Molecular and Cellular Neuroscience Commons^™

Understanding Exosomal Extracellular Vesicles And Morphine In The Neuropathology Of Human Immunodeficiency Virus And Differential Zika Virus Strain-Associated Pathology, Allen Caobi

FIU Electronic Theses and Dissertations

Exosomal Extracellular Vesicles (xEVs), integral to intercellular communication and regulation of immune responses, have functional effects based on their contents, which they transport to neighboring cells. However, in the context of infection, EV cargo can be modulated, by either infected or uninfected cells. We hypothesize that CNS-associated neuropathology, is partially, due to the cargo transported by the exosomes. We theorize that the cargo released from infected cell-derived xEVs may either facilitate or inhibit viral neuropathogenicity. Here we investigated xEVs in the case of two neurotropic viruses, Zika virus (ZIKV) and Human Immunodeficiency Virus (HIV). The hallmark characteristic of ZIKV-infection is …

Importin-Mediated Pathological Tau Nuclear Translocation Causes Disruption Of The Nuclear Lamina, Tdp-43 Mislocalization And Cell Death, Robert F. Candia, Leah S. Cohen, Viktoriya Morozova, Christopher Corbo, Alejandra D. Alonso

Publications and Research

Tau is a cytosolic protein that has also been observed in the nucleus, where it has multiple proposed functions that are regulated by phosphorylation. However, the mechanism underlying the nuclear import of tau is unclear, as is the contribution of nuclear tau to the pathology of tauopathies. We have previously generated a pathological form of tau, PH-tau (pseudophosphorylation mutants S199E, T212E, T231E, and S262E) that mimics AD pathological behavior in cells, Drosophila, and a mouse model. Here, we demonstrated that PH-tau translocates into the nucleus of transiently transfected HEK-293 cells, but wildtype tau does not. We identified a putative …

Somatic Inhibition By Microscopic Magnetic Stimulation, Hui Ye

Biology: Faculty Publications and Other Works

Electric currents can produce quick, reversible control of neural activity. Externally applied electric currents have been used in inhibiting certain ganglion cells in clinical practices. Via electromagnetic induction, a miniature-sized magnetic coil could provide focal stimulation to the ganglion neurons. Here we report that high-frequency stimulation with the miniature coil could reversibly block ganglion cell activity in marine mollusk Aplysia californica, regardless the firing frequency of the neurons, or concentration of potassium ions around the ganglion neurons. Presence of the ganglion sheath has minimal impact on the inhibitory effects of the coil. The inhibitory effect was local to the …

The Neurological Asymmetry Of Self-Face Recognition, Aleksandra Janowska, Brianna Balugas, Matthew Pardillo, Victoria Mistretta, Katherine Chavarria, Janet Brenya, Taylor Shelansky, Vanessa Martinez, Kitty Pagano, Nathira Ahmad, Samantha Zorns, Abigail Straus, Sarah Sierra, Julian Keenan

Department of Biology Faculty Scholarship and Creative Works

While the desire to uncover the neural correlates of consciousness has taken numerous directions, self-face recognition has been a constant in attempts to isolate aspects of self-awareness. The neuroimaging revolution of the 1990s brought about systematic attempts to isolate the underlying neural basis of self-face recognition. These studies, including some of the first fMRI (functional magnetic resonance imaging) examinations, revealed a right-hemisphere bias for self-face recognition in a diverse set of regions including the insula, the dorsal frontal lobe, the temporal parietal junction, and the medial temporal cortex. In this systematic review, we provide confirmation of these data (which are …

Ubc-9 Acts In Gaba Neurons To Control Neuromuscular Signaling In C. Elegans, Victoria A. Kreyden, Elly B. Mawi, Jennifer Kowalski

