Physiology Commons^™

The Role Of Melatonin In Biological Rhythms Of Songbirds, Clifford E. Harpole

Theses and Dissertations--Biology

In vertebrates, melatonin is a hormone that is produced and secreted at night and inhibited by light. This unique “darkness-only” expression profile makes it an intellectually appealing candidate for a means of transmitting temporal information to an individual, both time of day and time of year.

In passerine birds, “time of day” information is certainly transmitted via melatonin secretion. The primary producer of systemic melatonin in this family of birds is the pineal gland, and surgical removal of it causes a bird to become arrhythmic in constant conditions. I find that as pinealectomized house sparrows (Passer domesticus) become …

Divergence In Neuronal Calcium Dysregulation In Brain Aging And Animal Models Of Ad, Adam Ghoweri

Theses and Dissertations--Pharmacology and Nutritional Sciences

Neuronal calcium dysregulation first garnered attention during the mid-1980’s as a key factor in brain aging, which led to the formulation of the Ca²⁺ hypothesis of brain aging and dementia. Indeed, many Ca²⁺-dependent cellular processes that change with age, including an increase in the afterhyperpolarization, a decrease in long-term potentiation, an increased susceptibility to long-term depression, and a reduction in short-term synaptic plasticity, have been identified. It was later determined that increased intracellular Ca²⁺ with age was due to increased Ca²⁺ channel density, elevated release from intracellular Ca²⁺ stores, and decreased Ca²⁺ buffering …

Striated Muscle Specific Ribosomal Protein L3-Like: Effect Of Knockout On Cardiac Function And Protein Translation, Laura P. Brown

Theses and Dissertations--Physiology

Ribosomes are the molecular machinery of the cell that catalyzes synthesis of peptides from amino acids. The eukaryotic ribosome is made up of four strands of ribosomal RNA (rRNA) and ~80 ribosomal proteins. While many tissues routinely exhibit variations of ribosomal protein stoichiometry, tissue specific ribosomal proteins are rare. The ribosomal protein with the highest tissue specificity of any ribosomal protein is found in striated muscle, ribosomal protein L3-like (RPL3L). Other than its tissue specificity, association with atrial fibrillation, and chromosomal location, there is little known about the function of RPL3L. However, its ubiquitously expressed paralog, RPL3, has been well …

Remodeling In The Actin Core Of The Auditory Hair Cell Stereocilia As A Novel Component Of Temporary Noise-Induced Hearing Loss, Jonathan Michael Grossheim

Theses and Dissertations--Physiology

The rigid, paracrystalline actin core of auditory hair cell stereocilia is extremely stable and after initial formation must persist for the life of the cell to preserve hearing in mammals. In healthy hair cells, turnover of actin molecules occurs only in a small region near the tips of stereocilia, while the actin filaments of the shaft are stable. For decades damage to the actin core of stereocilia from acoustic trauma has only been attributed to cases of permanent noise-induced hearing loss. Here, we show that repairable actin core damage occurs in temporary noise-induced hearing loss from moderate acoustic trauma.

We …

Appetite-Regulating Hormones In Energy Compensation With Exercise, Jack Moreland

Theses and Dissertations--Nutrition and Food Systems

Background: The appetite-regulating hormones may influence compensatory increases in energy intake with exercise, although this causal relationship has been difficult to prove in a longitudinal trial.

