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Full-Text Articles in Life Sciences

Long-Term Depression Of Excitatory Inputs To Gabaergic Neurons In The Ventral Tegmental Area, Philip J. Sandoval Dec 2012

Long-Term Depression Of Excitatory Inputs To Gabaergic Neurons In The Ventral Tegmental Area, Philip J. Sandoval

Theses and Dissertations

Dopamine cells within the ventral tegmental area of the brain are involved in motivation and reward. Drugs of abuse target these dopamine cells altering their activity and plasticity resulting in addiction. While dopamine cell activity is primarily involved in addiction, the GABA neurons in the VTA have also been shown to have an indirect role. By decreasing the activity of the inhibitory GABA inputs onto dopamine neurons abusive drugs can indirectly increase dopamine cell activity resulting in addictive behaviors. However, although GABA neurons are important in the perception of reward, much less is known about how the excitatory inputs to …


Regulation Of Sensory Neurogenesis In The Trigeminal Placode: Notch Pathway Genes, Pax3 Isoforms, And Wnt Ligands, Jason Samuel Adams Nov 2012

Regulation Of Sensory Neurogenesis In The Trigeminal Placode: Notch Pathway Genes, Pax3 Isoforms, And Wnt Ligands, Jason Samuel Adams

Theses and Dissertations

This dissertation is divided into three chapters, each discussing the study of different regulatory molecules involved in sensory neurogenesis occurring in the trigeminal placode. Chapter one is a spatiotemporal description of Notch pathway genes in chick opV placode by stage-specific expression analysis, showing expression of many Notch pathway genes and effectors in the opV placode. Notch pathway gene expression is primarily confined to the ectoderm with highest expression of these genes at the beginning stages of peak neuronal differentiation. This information preceded studies of the functional roles that Notch signaling has in the opV placode and how it may affect …


Membrane Properties Involved In Calcium-Stimulated Microparticle Release From The Plasma Membranes Of S49 Lymphoma Cells, Lauryl Elizabeth Campbell Aug 2012

Membrane Properties Involved In Calcium-Stimulated Microparticle Release From The Plasma Membranes Of S49 Lymphoma Cells, Lauryl Elizabeth Campbell

Theses and Dissertations

The mechanism of microparticle shedding from the plasma membrane of calcium-loaded cells has been investigated in erythrocytes and platelets. Recent studies have revealed the physiological and clinical importance of microparticle release from nucleated cells such as lymphocytes and endothelium. The experiments of this study were designed to address whether simple mechanisms discovered in platelets and erythrocytes also apply to the more complex nucleated cells. Four such mechanisms were addressed: potassium efflux, transbilayer phosphatidylserine migration, cytoskeleton degradation, and membrane lipid order. The rate and amount of microparticle release in the presence of a calcium ionophore, ionomycin, was assayed by light scatter …


Tissue Specific Porcupine Deletion Reveals A Novel Role For Ectodermal Wnts In Musculotendon Development, Aaron P. Smith Jul 2012

Tissue Specific Porcupine Deletion Reveals A Novel Role For Ectodermal Wnts In Musculotendon Development, Aaron P. Smith

Theses and Dissertations

The Wnt family of secreted proteins consists of 19 family members (in the mouse) and is known to signal through multiple pathways that regulate crucial processes in the development of almost all tissues. Dissecting the roles of individual Wnts has been hampered due to functional redundancy that exists between family members. We made use of a conditional allele of the acyltransferase, Porcupine (Porcn), that is required for the secretion of all Wnt ligands, and the Msx2Cre deleter to eliminate the secretion of all Wnt ligands from the ventral limb ectoderm, ventral abdominal ectoderm, and urogenital ectoderm. Phenotypically the …


The Pro-Inflammatory Contributions Of Receptors For Advanced Glycation End-Products (Rage) In Alveolar Macrophages Following Cigarette Smoke Exposure, Adam Benjamin Robinson Jun 2012

The Pro-Inflammatory Contributions Of Receptors For Advanced Glycation End-Products (Rage) In Alveolar Macrophages Following Cigarette Smoke Exposure, Adam Benjamin Robinson

Theses and Dissertations

Receptors for advanced glycation end-products (RAGE) are multi-ligand cell surface receptors of the immunoglobin family expressed by epithelium and macrophages. RAGE expression increases following ligand binding and when diverse cells are exposed to a variety of insults including cigarette smoke extract (CSE). The current research sought to characterize the pro-inflammatory contributions of RAGE expressed by alveolar macrophages (AMs) following CSE exposure. Acute exposure of mice to CSE via nasal instillation revealed diminished bronchoalveolar lavage (BAL) cellularity and fewer AMs in RAGE null mice compared to controls. Primary AMs were obtained from BAL, exposed to CSE in vitro, and RNA, DNA, …


