Neuroscience and Neurobiology Commons^™

Age-Dependent Breakdown Of The Blood Brain Barrier And Associated Changes In S100b Ko Mice, Eric V. Brown

Graduate School of Biomedical Sciences Theses and Dissertations

Autoantibodies play an important role in many autoimmune diseases. Recent research has shown that breakdown of the blood brain barrier (BBB) occurs concomitant to generation of brain reactive autoantibodies in many neurodegenerative diseases, which serve as biomarkers and drivers of pathology. SI00B, a calcium binding protein found most highly expressed in astrocytes which ensheathe the BBB, has many functions in neural development and signaling. Currently literature indicates that S100B KO mice develop normally, with no phenotypic abnormalities. Here, it is demonstrated that S100B KO mice seem to develop a chronic BBB breakdown similar to that seen in human neurodegenerative diseases. …

Efficient In Vitro Development Of Photoreceptors From Human Pluripotent Stem Cells, Joseph C. Reynolds

Dissertations, Masters Theses, Capstones, and Culminating Projects

Degeneration of the rod and cone photoreceptors in the human retina is among the most common causes of blindness. Replacing these damaged photoreceptors may help to restore vision. Repairing the damaged retina relies on the insertion of new, healthy cells. Embryonic stem (ES) cells and induced pluripotent stem (iPS) cells are two possible sources of photoreceptors to restore vision. Previous data shows that human ES cells and iPS cells can be differentiated into photoreceptors and transplanted into the eye to restore some vision. However, this process is inefficient, and costly. Here, we show a new method for inducing photoreceptor production …

Glycine And Gabaa Receptors Mediate Tonic And Phasic Inhibitory Processes That Contribute To Prepulse Inhibition In The Goldfish Startle Network, Paul C.P. Curtin, Thomas Preuss

Publications and Research

Prepulse inhibition (PPI) is understood as a sensorimotor gating process that attenuates sensory flow to the startle pathway during early stages (20--1000 ms) of information processing. Here, we applied in vivo electrophysiology and pharmacology to determine if PPI is mediated by glycine receptors (GlyRs) and/or GABAA receptors (GABAARs) in the goldfish auditory startle circuit. Specifically, we used selective antagonists to dissect the contributions of target receptors on sound-evoked postsynaptic potentials (PSPs) recorded in the neurons that initiate startle, the Mauthner-cells (M-cell). We found that strychnine, a GlyR antagonist, disrupted a fast-activated (5 ms) and rapidly (<50 >ms) decaying (feed-forward) inhibitory …

Pcdh19 Expression In Normal And Regenerating Adult Zebrafish Retinas, Kristin N. Forkapa Ms.

Williams Honors College, Honors Research Projects

My Honors Research Project will test the function of the N-cadherin molecule on the zebrafish optic nerve regeneration. N-cadherin is a member of the cadherin superfamily. Cadherins are cell adhesion molecules important for animal development and maintenance of adult structures. Unlike mammals, fish and amphibians have the ability to regenerate their optic nerve after damages. Molecular mechanisms underlying the optic nerve regeneration are still under intense investigation. Studies in Dr. Liu’s laboratory showed that expression of several cadherins, including N-cadherin, was greatly increased during adult zebrafish optic nerve regeneration, suggesting that cadherins may be involved in the optic nerve regeneration …

Elucidating The Role Of Endogenous Electric Fields In Regulating The Astrocytic Response To Injury In The Mammalian Central Nervous System, Matthew L. Baer

Theses and Dissertations

Endogenous bioelectric fields guide morphogenesis during embryonic development and regeneration by directly regulating the cellular functions responsible for these phenomena. Although this role has been extensively explored in many peripheral tissues, the ability of electric fields to regulate wound repair and stimulate regeneration in the mammalian central nervous system (CNS) has not been convincingly established. This dissertation explores the role of electric fields in regulating the injury response and controlling the regenerative potential of the mammalian CNS. We place particular emphasis on their influence on astrocytes, as specific differences in their injury-induced behaviors have been associated with differences in the …

