension test and decreased sucrose consumption. MIRT or MIRT+ALA are effective in reversing anxiety- and depressive-like behaviors induced by CORT. CORT and MIRT alone prolonged sleeping time and this effect was reversed by MIRT+ALA. CORT significantly increased LP, which was reversed by MIRT or MIRT+ALA. Nitrite levels were increased in CORT-treated animals and reversed by MIRT+ALA200 (HC), MIRT or MIRT+ALA (ST). A relative small sample size and lack of a washout period between drug administration and behavioral testing. MIRT or MIRT+ALA reverse CORT-induced anxiety- and depressive-like behaviors probably via their central antioxidant effects. Augmentation of MIRT with ALA may reverse sedation, an important side effect of MIRT. Randomized controlled studies are needed to examine the clinical efficacy of this combination in human depression. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Brain aromatase and circulating corticosterone are rapidly regulated by combined acute stress and sexual interaction in a sex-specific manner.

    Science.gov (United States)

    Dickens, M J; Balthazart, J; Cornil, C A

    2012-10-01

    Neural production of 17β-oestradiol via aromatisation of testosterone may play a critical role in rapid, nongenomic regulation of physiological and behavioural processes. In brain nuclei implicated in the control of sexual behaviour, sexual or stressfull stimuli induce, respectively, a rapid inhibition or increase in preoptic aromatase activity (AA). In the present study, we tested quail that were either nonstressed or acutely stressed (15 min of restraint) immediately before sexual interaction (5 min) with stressed or nonstressed partners. We measured nuclei-specific AA changes, corresponding behavioural output, fertilisation rates and corticosterone (CORT) concentrations. In males, sexual interaction rapidly reversed stress-induced increases of AA in the medial preoptic nucleus (POM). This time scale (sexual stimuli on POM AA may actively preserve sexual behaviour despite stress exposure. We also found distinct sex differences in contextual physiological responses: males did not show any effect of partner status, whereas females responded to both their stress exposure and the male partner's stress exposure at the level of circulating CORT and AA. In addition, fertilisation rates and female CORT correlated with the male partner's exhibition of sexually aggressive behaviour, suggesting that female perception of the male can affect their physiology as much as direct stress. Overall, male reproduction appears relatively simple: sexual stimuli, irrespective of stress, drives major neural changes including rapid reversal of stress-induced changes of AA. By contrast, female reproduction appears more nuanced and context specific, with subjects responding physiologically and behaviourally to stress, the male partner's stress exposure, and female-directed male behaviour. © 2012 The Authors. Journal of Neuroendocrinology © 2012 British Society for Neuroendocrinology.

  3. The prolactin response to an acute stressor in relation to parental care and corticosterone in a short-lived bird, the Eurasian hoopoe.

    Science.gov (United States)

    Schmid, Baptiste; Chastel, Olivier; Jenni, Lukas

    2011-10-01

    Prolactin plays an important role in mediating parental care in birds, but little is known about changes in prolactin levels when animals disrupt their reproductive behaviour during emergency life-history stages. We investigated the variation of prolactin levels with breeding stage, sex, body condition and as a response to a standardized acute stressor in a small short-lived bird, the Eurasian hoopoe Upupa epops under natural field conditions. We found higher baseline levels of prolactin in females during the brooding phase than in their mates which feed them and their chicks at this stage. Moreover, this is the first report of a differential prolactin stress-response between sexes with contrasting parental care within a breeding phase. Capture, handling and restraint induced a clear decrease of prolactin levels which was less pronounced in females at the very early stage of brooding compared to females in later stages. In contrast, the prolactin stress response in males remained nearly constant over the breeding stages and was stronger than in females. Baseline levels of prolactin, but not handling-induced levels, were positively correlated with body condition. We found a weak relationship between the decrease in prolactin due to acute handling stress and handling-induced levels of corticosterone. Taken together, both baseline and stress response levels of prolactin were related to the amount of parental care, although we found no relationship with reproductive success. It appears that the response to an acute stressor in prolactin levels is finely tuned to parental duties and investment. Hence, prolactin appears to be involved in mediating the trade-off between current reproduction versus self-maintenance and future reproduction. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. Climate Impacts on Soil Carbon Processes along an Elevation Gradient in the Tropical Luquillo Experimental Forest

    Directory of Open Access Journals (Sweden)