Scholarship and Professional Work - LAS

Regulation of excitatory to inhibitory signaling balance is essential to nervous system health and is maintained by numerous enzyme systems that modulate the activity, localization, and abundance of synaptic proteins. SUMOylation is a key post-translational regulator of protein function in diverse cells, including neurons. There, its role in regulating synaptic transmission through pre- and postsynaptic effects has been shown primarily at glutamatergic central nervous system synapses, where the sole SUMO-conjugating enzyme Ubc9 is a critical player. However, whether Ubc9 functions globally at other synapses, including inhibitory synapses, has not been explored. Here, we investigated the role of UBC-9 and the …

Preliminary Evidence Of The Role Of Medial Prefrontal Cortex In Self-Enhancement: A Transcranial Magnetic Stimulation Study, Birgitta Taylor-Lillquist, Vivek Kanpa, Maya Crawford, Mehdi El Filali, Julia Oakes, Alex Jonasz, Amanda Disney, Julian Keenan

Department of Biology Faculty Scholarship and Creative Works

Humans employ a number of strategies to improve their position in their given social hierarchy. Overclaiming involves presenting oneself as having more knowledge than one actually possesses, and it is typically invoked to increase one’s social standing. If increased expectations to possess knowledge is a perceived social pressure, such expectations should increase bouts of overclaiming. As the medial prefrontal cortex (MPFC) is sensitive to social pressure and disruption of the MPFC leads to decreases in overclaiming, we predicted that transcranial magnetic stimulation (TMS) applied to the MPFC would reduce overclaiming and the effects would be enhanced in the presence of …

Kcnq2 Localization In The Brainstem, Christina Valera

Honors Scholar Theses

KCNQ2 channels are potassium channels that serve to control neuronal excitability. Loss of function mutations in these channels are known to cause various forms of epilepsy. Recently, KCNQ2 R201C and R201H gain of function mutations have been shown to exhibit an exaggerated startle response and other unique phenotypes uncharacteristic of epilepsy. These phenotypes resemble hyperekplexia, a condition in which glycine neurotransmission in the spinal cord and brainstem is affected. While KCNQ2 has widespread localization throughout the brain, its presence in the brainstem remains unknown. We used immunostaining to determine the localization of KCNQ2 in the vagus nerve and hypoglossal nerve …

Sexually Dimorphic Alterations In Brain Morphology Of Astrocyte Conditional System Xc- Knockout Mice, Gabrielle Emily Samulewicz

Biology - All Scholarship

Astrocytes play a vital role in orchestrating the precise brain wiring that occurs during development and are essential for maintaining homeostasis into adulthood. The cystine/glutamate antiporter, system xc-, in the central nervous system is especially abundant in astrocytes and itself is known to contribute importantly to the basal extracellular glutamate concentration as well as the intracellular and extracellular glutathione levels, either of which, if perturbed, could alter brain development and/or contribute to degeneration. Thus, to determine whether loss of astrocyte system xc- might alter brain morphology, I studied a conditional astrocyte system xc- knockout mouse (AcKO). Tissue was harvested from …

Evolutionary Expansions And Neofunctionalization Of Ionotropic Glutamate Receptors In Cnidaria, Ellen G. Dow

FIU Electronic Theses and Dissertations

Reef ecosystems are composed of a variety of organisms, transient species of fish and invertebrates, microscopic bacteria and viruses, and structural organisms that build the living foundation, coral. Sessile cnidarians, corals and anemones, interpret dynamic environments of organisms and abiotic factors through a molecular interface. Recognition of foreign molecules occurs through innate immunity via receptors identifying conserved molecular patterns. Similarly, chemosensory receptors monitor the environment through specific ligands. Chemosensory receptors include ionotropic glutamate receptors (iGluRs), transmembrane ion channels involved in chemical sensing and neural signal transduction. Recently, an iGluR homolog was implicated in cnidarian immunological resistance to recurrent infections of …

Role Of Withaferin A As A Neuroprotectant Against Beta Amyloid Induced Toxicity And Associated Mechanism, Sneham Tiwari

