Physiology Commons^™

Proton Conductance Through The Membrane Protein Gramicidin M, Jason D. Merrell, David D. Busath

Journal of Undergraduate Research

After discussion with my faculty mentor, together we decided that my original ORCA proposal would not best suit the needs of the laboratory in which I am allowed to work. Upon reaching this conclusion, a new research plan was organized. The following outlines the progress of this new plan and demonstrates the on-going research that was facilitated via my ORCA scholarship.

Effect Of Phytoestrogens On Brain Development And Function, Jacob C. Ong, Dr. Edwin D. Lephart

Journal of Undergraduate Research

Phytoestrogens are estrogen-like compounds derived from plants such as the soy plant and can mimic the function of the human estrogen hormone by binding to estrogen receptors. Estrogen plays a major role in the prevention of osteoperosis and cardiovascular disease in woman. Evidence also suggests that estrogen influences various parts of the memory process and that its impact on an organism is dependent on the developmental stage at which exposure occurs [1].

Determining Homology Of Turkey Round Heart Disease Marker Sequences: A Computer-Based Study, Ryan D. Mcallister, Dr. David Kooyman

Journal of Undergraduate Research

Round heart disease (RHD) is a spontaneous occurring cardiomyopathy in turkeys. The domestic turkey Meleagris gallopavo is affected by low body weight and premature death due to congestive heart failure from RHD (1). RHD results in decreased profitability for the animal agriculturists and higher prices for turkey products. DNA markers have been identified for both normal turkeys and for turkeys affected by RHD. These genetic markers have been amplified using Random Amplified Polymorphic DNA (RAPD) analysis (2). 16 DNA marker sequences amplified by RAPD have now been determined (3). Basic Local Alignment Search Tool (BLAST) is a computer program designed …

Comparison Of Gramicidin A And Gramicidin M Channel Properties In Kcl, Nacl, And Hcl, Jeffrey C. Markham, David D. Busath

Journal of Undergraduate Research

The oligopeptide gramicidin is one of the simplest proteins which can form channels in cell membranes to conduct ions into or out of a cell. The peptide is produced by the bacteria Bacillus brevis. It can also be synthesized by scientists for research purposes. By producing slightly modified variants of the standard gramicidin structure, conclusions can be drawn about structurefunction relationships based on experimentation with the variants.

Walking Stick (Insect: Phasmida) Phylogeny And The Evolution Of Insect Flight Based On Molecular Data, Taylor J. Maxwell, Dr. Michael F. Whiting

Journal of Undergraduate Research

The evolution and development of wings and flight has fascinated scientists for decades. From our research we happened upon an exciting discovery concerning flight in the phylogeny of walking sticks. A basic phylogeny was to be reconstructed from molecular data with the purpose of understanding the classification of the group. The phylogeny enabled us to discover the initial loss of wings and flight in phasmid history and the consequent gain of flight in later lineages. We are not aware of any other organism, which has lost and subsequently regained such a complex character.

Non-Equilibrium Molecular Dynamics Study Of An Ion Channel With Aqueous Nacl: A Slab Geometry Approach, Nathan B. Holladay, David D. Busath

Journal of Undergraduate Research

An ion channel is a tunnel that allows ions to cross a barrier. Ion channels are common components of cellular membranes, helping to regulate ionic concentrations in different areas inside or outside cells. Electrical and/or concentration differences between one side of a membrane and the other often drive the net flow of ions in one direction or the other across the membrane. Theoretical biophysicists have used computer-based molecular dynamics simulations for years now to study the behavior of ions within ion channels under equilibrium conditions. Before our study, however, few or no studies had been done in which molecular dynamics …

Increasing Bilayer Membrance Fusion Rates By Increasing Cholesterol Content, David Lee, Dr. Dixon Woodbury

Journal of Undergraduate Research

A bilayer is a two-layered membrane made of lipids that form around cells. These membranes are formed by hydrophobic tails (water fearing) and hydrophilic heads (water loving) that align such that the tails are isolated from water, while the heads are exposed to water to form micelles, liposomes, or sheets (Fig. 1). They are used to regulate what can enter and exit a cell. A fusion event occurs when a liposome fuses with a sheet. In our experiments, we are able to see the effects on fusion rate by altering the cholesterol content of the sheets.

