Physiology Commons^™

Rapid Glucocorticoid-Induced Activation Of Trp And Cb1 Receptors Causes Biphasic Modulation Of Glutamate Release In Gastric-Related Hypothalamic Preautonomic Neurons, Carie R. Boychuk, Andrea Zsombok, Jeffrey G. Tasker, Bret N. Smith

Physiology Faculty Publications

Glucocorticoids rapidly regulate synaptic input to neuroendocrine cells in the hypothalamic paraventricular nucleus (PVN) by inducing the retrograde release of endogenous messengers. Here we investigated the rapid effects of dexamethasone (DEX) on excitatory synaptic input to feeding-related, preautonomic PVN neurons using whole-cell patch-clamp recordings. In ∼50% of identified gastric-related preautonomic PVN neurons, DEX elicited a biphasic synaptic response characterized by an initial rapid and transient increase in the frequency of miniature excitatory postsynaptic currents (mEPSCs), followed by a decrease in mEPSC frequency within 9 min; remaining cells displayed only a decrease in mEPSC frequency. The late-phase decrease in mEPSC frequency …

Modulation Of Renin Secretion By Renal Cortical Interstitial Calcium, Douglas K. Atchison

Wayne State University Dissertations

Renin is secreted from the juxtaglomerular (JG) cells of the afferent arteriole of the kidney, and is the rate-limiting enzyme of the renin-angiotensin system. Renin is quantified in vivo as plasma renin activity (PRA). Acutely elevating plasma calcium decreases PRA, but the mechanisms by which this occurs is unknown. The overall goal of our study was to determine how elevated plasma calcium decreases PRA. The calcium-sensing receptor (CaSR) is a ubiquitously expressed receptor that translates changes in plasma calcium into changes in intracellular signaling. JG cells are basolaterally bordered by the renal cortical interstitium, and parathyroid hormone (PTH) positively regulates …

Mechanisms Mediating Modulation Of The Cardiopulmonary Chemoreflex Control Of Regional Sympathetic Outputs By Adenosine A1 And A2a Receptors In The Nts, Zeljka Minic

Wayne State University Dissertations

ABSTRACT

by

ZELJKA MINIC

August 2013

Advisor: Dr. Tadeusz J. Scislo

Major: Physiology

Degree: Doctor of Philosophy

Adenosine is an important neuromodulator of cardiovascular control at the level of the nucleus of the solitary tract (NTS) where cardiovascular and other autonomic reflexes are primarily integrated. Levels of adenosine increase in the NTS during life threatening hypotension, ischemia and hypoxia. Adenosine may modulate cardiovascular reflexes to correct hemodynamic imbalance, acting via A₁ and A_2a receptors which inhibit and facilitate neurotransmitter release, respectively. Previous studies from our laboratory showed that NTS A₁ adenosine receptors inhibit the arterial baroreflex whereas …

The Regulation And Packaging Of Synaptic Vesicles Related To Recruitment Within Crayfish And Fruit Fly Neuromuscular Junctions: Variations In Low- And High-Output Terminals, Wenhui Wu

Theses and Dissertations--Biology

Glutamate is the main excitatory neurotransmitter in the CNS and at the neuromuscular junctions (NMJs) of invertebrate. The characteristic similarities to CNS glutamatergic synapses in vertebrate and the anatomical simplicity of invertebrate NMJs favor the investigation of glutamatergic synaptic functions in this system. This dissertation mainly aimed to physiologically separate two functional vesicle groups, the reserve pool (RP) and readily releasable pool (RRP) within presynaptic nerve terminals of Procambarus Clarkii and Drosophila melanogaster. This was addressed in part by blocking the vesicular glutamate transporter (VGlut) with bafilomycin A1. Various frequencies of motor nerve stimulation, exposure time, and concentration of …

Do Changes In Muscle Architecture Effect Post- Activation Potentiation, Danielle Reardon