    Dingfang Chen

    2017-03-01

    Full Text Available Tropical forests play an important role in regulating the global climate and the carbon cycle. With the changing temperature and moisture along the elevation gradient, the Luquillo Experimental Forest in Northeastern Puerto Rico provides a natural approach to understand tropical forest ecosystems under climate change. In this study, we conducted a soil translocation experiment along an elevation gradient with decreasing temperature but increasing moisture to study the impacts of climate change on soil organic carbon (SOC and soil respiration. As the results showed, both soil carbon and the respiration rate were impacted by microclimate changes. The soils translocated from low elevation to high elevation showed an increased respiration rate with decreased SOC content at the end of the experiment, which indicated that the increased soil moisture and altered soil microbes might affect respiration rates. The soils translocated from high elevation to low elevation also showed an increased respiration rate with reduced SOC at the end of the experiment, indicating that increased temperature at low elevation enhanced decomposition rates. Temperature and initial soil source quality impacted soil respiration significantly. With the predicted warming climate in the Caribbean, these tropical soils at high elevations are at risk of releasing sequestered carbon into the atmosphere.

  5. The benefits of improved national elevation data

    Science.gov (United States)

    Snyder, Gregory I.

    2013-01-01

    This article describes how the National Enhanced Elevation Assessment (NEEA) has identified substantial benefits that could come about if improved elevation data were publicly available for current and emerging applications and business uses such as renewable energy, precision agriculture, and intelligent vehicle navigation and safety. In order to support these diverse needs, new national elevation data with higher resolution and accuracy are needed. The 3D Elevation Program (3DEP) initiative was developed to meet the majority of these needs and it is expected that 3DEP will result in new, unimagined information services that would result in job growth and the transformation of the geospatial community. Private-sector data collection companies are continuously evolving sensors and positioning technologies that are needed to collect improved elevation data. An initiative of this scope might also provide an opportunity for companies to improve their capabilities and produce even higher data quality and consistency at a pace that might not have otherwise occurred.

  6. Elevated oxidized glutathione in cystinotic proximal tubular epithelial cells.

    Science.gov (United States)

    Wilmer, Martijn J G; de Graaf-Hess, Adriana; Blom, Henk J; Dijkman, Henry B P M; Monnens, Leo A; van den Heuvel, Lambertus P; Levtchenko, Elena N

    2005-11-18

    Cystinosis, the most frequent cause of inborn Fanconi syndrome, is characterized by the lysosomal cystine accumulation, caused by mutations in the CTNS gene. To elucidate the pathogenesis of cystinosis, we cultured proximal tubular cells from urine of cystinotic patients (n = 9) and healthy controls (n = 9), followed by immortalization with human papilloma virus (HPV E6/E7). Obtained cell lines displayed basolateral polarization, alkaline phosphatase activity, and presence of aminopeptidase N (CD-13) and megalin, confirming their proximal tubular origin. Cystinotic cell lines exhibited elevated cystine levels (0.86 +/- 0.95 nmol/mg versus 0.09 +/- 0.01 nmol/mg protein in controls, p = 0.03). Oxidized glutathione was elevated in cystinotic cells (1.16 +/- 0.83 nmol/mg versus 0.29 +/- 0.18 nmol/mg protein, p = 0.04), while total glutathione, free cysteine, and ATP contents were normal in these cells. In conclusion, elevated oxidized glutathione in cystinotic proximal tubular epithelial cell lines suggests increased oxidative stress, which may contribute to tubular dysfunction in cystinosis.

  7. Hydroponics: Content and Rationale

    Science.gov (United States)

    Ernst, Jeremy V.; Busby, Joe R.

    2009-01-01

    Technology education has the means of becoming the catalyst for integrated content and curricula, especially in core academic areas, such as science and mathematics, where it has been found difficult to incorporate other subject matter. Technology is diverse enough in nature that it can be addressed by a variety of content areas, serving as a true…

  8. Branded content infantil

    OpenAIRE

    Raúl RODRÍGUEZ-FERRÁNDIZ

    2017-01-01

    Reseña del libro Bajo la influencia del branded content. Efectos de los contenidos de marca en niños y jóvenes. Review of the book Bajo la influencia del branded content. Efectos de los contenidos de marca en niños y jóvenes.

  9. Branded content infantil

    Directory of Open Access Journals (Sweden)

    Raúl RODRÍGUEZ-FERRÁNDIZ

    2017-01-01

    Full Text Available Reseña del libro Bajo la influencia del branded content. Efectos de los contenidos de marca en niños y jóvenes. Review of the book Bajo la influencia del branded content. Efectos de los contenidos de marca en niños y jóvenes.