Colour And Odour Drive Fruit Selection And Seed Dispersal By Mouse Lemurs, Kim Valenta, Ryan J. Burke, Sarah A. Styler, Derek A. Jackson, Amanda D. Melin, Shawn M. Lehman

Dartmouth Scholarship

Animals and fruiting plants are involved in a complex set of interactions, with animals relying on fruiting trees as food resources, and fruiting trees relying on animals for seed dispersal. This interdependence shapes fruit signals such as colour and odour, to increase fruit detectability, and animal sensory systems, such as colour vision and olfaction to facilitate food identification and selection. Despite the ecological and evolutionary importance of plant-animal interactions for shaping animal sensory adaptations and plant characteristics, the details of the relationship are poorly understood. Here we examine the role of fruit chromaticity, luminance and odour on seed dispersal by …

Phytoestrogens: Effects On Male Sexual Health Parameters, Trevor Hansen, Dr. Edwin Lephart

Journal of Undergraduate Research

Phytoestrogens are estrogen-like molecules derived from soy-based foodstuffs such as soybeans, tofu and even certain cereals. In particular, our study focused on a subclass of phytoestrogens called isoflavones. Of the many isoflavones, daidzene and genistein are thought to exert the most potent estrogenic hormone activity, and thus have been the subject of much recent research.

The Role Of Rage In Inflammatory Lung Disease Induced By Diesel Particulate Matter, Karisa Wasley, Dr. Paul Reynolds

Journal of Undergraduate Research

The causes of high morbidity and mortality associated with inflammatory respiratory diseases are not well understood. My research project helped to shed light on cellular signaling pathways associated with inflammatory disease, particularly those caused by or worsened by air pollutants. Asthmatics, in particular, have a difficult time dealing with common pollutants found in cities, including diesel particulate matter (PM). I focused specifically on the inflammation induced by air pollutants such as diesel PM and the activation of signaling pathways initiated by their binding with the receptors for advanced glycation end-products (RAGE). RAGE is involved developmentally in the lungs and specifically …

There’S No Wrong Way For A Cell To Die: Caspase-Independent Programmed Cell Death Pathways Resulting In Apoptotic Characteristics, Katalyn Pickett, Dr. John D. Bell

Journal of Undergraduate Research

There are a number of ways that cells can die. One way is through apoptosis, also known as programmed cell death. This death pathway is characterized by orderly signals and mechanisms that essentially tell the cell to die without “making a mess”. Necrosis, another form of cell death, can be thought of as cell “homicide”; cells, generally in response to some environmental stress, are simply unable to survive and therefore die quickly and seemingly without regulation. Previously, the line between apoptosis and necrosis was thought to be distinct, but recent studies have shown that there are cell death pathways that …

Destabilization Of The Medial Meniscus: A Non-Genetic Approach To Inducing Osteoarthritis In Mice, Christopher Stockdale, Joshua Lloyd, Dr. Robert E. Seegiller

Journal of Undergraduate Research

Osteoarthritis (OA) is a common disease that causes discomfort and pain due to the degradation of the articular cartilage found on the surface of bones within the body’s joints. A properly functioning joint has a strong network of articular cartilage that can handle the constant strain caused by the use and movement of the joints. Individuals who suffer with OA have a compromised cartilage network that can result in softening of the cartilage, rough joint surfaces, fissures in the cartilage, and eventually direct bone on bone contact within the joint.

A Study Of Biological Photonic Crystals In The Effects Of Beta Amyloid On Nicotinic Acetylcholine Receptors In Alzheimer’S: Internal Opal Scale Structures Of Iridescent Beetle Species In The Cerambycidae Family, Andrew Romney, Dr. Sterling Sudweeks

Journal of Undergraduate Research

For the past two years, I have worked in Dr. Sterling Sudweeks’ research lab experimenting with neurotransmitter receptors that are implicated in the development of Alzheimer’s Disease. When functioning normally, these receptors act as ion channels which open upon binding nicotine or acetylcholine and are thus appropriately named nicotinic acetylcholine receptors (nAcRs). nAcRs’s are found at the neuromuscular junction as well as in nervous tissue and are comprised of 5 subunits. Dr. Sudweeks’ previous research suggests that the alpha 3 and beta 2 subunits are the most common subunits in receptors in the hippocampus, which is the primary area of …