A Novel Method For Studying Gene Regulatory Elements In Vivo Reveals Essential Roles For Intron Splicing In Neurofilament Gene Expression, Chen Wang

Legacy Theses & Dissertations (2009 - 2024)

Axon outgrowth requires coordinated expression of critical cytoskeletal genes in response to extracellular cues. The spatial and temporal expression of these genes is regulated transcriptionally and posttranscriptionally. Such regulation is largely mediated through the activity of cis-regulatory elements within the cytoskeletal DNAs and RNAs, which recruit specific sets of trans-factors such as DNA- and RNA-binding proteins, as well as microRNAs. To identify the functionally active cis-elements, characterize their dynamically changing sets of trans-factors, and investigate the association between the two sets of regulators in the context of an intact developing nervous system, one needs to combine appropriate in vivo strategies …

Clique Topology Reveals Intrinsic Geometric Structure In Neural Correlations, Chad Giusti, Eva Pastalkova, Carina Curto, Vladimir Itskov

Department of Mathematics: Faculty Publications

Detecting meaningful structure in neural activity and connectivity data is challenging in the presence of hidden nonlinearities, where traditional eigenvalue-based methods may be misleading. We introduce a novel approach to matrix analysis, called clique topology, that extracts features of the data invariant under nonlinear monotone transformations. These features can be used to detect both random and geometric structure, and depend only on the relative ordering of matrix entries. We then analyzed the activity of pyramidal neurons in rat hippocampus, recorded while the animal was exploring a 2D environment, and confirmed that our method is able to detect geometric organization using …

Characterization Of Calbindin Positive Interneurons Within The Ventral Horn Of The Mouse Spinal Cord, Taylor L. Floyd, David R. Ladle

Celebration of Undergraduate & Graduate Research, Scholarship, and Creative Activities Materials

Sensory-motor circuits in the spinal cord integrate sensory feedback from muscles and modulate locomotor behavior. Although we know how the sensory-motor system generally works, the main issue lies in identifying all neurons involved and understanding their interrelationships. Many interneurons contribute to sensory-motor circuits and have been well studied. For example, Renshaw cells (RC) are inhibitory interneurons that prevent motor neurons from over-activity. A distinguishing feature of RCs is that they are the only interneurons within the ventral-most region of the spinal cord expressing the calcium binding protein calbindin (CB). Recent studies have found other subpopulations of ventral horn interneurons outside …

Role Of Sox11 During Vertebrate Ocular Morphogenesis And Retinal Neurogenesis, Lakshmi Shashidharan Pillai

Theses and Dissertations--Biology

Microphthalmia, anophthalmia, and coloboma (MAC) are distinct abnormalities demonstrating a continuum of developmental eye defects that contribute to 15-20% of blindness and severe vision deficiencies in children worldwide. The genetic etiology of MAC is large, complex and encompasses the whole developmental biology of the eye. Understanding how the eye develops will aid in identifying genes and developmental pathways involved in MAC. Although investigation of the genetic architecture of congenital anomalies is growing exponentially, much work remains to be accomplished to understand the complex, genetically heterogeneous congenital anomalies, which significantly impact childhood vision.

With an interest in elucidating the mechanisms that …

Dual Functions For Insulinoma-Associated 1 In Retinal Development, Marie A. Forbes-Osborne

Theses and Dissertations--Biology

Proper visual system function requires tightly controlled proliferation of a pool of relatively homogeneous retinal progenitor cells, followed by the stepwise specification and differentiation of multiple distinct cell types. These retinal cells, both neuronal and glial, must be generated in the correct numbers, and the correct laminar location to permit the formation of synaptic connections between individual cell types. After synapses are made, constant signaling is required as part of normal retinal function, and to maintain cellular identity and connectivity. These processes rely on both extrinsic and intrinsic signaling, with regulation of gene expression by cascades of transcription factors having …

Gene Expression And Alzheimer's Disease: Evaluation Of Gene Expression Patterns In Brain And Blood For An Alzheimer's Disease Mouse Model, Amanda Hazy