Methods: 37 participants (29 female) aged 18 to 40 years performed aerobic exercise 6 days (6d), 2 days (2d), or 0 days per week for 12-weeks. Concentrations of ghrelin, leptin, glucagon-like peptide 1 (GLP-1), and insulin were assessed before (fasting, minute 0) and after a standardized meal at minute 15, 30, 45, 60, 90, 120, 150, and 180. Linear mixed-effects models were used to model the relationships between time point (12 weeks vs. baseline) …

Characterization Of Deiodinase Expression In The Hypothyroid Developing Cochlea, Maria A. Uscategui Calderon

All Graduate Theses, Dissertations, and Other Capstone Projects

Thyroid hormone (TH) is essential for cochlear development and normal auditory function. Considering the importance of TH in mediating cochlear development, understanding the degree to which developing tissues can adapt to perturbations in thyroid hormone signaling is extremely important. The deiodinases (D2 and D3) are enzymes that tightly control TH availability at the tissue level and have been proposed to function as adaptive mechanisms that maintain tissue TH homeostasis. D2 converts thyroxine (T4) to a biologically active ligand triiodothyronine (T3); locally amplifying a T3 signal. Conversely, Dio3 inactivates T3 and T4 by converting these iodothyronines to the inactive metabolites diiodothyronine …

The Value Of Patient-Provider Interactions In Orthopedic Settings: An Evidence-To-Practice Review, Matthew S. Panetta, Carly J. Wilson, Zachary Winkelmann

Clinical Practice in Athletic Training

Clinical outcomes are influenced by specific physical therapy interventions and several nonspecific factors associated with the healthcare professional, patient, and setting. The relationship built between patients and providers is based on treatment outcomes is referred to as the patient-provider interaction, which is a nonspecific factor. The purpose of this review was to investigate patients’ and clinicians’ perceptions of factors that influence patient-provider interactions. Eleven different databases were accessed as potential research sources. Thirteen qualitative studies were selected that examined the perceptions of non-specific factors which impact the patient-clinician relationship as well as the perceptions that healthcare providers and patients in …

Towards A Hybrid Comfortable Passenger Cabin Interior For The Flying V Aircraft, Peter Vink, Thomas Rotte, Shabila Anjani, Chiara Percuoco, Roelof Vos

International Journal of Aviation, Aeronautics, and Aerospace

The Flying-V is a V-shaped airplane in development, which uses less fuel due its form. Passengers are in the oval cabin in the wing, which asks for an alternative design to the interior. At the same time there is a demand for more comfortable interiors.

80 students were asked to develop interior design ideas for this Flying V concept. A jury of experts selected four aircraft interior concepts and these were developed and a 1:1 scale mockup was made, with a hybrid interior. It included a chaise longue seats, the group space, beds and ‘staggered’ seats for the middle of …

Effects Of Gap Junction Blockage On Regenerating Body Segments Of Lumbriculus Variegatus, Monica K. Richmond

Cal Poly Humboldt theses and projects

Lumbriculus variegatus is a freshwater annelid that is well known for its regenerative capacity. There are many different factors that affect regeneration in animals. Cell-to-cell communication is a key component of regeneration. Gap junctions are made up of proteins that create a channel that connects the cytoplasm of two cells. Many molecules and ions pass through the gap junctions that can affect regeneration. The purpose of this study was to determine if blocking gap junctions would have an impact on regenerating body segments of L. variegatus and what effects it would produce. L. variegatus was exposed to a known gap …

Link Between Energy Investment In Biosynthesis And Cellular Resistance To Oxidative Insult: Test The Cost-Quality Hypothesis In Insects, Taiwo Bolanle Iromini

Masters Theses

“The metabolic cost of growth is the amount of energy invested to fuel the anabolic biochemical reactions of biosynthesis. It has been implicated in the efficiency of farm animals and fishes, thus, increased economic profit. The metabolic cost of growth in the cockroach nymph was reported to be 20-fold higher than that of the painted lady butterfly caterpillar. The cost-quality hypothesis was proposed to explain the extremely low biosynthesis energy cost in painted lady caterpillar when physiological and ecological processes the metabolic growth cost was attributed to could not. In this study, the cost-quality hypothesis was tested.