Electronic Theses and Dissertations

Purpose: To examine the effect of three muscle potentiation protocols on changes in muscle architecture and the subsequent effect on jump power performance. Methods: Maximal (1RM) squat strength (Mean SD=178.3 ± 36.6kg), vertical jump power, and muscle architecture were obtained in 12 resistance trained men (25.2±3.6y; 90.67±12.7kg). Participants randomly completed three squatting protocols at 75% (3 x 10 reps), 90% (3 x 3 reps) or 100% (1 x 1) of their 1RM, or no workout (CON), with each protocol being separated by one week. During each testing session ultrasound and vertical jump testing were assessed at baseline (BL), 8min post …

Eccentric Resistance Training And Blood Flow Restriction, Zachary Pope

Masters Theses

The purpose of this study was to compare the muscular strength and hypertrophic response following a four week training intervention involving resistance exercise utilizing only eccentric muscle contractions with, or without blood flow restriction (BFR), as well as a control group maintaining their current training regimen. Sixteen young male volunteers were recruited to participate in this study. Prior to the training intervention, subjects attended three sessions in order to obtain demographic information (age, height, body mass) and familiarize each of the participants with the testing and training equipment. After the familiarization session, muscular strength was assessed via elbow flexion one …

Comparative Sugar Transport By Crustacean Hepatopancreas And Intestine, Ada Duka

UNF Graduate Theses and Dissertations

Glucose is transported in crustacean hepatopancreas and intestine by Na⁺-dependent co-transport, while Na⁺-dependent D-fructose influx has only been described for the hepatopancreas. It is still unclear if the two sugars are independently transported by two distinct cotransporter carrier systems. In this study lobster (Homarus americanus) hepatopancreas brush border membrane vesicles (BBMV) were used to characterize, in detail, the cation-dependency of both D-[³H] glucose and D-[³H] fructose influxes, while in vitro perfused intestines were employed to determine the nature of cation-dependent sugar transport in this organ. Over the sodium concentration range …

Expression Of Borderline Personality Disorder Symptoms Across The Ovulatory Cycle: A Multilevel Investigation, Tory A. Eisenlohr-Moul

Theses and Dissertations--Psychology

Borderline Personality Disorder (BPD) is a disabling condition characterized by chronic emotion dysregulation and behavioral impulsivity. Prospective studies that test proposed mechanisms of within-person change in BPD hold the key to improving symptom predictability and control in this disorder. A small body of evidence suggests that fluctuations in estradiol such as those occurring naturally at ovulation during the monthly female reproductive cycle may increase symptoms in women with BPD (DeSoto et al., 2003). Furthermore, there is preliminary evidence that both self-esteem and feelings of social rejection are highest at ovulation, when estradiol peaks (Durante and Hill, 2009; Eisenlohr-Moul et al., …

Age-Associated Metabolic And Morphologic Changes In Mitochondria Of Individual Mouse And Hamster Oocytes, Fatma Simsek-Duran, Fang Li, Wentia Ford, R. James Swanson, Howard W. Jones Jr., Frank J. Castora

Biological Sciences Faculty Publications

Background: In human oocytes, as in other mammalian ova, there is a significant variation in the pregnancy potential, with approximately 20% of oocyte-sperm meetings resulting in pregnancies. This frequency of successful fertilization decreases as the oocytes age. This low proportion of fruitful couplings appears to be influenced by changes in mitochondrial structure and function. In this study, we have examined mitochondrial biogenesis in both hamster (Mesocricetus auratus) and mouse (Mus musculus) ova as models for understanding the effects of aging on mitochondrial structure and energy production within the mammalian oocyte.

Methodology/Principal Findings: Individual metaphase …

Developmental Changes In Postural Stability During The Performance Of A Precision Manual Task, Jeffrey M. Haddad, Laura J. Claxton, Dawn Melzer, Joseph Hamill, Richard E. A. Van Emmerik

Psychology Faculty Publications

Posture becomes integrated with other goal-directed behaviors early in infancy and continues to develop into the second decade of life. However, the developmental time course over which posture is stabilized relative to the base of support during a dynamic manual precision task has not been examined. Postural-manual integration was assessed in 7-year-olds, 10-year-olds, and adults using a postural-manual task in which task precision (target fitting size) and postural difficulty (reaching distance to a target) were manipulated. The main dependent variable was postural time-to-contact (TtC). Results indicated systematic age effects in which TtC was shortest in the 7-year-olds, increased in the …