Senior Honors Theses

Previous studies have established a causative role for altered gene expression in development of Alzheimer’s disease (AD). These changes can be affected by methylation and miRNA regulation. In this study, expression of miRNA known to change methylation status in AD was assessed by qPCR. Genome-wide expression changes were determined by RNA-sequencing of mRNA from hippocampus and blood of control and AD mice. The qPCR data showed significantly increased expression of Mir 17 in AD, and sequencing data revealed 230 genes in hippocampus, 58 genes in blood, and 8 overlapping genes showing significant differential expression (p value ≤ 0.05). Expression data …

Evaluation Of The Developmental Toxicity Of Lead In The Danio Rerio Body, Nicole M. Roy, Sarah Dewolf, Bruno Carneiro

Biology Faculty Publications

Lead has been utilized throughout history and is widely distributed and mobilized globally. Although lead in the environment has been somewhat mitigated, the nature of lead and its extensive uses in the past prohibit it from being completely absent from our environment and exposure to lead is still a public health concern. Most studies regarding lead toxicity have focused on the brain. However, little is found in the literature on the effects of lead in other tissues. Here, we utilize the zebrafish model system to investigate effects of lead exposure during early developmental time windows at 24, 48 and 72 …

Sustained Adrenergic Signaling Promotes Cervical Cancer Progression, Nouara C. Sadaoui

Dissertations and Theses (Open Access)

Background: Chronic stress and sustained adrenergic signaling are known to promote tumor progression. The underlying mechanisms behind this process are not well understood. We examined the effects of sustained adrenergic signaling on cervical cancer progression through increased expression of HPV oncogenes, E6 and E7.

Materials and Methods: ADRβ expression levels were examined in patient-derived cervical cancer samples. We used an orthotopic model of cervical cancer to investigate the effects of restraint stress on tumor growth and metastasis. We evaluated the in vivo effects of a β-blocker, propranolol, and HPV E6/E7 siRNA. In vitro, ADRβ positive cervical cancer cells were …

Large-Scale Identification Of Chemically Induced Mutations In Drosophila Melanogaster, Nele A Haelterman, Lichun Jiang, Yumei Li, Vafa Bayat, Hector Sandoval, Berrak Ugur, Kai Li Tan, Ke Zhang, Danqing Bei, Bo Xiong, Wu-Lin Charng, Theodore Busby, Adeel Jawaid, Gabriela David, Manish Jaiswal, Koen J T Venken, Shinya Yamamoto, Rui Chen, Hugo J Bellen

Faculty, Staff and Students Publications

Forward genetic screens using chemical mutagens have been successful in defining the function of thousands of genes in eukaryotic model organisms. The main drawback of this strategy is the time-consuming identification of the molecular lesions causative of the phenotypes of interest. With whole-genome sequencing (WGS), it is now possible to sequence hundreds of strains, but determining which mutations are causative among thousands of polymorphisms remains challenging. We have sequenced 394 mutant strains, generated in a chemical mutagenesis screen, for essential genes on the Drosophila X chromosome and describe strategies to reduce the number of candidate mutations from an average of …

Fty720 (Fingolimod) Provides Insight Into The Molecular Mechanisms Of Multiple Sclerosis, Madelyn Elizabeth Crawford

Pursuit - The Journal of Undergraduate Research at The University of Tennessee

Multiple sclerosis (MS) is a neurodegenerative disorder caused by a prolonged immune- mediated inflammatory response that targets myelin. Nearly all of the drugs approved for the treatment of MS are general immunosuppressants or only function in symptom management. The oral medication fingolimod, however, is reported to have direct therapeutic effects on cells of the central nervous system in addition to immunomodulatory functions. Fingolimod is known to interact with sphingosine-1-phosphate (S1P) receptors, and the most widely- accepted theory for its mechanism of action is functional antagonism of the receptor. This review examines significant neuromodulatory effects achieved by functional antagonism of the …

The Effect Of Repeated Mild Traumatic Brain Injury On Ventricular Volume And Microglial Activation, Lillian Rose Talbot