Midgut cells were …

A Tale Of Winglets: Evolution Of Flight Morphology In Stick Insects, Yu Zeng, Connor O'Malley, Sonal Singhal, Faszly Rahim, Sehoon Park, Xin Chen, Robert Dudley

Publications and Research

The evolutionary transition between winglessness and a full-winged morphology requires selective advantage for intermediate forms. Conversely, repeated secondary wing reductions among the pterygotes indicates relaxation of such selection. However, evolutionary trajectories of such transitions are not well-characterized. The stick insects (Phasmatodea) exhibit diverse wing sizes at both interspecific and intersexual levels, and thus provide a system for examining how selection on flight capability, along with other selective forces, drives the evolution of flight-related morphology. Here, we examine variation in relevant morphology for stick insects using data from 1,100+ individuals representing 765 species. Although wing size varies along a continuous spectrum, …

Isothermal Environmental Heat Energy Utilization By Transmembrane Electrostatically Localized Protons At The Liquid-Membrane Interface, James Weifu Lee

Chemistry & Biochemistry Faculty Publications

This study employing the latest theory on transmembrane electrostatic proton localization has now, for the first time, consistently elucidated a decades-longstanding bioenergetic conundrum in alkalophilic bacteria and more importantly discovered an entirely new feature: isothermal environmental heat utilization by electrostatically localized protons at the liquid-membrane interface. It was surprisingly revealed that the protonic motive force (equivalent to Gibbs free energy) from the isothermal environmental heat energy utilization through the electrostatically localized protons is not constrained by the overall energetics of the redox-driven proton pump system because of the following: (a) the transmembrane electrostatically localized protons are not free to move …

Prenatal Aromatase Inhibition Alters Postnatal Immunity In Domestic Chickens (Gallus Gallus), Jeff W. Simkins, Abby E. Joseph, Frances Bonier, Z. Morgan Benowitz-Fredericks

Faculty Journal Articles

In birds, exposure to exogenous testosterone during embryonic development can suppress measures of immune function; however, it is unclear whether these effects are due to direct or indirect action via aromatization. Estradiol (E2) is synthesized from testosterone by the enzyme aromatase, and this conversion is a necessary step in many signaling pathways that are ostensibly testosterone-dependent. Many lines of evidence in mammals indicate that E2 can affect immune function. We tested the hypothesis that some of the immunomodulatory effects observed in response to in ovo testosterone exposure in birds are mediated by conversion to E2 by aromatase, by using fadrozole …

Neuroanatomy Of The Blackspotted Rockskipper, Entomacrodus Striatus, Pooja Dayal

Williams Honors College, Honors Research Projects

Here I characterized the central neuroanatomy of the Blackspotted Rockskipper, Entomacrodus striatus, native to French Polynesia. The neuroanatomy of E. striatus has not been studied prior to this paper. I used several histology and antibody staining techniques to accomplish this, including Crystal Violet, immunohistochemistry, immunofluorescence, and Bielschowsky’s Silver Nitrate staining. This paper describes the most successful techniques used, identifies major structures in the species’ neuroanatomy, and also explains why studying E. striatus is important in the future of vertebrate research.

The Cardiovascular Response To Acute Hypoxic Conditions In Danio Rerio, Bryce Fetterman

Williams Honors College, Honors Research Projects

There are many fish that can withstand hypoxia levels. One in particular is the zebrafish (Danio rerio). The zebrafish is a small-sized, Cyprinid teleost fish, and has been used in a laboratory setting for many reasons. A few reasons being that they are widely available, easy to care for, and the cost for these fish are very low. There are various reasons why these fish are used as a model. One main reason is because their cardiovascular system is one of the first developing organs. This allows for better resolution when studying the cardiovascular system. The purpose of …

Oxidative Stress Analysis Of Placental Tissue In The Rupp Pregnant Rat, Natalie Ganios