FIU Electronic Theses and Dissertations

Neurological disorders are the biggest concern globally and ageing contributes in worsening the disease scenarios. In AD or AD like diseases, there is abnormal accumulation of extracellular amyloid beta produced due to abnormal processing of the transmembrane amyloid precursor protein, by β and γ-secretases. It spreads in the cortical and limbic regions of the brain leading to neuronal toxicity, impairment in memory and neurological functions. Aβ deposition in the CNS is common in aging HIV patients. Neurotoxic protein Tat, results in increased Aβ in combination with drugs of abuse cocaine. We examined the role of Withaferin A, against Aβ induced …

Data Collection Curated With An Application Ontology Describes The Methods And Results Upon Performing An Ex-Vivo Voltage-Clamp Assay On Outer Hair Cells Of The Mammalian Cochlea, Brenda Farrell, Jason Bengtson

Research Data

This data collection describes the electrical properties of outer hair cells isolated from the mammalian cochlea of the domestic guinea pig. This data was obtained by performing whole-cell patch clamp voltage clamp assay on cells and monitoring the electrical admittance during a DC voltage ramp. The membrane capacitance was then calculated at each membrane potential from this admittance, and the voltage-independent and voltage-dependent membrane capacitance was determined upon further analysis. In some case the DC conductance was also measured by interrogation of the cell with voltage-step function which was calculated from the change in the mean steady-state current with respect …

Polyglutamine Repeat Proteins Disrupt Actin Structure In Drosophila Photoreceptors., Annie Vu, Tyler Humphries, Sean Vogel, Adam Haberman

Biology: Faculty Scholarship

Expansions of polygutamine-encoding stretches in several genes cause neurodegenerative disorders including Huntington's Disease and Spinocerebellar Ataxia type 3. Expression of the human disease alleles in Drosophila melanogaster neurons recapitulates cellular features of these disorders, and has therefore been used to model the cell biology of these diseases. Here, we show that polyglutamine disease alleles expressed in Drosophila photoreceptors disrupt actin structure at rhabdomeres, as other groups have shown they do in Drosophila and mammalian dendrites. We show this actin regulatory pathway works through the small G protein Rac and the actin nucleating protein Form3. We also find that Form3 has …

Cell Specific Control Of The Pallidostriatal Pathway, Shubha Verma '19

Student Publications & Research

Parkinson’s Disease is a neurodegenerative disorder of the basal ganglia. The main cause for Parkinson’s Disease is the depletion of dopamine, a neurotransmitter. The basal ganglia contains four major nuclei: the substantia nigra, the subthalamic nucleus, the external globus pallidus, and the striatum. These nuclei communicate with each other by the use of neurons.

Spinal Cord Trauma: An Overview Of Normal Structure And Function, Primary And Secondary Mechanisms Of Injury, And Emerging Treatment Modalities, Daniel Morin

Senior Honors Theses

The structures of the spinal cord and vertebral column are designed to provide flexibility, while still providing ample protection for the spinal cord deep within. While it does offer remarkable protection against most routine trauma, the spinal cord is still vulnerable to high-force etiologies of trauma and may become damaged as a result. These events are referred to as primary injury. Following the initial injury, the body’s own physiological responses cause a cascade of deleterious effects, known as secondary injury. Secondary injury is a major therapeutic target in mitigating the effects of spinal cord injury (SCI), and much research is …

Quantification Of Twist From The Central Lines Of Β-Strands, Tunazzina Islam, Michael Poteat, Jing He

Computer Science Faculty Publications

Since the discovery of right-handed twist of a β-strand, many studies have been conducted to understand the twist. Given the atomic structure of a protein, twist angles have been defined using atomic positions of the backbone. However, limited study is available to characterize twist when the atomic positions are not available, but the central lines of β-strands are. Recent studies in cryoelectron microscopy show that it is possible to predict the central lines of β-strands from a medium-resolution density map. Accurate measurement of twist angles is important in identification of β-strands from such density maps. We propose an effective method …