  10. Print advertising: vivid content

    NARCIS (Netherlands)

    Fennis, B.M.; Das, E.; Fransen, M.L.

    2012-01-01

    The present research examines the effects of vivid ad content in two types of appeal in print ads as a function of individual differences in chronically experienced vividness of visual imagery. For informational ads for a functional product, vivid ad content strongly affected individuals high in

  11. Print advertising : Vivid content

    NARCIS (Netherlands)

    Fennis, B.M.; Das, E.H.H.J.; Fransen, M.L.

    The present research examines the effects of vivid ad content in two types of appeal in print ads as a function of individual differences in chronically experienced vividness of visual imagery. For informational ads for a functional product, vivid ad content strongly affected individuals high in

  12. Qualitative Content Analysis

    OpenAIRE

    Satu Elo; Maria Kääriäinen; Outi Kanste; Tarja Pölkki; Kati Utriainen; Helvi Kyngäs

    2014-01-01

    Qualitative content analysis is commonly used for analyzing qualitative data. However, few articles have examined the trustworthiness of its use in nursing science studies. The trustworthiness of qualitative content analysis is often presented by using terms such as credibility, dependability, conformability, transferability, and authenticity. This article focuses on trustworthiness based on a review of previous studie...

  13. Changes in Nutritional Metabolites of Young Ginger (Zingiber officinale Roscoe in Response to Elevated Carbon Dioxide

    Directory of Open Access Journals (Sweden)

    Ali Ghasemzadeh

    2014-10-01

    Full Text Available The increase of atmospheric CO2 due to global climate change or horticultural practices has direct and indirect effects on food crop quality. One question that needs to be asked, is whether CO2 enrichment affects the nutritional quality of Malaysian young ginger plants. Responses of total carbohydrate, fructose, glucose, sucrose, protein, soluble amino acids and antinutrients to either ambient (400 μmol/mol and elevated (800 μmol/mol CO2 treatments were determined in the leaf and rhizome of two ginger varieties namely Halia Bentong and Halia Bara. Increasing of CO2 level from ambient to elevated resulted in increased content of total carbohydrate, sucrose, glucose, and fructose in the leaf and rhizome of ginger varieties. Sucrose was the major sugar followed by glucose and fructose in the leaf and rhizome extract of both varieties. Elevated CO2 resulted in a reduction of total protein content in the leaf (H. Bentong: 38.0%; H. Bara: 35.4% and rhizome (H. Bentong: 29.0%; H. Bara: 46.2%. In addition, under CO2 enrichment, the concentration of amino acids increased by approximately 14.5% and 98.9% in H. Bentong and 12.0% and 110.3% in H. Bara leaf and rhizome, respectively. The antinutrient contents (cyanide and tannin except phytic acid were influenced significantly (P ≤ 0.05 by CO2 concentration. Leaf extract of H. Bara exposed to elevated CO2 exhibited highest content of cyanide (336.1 mg HCN/kg DW, while, highest content of tannin (27.5 g/kg DW and phytic acid (54.1 g/kg DW were recorded from H.Bara rhizome grown under elevated CO2. These results demonstrate that the CO2 enrichment technique could improve content of some amino acids and antinutrients of ginger as a food crop by enhancing its nutritional and health-promoting properties.

  14. Social video content delivery

    CERN Document Server

    Wang, Zhi; Zhu, Wenwu

    2016-01-01

    This brief presents new architecture and strategies for distribution of social video content. A primary framework for socially-aware video delivery and a thorough overview of the possible approaches is provided. The book identifies the unique characteristics of socially-aware video access and social content propagation, revealing the design and integration of individual modules that are aimed at enhancing user experience in the social network context. The change in video content generation, propagation, and consumption for online social networks, has significantly challenged the traditional video delivery paradigm. Given the massive amount of user-generated content shared in online social networks, users are now engaged as active participants in the social ecosystem rather than as passive receivers of media content. This revolution is being driven further by the deep penetration of 3G/4G wireless networks and smart mobile devices that are seamlessly integrated with online social networking and media-sharing s...