Williams Honors College, Honors Research Projects

Preeclampsia is a disease associated with a vasoconstrictive phenotype due to disrupted signaling in the vascular endothelial growth factor (VEGF) relaxation pathway. The purpose of these studies is to determine the level of oxidative damage that is occurring in the placenta of the reduced uterine perfusion pressure (RUPP) rat, which serves as a common model for preeclampsia. RUPP and SHAM placenta tissue will be examined for oxidative stress as an indicator of tissue damage associated with the pathologically induced ischemia. Oxidative stress in the placental tissue will be measured by performing the following oxidative stress assays: 8-isoprostane test, TBARS assay, …

The Associations Between Socioeconomic Status And Childhood And Adult Psychosocial Experiences Among Men Living In El Paso, Texas, Sophia Marie Ornelas

Open Access Theses & Dissertations

BACKGROUND: Substantial evidence indicates that low levels of Socioeconomic Status (SES) can have adverse psychosocial health implications in early childhood that can persist into adulthood. While there is extensive research about this relationship very little is known about the relationship between SES characteristics and adult psychosocial burden among Hispanic men. OBJECTIVE: This research aims to explore the associations between SES characteristics and childhood adverse experiences, adult perceived stress burden, and depressive symptoms among Hispanic men living in El Paso, Texas. METHODS: This research used data from a cross-sectional study of 100 adult men residing in El Paso, Texas in 2018. …

Modulation Of Epileptogenesis: A Paradigm For The Integration Of Enzyme-Based Microelectrode Arrays And Optogenetics, Corwin R. Butler, Jeffery A. Boychuk, Francois Pomerleau, Ramona Alcala, Peter Huettl, Yi Ai, Johan Jakobsson, Sidney W. Whiteheart, Greg A. Gerhardt, Bret N. Smith, John T. Slevin

Physiology Faculty Publications

BACKGROUND: Genesis of acquired epilepsy includes transformations spanning genetic-to- network-level modifications, disrupting the regional excitatory/inhibitory balance. Methodology concurrently tracking changes at multiple levels is lacking. Here, viral vectors are used to differentially express two opsin proteins in neuronal populations within dentate gyrus (DG) of hippocampus. When activated, these opsins induced excitatory or inhibitory neural output that differentially affected neural networks and epileptogenesis. In vivo measures included behavioral observation coupled to real-time measures of regional glutamate flux using ceramic-based amperometric microelectrode arrays (MEAs).

RESULTS: Using MEA technology, phasic increases of extracellular glutamate were recorded immediately upon application of blue light/488 nm …

Divalent Metal Cation Entry And Cytotoxicity In Jurkat T Cells: Role Of Trpm7 Channels, Alayna N. Mellott

Browse all Theses and Dissertations

Humans are exposed daily to a variety of metals that can be harmful to our immune system. Although certain divalent metal cations are essential for numerous cellular functions and are critical trace elements in humans, the uptake mechanisms of these ions remain mostly unknown. Transient receptor potential melastatin 7 (TRPM7), which is expressed in a variety of human cell types, including lymphocytes and macrophages, conducts many divalent metal cations. TRPM7 channels are largely inactive under normal physiological conditions due to cytoplasmic magnesium acting as a channel inhibitor. Magnesium is a cofactor for many biochemical reactions. Low serum levels of magnesium, …

The Dynamics Of Life And Death: Mitochondrial Fragmentation, Mitophagy, And Swelling During Neuronal Ischemia/Reperfusion Injury, Anthony Roy Anzell

Wayne State University Dissertations

Ischemic brain injury caused by cardiac arrest or stroke continue to be leading caused of death and disability in the U.S. While restoration of blood flow is necessary to salvage ischemic tissue, reperfusion paradoxically exacerbates injury via the production of reactive oxygen species, which, damage mitochondria and induce cell death. Therefore, it is critical to have stringent quality control mechanisms to ensure a healthy mitochondrial network. Mitochondrial fragmentation has been well characterized in the progression of ischemia/reperfusion and its association with cell death. Conversely, the role of mitophagy has been controversial regarding whether upregulation of mitophagy serves as a restorative …