Sibling presence during fostering ameliorates endocrine stress profile changes in a social rodent species (Octodon degus) in a sex-specific manner.

During early life, disruption of the parent-offspring bond can substantially impact development of offspring physiology and behavior. In rodents, it has been well-documented that parental separation, reduction in parental care, and cross-fostering can affect development of the endocrine stress response. For social species, however, several social factors may mitigate the stress of cross-fostering, such as remaining with other known adult caregivers or siblings.

Social environment and anogenital distance length phenotype interact to explain testosterone levels in a communally rearing rodent: Part 1: The male side.

In vertebrates, male testosterone levels vary across the year being generally higher during the mating season relative to the offspring rearing season. However, male testosterone levels may also be associated with male anogenital distance (AGD) length (a proxy of prenatal androgen exposition), and influenced by the social group environment. In social species, it has been proposed that high levels of testosterone could be incompatible with the development of an amicable social environment.

COVID-19 as a chronic stressor and the importance of individual identity: A data-driven look at academic productivity during the pandemic.

The COVID-19 pandemic impacted personal and professional life. For academics, research, teaching, and service tasks were upended and we all had to navigate the altered landscape. However, some individuals faced a disproportionate burden, particularly academics with minoritized identities or those who were early career, were caregivers, or had intersecting identities.

Fostered offspring develop hyper-reactive endocrine stress responses in a plural-breeding rodent, Octodon degus.

Long-term parental separation can lead to altered behavioral and physical development in human children. Rodent models are popular for studying parent-child separation, and several studies have found that maternal separation leads to chronic changes in the endocrine stress response. However, while human children are generally raised by multiple caregivers, most rodent studies utilize solitary breeding species.

Corticosterone Alters Body Weight, but Not Metabolites, during Chronic Stress.

AbstractThe stress response is partially mediated by increased levels of circulating glucocorticoids. While the stress response may be adaptive in the short term, chronically elevated levels of glucocorticoids can be pathological. We aimed to verify that chronic stress causes metabolic dysregulation via increased corticosterone (Cort) exposure by monitoring free fatty acid (FFA) concentrations (evidence of fat breakdown), uric acid concentrations (evidence of protein breakdown), and organ weights (furcular fat, abdominal fat, liver, and pectoralis muscle) in chronically stressed juvenile house sparrows ().

Interdisciplinary Care and Preparedness for Kidney Failure Management in a High-Risk Population.

Rationale & Objective: Interdisciplinary care may improve health outcomes in patients with chronic kidney disease (CKD). Few studies have evaluated this model of health care delivery in racial and ethnic minorities.

Study Design: Retrospective cohort study.

Corticosterone's roles in avian migration: Assessment of three hypotheses.

While corticosterone (CORT) is often suggested to be an important hormone regulating processes necessary for avian migration, there has been no systematic assessment of CORT's role in migration. Prior to migration, birds increase fat stores and flight muscle size to prepare for the high energetic costs associated with long-distance flight. After attaining sufficient energetic stores, birds then make the actual decision to depart from their origin site.

Onset of Daily Activity in a Female Songbird Is Related to Peak-Induced Estradiol Levels.

Research in captive birds and mammals has demonstrated that circadian (i.e., daily) behavioral rhythms are altered in response to increases in sex-steroid hormones.

Corticosterone negative feedback is weaker during spring vs. autumn migration in a songbird (Junco hyemalis).

Birds face many challenges during seasonal migrations and must make important decisions about whether to accelerate, maintain, or delay travel to their final destinations. Spring migration is likely more challenging than autumn migration as spring journeys are completed more quickly and weather conditions are harsher during this time. These differential challenges may be reflected in the endocrine stress response, as the hypothalamic-pituitary-adrenal (HPA) axis is important for both daily energetic needs and coping with stressors.

Early-breeding females experience greater telomere loss.

Annual reproductive success is often highest in individuals that initiate breeding early, yet relatively few individuals start breeding during this apparently optimal time. This suggests that individuals, particularly females who ultimately dictate when offspring are born, incur costs by initiating reproduction early in the season. We hypothesized that increases in the ageing rate of somatic cells may be one such cost.

Seasonally sympatric but allochronic: differential expression of hypothalamic genes in a songbird during gonadal development.

Allochrony, the mismatch of reproductive schedules, is one mechanism that can mediate sympatric speciation and diversification. In songbirds, the transition into breeding condition and gonadal growth is regulated by the hypothalamic-pituitary-gonadal (HPG) axis at multiple levels. We investigated whether the difference in reproductive timing between two seasonally sympatric subspecies of dark-eyed juncos () was related to gene expression along the HPG axis.

Changes in processes downstream of the hypothalamus are associated with seasonal follicle development in a songbird, the dark-eyed junco (Junco hyemalis).

Mechanisms related to seasonal reproductive timing in vertebrates have received far more study in males than in females, despite the fact that female timing decisions dictate when rearing of offspring will occur. Production and release of gonadotropin-releasing hormone (GnRH) by the hypothalamus stimulates the pituitary to secrete gonadotropins, initiating the beginning stages of gonadal recrudescence and production of the sex steroids, testosterone and estradiol, which are necessary to prime the liver for secretion of yolk precursors in breeding female birds. While stimulation by the hypothalamus can occur during the pre-breeding period, egg development itself is likely regulated downstream of the hypothalamus.

