Medical Neurobiology Commons^™

Sequence-Specific Extracellular Micrornas Activate Tlr7, Niming Wu

Theses & Dissertations

Toll-like receptors (TLRs) play an important role in the innate immune system. Emerging evidence shows that TLRs, especially endosomal TLRs, can participate in CNS diseases by increasing the production of proinflammatory cytokines via recognition of microRNAs (miRNAs), however which of the miRNAs are able to activate signaling and whether specific sequence motifs are involved remains incompletely defined. Here we found that numerous miRNAs induced TNF-a production across multiple myeloid cell types, including microglia, and that this effect was abolished in cells deficient of TLR7. In particular, miR-20a-5p and miR-148b-3p preferentially stimulate cytokine secretion compared to miR-20b-5p and miR-148a-3p, respectively, despite …

The Migration And Developmental Remodeling Of Intrinsic Interneurons In Visual Thalamus And The Role Of Retinal Signaling., Naomi E. Charalambakis

Electronic Theses and Dissertations

The dorsal lateral geniculate nucleus (dLGN) of the mouse is a model system to study the development of thalamic circuitry. While most studies focus on relay neurons of dLGN, little is known about the factors regulating the development of the other principal cell type, intrinsic interneurons. To date, the targeting and migratory path of dLGN interneurons as well as their morphological development remains unclear. Here we examined whether the migration, structure, and function of interneurons relies on retinal signaling. We took a loss-of-function approach and crossed GAD67-GFP mice, which express green fluorescent protein (GFP) in dLGN interneurons, with math5 nulls …

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.

Heat Shock Protein 40 And Immune Function In Altered Gravity, Amber M. Paul, Brooke D. Shepard, Sharmila Bhattacharya

Publications

In space, astronauts are more susceptible to pathogens, viral reactivation and immunosuppression, which poses limits to their health and the mission. Interestingly, during space flight, stress-inducible heat shock proteins (HSP) are robustly induced, and the overexpression of HSPs have been implicated in immune dysregulation, therefore HSPs may be critically involved in regulating immune homeostasis. HSP40/DNAJ1 plays a major role in proper protein translation and folding. Its loss of function has been implicated in susceptibility to microbial infection, while its overexpression has been implicated in autoimmunity, collectively suggesting its complicated, but necessary, role in maintaining immunological function. To determine the role …

Hyperhomocysteinemia As A Risk Factor For Vascular Contributions To Cognitive Impairment And Dementia, Brittani R. Price, Donna M. Wilcock, Erica M. Weekman

Physiology Faculty Publications

Behind only Alzheimer’s disease, vascular contributions to cognitive impairment and dementia (VCID) is the second most common cause of dementia, affecting roughly 10–40% of dementia patients. While there is no cure for VCID, several risk factors for VCID, such as diabetes, hypertension, and stroke, have been identified. Elevated plasma levels of homocysteine, termed hyperhomocysteinemia (HHcy), are a major, yet underrecognized, risk factor for VCID. B vitamin deficiency, which is the most common cause of HHcy, is common in the elderly. With B vitamin supplementation being a relatively safe and inexpensive therapeutic, the treatment of HHcy-induced VCID would seem straightforward; however, …

How Concussions Alter Brain Network Properties: Towards Better Diagnoses Of Concussions, Sara Krehbiel, Joanna R. Wares

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.

The Evidence For The Benefits From Breast Milk In The Neurodevelopment Of Premature Babies – A Review Of The Recent Literature, Danuta Iulia Paduraru

Journal of Mind and Medical Sciences

Introduction. The brain in preterm babies is usually not fully developed and therefore early post-term events can have long-lasting neurodevelopment and cognitive outcomes. It is known that cerebral white matter connectivity is important for later intact cognitive functioning amongst children born very preterm and that breast milk imparts neurotrophic factors. The relationship between breastfeeding and child development is a long and well-studied area, and the evidence in support of breast milk is already substantial. Here we review the recent literature on the topic to establish whether additional evidence is available to strengthen the view that breast milk is superior in …

Thrombospondin Receptor Α2Δ-1 Promotes Synaptogenesis And Spinogenesis Via Postsynaptic Rac1, W. Chris Risher, Namsoo Kim, Sehwon Koh, Ji‑Eun Cho, Petar Mitev, Erin F. Spence, Louis‑Jan Pilaz, Dongqing Wang, Guoping Feng, Debra L. Silver, Scott H. Soderling, Henry H. Yin, Cagla Eroglu

Biomedical Sciences

Astrocytes control excitatory synaptogenesis by secreting thrombospondins (TSPs), which function via their neuronal receptor, the calcium channel subunit α2δ-1. α2δ-1 is a drug target for epilepsy and neuropathic pain; thus the TSP–α2δ-1 interaction is implicated in both synaptic development and disease pathogenesis. However, the mechanism by which this interaction promotes synaptogenesis and the requirement for α2δ-1 for connectivity of the developing mammalian brain are unknown. In this study, we show that global or cell-specific loss of α2δ-1 yields profound deficits in excitatory synapse numbers, ultrastructure, and activity and severely stunts spinogenesis in the mouse cortex. Postsynaptic but not presynaptic α2δ-1 …