Sphingosine-1-Phosphate And Fingolimod (Fty720) Regulate Icl,Swell In Hl-1 Cardiac Myocytes Via Intracellular Binding And Mitochondrial Ros Production, Pooja Desai

Theses and Dissertations

Swelling-activated Cl− current (ICl,swell) is an outwardly-rectifying current that plays an important role in cardiac electrical activity, cellular volume regulation, apoptosis, and acts as a potential effector of mechanoelectrical feedback. Persistent activation of ICl,swell has been observed in models of cardiovascular disease. We previously suggested sphingosine-1-phosphate (S1P) activates volume-sensitive Cl- current (ICl,swell) by ROS-dependent signaling. S1P and its analog, FTY720 (fingolimod), primarily act via G-protein coupled receptors (S1PR; S1PR1-3 in heart), but several intracellular S1P ligands are known. We investigated how these agents regulate ICl,swell. ICl,swell was elicited by bath S1P (500 nM), FTY720 (S1PR1,3 agonist; 10 μM), and SEW2871 …

Biochemical Aspects Of The Thermal Sensitivity And Energy Balance Of Polar, Tropical And Subtropical Teleosts, Eloy Martinez

USF Tampa Graduate Theses and Dissertations

The maintenance of a functional energy balance in ectothermic fauna could be challenging in a thermally disparate environment. Biochemical adaptations at the enzyme and membrane levels allows for a set compensatory mechanism that allow the individual to maintain an energetic surplus, thus allocating energy for growth and reproduction. The present work describes how the energetic machinery in the cell, particularly the mitochondrion, could be affected by temperature changes. More specifically, this work aimed to determine how environmental temperature affects the mitochondria energetic performance of fishes from disparate thermal regimes.

Mitochondrial ATP production efficiency was evaluated in fishes from polar, tropical …

Gradients In Season, Latitude, And Sea Ice: Their Effect On Metabolism And Stable Isotopic Composition Of Antarctic Micronekton, Erica H. Ombres

USF Tampa Graduate Theses and Dissertations

Respiration, metabolic enzyme assays, and body composition parameters were measured in the Antarctic krill Euphausia superba during the summer, fall and winter on the Western Antarctic Peninsula (WAP). E. superba of all sizes decrease their metabolism from the summer to the winter. These same parameters were also measured along the WAP during the austral fall 2010. E. superba's enzyme activity indicated that there was a latitudinal gradient to the decline in metabolism along the WAP with the more northerly sites having significantly higher metabolic enzyme activities than the sites to the south.

Carbon (δ¹³C) and nitrogen (δ^{15 …}

Environmental Effects On The Biomechanics And Motor Physiology Of Elastically Powered Movements In Chameleons, Christopher Van Anderson

USF Tampa Graduate Theses and Dissertations

Environmental temperature exhibits profound effects on the activity and ecology of ectotherms through its impact on muscle contractile physiology. While the performance of locomotor behaviors powered by muscle contraction directly decreases by at least 33% over a 10°C drop in body temperature, chameleons are known to feed, presumably with high performance, at body temperatures where sympatric lizard species remain inactive. I propose that ballistic movements that are powered by the recoil of preloaded elastic and collagenous tissues are less thermally dependent than movements that rely on direct muscular power. Despite the reduced thermal sensitivity of the elastic-recoil powered movement, I …

Variations Of Ghrelin, Growth Hormone, And Insulin-Like Growth Factor I In The West Indian Manatee (Trichechus Manatus), Rachel Lynn Cimino

UNF Graduate Theses and Dissertations

The metabolic hormones ghrelin, growth hormone, and insulin-like growth factor I are influenced by developmental age, sex, and nutritional status in domestic and free-ranging species. However the role these hormones play has not previously been explored in sub-tropical/ tropical mammals. Furthermore, the seasonality of species with less dynamic environmental cues, such as the West Indian manatee, have not been studied. The West Indian manatee is and endangered species distributed in the southeastern United States and throughout the Caribbean basin, and its nutritional physiology is influenced by environmental factors. Understanding the hormone response to nutritional status in this species and its …

