Physiology Commons^™

Mechanotransduction Current Is Essential For Stability Of The Transducing Stereocilia In Mammalian Auditory Hair Cells, A. Catalina Vélez-Ortega, Mary J. Freeman, Artur A. Indzhykulian, Jonathan M. Grossheim, Gregory I. Frolenkov

Physiology Faculty Publications

Mechanotransducer channels at the tips of sensory stereocilia of inner ear hair cells are gated by the tension of 'tip links' interconnecting stereocilia. To ensure maximal sensitivity, tip links are tensioned at rest, resulting in a continuous influx of Ca²⁺ into the cell. Here we show that this constitutive Ca²⁺ influx, usually considered as potentially deleterious for hair cells, is in fact essential for stereocilia stability. In the auditory hair cells of young postnatal mice and rats, a reduction in mechanotransducer current, via pharmacological channel blockers or disruption of tip links, leads to stereocilia shape changes and shortening. …

A Prototypical First-Generation Electronic Cigarette Does Not Reduce Reports Of Tobacco Urges Or Withdrawal Symptoms Among Cigarette Smokers, Arit M. Harvanko, Catherine A. Martin, Richard J. Kryscio, William W. Stoops, Joshua A. Lile, Thomas H. Kelly

Psychology Faculty Publications

It is unknown whether first-generation electronic cigarettes reduce smoking urges and withdrawal symptoms following a 24 h deprivation period. This study tested whether a first-generation electronic cigarette reduces smoking urges and withdrawal symptoms in cigarette smokers. Following 24 h of tobacco deprivation, using a within-subjects design, eight nontreatment seeking tobacco cigarette smokers (3 females) administered 10 puffs from a conventional cigarette or a first-generation electronic cigarette containing liquid with 0, 8 or 16 mg/ml nicotine. Conventional cigarettes ameliorated smoking urges and electronic cigarettes did not, regardless of nicotine concentration. First-generation electronic cigarettes may not effectively substitute for conventional cigarettes in …

Odor, Not Performance, Dictates Bemisia Tabaci'S Selection Between Healthy And Virus Infected Plants, Gong Chen, Qi Su, Xiaobin Shi, Xin Liu, Zhengke Peng, Huixin Zheng, Wen Xie, Baoyun Xu, Shaoli Wang, Qingjun Wu, Xuguo Zhou, Youjun Zhang

Entomology Faculty Publications

Although, insect herbivores are generally thought to select hosts that favor the fitness of their progeny, this “mother-knows-best” hypothesis may be challenged by the presence of a plant virus. Our previous study showed that the whitefly, Bemisia tabaci, the obligate vector for transmitting Tomato yellow leaf curl virus (TYLCV), preferred to settle and oviposit on TYLCV-infected rather than healthy host plant, Datura stramonium. The performances of B. tabaci larvae and adults were indeed improved on virus-infected D. stramonium, which is consistent with “mother-knows-best” hypothesis. In this study, B. tabaci Q displayed the same preference to settle and …

A Role Of Central Nell2 In The Regulation Of Feeding Behavior In Rats., Jin Kwon Jeong, Jae Geun Kim, Han Rae Kim, Tae Hwan Lee, Jeong Woo Park, Byung Ju Lee

Pharmacology and Physiology Faculty Publications

A brain-enriched secreting signal peptide, NELL2, has been suggested to play multiple roles in the development, survival, and activity of neurons in mammal. We investigated here a possible involvement of central NELL2 in regulating feeding behavior and metabolism. In situ hybridization and an immunohistochemical approach were used to determine expression of NELL2 as well as its colocalization with proopiomelanocortin (POMC) and neuropeptide Y (NPY) in the rat hypothalamus. To investigate the effect of NELL2 on feeding behavior, 2 nmole of antisense NELL2 oligodeoxynucleotide was administered into the lateral ventricle of adult male rat brains for 6 consecutive days, and changes …

Vestibular Activation Habituates The Vasovagal Response In The Rat, Bernard Cohen, Giorgio P. Martinelli, Yongqing Xiang, Theodore Raphan, Sergei B. Yakushin