C. Elegans Avoids Toxin-Producing Streptomyces Using A Seven Transmembrane Domain Chemosensory Receptor, Alan Tran, Angelina Tang, Colleen O’Loughlin, Anthony Balistreri, Eric Chang, Doris Coto Villa, Joy Li, Aruna Varshney, Vanessa Jimenez, Jacqueline Pyle, Bryan Tsujimoto, Christopher Wellbrook, Christopher Vargas, Alex Duong, Nebat Ali, Sarah Matthews, Samantha Levinson, Sarah Woldemariam, Sami Khuri, Martina Bremer, Daryl Eggers, Noelle L’Etoile, Laura Miller Conrad, Miri Vanhoven

Faculty Publications, Chemistry

Predators and prey co-evolve, each maximizing their own fitness, but the effects of predator–prey interactions on cellular and molecular machinery are poorly understood. Here, we study this process using the predator Caenorhabditis elegans and the bacterial prey Streptomyces, which have evolved a powerful defense: the production of nematicides. We demonstrate that upon exposure to Streptomyces at their head or tail, nematodes display an escape response that is mediated by bacterially produced cues. Avoidance requires a predicted G-protein-coupled receptor, SRB-6, which is expressed in five types of amphid and phasmid chemosensory neurons. We establish that species of Streptomyces secrete dodecanoic acid, …

The Role Of Daf-19 In Non-Ciliated Neurons: How Is Neural Development Regulated By Different Daf-19 Isoforms?, Zabdiel Ek Vazquez

Lawrence University Honors Projects

A degenerative disease-like phenotype, specifically reduction in synaptic protein levels in adult worms, is correlated with loss-of-function of the only RFX transcription factor gene, daf-19, in C. elegans. This gene encodes four known transcription factor isoforms, two of which are correlated with particular functions. The DAF-19C isoform activates genes responsible for cilia development, while DAF-19M is needed for cilia specification in males. A comparison of the transcriptome of daf-19 null and isogenic wild type adult worms suggests both positive and negative regulation of gene expression is correlated with the presence of DAF-19 proteins. We have assessed DAF-19 regulation …

Pathological Effects Of Repeated Concussive Tbi In Mouse Models: Periventricular Damage And Ventriculomegaly, Richard H. Wolferz Jr.

Honors Scholar Theses

Repeated concussive traumatic brain injury (rcTBI) is the most prominent form of head injury affecting the brain, with an estimated 1.7 million Americans affected each year (Kuhn 2012). Neurologists have been concerned about the danger of repeated head impacts since the 1920’s, but researchers have only begun to understand the long-term effects of rcTBI (McKee 2009). Although symptoms can be as mild as dizziness, current research suggests that multiple concussions can lead to a progressive degenerative brain disease known as chronic traumatic encephalopathy (CTE) (Luo 2008, McKee 2009, Kane 2013). Research on the brain is just beginning to scratch the …

Long-Term Cre-Mediated Retrograde Tagging Of Neurons Using A Novel Recombinant Pseudorabies Virus, Hysell V. Oviedo, Hassasna K. Oyibo, Petr Znamenskiy, Lynn W. Enquist, Anthony M. Zador

Publications and Research

Brain regions contain diverse populations of neurons that project to different long-range targets. The study of these subpopulations in circuit function and behavior requires a toolkit to characterize and manipulate their activity in vivo. We have developed a novel set of reagents based on Pseudorabies Virus (PRV) for efficient and long-term genetic tagging of neurons based on their projection targets. By deleting IE180, the master transcriptional regulator in the PRV genome, we have produced a mutant virus capable of infection and transgene expression in neurons but unable to replicate in or spread from those neurons. IE180-null mutants showed no cytotoxicity, …

Characterization Of The Ependymal Barrier Due To Human Aging And Injury In Murine Models, Ye Sun