Inhibition Of Notch Signaling Increases Neurogenesis In The Ophthalmic Trigeminal Placode Without Expanding The Domain Of Neurogenin2 Expression., Brian Wright, Dr. Michael Stark

Journal of Undergraduate Research

The ever-increasing knowledge regarding cellular regulation and programming requires important insights into the biochemical pathways that determine a cell’s fate. For example, the ability to take a stem cell and grow it into a neuron will directly depend on our knowledge of the steps used in the embryo for normal neurogenesis, or the formation of neurons. The ophthalmic placode (a region of thickening cells) of the trigeminal nerve provides a valuable model for studying sensory neurogenesis, since it gives rise exclusively to sensory neurons. This nerve provides tactile sensation to the upper region of the face.

Establishing The Spondyloepiphyseal Congenita Heterozygous Mouse As An Animal Model For Human Osteoarthritis, Michael Henderson, Dr. Robert Seegmiller

Journal of Undergraduate Research

Osteoarthritis (OA) causes discomfort and immobility to millions of Americans every year. Due to the high demand for patient pain relief and improved mobility, scientists are seeking to understand the pathway of OA and develop drugs which would illuminate the onset of, and/or the progression of, OA.

The Cerebral Cortex As An Effect Site For Anesthetic Induced Unconsciousness, Ryan Martin, David Busath

Journal of Undergraduate Research

General anesthetics are widely used today in medicine. Their molecular mechanisms however, still remain a mystery. For centuries, general anesthetics were thought to be “drugs without receptors” because of the lack of knowledge about their mechanism of action (Hemmings, et al., 2005). While some advances have been made by Neuroscientists and Biologists there is still a lot that is not known about general anesthetics. The exact location of general anesthetic action is thought to be complex, but two particular locations have been suggested—the cerebral cortex and the midbrain. Detailed understanding of where general anesthetics act is important because it would …

The Role Of Htra1, Ddr2, And Mmp-13 Proteins In The Mechanistic Pathway Leading To Osteoarthritis In Sedc Mice, David Holt, Robert Seegmiller

Journal of Undergraduate Research

In the present study, we report OA in a mouse model that, like the human families presented by Kannu et al., bears a heterozygous mutation in the Col2a1 gene but has a phenotypically normal skeleton.1 The mouse mutation was named sedc by Donahue et al. because when homozygous, it produces feature that resemble the most common clinical phenotypes of SED congenita in humans, including abnormal epiphyses, flattened vertebral bodies, and problems with the eyes and ears.2 The mutation consists of a single base pair substitution in exon 48 of the Col2a1 gene, which changes an arginine to a cysteine in …

Lifetime Dietary Exposure To Soy Isoflavones Is Beneficial To Prostate And Testicular Health In 100-Day Old Male Long-Evans Rats, Benjamin Hogan, Dr. Edwin Lephart

Journal of Undergraduate Research

Phytoestrogens are plant-derived compounds that are structurally and functionally similar to estradiol. Isoflavones are a major type of phytoestrogen that can be found in foods such as soy beans, tofu, and soy milk. They have become popular due to the health benefits they effect by binding to estrogen receptors throughout the body. However, while their action is similar to that of estradiol, they are non-steroidal and therefore less potent.

Ror2/Wnt5a Mediated Directional Limb Outgrowth, Aaron Smith, Dr. Jeff Barrow

Journal of Undergraduate Research

The apical ectodermal ridge (AER) is a small strip of epithelial tissue that is found at the distal tip of the embryonic vertebrate limb and runs from anterior to posterior. It is known that the AER is necessary to maintain the life of mesenchymal cells (interior non-surface cells) of the limb and is also necessary to maintain other important signaling centers in the limb (citations). The AER is also believed to be responsible for patterning the limb along the proximal to distal axis. However, it is unknown what precise role the AER plays in this and researchers have been attempting …