Characterization Of Altered Epithelial Cell Turnover And Differentiation In Embryonic Murine Lungs That Over-Express Receptors For Advanced Glycation End-Products (Rage), Jeffrey Alan Stogsdill May 2012

Characterization Of Altered Epithelial Cell Turnover And Differentiation In Embryonic Murine Lungs That Over-Express Receptors For Advanced Glycation End-Products (Rage), Jeffrey Alan Stogsdill

Theses and Dissertations

Receptors for advanced glycation end-products (RAGE) are multi-ligand cell surface receptors highly expressed in the lung that modulate pulmonary inflammation during disease. However, the contributions of RAGE signaling are unknown during pulmonary organogenesis. In order to test the hypothesis that RAGE misexpression adversely affects lung morphogenesis, conditional transgenic mice were generated that over-express RAGE in alveolar type II cells of the lung. When RAGE is over-expressed throughout embryogenesis, severe lung hypoplasia ensues, culminating in perinatal lethality. Flow cytometry and immunohistochemistry employing cell-specific markers for various distal cell types demonstrated anomalies in key epithelial cell populations resulting from RAGE up-regulation through …


Mechanism Of Inhibition Of Influenza A Virus M2 Proton Channel, Douglas Randall Bretzing, Victoria Man-Fung Burr May 2012

Mechanism Of Inhibition Of Influenza A Virus M2 Proton Channel, Douglas Randall Bretzing, Victoria Man-Fung Burr

Faculty Publications

The influenza A virus integral membrane protein, M2, is a proton-conducting channel. The ability of influenza A virus to unpack its genome, replicate, and infect its host is contingent upon the M2-mediated acidification of the viral interior. The antiviral drugs amantadine and rimantadine were previously effective in blocking proton influx through M2; however, mutations in the proton channel have rendered these drugs ineffective. Multiple models for the inhibiting mechanism of the adamantane drugs have been hypothesized. In an attempt to better understand the mechanism of M2 inhibition, and ultimately to assist in the development of a replacement M2-targeting antiviral drug, …


Iron Deficiency Causes A Shift In Amp-Activated Protein Kinase (Ampk) Catalytic Subunit Composition In Rat Skeletal Muscle, John Merrill Apr 2012

Iron Deficiency Causes A Shift In Amp-Activated Protein Kinase (Ampk) Catalytic Subunit Composition In Rat Skeletal Muscle, John Merrill

Theses and Dissertations

To determine effects of iron deficiency on AMPK activation and signaling, as well as the AMPKα subunit composition in skeletal muscle, rats were fed a control (C=50-58 mg/kg Fe) or iron deficient (ID=2-6 mg/kg Fe) diet for 6-8 wks. Their respective hematocrits were 47.5% ± 1.0 and 16.5% ± 0.6. Iron deficiency resulted in 28.3% greater muscle fatigue (p<0.01) in response to 10 min of stimulation (1 twitch/sec) and was associated with a greater reduction in phosphocreatine (C: Resting 24.1 ± 0.9 micromol/g, Stim 13.1 ± 1.5 micromol/g; ID: Resting 22.7 ± 1.0 micromol/g, Stim 3.2 ± 0.7 micromol/g; p<0.01) and ATP levels (C: Resting 5.89 ± 0.48 micromol/g, Stim 6.03 ± 0.35 micromol/g; ID: Resting 5.51 ± 0.20 micromol/g, Stim 4.19 ± 0.47 micromol/g; p<0.05). AMPK activation increased with stimulation in muscles of C and ID animals. A reduction in Cytochrome c and other iron-dependent mitochondrial proteins was observed in ID animals (p<0.01). The AMPK catalytic subunit (alpha) was also examined because both isoforms are known to play different roles in responding to energy challenges. In ID animals, AMPK alpha2 subunit protein content was reduced to 71.6% of C (p<0.05), however this did not result in a significant difference in resting AMPK alpha2 activity. AMPK alpha1 protein was unchanged, however an overall increase in AMPK alpha1 activity was observed (C: 0.91 pmol/mg/min; ID: 1.63 pmol/mg/min; p<0.05). Resting phospho Acetyl CoA Carboxylase (pACC) was unchanged. This study indicates that chronic iron deficiency causes a shift in the expression of AMPK alpha subunit composition and potentially altered sensitivity to cellular energy challenges.