University Scholar Projects

Ventriclulomegaly, or the expansion of the ventricles in the brain, is a phenomenon associated with age and injury to the brain. The ependymal layer that encases the ventricles displays certain degrees of plasticity and regenerative ability due to its associated stem cell niche, the subventricular zone (SVZ). Previous research in the Conover Lab has shown that in the mouse, which maintains an actively proliferating SVZ into adulthood, there is an intact ependymal monolayer throughout normal aging, with maintained lateral ventricle size with some degree of stretching. In contrast, the human SVZ declines in proliferative capacity after infancy, and age-related changes …

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 …

The Role Of Er-Alpha And The Ovaries In The Enduring Altered Behavioral Response To Pubertal Immune Stress, Bethany Rappleyea

Masters Theses 1911 - February 2014

Peripubertal immune stress alters adult responsiveness to estradiol (E₂) and progesterone (P). When female mice are injected with the bacterial endotoxin lipopolysaccharide (LPS) at six weeks of age, or during pubertal development, they display a decrease in response to ovarian hormones. In contrast, females ovariectomized prior to peripubertal immune stress display typical levels of sexual behavior following sequential injections of E₂ and P in adulthood. Additionally, intact females exposed to peripubertal immune stress display a decrease in estrogen receptor alpha (ER-α)-immunoreactive (ir) cells in the medial preoptic area (MPOA) and ventromedial nucleus of the hypothalamus (VMH) in …

Investigating Potential Target Genes Of The Rfx Transcription Factor Daf-19 In Caenorhabditis Elegans, He Zhang

Lawrence University Honors Projects

Neurodegenerative diseases, such as Alzheimer’s disease, are characterized by an age-related decrease in the synaptic activity of the patient’s brain. Previous research suggested that a RFX transcription factor DAF-19 in the nematode Caenorhabditis elegans (C. elegans) may be involved in the maintenance of synaptic protein levels. Particularly, worms that were DAF-19A/B defective showed reduced synaptic activities when compared to their age-matched controls.

This study investigated the role of DAF-19A/B isoforms in the C. elegans nervous system. Three genes, F46G11.3, F57B10.9, and F58E2.3 were selected as potential downstream targets of DAF-19A/B based on their potential neuronal expression. …

The Triggering Receptor Expressed On Myeloid Cells 2: “Trem-Ming” The Inflammatory Component Associated With Alzheimer's Disease, Troy T. Rohn

Biology Faculty Publications and Presentations

Alzheimer's disease (AD) is an age-related neurodegenerative disorder characterized by a progressive loss of memory and cognitive skills. Although much attention has been devoted concerning the contribution of the microscopic lesions, senile plaques, and neurofibrillary tangles to the disease process, inflammation has long been suspected to play a major role in the etiology of AD. Recently, a novel variant in the gene encoding the triggering receptor expressed on myeloid cells 2 (TREM2) has been identified that has refocused the spotlight back onto inflammation as a major contributing factor in AD. Variants in TREM2 triple one's risk of developing late-onset AD. …

Aβ Alters The Dna Methylation Status Of Cell-Fate Genes In An Alzheimer’S Disease Model, Gary D. Isaacs, Noor Taher, Courtney Mckenzie, Rebecca Garrett, Matthew Baker, Nena Fox

Faculty Publications and Presentations

Alzheimer’s disease (AD) is characterized by neurofibrillary tangles and extracellular amyloid-β plaques (Aβ). Despite ongoing research, some ambiguity remains surrounding the role of Aβ in the pathogenesis of this neurodegenerative disease. While several studies have focused on the mutations associated with AD, our understanding of the epigenetic contributions to the disease remains less clear. To that end, we determined the changes in DNA methylation in differentiated human neurons with and without Aβ treatment. We isolated the DNA from neurons treated with Aβ or vehicle, and digested the two samples with either a methylation-sensitive (HpaII) or a methylation-insensitive (MspI) restriction endonuclease. …

Integration Of Subthreshold And Suprathreshold Excitatory Barrages Along The Somatodendritic Axis Of Pyramidal Neurons, Hysell V. Oviedo, Alex D. Reyes