Honors Scholar Theses

As the leading cause of death and disability in individuals under the age of 45-years-old, Traumatic Brain Injury (TBI) is a public health crisis that demands the attention of the scientific and medical community [28]. The majority of all TBIs that occur in the United States each year are a non-deadly yet detrimental form of closed brain injury known as mild TBI (mTBI) or concussion [6]. Athletes, young people and military personnel all face a high risk of acquiring mTBI as a result of their environments. In our study we have chosen to model repeated mTBI (rmTBI) in the mouse …

Electrical Stimulation Has Opposing Effects On Glial Cell Line-Derived Neurotrophic Factor Expression In Voluntary And Involuntary Muscle, John-Mary Vianney, John Spitsbergen

Research and Creative Activities Poster Day

Glia cell line-derived neurotrophic factor (GDNF) is a potent survival factor for sub-populations of neurons including somatic and autonomic motor neurons. These neurons depend, in part, on GDNF that is synthesized and secreted by their target tissues. Whether the processes regulating GDNF production in these tissues is similar or different is poorly understood. The current study compares the regulation of production of GDNF in skeletal muscle and cardiac muscle following electrical and chemical stimulation. We show that electrical stimulation has opposing effects on GDNF production in cardiac and skeletal muscle, where GDNF levels increase with long-term electrical stimulation in skeletal …

The Characterization Of Pb2+ Toxicity In Rat Neural Development: An Assessment Of Pb2+ Effects On The Gaba Shift In Neural Networks And Implications For Learning And Memory Disruption, Lorenz Simon Neuwirth

Dissertations, Theses, and Capstone Projects

The toxic effects of Pb2+ on the developing rat nervous system has been investigated to assess early developmental GABAergic disruption and its implications with altering inhibitory learning and memory. This goal was achieved using a multi-systems approach: blood lead levels (clinical physiology), qRT-PCR (molecular genetics), brain and primary neuronal culture immunology (immunohistochemical and cellular approaches), physiological cellular components (synaptosomes and protein expression) and finally through learning and memory assessment with GABA mimetic drug manipulations in the intact animal (behavioral pharmacology). The influence of a 956ppm Pb2+ gestational diet (i.e. from birth to sacrifice) resulted in pup mean blood lead levels …

Nel Positively Regulates The Genesis Of Retinal Ganglion Cells By Promoting Their Differentiation And Survival During Development, Chizu Nakamoto, Soh-Leh Kuan, Amy Findlay, Elaine Durward, Zhufeng Ouyang, Masaru Nakamoto, Ewa Zakrewska, Takuma Endo

Biology Faculty Publications

For correct functioning of the nervous system, the appropriate number and complement of neuronal cell types must be produced during development. However, the molecular mechanisms that regulate the production of individual classes of neurons are poorly understood. In this study, we investigate the function of the thrombospondin-1–like glycoprotein, Nel (neural epidermal growth factor [EGF]-like), in the generation of retinal ganglion cells (RGCs) in chicks. During eye development, Nel is strongly expressed in the presumptive retinal pigment epithelium and RGCs. Nel overexpression in the developing retina by in ovo electroporation increases the number of RGCs, whereas the number of displaced amacrine …

The Postsynaptic Regulation Of Synaptic Strength In Drosophila, Daniel Michael Gertner

Legacy Theses & Dissertations (2009 - 2024)

Postsynaptic Ca2+ plays an important role in synaptic homeostasis and synaptic plasticity. Postsynaptic Ca2+ signals have been shown to regulate synaptic transmission at the Drosophila larval neuromuscular junction (NMJ), however, these signals have not been well characterized. This will explore how these signals regulate synaptic strength and what channels are involved. In previous lab experiments Ca2+ transients were observed during evoked and spontaneous release (Desai and Lnenicka, 2011). It was further demonstrated that a reduction in synaptic strength occurs following synaptic stimulation. It was hypothesized that the increase in postsynaptic Ca2+ following synaptic stimulation activates the gCS and causes a …

Gbetagamma-Microtubule Mediated Mechanism Of Neuronal Differentiation, Jorge Anibal Sierra Fonseca