Amantadine Blockage Of The Influenza A M2 Proton Transporter, Jared Kelson, David Busath

Journal of Undergraduate Research

The reproduction of influenza A is very closely regulated by the pH levels maintained both in the cytoplasm and in various organelles of a host cell. To accommodate this, the virus provides genetic coding to assemble an M2 transporter which regulates the flow of protons across the different membranes. Until recently, influenza A was treated with a drug known commonly as amantadine (1-aminoadamantane), which blocked M2 proton transport. Unfortunately, by the year 2005, 91% of known influenza A strains had mutated to the extent that amantadine was no longer an effective reagent (High, 2006 p. 44). The 2009 epidemic of …

Effect Of Muscle Stimulation On Gene Expression For Mitochondrial Proteins, Darren Goring, Dr. David Thomson

Journal of Undergraduate Research

The original purpose of this study was to elucidate the effects of muscle stimulation on gene expression for mitochondrial proteins in mLKB1-KO mice (mice in which the LKB1 gene has been knocked out of the muscles and heart). LKB1 is an important protein involved in the signaling of mitochondrial protein production. The original protocol was to run the mice on a treadmill fast enough and long enough to cause transcription of mitochondrial proteins. I hypothesized that the mLKB1-KO mice would still have some mitochondrial gene expression but to a lesser degree than the conditional mice.

Trash Brings A New Diet Water Conservation In Cape Verde, Africa, Tanner Goff, Dr. Bruce Woolley

Journal of Undergraduate Research

In Sub-Saharan African countries the resource of most significance, we Americans take for granted: water. The African people know this and strive to minimize wasting such a precious resource. However, with little education on how to conserve water, waste is inevitable. The country of Cape Verde is no stranger to a huge water deficit and this water deficit has a direct effect on the diet of the people. Most of the country relies on beans and rice with no variety of vegetables in their diet. The typical Cape Verdeans diet is characterized by “repeated rice meals” and “as the water …

The Role Of Nectin In Zyxin Localization, Jace Bullard, Dr. Marc Hansen

Journal of Undergraduate Research

A major difficulty of treating cancer rises from its ability to metastasize. During metastasis, strong adhesions between cells break, allowing individual cells to separate and migrate to different locations in the body. Strong cell-cell junctions are formed by protein interactions between actin cables and cell junction proteins. Zyxin is an actin regulator that localizes at cadherin-based cell-cell adhesions. Our lab has shown that cells expressing constitutively active forms of zyxin lose the ability to completely detach from each other, a result of maintained actin-membrane associations. How zyxin is localized to the cell membrane is unknown. Given zyxin’s role in maintaining …

Biophysical Cell Membrane Changes During Chemotherapeutic Drug-Induced Apoptosis, Amanda Berbert, Dr. John Bell

Journal of Undergraduate Research

Our project provided us the opportunity to gain insight into how chemotherapy drugs affect the cell membrane and how secretory phospholipase A₂ (sPLA₂) can work in tandem with these drugs to accelerate the cell death process. The enzyme sPLA2 produces a pro-inflammatory response that plays an important role in wound protection and healing and is also associated with diseases including septic shock, atherosclerosis, and cancer. This enzyme preferentially hydrolyzes cells that exhibit specific physical membrane properties in response to cellular trauma or apoptosis (programmed cell death). We hypothesized that although chemotherapeutic agents work through different mechanisms, the …

Exploring Folate Uptake In Chicken Understanding Prevention Of Neural Tube Defects, Bret Gardner, Dr. Michael Stark

Journal of Undergraduate Research

Neural tube defects (NTDs) are among the most common congenital malformations, afflicting .5- 8/1000 live births (Saitsu, 2003). Examples of such defects include spina bifida and anencephaly, resulting from failed closure of the posterior and anterior neural tube, respectively. The neural tube is the fetal precursor to the central nervous system. Currently the most common and effective method for preventing such defects consists of periconceptional folate intake. In developed countries, sufficient folate (folic acid or vitamin B12) is readily obtained from multivitamins, enriched cereals, or other items in a balanced diet. This preventative treatment, however, remains ineffective in 30-50% of …

Mouse Strain Determines Cardiac Growth Potential, Carmen Kiper, Barry Grimes, Gary Van Zant, Jonathan Satin

Physiology Faculty Publications

RATIONALE: The extent of heart disease varies from person to person, suggesting that genetic background is important in pathology. Genetic background is also important when selecting appropriate mouse models to study heart disease. This study examines heart growth as a function of strain, specifically C57BL/6 and DBA/2 mouse strains.