Publications and Research

Neurons integrate inputs arriving in different cellular compartments to produce action potentials that are transmitted to other neurons. Because of the voltage- and time-dependent conductances in the dendrites and soma, summation of synaptic inputs is complex. To examine summation of membrane potentials and firing rates, we performed whole-cell recordings from layer 5 cortical pyramidal neurons in acute slices of the rat’s somatosensory cortex. We delivered subthreshold and suprathreshold stimuli at the soma and several sites on the apical dendrite, and injected inputs that mimic synaptic barrages at individual or distributed sites. We found that summation of subthreshold potentials differed from …

Pten Regulation Of Local And Long-Range Connections In Mouse Auditory Cortex, Qiaojie Xiong, Hysell V. Oviedo, Lloyd C. Trotman, Anthony M. Zador

Publications and Research

Autism spectrum disorders (ASDs) are highly heritable developmental disorders caused by a heterogeneous collection of genetic lesions. Here we use a mouse model to study the effect on cortical connectivity of disrupting the ASD candidate gene PTEN (phosphatase and tensin homolog deleted on chromosome 10). Through Cre-mediated recombination, we conditionally knocked out PTEN expression in a subset of auditory cortical neurons. Analysis of long-range connectivity using channelrhodopsin-2 revealed that the strength of synaptic inputs from both the contralateral auditory cortex and from the thalamus onto PTEN-cko neurons was enhanced compared with nearby neurons with normal PTEN expression. Laser-scanning photostimulation showed …

Interspecies Comparison Of Αii-Spectrin Abundance Between Chinook Salmon And Steelhead, Brielle D. Kemis, Ann L. Miracle, Katie A. Wagner, Christa M. Woodley

STAR Program Research Presentations

Salmonids, such as Chinook salmon (Oncorhynchus tshawytscha) and steelhead (O. mykiss), are a staple economic, recreational, tribal, and environmental resource, yet many populations are unsustainable. This study was part of a broad scale effort to monitor the impact of downstream migration obstacles on juvenile salmonid health and survival, which is an essential step towards increasing Smolt-to-Adult Return ratios (SARs). The objective of this study was to determine if juvenile Chinook salmon and steelhead exhibit differing quantities of alphaII-Spectrin Breakdown Products (SBDPs) over two consecutive spring migration periods, indicative of neurogenesis rate and/or biological response to head …

A New Laser Pointer Driven Optical Microheater For Precise Local Heat Shock, Mike Placinta

Masters Theses 1911 - February 2014

The zebrafish has emerged as an important genetic model system for the study of vertebrate development. However, while genetics is a powerful tool for the study of early gene functions, the approach is more limited when it comes to understanding later functions of genes that have essential roles in early embryogenesis. There is thus a need to manipulate gene expression at different times, and ideally only in some regions of the developing embryo. Methods for conditional gene regulation have been established in Drosophila, C.elegans and the mouse, utilizing conditional gene activation systems such as the Gal4-UAS system (fly) and the …

Cholinergic Neurons Regulate And Utilize Gdnf Secreted By C2c12 Skeletal Muscle Cells In Culture, John-Mary Vianney, John Spitsbergen

Biological Sciences Faculty and Graduate Student Research

Glialcell line-derived neurotrophicfactor (GDNF) has been regarded as a potent survival factor for a subpopulation of neurons. It has been shown that GDNF expression is upregulated in skeletal muscle of patients with early stage of neuromuscular diseases such as amyotrophic lateral sclerosis (ALS). Previous results from our laboratory showed that neural cells regulate GDNF secretion by skeletal muscle; non-innervated skeletal muscle appear to secrete more GDNF compared to innervated skeletal muscle. Two aims were examined in the current study. First, to examine whether neural cells inhibit GDNF through acetylcholine release. Second was to examine whether differentiated NG108-15 neural cells secrete …