Diapause And Anhydrobiosis In Embryos Of Artemia Franciscana : Metabolic Depression, Lea Proteins And Water Stress., Steven Handel, Yuvraj Patil, Shumin Li, Nilay Charkraborty, Arpurva Borcar, Michael Menze, Leaf Boswell, Daniel Moore, Mehmet Toner

Faculty and Staff Scholarship

Metabolic depression is typically correlated with extended survival of environmental challenge and energy-limitation in early life stages of various invertebrates and vertebrates. Diapause is an ontogenetically-programmed reduction of development and often metabolism seen in many invertebrates. When embryos of Artemia franciscana enter the state of diapause, the overall metabolic depression is estimated to be greater than 99%. These embryos also contain trehalose and express multiple isoforms of Late Embryogenesis Abundant (LEA) proteins, constituents often present in a number of such anhydrobiotic animals. The mRNA levels for LEA proteins are highest in diapause and post-diapause embryos that possess desiccation tolerance, but …

Knockdown Of Vitellogenin By Rnai Increases Survivorship But Exhibits Similar Physiological Responses To Ovariectomy In Grasshoppers, Alicia G. Linquist

UNF Graduate Theses and Dissertations

Reduced reproduction has been shown to increase lifespan in many animals, yet the mechanisms behind this trade-off are mostly unknown. A previous study has shown that in the lubber grasshopper, Romalea microptera, ovariectomized (OVX) individuals have a 30% increase in lifespan relative to controls (Sham). In a separate study, an increase in fat body mass and a halting of ovarian growth were seen upon reduction of vitellogenin transcript via RNAi (VgRNAi). These data suggest that VgRNAi increases lifespan through the trade-off between reproduction and longevity and animals with combined ovariectomy and VgRNAi, might show additive physiological responses. In this …

Impact Of Nutritional Status On The Somatotropic Axis And Ghrelin In Phocid Seals, Rachael Dailey

UNF Graduate Theses and Dissertations

Metabolic hormones and their axes, including the target tissues and receptors, regulate the tissue specific utilization of nutrients with in the body. The purpose of this research was to understand the hormonal control of complex nutrient partitioning mechanisms involved in young, growing animals. Specifically, this involved the investigation of metabolic hormones and the regulation of growth in two common species of phocids (true seals): harbor seal (Phoca vitulina) and Northern elephant seal (Mirounga angustirostris) pups. This longitudinal study examines young phocids from nutritional nadir through realimentation (realimentation) to investigate how metabolic hormones involved in both food intake and nutrient partitioning …

Mechanisms Of Nitrogenous Waste Excretion During The Complex Life Cycle Of The Sea Lamprey (Petromyzon Marinus), James M. Neal Mr.

Theses and Dissertations (Comprehensive)

Sea lampreys (Petromyzon marinus) are a phylogenetically ancient jawless fish, with a multi-staged life cycle characterized by a prolonged suspension-feeding larval stage, which is followed by metamorphosis into parasitic lampreys that feed on the protein-rich blood of fishes. The switch from a nutrient poor to protein-rich diet in the sea lamprey is associated with an increased capacity to deaminate excess amino acids and to excrete ammonia and urea following metamorphosis. The focus of this thesis was to determine if changes in nitrogenous waste transporter protein abundance facilitate ammonia and urea excretion during different stages of the sea lamprey …

(R)-Β-Lysine Modified Elongation Factor P Functions In Translation Elongation, Tammy J. Bullwinkle, S. Betty Zou, Andrei Rajkovic, Steven J. Hersch, Sara Elgamal, Nathaniel Robinson, David Smil, Yuri Bolshan, William Wiley Navarre, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Post-translational modification of bacterial elongation factor P (EF-P) with (R)-β-lysine at a conserved lysine residue activates the protein in vivo and increases puromycin reactivity of the ribosome in vitro. The additional hydroxylation of EF-P at the same lysine residue by the YfcM protein has also recently been described. The roles of modified and unmodified EF-P during different steps in translation, and how this correlates to its physiological role in the cell, have recently been linked to the synthesis of polyproline stretches in proteins. Polysome analysis indicated that EF-P functions in translation elongation, rather than initiation as proposed previously. This was …