  15. Montessori Preschool Elevates and Equalizes Child Outcomes: A Longitudinal Study.

    Science.gov (United States)

    Lillard, Angeline S; Heise, Megan J; Richey, Eve M; Tong, Xin; Hart, Alyssa; Bray, Paige M

    2017-01-01

    Quality preschool programs that develop the whole child through age-appropriate socioemotional and cognitive skill-building hold promise for significantly improving child outcomes. However, preschool programs tend to either be teacher-led and didactic, or else to lack academic content. One preschool model that involves both child-directed, freely chosen activity and academic content is Montessori. Here we report a longitudinal study that took advantage of randomized lottery-based admission to two public Montessori magnet schools in a high-poverty American city. The final sample included 141 children, 70 in Montessori and 71 in other schools, most of whom were tested 4 times over 3 years, from the first semester to the end of preschool (ages 3-6), on a variety of cognitive and socio-emotional measures. Montessori preschool elevated children's outcomes in several ways. Although not different at the first test point, over time the Montessori children fared better on measures of academic achievement, social understanding, and mastery orientation, and they also reported relatively more liking of scholastic tasks. They also scored higher on executive function when they were 4. In addition to elevating overall performance on these measures, Montessori preschool also equalized outcomes among subgroups that typically have unequal outcomes. First, the difference in academic achievement between lower income Montessori and higher income conventionally schooled children was smaller at each time point, and was not (statistically speaking) significantly different at the end of the study. Second, defying the typical finding that executive function predicts academic achievement, in Montessori classrooms children with lower executive function scored as well on academic achievement as those with higher executive function. This suggests that Montessori preschool has potential to elevate and equalize important outcomes, and a larger study of public Montessori preschools is warranted.

  16. Montessori Preschool Elevates and Equalizes Child Outcomes: A Longitudinal Study

    Directory of Open Access Journals (Sweden)

    Angeline S. Lillard

    2017-10-01

    Full Text Available Quality preschool programs that develop the whole child through age-appropriate socioemotional and cognitive skill-building hold promise for significantly improving child outcomes. However, preschool programs tend to either be teacher-led and didactic, or else to lack academic content. One preschool model that involves both child-directed, freely chosen activity and academic content is Montessori. Here we report a longitudinal study that took advantage of randomized lottery-based admission to two public Montessori magnet schools in a high-poverty American city. The final sample included 141 children, 70 in Montessori and 71 in other schools, most of whom were tested 4 times over 3 years, from the first semester to the end of preschool (ages 3–6, on a variety of cognitive and socio-emotional measures. Montessori preschool elevated children’s outcomes in several ways. Although not different at the first test point, over time the Montessori children fared better on measures of academic achievement, social understanding, and mastery orientation, and they also reported relatively more liking of scholastic tasks. They also scored higher on executive function when they were 4. In addition to elevating overall performance on these measures, Montessori preschool also equalized outcomes among subgroups that typically have unequal outcomes. First, the difference in academic achievement between lower income Montessori and higher income conventionally schooled children was smaller at each time point, and was not (statistically speaking significantly different at the end of the study. Second, defying the typical finding that executive function predicts academic achievement, in Montessori classrooms children with lower executive function scored as well on academic achievement as those with higher executive function. This suggests that Montessori preschool has potential to elevate and equalize important outcomes, and a larger study of public Montessori

  17. Elevated tumour marker: an indication for imaging?

    LENUS (Irish Health Repository)

    McMahon, Colm J

    2012-02-01

    INTRODUCTION: The purpose of this study was to evaluate the utility of imaging examinations in patients with elevated tumour markers when (a) the tumour marker is not validated for as a primary diagnostic test; (b) the patient had no personal history of cancer and (c) the patient had no other imaging indication. MATERIALS AND METHODS: Patients without known cancer who had abnormal carcinoembryonic antigen, CA19-9, CA125 and\\/or CA15-3 serology over a one-year period were included. A retrospective medical record review was performed to assess the number of these cases who underwent imaging because of \\'elevated tumour marker\\' in the absence of a clinical indication for imaging. The number and result of these imaging studies were evaluated. RESULTS: Eight hundred and nineteen patients were included. Of those, 25 patients (mean age: 67.8 [range 41-91] y), were imaged to evaluate: \\'elevated tumour marker\\'. They underwent 29 imaging studies (mean [+\\/-standard deviation (SD)] per patient = 1.2 [+\\/-0.4]), and had 42 elevated tumour marker serology tests (mean [+\\/-SD] per patient = 1.7 [+\\/-0.7]). Four patients had >1 imaging test. No patient had an imaging study which diagnosed a malignancy or explained the elevated tumour marker. CONCLUSION: The non-judicious use of tumour markers can prompt further unnecessary investigations including imaging. In this study, there was no positive diagnostic yield for imaging performed for investigation of \\'elevated tumour marker\\'. \\'Elevated tumour marker\\

  18. ST Elevations and Elevated Cardiac Enzymes Not Always a STEMI: Two Case Reports.

    Science.gov (United States)

