Endocrinology Commons^™

Invited Review: Adrenocortical Function In Avian And Non-Avian Reptiles: Insights From Dispersed Adrenocortical Cells., Rocco V. Carsia, Patrick J. Mcilroy, Henry B John-Alder

Rowan-Virtua School of Osteopathic Medicine Departmental Research

Herein we review our work involving dispersed adrenocortical cells from several lizard species: the Eastern Fence Lizard (Sceloporus undulatus), Yarrow's Spiny Lizard (Sceloporus jarrovii), Striped Plateau Lizard (Sceloporus virgatus) and the Yucatán Banded Gecko (Coleonyx elegans). Early work demonstrated changes in steroidogenic function of adrenocortical cells derived from adult S. undulatus associated with seasonal interactions with sex. However, new information suggests that both sexes operate within the same steroidogenic budget over season. The observed sex effect was further explored in orchiectomized and ovariectomized lizards, some supported with exogenous testosterone. Overall, a suppressive effect of testosterone was evident, especially in cells …

Effects Of Sunrise/Sunset Lighting On Corticosterone Levels In Coturnix Quail (Coturnix Coturnix), Hannah Feuerborn

Poultry Science Undergraduate Honors Theses

Both genetics and environment play an important role in the growth, performance and overall welfare of poultry species. Current commercial production practices typically do not mimic the natural environmental conditions of ancestral poultry species, specifically lighting requirements. In nature, poultry species are subjected to natural day length and the slow rising and setting of the sun. This is compared to commercial conditions in which lights are sudden on/off, not mimicking the natural trajectory of the sun in terms of light intensity and exposure. The current study aimed to evaluate the impact of genetics and the effect of sunrise/sunset lighting on …

Effects Of Glucocorticoids Upon Pro-Inflammatory Responses To Acute Sleep Fragmentation, Hunter Weaver

Masters Theses & Specialist Projects

Sleep loss is a common problem in humans who suffer from obstructive sleep apnea. Sleep aids in the regulation of immune responses, some of which induce inflammatory responses. Cytokines regulate the inflammatory process and are released in response to sleep fragmentation (SF) in mice. Glucocorticoids are hormones that are released from the adrenal cortices during a stress response and are considered to be anti-inflammatory and immunosuppressive at high doses but may stimulate immune function on an acute level. The first hypothesis tested was that normal physiological expression of glucocorticoids (Sham) will display increased IL-1β and TNFα expression levels, while high …

Effects Of Sunrise/Sunset Lighting On Corticosterone Levels In Coturnix Quail (Coturnix Coturnix), Hannah M. Feuerborn, Sara K. Orlowski

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Both genetics and environment play important roles in the growth, performance, and overall welfare of poultry species. Current commercial production practices typically do not mimic the natural environmental conditions of ancestral poultry species, specifically lighting. The current study aimed to evaluate the impact of genetics and the effect of sunrise/sunset lighting on the stress response of 4 genetic lines of Coturnix quail. The 4 lines utilized in this study included high stress (H), low stress (L), stress control (R), and Arkansas randombred (A) quail lines. Day old chicks from these lines were placed in one of two environmentally controlled rooms. …

Impact Of Nacl Tolerance On The Stress Physiology And Fitness Of Larval Wood Frogs (Rana Sylvatica), Grascen Shidemantle, Nicholas Buss, Jessica Hua

Biological Sciences Student Scholarship

No abstract provided.

Developing Tools To Understand Stress And Nest Abandonment In Birds, Hannah Elena Beyl

Graduate Student Theses, Dissertations, & Professional Papers

No abstract provided.

Stress And Body Composition Of Juvenile Alligator Snapping Turtles (Macrochelys Temminckii), Brandon Scott Tappmeyer

Graduate Theses/Dissertations

The alligator snapping turtle (Macrochelys temminckii), is a species of conservation concern that is the subject of multiple head-start and reintroduction efforts across its range. In captive propagation programs, producing offspring that are in optimal physiological condition maximizes the likelihood of success after release. The purpose of my study was to compare stress and body composition between one free-ranging reintroduced population and two captive populations. The two captive populations were both housed in southern Oklahoma, but one group was reared indoors whereas the other inhabited outdoor ponds at a national fish hatchery. I used circulating glucocorticoid (corticosterone) concentrations as an …

Population Health Of Spotted Salamanders (Ambystoma Maculatum) In Created Vernal Pools: An Integrative Approach, Alice R. Millikin

Graduate Theses, Dissertations, and Problem Reports (ETD)

Habitat creation is an important tool for conservation to counteract habitat loss and degradation. Vernal pools are susceptible to destruction due to limited detection, protection, and regulation. These wetlands provide fishless breeding habitat for many amphibian species including spotted salamanders (Ambystoma maculatum) in eastern North America. Determining whether created vernal pool habitat is successful is often determined by demographic data of colonizing populations. I suggest that hormone levels, population genetics, and disease prevalence can improve our understanding of population health in created habitat. The goal of this dissertation was to assess the health of spotted salamander larvae in …