OBJECTIVE: In this study, we test the hypothesis that two strains of mice, C57BL/6 and DBA/2, will produce varying degrees of heart growth in both physiological and pathological settings.

METHODS AND RESULTS: Differences in heart dimensions are detectable by echocardiography at 8 weeks of age. Percentages of cardiac progenitor cells (c-kit+ …

Neurotensin And Cholecystokinin Contract Gallbladder Circular Muscle In Chickens, Teresa F. Degolier, D. R. Brown, Gary E. Duke, M. M. Palmer, J. R. Swenson, Robert E. Carraway

Biological Sciences Faculty Publications

The contractile effects of neurotensin (NT) and cholecystokinin octapeptide (CCK-8) on isolated circular smooth muscle strips of chicken gallbladder were investigated. The NT (0.25-300 nM) produced concentration-dependent contractions on smooth muscle with an EC50 of 8.5 nM (95% confidence limits = 5.3-13.6 nM). In comparison, CCK-8 produced concentration-dependent contractions with an EC50 of 13 nM (95% confidence limits of 9-20 nM). There were no statistical differences in contractile responses when comparing NT and CCK-8 at equimolar concentrations. The NT appears to act directly on smooth muscle tissue in the chicken; the contractile responses were not blocked by 10 μM atropine …

Med13p Prevents Stress-Independent Mitochondrial Hyperfragmentation And Aberrant Apoptosis Activation In Saccharomyces Cerevisiae By Controlling Cyclin C Nuclear Localization, Svetlana Khakhina

Graduate School of Biomedical Sciences Theses and Dissertations

During aging, and as a result of environmental changes, cells are exposed to elevated levels of reactive oxygen species (ROS). High ROS levels induce lipid oxidation, protein aggregation, mitochondrial hyperfragmentation, DNA damage and programmed cell death (PCD), also called apoptosis. PCD is a highly regulated process and its misregulation has been linked to neurodegenerative diseases and cancer development.

Our hypothesis is that cyclin C plays a role in the initiation of apoptosis. During normal conditions, cyclin C represses the transcription of stress response genes (SRG). In response to stress, cyclin C translocates to the cytoplasm where it facilitates mitochondrial hyperfragmentation …

Exercise Participation During Weight Loss On A High Protein – Low Carbohydrate Diet Plan In Females Aged 15-25 Years, Margaret Mobley-Meulman

Electronic Theses and Dissertations

Weight gain due to poor diet and lack of exercise is responsible for over 300,000 deaths each year (U.S. Department of Health and Human Services, 2010). Obese adults have an increased risk for serious health conditions including high blood pressure and cholesterol, type 2 diabetes, coronary heart disease, stroke, gallbladder disease, osteoarthritis, sleep apnea, respiratory problems, and certain cancers (National Cancer Institute, 2012). Participation in exercise can help control weight, strengthen muscles and bones, and reduce the incidence of cardiac events, stroke, hypertension, type 2 diabetes, colon and breast cancers, osteoporotic fractures, gallbladder disease, obesity, depression, anxiety, and delay mortality …

Surfing Injuries Requiring First Aid In New Zealand, 2007-2012, Kevin Moran, Jonathon Webber

International Journal of Aquatic Research and Education

In an island nation such as New Zealand with easy access to surf beaches, surfing activities are very popular and, while generally perceived as a healthy form of outdoor recreation, they do have attendant risks. This study reports on nondrowning, surfing-related incidents that required medical first aid on beaches during five summer seasons from 2007-2012. Retrospective descriptive analysis of data from lifeguard first aid reports found that 16% (n = 1,327) of injuries were the consequence of surfing activity. More males than females were treated for surfing injuries (68% male, 31% female). Lacerations (59%) and bruising (15%) accounted for most …