    Fernández Fernández, Juan; Deliz-Guzmán, Claudia; Andino-Colón, César; Claudio-Hernández, Héctor; Lugo-Amador, Nannette

    2016-01-01

    Chest pain is a common complaint in the emergency department (ED). Besides a careful history and physical exam; electrocardiogram, laboratory tests and imaging studies are widely available diagnostic tests that are used for patient assessment. When ST elevation and elevated cardiac enzymes are present the most likely diagnosis are ST elevation myocardial infarction (STEMI) or myocarditis. In this case report we present two low risk patients for major adverse cardiac event with ST elevation and elevated cardiac enzymes and how a careful risk assessment and detailed electrocardiogram evaluation could help differentiating between these two diagnoses.

  19. Involvement of high plasma corticosterone status and activation of brain regional serotonin metabolism in long-term erythrosine-induced rearing motor hyper activity in young adult male rats.

    Science.gov (United States)

    Dalal, Arindam; Poddar, Mrinal K

    2010-07-01

    Long-term consumption of artificial food color(s) can induce behavioral hyperactivity in human and experimental animals, but no neurobiochemical mechanism is defined. This study investigates the role of brain regional serotonin metabolism including its turnover, MAO-A activity, and plasma corticosterone status in relation to behavioral disturbances due to an artificial food color, erythrosine. Long-term (15 or 30 consecutive days) erythrosine administration with higher dosage (10 or 100 mg/kg/day, p.o.) produced optimal hyperactive state in exploratory behavior (rearing motor activity) after 2 h of last erythrosine administration, in young adult male albino rats. Erythrosine-induced stimulation in brain regional (medulla-pons, hypothalamus, hippocampus, and corpus striatum) serotonin metabolism (measuring steady state levels of 5-HT and 5-HIAA, MAO-A activity), including its turnover (pargyline-induced 5-HT accumulation and 5-HIAA declination rate), as well as plasma corticosterone were also observed depending on dosage(s) and duration(s) of erythrosine administration under similar experimental conditions. The lower dosage of erythrosine (1 mg/kg/day, p.o.) under similar conditions did not affect either of the above. These findings suggests (a) the induction as well as optimal effect of long-term erythrosine (artificial food color) on behavioral hyperactivity in parallel with increase in 5-HT level in brain regions, (b) the activation of brain regional serotonin biosynthesis in accordance with plasma corticosterone status under such behavioral hyperactivity, and (c) a possible inhibitory influence of the enhanced glucocorticoids-serotonin interaction on erythrosine-induced rearing motor hyperactivity in young adult mammals.

  20. Effect of elevated atmospheric CO2 on carbohydrate partitioning and plant growth

    NARCIS (Netherlands)

    Stulen, G; mw. Steg, K.; mw. Schalkwijk, I.; Posthumus, F.S

    2000-01-01

    The effect of elevated CO2 on changes in shoot and root soluble carbohydrate and starch content, and various growth parameters was investigated in an apoplastic (Bellis perennis) and a symplastic loader (Epilobium hirsutum). Comparison with data on other plant species, grown under the same climatic

  1. Elevation-based upscaling of organic carbon stocks in High-Arctic permafrost terrain

    DEFF Research Database (Denmark)

    Weiss, Niels; Faucherre, Samuel; Lampiris, Nikos

    2017-01-01

    Accurate quantity and distribution estimates of permafrost soil organic carbon (SOC) stocks are needed to project potential feedbacks to climate, following warming. Still, upscaling from local field observations to regional estimates to circumarctic assessments remains a challenge. Here we explore...... elevation-based upscaling techniques for High-Arctic permafrost SOC stocks. We combine two detailed, high-resolution SOC inventories on Spitsbergen (Svalbard) with regional validation data. We find a clear relationship between elevation and SOC content, and use this observed exponential correlation, as well...... as discrete elevation classes, as upscaling models for Spitsbergen. We estimate the total amount of permafrost SOC currently present in soils on Spitsbergen to be 105.36 Tg (0.11 Pg), with a mean SOC content of 2.84 ± 0.74 kg C m−2 (mean ± 95% confidence interval). Excluding glaciers and permanent snowfields...

  2. Effect of Home Cage Bedding in the Induction Chamber on Serum Cortisol and Corticosterone Levels in Response to Isoflurane-induced Anesthesia in C57BL/6J Mice.