Chronological and Biological Age Predict Seasonal Reproductive Timing: An Investigation of Clutch Initiation and Telomeres in Birds of Known Age.

Female vertebrates that breed earlier in the season generally have greater reproductive success. However, evidence suggests that breeding early may be costly, thus leading to the prediction that females with fewer future reproductive events will breed earlier in the season. While chronological age is a good indicator of remaining life span, telomere lengths may also be good biomarkers of longevity as they potentially reflect lifetime wear and tear (i.

Stress, sleep, and sex: A review of endocrinological research in Octodon degus.

The Common Degu (Octodon degus) is a small rodent endemic to central Chile. It has become an important model for comparative vertebrate endocrinology because of several uncommon life-history features - it is diurnal, shows a high degree of sociality, practices plural breeding with multiple females sharing natal burrows, practices communal parental care, and can easily be studied in the laboratory and the field. Many studies have exploited these features to make contributions to comparative endocrinology.

Vascular access placement in patients with chronic kidney disease Stages 4 and 5 attending an inner city nephrology clinic: a cohort study and survey of providers.

Background: The majority of incident hemodialysis (HD) patients initiate dialysis via catheters. We sought to identify factors associated with initiating hemodialysis with a functioning arterio-venous (AV) access.

Methods: We conducted a retrospective chart review of all adult patients, age >18 years seeing a nephrologist with a diagnosis of CKD stage 4 or 5 during the study period between 06/01/2011 and 08/31/2013 to evaluate the placement of an AV access, initiation of dialysis and we conducted a survey of providers about the process.

Effect of oral sodium bicarbonate on fibroblast growth factor-23 in patients with chronic kidney disease: a pilot study.

Background: The regulation of fibroblast growth factor-23 (FGF23) secretion in patients with chronic kidney disease (CKD) is incompletely understood. An in vitro study showed that metabolic acidosis increased FGF23 in mouse bone. The objective of this study is to evaluate the effect of oral sodium bicarbonate on circulating FGF23 levels in patients with CKD.

Postnatal Development of the Degu (Octodon degus) Endocrine Stress Response Is Affected by Maternal Care.

Maternal stress and care significantly affect offspring's future behavior and physiology. Studies in laboratory rats have shown that maternal stress decreases maternal care and that low rates of certain maternal behaviors cause offspring to develop hyperreactive stress responses. Plurally breeding rodents that practice communal care, such as degus (Octodon degus), may be able to buffer some of these effects since offspring receive care from multiple females.

Hypothalamic-pituitary-adrenal axis activity is not elevated in a songbird (Junco hyemalis) preparing for migration.

During spring, increasing daylengths stimulate gonadal development in migratory birds. However, late-stage reproductive development is typically postponed until migration has been completed. The hypothalamic-pituitary-adrenal (HPA) axis regulates the secretion of glucocorticoids, which have been associated with pre-migratory hyperphagia and fattening.

Interdisciplinary care clinics in chronic kidney disease.

The burden of chronic kidney disease (CKD) is substantial, and is associated with high hospitalization rates, premature deaths, and considerable health care costs. These factors provide strong rationale for quality improvement initiatives in CKD care. The interdisciplinary care clinic (IDC) has emerged as one solution to improving CKD care.

Maternal stress and plural breeding with communal care affect development of the endocrine stress response in a wild rodent.

Maternal stress can significantly affect offspring fitness. In laboratory rodents, chronically stressed mothers provide poor maternal care, resulting in pups with hyperactive stress responses. These hyperactive stress responses are characterized by high glucocorticoid levels in response to stressors plus poor negative feedback, which can ultimately lead to decreased fitness.

Seasonal variation in the degu (Octodon degus) endocrine stress response.

Many wild animals show seasonal variation in circulating levels of stress hormones. Seasonal changes in the stress response may help animals better cope with the different challenges faced during each life history stage. We determined the seasonal stress profile of wild, free-living degus in Chile.

Habitat type influences endocrine stress response in the degu (Octodon degus).

While many studies have examined whether the stress response differs between habitats, few studies have examined this within a single population. This study tested whether habitat differences, both within-populations and between-populations, relate to differences in the endocrine stress response in wild, free-living degus (Octodon degus). Baseline cortisol (CORT), stress-induced CORT, and negative feedback efficacy were measured in male and female degus from two sites and three habitats within one site during the mating/early gestation period.

Effects of oral sodium bicarbonate in patients with CKD.

Background And Objectives: Metabolic acidosis contributes to muscle breakdown in patients with CKD, but whether its treatment improves functional outcomes is unknown. The choice of dose and tolerability of high doses remain unclear. In CKD patients with mild acidosis, this study evaluated the dose-response relationship of alkali with serum bicarbonate, its side effect profile, and its effect on muscle strength.

Pharmacological characterization of intracellular glucocorticoid receptors in nine tissues from house sparrow (Passer domesticus).

Glucocorticoid hormones play a key role in the stress response, but plasma concentrations vary based on physiological, environmental, or social parameters. However, hormone titers alone do not determine organismal response. To enhance our understanding of glucocorticoid actions we can examine 'downstream' factors in the organismal stress response, measuring glucocorticoid receptors across target tissues.