Open Access Theses & Dissertations

Neurodegeneration, a progressive loss of nerve cells (neurons), occurs in many neurological disorders, including Alzheimer's and Parkinson's diseases, as well as in the aging brain. Disruption of microtubules in neurons and the aggregation of proteins associated with them is the hallmark of neurodegeneration. Nevertheless, the cause of this disorder is largely unknown, and no effective drugs are available to treat the disease processes. Therefore, there is a need to understand the molecular mechanisms that drive the assembly and disassembly of microtubules during neurite outgrowth and differentiation. Evidence suggests that nerve growth factor (NGF) induces neurite outgrowth from PC12 cells by …

Calpain 5: A Non-Classical Calpain Highly Expressed In The Cns And Localized To Mitochondria And Nuclear Pml Bodies, Ranjana Singh

Theses and Dissertations--Neuroscience

Calpain 5 (CAPN5) is a non-classical member of the calpain family. It lacks the EF-hand motif characteristic of the classical calpains, calpain 1 and 2, but retains catalytic and Ca²⁺ binding non EF domains. Tra-3, an ortholog of CAPN5, is involved in necrotic cell death in C.elegans; although specific role of CAPN5 has not been investigated in the mammalian CNS. I compared relative mRNA levels of calpains in rat CNS, which revealed that CAPN5 is the second most highly expressed calpain. We examined relative levels of CAPN5 from late embryonic day 18 to postnatal day 90 and …

Quantification Of Protoporphyrin Ix Accumulation In Glioblastoma Cells – A New Technique, John E Lawrence

Journal Articles

5-Aminolevulinic Acid (5-ALA) is a precursor of heme synthesis. A metabolite, protoporphyrin IX (PpIX), selectively accumulates in neoplastic tissue including glioblastoma. Presurgical administration of 5-ALA forms the basis of fluorescence-guided resection (FGR) of glioblastoma (GBM) tumors. However, not all gliomas accumulate sufficient quantities of PpIX to fluoresce, thus limiting the utility of FGR. We therefore developed an assay to determine cellular and pharmacological factors that impact PpIX fluorescence in GBM. This assay takes advantage of a GBM cell line engineered to express yellow fluorescent protein. Methods. The human GBM cell line U87MG was transfected with a YFP expression vector. After …

Developmental And Molecular Functions Of Plakophilin-3, William A. Munoz

Dissertations and Theses (Open Access)

Plakophilin-3, the less studied member of the plakophilin-catenin subfamily, and the larger catenin family, binds directly to desmosomal cadherin cytoplasmic domains and enhances desmosome formation and stability. In mammals, plakophilin-3 is expressed at the highest levels in desmosome-enriched tissues such as epithelia, with the knock-out in mice producing corresponding reductions in ectodermal integrity. In tissue, cellular and intracellular contexts where plakophilin-3 is not at the desmosomal plaque, little is known about its functions in the cytoplasm or nucleus, where it also localizes.

My work employed embryos of the amphibian, Xenopus laevis, to examine plakophilin-3’s developmental roles. I first evaluated …

Cellular Life Beyond An Individual’S Death, Emily Schmitt

CAHSS Intellectual Conversations

One of the most famous examples of cell lines surviving long after a person has died comes from a tumor found in the body of Henrietta Lacks, who died of cervical cancer in 1950. The study of approximately 50 million tons of her cells, which would conservatively equal the amount of cells in one billion people, has resulted in nearly 11,000 patents, including the polio vaccine. These cells have become a focus of public attention since Rebecca Skloot’s 2010 book, The Immortal Life of Henrietta Lacks. This talk will discuss what happens to cells once they leave our bodies, …

Impairment Of Trkb-Psd-95 Signaling In Angelman Syndrome, Cong Cao, Mengia S. Rioult-Pedotti, Paolo Migani, Crystal J. Yu, Rakesh Tiwari, Keykavous Parang, Mark R. Spaller, Dennis J. Goebel, John Marshall