    Science.gov (United States)

    Reiter, Cara P; Christy, Amanda C; Olsen, Cara H; Bentzel, David E

    2017-03-01

    Mice are routinely anesthetized with isoflurane in an induction chamber. The AVMA Guidelines for the Euthanasia of Animals states that distress should be minimized during euthanasia but does not address this point in regard to induction of anesthesia. Here we evaluated the potential for familiar surroundings to reduce the adrenocortical response of mice during anesthesia induction with isoflurane. However, adding bedding from the animals' home cage to the induction chamber failed to significantly reduce serum cortisol or corticosterone levels in male and female C57BL/6J mice. These results indicate that familiar surroundings do not appear sufficient to reduce the adrenocortical response of mice during anesthesia induction with isoflurane.

  3. Influence of soil moisture content on surface albedo and soil thermal ...

    Indian Academy of Sciences (India)

    Half hourly data of soil moisture content, soil temperature, solar irradiance, and reflectance are measured ... and the influence of solar elevation angle and cloud cover are also investigated. .... ters are important factors in climate modelling and.

  4. Keauhou, Hawaii Coastal Digital Elevation Model

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA's National Geophysical Data Center (NGDC) is building high-resolution digital elevation models (DEMs) for select U.S. coastal regions. These integrated...

  5. Atka, Alaska Coastal Digital Elevation Model

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA's National Geophysical Data Center (NGDC) is building high-resolution digital elevation models (DEMs) for select U.S. coastal regions. These integrated...

  6. King Cove, Alaska Coastal Digital Elevation Model

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA's National Geophysical Data Center (NGDC) is building high-resolution digital elevation models (DEMs) for select U.S. coastal regions. These integrated...

  7. Chenega, Alaska Coastal Digital Elevation Model

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA's National Geophysical Data Center (NGDC) is building high-resolution digital elevation models (DEMs) to support individual coastal States as part of the...

  8. Juneau, Alaska Coastal Digital Elevation Model

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA's National Geophysical Data Center (NGDC) is building high-resolution digital elevation models (DEMs) to support individual coastal States as part of the...

  9. Lahaina, Hawaii Coastal Digital Elevation Model

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA's National Geophysical Data Center (NGDC) is building high-resolution digital elevation models (DEMs) for select U.S. coastal regions. These integrated...

  10. Kawaihae, Hawaii Coastal Digital Elevation Model

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA's National Geophysical Data Center (NGDC) is building high-resolution digital elevation models (DEMs) for select U.S. coastal regions. These integrated...

  11. Shaded Relief of Minnesota Elevation - Color

    Data.gov (United States)

    Minnesota Department of Natural Resources — This file is a product of a shaded relief process on the 30 meter resolution Digital Elevation Model data (dem30im3). This image was created using a custom AML...

  12. Shaded Relief of Minnesota Elevation - Black & White

    Data.gov (United States)

    Minnesota Department of Natural Resources — This file is a product of a shaded relief process on the 30 meter resolution Digital Elevation Model data (dem30im3). This image was created using a custom AML...

  13. Tatitlek, Alaska Coastal Digital Elevation Model

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA's National Geophysical Data Center (NGDC) is building high-resolution digital elevation models (DEMs) to support individual coastal States as part of the...

  14. Hoonah, Alaska Coastal Digital Elevation Model

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA's National Geophysical Data Center (NGDC) is building high-resolution digital elevation models (DEMs) to support individual coastal States as part of the...

  15. Whittier, Alaska Coastal Digital Elevation Model

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA's National Geophysical Data Center (NGDC) is building high-resolution digital elevation models (DEMs) to support individual coastal States as part of the...

  16. Gustavus, Alaska Coastal Digital Elevation Model

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA's National Geophysical Data Center (NGDC) is building high-resolution digital elevation models (DEMs) to support individual coastal States as part of the...

  17. Taholah, Washington Coastal Digital Elevation Model

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA's National Geophysical Data Center (NGDC) is building high-resolution digital elevation models (DEMs) for select U.S. coastal regions. These integrated...

  18. Chignik, Alaska Coastal Digital Elevation Model

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA's National Geophysical Data Center (NGDC) is building high-resolution digital elevation models (DEMs) for select U.S. coastal regions. These integrated...

  19. Panama City, Florida Coastal Digital Elevation Model

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA's National Geophysical Data Center (NGDC) is building high-resolution digital elevation models (DEMs) for select U.S. coastal regions. These integrated...

  20. Mariana Trench Bathymetric Digital Elevation Model

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA's National Geophysical Data Center (NGDC) created a bathymetric digital elevation model (DEM) for the Mariana Trench and adjacent seafloor in the Western...