Publications and Research

Vasovagal syncope is a significant medical problem without effective therapy, postulated to be related to a collapse of baroreflex function. While some studies have shown that repeated static tilts can block vasovagal syncope, this was not found in other studies. Using anesthetized, male Long–Evans rats that were highly susceptible to generation of vasovagal responses, we found that repeated activation of the vestibulosympathetic reflex (VSR) with ±2 and ±3 mA, 0.025 Hz sinusoidal galvanic vestibular stimulation (sGVS) caused incremental changes in blood pressure (BP) and heart rate (HR) that blocked further generation of vasovagal responses. Initially, BP and HR fell ≈20–50 …

High-Fat Feeding Does Not Disrupt Daily Rhythms In Female Mice Because Of Protection By Ovarian Hormones, Brian T. Palmisano, John M. Stafford, Julie S. Pendergast

Biology Faculty Publications

Obesity in women is increased by the loss of circulating estrogen after menopause. Shift work, which disrupts circadian rhythms, also increases the risk for obesity. It is not known whether ovarian hormones interact with the circadian system to protect females from obesity. During high-fat feeding, male C57BL/6J mice develop profound obesity and disruption of daily rhythms. Since C57BL/6J female mice did not develop diet-induced obesity (during 8 weeks of high-fat feeding), we first determined if daily rhythms in female mice were resistant to disruption from high-fat diet. We fed female PERIOD2:LUCIFERASE mice 45% high-fat diet for 1 week and measured …

Development Of Near-Isogenic Lines In A Parthenogenetically Reproduced Thrips Species, Frankliniella Occidentalis, Guangdi Yuan, Yanran Wan, Xiaoyu Li, Bingqing He, Youjun Zhang, Baoyun Xu, Shaoli Wang, Wen Xie, Xuguo Zhou, Qingjun Wu

Entomology Faculty Publications

Although near-isogenic lines (NILs) can standardize genetic backgrounds among individuals, it has never been applied in parthenogenetically reproduced animals. Here, through multiple rounds of backcrossing and spinosad screening, we generated spinosad resistant NILs in the western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), with a haplo-diploid reproduction system. The resultant F. occidentalis NIL-R strain maintained a resistance ratio over 30,000-fold, which was comparable to its parental resistant strain, Spin-R. More importantly, F. occidentalis NIL-R shared 98.90% genetic similarity with its susceptible parental strain Ivf03. By developing this toolset, we are able to segregate individual resistance and facilitate the mechanistic study …

The Impact Of Various Predator Perceptions On Stress Response And Spatial Memory In Birds, Chlöe S. N. Carter

Western Research Forum

The Impact of Various Predator Perceptions on Stress Response and Spatial Memory in Birds

Background

This project will explore the impact of environmental stressors on the cognitive abilities of birds. Predator perception has been demonstrated to elicit a stress response by elevating stress hormones which can alter the behaviour of birds. The aim of this study is to observe if chronic stress from differently perceived threats of predation in an individual’s environment will lead to differences in the spatial memory abilities in two species of birds. I predict that chronic stress resulting from predator stimuli will impair the bird’s performance …

Pulmonary Surfactant Fortified With Cath-2 As A Novel Therapy For Bacterial Pneumonia, Brandon J. Baer

Western Research Forum

Background: Bacterial pneumonia is a leading cause of death worldwide, with high mortality rates persisting even after antibiotic treatment. Current treatments for pneumonia involve administration of antibiotics, however after the bacteria are killed they release toxic substances that induce inflammation and lung dysfunction. Host defense peptides represent a potential solution to this problem through their ability to down regulate inflammation. However, effective delivery to the lung is difficult because of the complex branching structure of the airways. My study addresses this delivery problem by using exogenous surfactant, a pulmonary delivery vehicle capable of improving spreading of these peptides throughout the …

Computational Predictions Of Β-Hairpins Containing Bulky Dehydroamino Acids, David W. Kastner, Ankur Jalan, Steven L. Castle