Glucocorticoids And Parental Effort In Tree Swallows (Tachycineta Bicolor), Mackenzie Prichard

Undergraduate Theses, Professional Papers, and Capstone Artifacts

All vertebrates respond to stressful situations through the release of hormones called glucocorticoids (CORT). These hormones alter processes within the body to prioritize long term survival over immediate reproduction. It is hypothesized that this is helps individuals survive until conditions become more favorable for successful reproduction. Historically, stress was hypothesized to primarily to pull organisms out of reproductive life history stages when unfavorable conditions made offspring survival slim (otherwise known as the “CORT-tradeoff hypothesis”). However, recent evidence suggests that birds actively feeding nestlings show elevated CORT levels, possibly due to the increased metabolic demands of parenthood. This relationship has been …

Maternal Sleep Loss During Fetal Development Alters Offspring Endocrine Responses To Stress Throughout Life, Audrey Brown

Mahurin Honors College Capstone Experience/Thesis Projects

The hypothalamic-pituitary-adrenal (HPA) axis releases glucocorticoids, including corticosterone (CORT), in response to stress. CORT then negatively feeds back to inhibit its own production by binding to glucocorticoid receptors (GRs) in the hypothalamus and pituitary gland. The HPA axis is subject to “programming” by abnormal stimuli during early development, which may permanently alter how the HPA axis responds to stress. These altered responses have been linked to an increased risk for human psychiatric and metabolic disorders in later life, but the mechanism by which this happens is not fully understood. This study tests the hypothesis that changes to GR expression patterns …

Stress Ecology Of The Pacific Rattlesnakes (Crotalus Oreganus And Crotalus Helleri), Natalie Claunch

Master's Theses

Stress is a physiological state induced by disturbance or adverse environmental conditions and is modulated by the glucocorticoid hormone corticosterone (CORT) in reptiles. Stressors can have various impacts on vertebrate trait expression and may affect survival or reproduction. Little is known about the effects of chronically elevated CORT in free-ranging reptiles, or the effect of disturbance stress on venom composition in captive snakes.

In chapter 1, we investigated the effects of researcher induced disturbance on CORT levels and venom composition in a group of captive Northern Pacific rattlesnakes (Crotalus oreganus). Venom protein concentration and plasma CORT levels were …

Effects Of Prenatal Environment Are Revealed By Post-Natal Challenges: Embryonic Hormone Exposure, Adrenocortical Function And Food In Seabird Chicks, Z. Morgan Benowitz-Fredericks, Jannik Schultner, Alexander S. Kitaysky

Faculty Journal Articles

The interaction between prenatal environments and postnatal environments is an important source of phenotypic variability. We examined the ability of prenatal steroid exposure and postnatal energy restriction to explain adrenocortical function and fledging age in captive seabird chicks. We proposed and tested two hypotheses: (1) the strength of prenatal effects is attenuated by challenging postnatal environments (postnatal override) and (2) the strength of prenatal effects increases with the severity of postnatal challenges (postnatal reveal). We reared common murre (Uria aalge) chicks and measured prenatal exposure to corticosterone (CORT) and testosterone (T) from allantoic waste. Adrenocortical function was assessed after 10 …

The Effects Of Stress Hormones On Preferences For Acoustic Signals In Female Green Treefrogs (Hyla Cinerea) And Barking Treefrogs (Hyla Gratiosa), Anna Gabriell Davis

Electronic Theses and Dissertations

Ecological stressors (i.e., high predator density, low food availability) are often associated with increased variation in mate choice by females. The association between environmental stressors and variation in mate choice suggests that circulating stress hormones (i.e., glucocorticoids) may mediate such effects, but this idea remains largely unexplored. I examined how circulating glucocorticoids affect preferences for male advertisement calls in female green treefrogs, Hyla cinerea, and barking treefrogs, Hyla gratiosa. Specifically, I examined whether administration of corticosterone (CORT) decreases preferences for call rate and/or call duration - two acoustic features that are highly variable and characteristically under directional selection via mate …

A Test Of Whether Human Handling Causes Developmental Or Habituation Effects On The Hypothalamic-Pituitary-Adrenal Stress Response Of Young American Kestrels (Falco Sparverius), Erin Leigh Wonder

Boise State University Theses and Dissertations

Early exposure to stressors affects subsequent stress responses in both mammalian and avian species, with the likelihood for lasting effects depending, in part, on the magnitude of the stressor. However, it is unclear whether lasting effects are the result of developmental changes to the hypothalamic-pituitary-adrenal (HPA) axis or habituation to the stressor. I investigated the effects of human handling, a known stressor, in free-living American kestrel (Falco sparverius) nestlings to determine if this brief, non-invasive stressor causes lasting changes in the stress response of handled birds, and whether alterations in the stress response were the result of developmental …