Pharmacy Faculty Articles and Research

Angelman syndrome (AS) is a neurodevelopment disorder characterized by severe cognitive impairment and a high rate of autism. AS is caused by disrupted neuronal expression of the maternally inherited Ube3A ubiquitin protein ligase, required for the proteasomal degradation of proteins implicated in synaptic plasticity, such as the activity-regulated cytoskeletal-associated protein (Arc/Arg3.1). Mice deficient in maternal Ube3A express elevated levels of Arc in response to synaptic activity, which coincides with severely impaired long-term potentiation (LTP) in the hippocampus and deficits in learning behaviors. In this study, we sought to test whether elevated levels of Arc interfere with brain-derived neurotrophic factor (BDNF) …

Regulation Of The Glycine Transporter 1 (Glyt1) By Pkca-Dependent Ubiquitination, Susana Barrera

Open Access Theses & Dissertations

Glycine is one of the major inhibitory neurotransmitters in the central nervous system. It is implicated in the regulation of motor-sensory function such as; pain perception, reflex responses, and is essential for early development of the CNS. In addition to its inhibitory actions, it acts as an obligatory co-agonist for the activation of glutamatergic NMDARs, which are of pivotal importance in the process of learning and memory, its dysfunction leads to several neurodegenerative diseases. Two high affinity Na+/Cl- dependent transporters GlyT1 and GlyT2 tightly regulate the availability of glycine present at the synapse for the activation of NMDARs and GlyRs. …

Post-Translational Modification Regulates Heterogeneous Nuclear Ribonucleoprotein K Function During Axon Outgrowth In Xenopus Laevis, Erica J. Hutchins

Legacy Theses & Dissertations (2009 - 2024)

The RNA-binding protein, heterogeneous nuclear ribonucleoprotein K (hnRNP K), is required for axon outgrowth. Its suppression in Xenopus embryos causes defects in the translation of mRNAs of multiple cytoskeletal genes. Studies in cell lines have established that hnRNP K shuttles between the nucleus and the cytoplasm to bind and regulate the fates of its target RNAs, from splicing to export and translation. At each step, hnRNP K is regulated through post-translational modifications that alter its nucleic acid and protein interactions, and subcellular localization. Precisely how this happens in developing neurons to coordinate cytoskeletal gene expression with the extracellular signals directing …

Inhibitors Of Polyisoprenylated Methylated Protein Methyl Esterase (Pmpmease) Cause Neurodegeneration By Altering Microtubules And Gβγ In Pc12 Cells, Jose A. Rivas Jr., Rebekah M. Bach, Jessica Martinez-Jurado, Jorge A. Siera-Fonseca, Sukla Roychowdhury

COURI Symposium Abstracts, Summer 2012

Neurodegeneration, a progressive loss of nerve cells (neurons), occurs in many neurological disorders including Alzheimer’s disease, Parkinson’s disease, Schizophrenia and drug addiction. Disruption of Microtubules (MTs), a major component of cytoskeleton and aggregation of proteins associated with them is the hallmark of neurodegeneration. Gβγ, an important component of G protein signaling has been shown to induce neurite outgrowth of PC12 cells by interacting with microtubules. The goal of the present study is to understand whether interfering with Gβγ-MT mediated pathway causes neurodegeneration. Because prenylation of γ subunits is important for the interaction of Gβγ with MTs, we used inhibitors (L-23 …

Gβγ-Microtubule Interaction And Neurodegeneration, Jane K. Martinez, Jorge Sierra, Sukla Roychowdhury Ph.D.

COURI Symposium Abstracts, Summer 2012

Aberrant organization of microtubules (MTs) is known to be a feature of neurodegeneration, which occurs in many neurological disorder including Alzheimer’s disease, Parkinson’s disease, neuropsychiatric illness such as schizophrenia, and drug addiction. Previously, Gβγ, an important component of G protein-coupled signaling pathways, has been shown to regulate neurite outgrowth by interacting with MTs. The aim of the present study is to understand the Gβγ regulation of MT assembly and its relation to neurodegeneration, using GRK-ct peptide (consists of the carboxy terminus of G protein-coupled-receptor kinase) which is known to inhibit Gβγ-dependent signaling by binding to and sequestering Gβγ. PC12 cells …