Library/Life Sciences Undergraduate Poster Competition 2017

Bulky α,β-dehydroamino acids (ΔAAs) can improve the proteolytic stability of peptides that contain them, presumably by altering the shape of the backbone of the peptide and by stabilizing folded states through their rigidifying effect. The stabilizing effects of ΔAAs that contain at least one hydrogen atom at the β-carbon are well-known, but the role of bulky ΔAAs that contain fully substituted β-carbons in the stability of larger peptides is less explored. To better explore the conformational contribution of α,β-dehydroamino acids in β-hairpins we performed NMR-based structural calculations to confirm our experimental observations. We used the simulated annealing program CYANA to …

Apolipoprotein E4 And Insulin Resistance Interact To Impair Cognition And Alter The Epigenome And Metabolome, Lance A. Johnson, Eileen Ruth S. Torres, Soren Impey, Jan F. Stevens, Jacob Raber

Physiology Faculty Publications

Apolipoprotein E4 (E4) and type 2 diabetes are major risk factors for cognitive decline and late onset Alzheimer’s disease (AD). E4-associated phenotypes and insulin resistance (IR) share several features and appear to interact in driving cognitive dysfunction. However, shared mechanisms that could explain their overlapping pathophysiology have yet to be found. We hypothesized that, compared to E3 mice, E4 mice would be more susceptible to the harmful cognitive effects of high fat diet (HFD)-induced IR due to apoE isoform-specific differences in brain metabolism. While both E3 and E4 mice fed HFD displayed impairments in peripheral metabolism and cognition, deficits in …

Molecular Regulation Of Stem Cell Behavior During Tissue Repair And Cancer Formation, Nestor J. Oviedo

Science Seminar Series

Oviedo will be presenting his work on identifying the mechanisms of adult stem cell fate determination based on their topographical location in the adult body. Understanding stem cell fate determination is crucial because tissue repair and neoplastic growth are greater in anterior than in posterior regions of adult animals. Despite its critical implications for stem cell biology, carcinogenesis and regenerative medicine, this physiological phenomenon has remained overlooked. Recent findings from his group provide intriguing evidence implying DNA repair mechanisms and cellular signaling through post-translational modifications regulate stem cell fate decision depending on their topographical location in the adult body. We …

Patterns Of Morphological And Molecular Evolution In The Antillean Tree Bat, Ardops Nichollsi (Chiroptera: Phyllostomidae), Roxanne J. Larsen, Peter A. Larsen, Caleb D. Phillips, Hugh H. Genoways, Gary G. Kwiecinski, Scott C. Pedersen, Carleton J. Phillips, Robert J. Baker

University of Nebraska State Museum: Mammalogy Papers

Species endemic to oceanic islands offer unique insights into the mechanisms underlying evolution and have served as model systems for decades. Often these species show phenotypic variation that is correlated with the ecosystems in which they occur and such correlations may be a product of genetic drift, natural selection, and/or environmental factors. We explore the morphologic and genetic variation within Ardops nichollsi, a species of phyllostomid bat endemic to the Lesser Antillean islands. Ardops nichollsi is an ideal taxon to investigate the tempo of evolution in Chiroptera, as it: is a recently derived genus in the family Phyllostomidae; contains …

Psychophysiological Tracking Of A Female Physique Competitor Through Competition Preparation, Brandon Jay Rohrig, Robert W. Pettitt, Cherie Pettitt, Todd Kanzenbach

International Journal of Exercise Science

International Journal of Exercise Science 10(2): 301-311, 2017. Natural physique competitions are based on subjective judgments of how a competitor appears on show day. Prior to competition, there is a prolonged dieting phase referred to as contest preparation. The primary goal is to reduce body fat levels while maintaining skeletal muscle mass. The study tracked the physiological and psychological changes for a 24 year old female preparing for a physique competition. Purpose: The study was conducted to describe the physiological and psychological changes of a female physique competitor who engages in long-term contest preparation. Methods: Diet, body composition, blood work, …

Effects Of Hypobaric And Normobaric Hypoxia On Heart Rate And Blood Oxygen Saturation, Madison Brooks Coleman

UNO Student Research and Creative Activity Fair

There has been recent debate on the difference in physiological response between exposure to normobaric hypoxia (oxygen fraction altered) and hypobaric hypoxia (barometric pressure altered). Purpose: To determine the effects of normobaric normoxia (NN), hypobaric hypoxia (HH), and normobaric hypoxia (NH) on heart rate and arterial oxygen saturation (SaO₂) after exercise. Methods: Fifteen recreationally active participants (eight males and seven females) completed three separate 1 h cycling bouts at 70% of their peak aerobic capacity. Following each trial, participants recovered in the supine position for 4 h in NN (975 m), HH (4420 m), or NH (4420 m). …

Human Stress Protein Response To Exercise And The Environment, Rebecca Cuthbert

UNO Student Research and Creative Activity Fair

Stress proteins are molecular chaperones that protect cells from the damaging effects that can be caused by exercise and environmental changes. Cold-inducible RNA binding protein (CIRP) and RNA binding motif protein 3 (RBM3) protect cells from mild hypothermia and hypoxia. They allow cells to rapidly respond to environmental stresses by regulating gene expression. Heat shock proteins 27, 70, and 90 protect skeletal tissue from exercise and heat stress. They accelerate cellular repair and prevent misfolding of proteins. These proteins, especially CIRP and RBM3, have been studied in cell cultures and animal models, but limited data exist in humans. Purpose: To …

Oxygen Transport In Normobaric Versus Hypobaric Hypoxia, Christina N. Angeli

UNO Student Research and Creative Activity Fair

BACKGROUND: Various physiological changes occur in the human body when ascending to altitude. Exposure to hypoxia increases heart rate and decreases arterial oxygen saturation (SaO₂), with both changes being expedited during exercise. Incremental exercise in ambient conditions decreases muscle oxygenation, specifically with increasing intensity. Previous research has examined heart rate and SaO₂ in response to normobaric versus hypobaric hypoxia. However, there is lack of research examining muscle oxygenation in response to these conditions. Therefore, additional research investigating acute responses to normobaric and hypobaric hypoxia during exercise is warranted. PURPOSE: To examine acute responses in arterial and muscle …

Responses Of Appetite And Appetite Regulating Hormones To Acute Altitude Exposure, Morgan Busboom

UNO Student Research and Creative Activity Fair

PURPOSE: To determine the acute response of appetite and appetite regulating hormones after exposure to simulated altitude in resting conditions. METHODS: Seven male and six female recreationally active subjects (height 178±8.1cm, weight: 77.3±24.8kg, body fat: 18.4±5.7%) participated in two, three-hour trials in an environmental chamber with one trial simulating 5000 m altitude (hypoxic) and the other simulating 350 m altitude (control). Blood samples from the antecubital vein were collected prior to entering the environmental chamber and immediately following the three hours of seated rest. Blood samples were analyzed for serum leptin, adiponectin, and ghrelin concentrations via enzyme-linked immunosorbent …

Effects Of Normobaric And Hypobaric Hypoxia On Mitochondrial Related Gene Expression, Robert J. Shute

UNO Student Research and Creative Activity Fair

Environmental stimuli such as temperature and hypoxia can influence cellular signaling in the skeletal muscle. Previously we have reported no changes in gene expression related to mitochondrial development with acute exposure to normobaric hypoxia. However, exposure to hypobaric hypoxia may elicit different physiological responses. Purpose: To determine the response of skeletal muscle mitochondrial related gene expression after 4 h of exposure to normobaric normoxia (NN), normobaric hypoxia (NH), and hypobaric hypoxia (HH) after exercise. Methods: Recreationally trained participants (8 male, 7 female) each completed three trials of 1-h cycling at 70% of W_max. Following exercise, participants sat in …

Comparison Of Whole-Body Cooling Techniques For Athletes And Military Personnel, Emma A. Nye, Lindsey E. Eberman, Kenneth E. Games, Colin Carriker

International Journal of Exercise Science

International Journal of Exercise Science 10(2): 294-300, 2017. The purpose of this study was to evaluate cooling rates of The Polar Life Pod®, a military protocol and cold water immersion. A randomized, repeated measures design was used to compare three treatment options. Participants exercised in an environmental chamber, where they followed a military march protocol on a treadmill, followed by the application of one of three treatments: Cold water immersion tub (5 – 10 °C), Polar Life Pod® (5 – 10 °C), Ice sheets at onset (5 – 10 °C). Mean cooling rate for CWI was 0.072 ºC/min, 0.046ºC/min for …