New Functions For The Proprioceptive System In Skeletal Biology, Ronen Blecher, Lia Heinemann-Yerushalmi, Eran Assaraf, Nitzan Konstantin, Jens R. Chapman, Timothy C. Cope, Guy S. Bewick, Robert W. Banks, Elazar Zelzer

Neuroscience, Cell Biology & Physiology Faculty Publications

Muscle spindles and Golgi tendon organs (GTOs) are two types of sensory receptors that respond to changes in length or tension of skeletal muscles. These mechanosensors have long been known to participate in both proprioception and stretch reflex. Here, we present recent findings implicating these organs in maintenance of spine alignment as well as in realignment of fractured bones. These discoveries have been made in several mouse lines lacking functional mechanosensors in part or completely. In both studies, the absence of functional spindles and GTOs produced a more severe phenotype than that of spindles alone. Interestingly, the spinal curve phenotype, …

In Vivo Brainstem Imaging In Alzheimer’S Disease: Potential For Biomarker Development, David J. Braun, Linda J. Van Eldik

Neuroscience Faculty Publications

The dearth of effective treatments for Alzheimer’s disease (AD) is one of the largest public health issues worldwide, costing hundreds of billions of dollars per year. From a therapeutic standpoint, research efforts to date have met with strikingly little clinical success. One major issue is that trials begin after substantial pathological change has occurred, and it is increasingly clear that the most effective treatment regimens will need to be administered earlier in the disease process. In order to identify individuals within the long preclinical phase of AD who are likely to progress to dementia, improvements are required in biomarker development. …

Brain Endothelial Erythrophagocytosis And Hemoglobin Transmigration Across Brain Endothelium: Implications For Pathogenesis Of Cerebral Microbleeds, Rudy Chang, Juan Castillo, Alexander C. Zambon, Tatiana B. Krasieva, Mark J. Fisher, Rachita K. Sumbria

Pharmacy Faculty Articles and Research

Peripheral endothelial cells are capable of erythrophagocytosis, but data on brain endothelial erythrophagocytosis are limited. We studied the relationship between brain endothelial erythrophagocytosis and cerebral microhemorrhage, the pathological substrate of MRI-demonstrable cerebral microbleeds. To demonstrate the erythrophagocytic capability of the brain endothelium, we studied the interactions between brain endothelial cells and red blood cells exposed to oxidative stress in vitro, and developed a new in vitro cerebral microbleeds model to study the subsequent passage of hemoglobin across the brain endothelial monolayer. Using multiple approaches, our results show marked brain endothelial erythrophagocytosis of red blood cells exposed to oxidative stress compared …

Repetitive Transcranial Electrical Stimulation Induces Quantified Changes In Resting Cerebral Perfusion Measured From Arterial Spin Labeling, Matthew Sherwood, Aaron T. Madaris, Casserly R. Mullenger, R. Andy Mckinley

Neuroscience, Cell Biology & Physiology Faculty Publications

The use of transcranial electrical stimulation (TES) as a method to augment neural activity has increased in popularity in the last decade and a half. The specific application of TES to the left prefrontal cortex has been shown to produce broad cognitive effects; however, the neural mechanisms underlying these effects remain unknown. In this work, we evaluated the effect of repetitive TES on cerebral perfusion. Stimulation was applied to the left prefrontal cortex on three consecutive days, and resting cerebral perfusion was quantified before and after stimulation using arterial spin labeling. Perfusion was found to decrease significantly more in a …

Pathogenicity And Protection Mediated By A Single Tcrβ In Experimental Autoimmune Encephalomyelitis, Tianhua Wu

Theses and Dissertations (ETD)

How the TCR repertoire, together with risk-associated major histocompatibility complex (MHC), imposes susceptibility for autoimmune disease is not fully understood. A small fraction of TCR α or β chains are “public”, and are shared by most individuals.High-throughput sequencing of the mouse TCRβ repertoire during myelin oligodendrocyte glycoprotein (MOG)-induced experimental autoimmuneencephalomyelitis (EAE) identified a public TCRβ chain, TCRβ1, which was highly shared among individual mice and preferentially deployed during EAE. Retrogenic expression of TCRβ1 resulted in spontaneous early-onset EAE in mice with high penetrance and severity, despite being paired with a diverse endogenous TCRα repertoire. To further study autoimmunity conferred by …

The Role Of Developmental Timing Regulators In Progenitor Proliferation And Cell Fate Specification During Mammalian Neurogenesis, Jennifer S. Romer-Seibert

Graduate School of Biomedical Sciences Theses and Dissertations

Developmental timing is a key aspect of tissue and organ formation in which distinct cell types are generated through a series of steps from common progenitors. These progenitors undergo specific changes in gene expression that signifies both a distinct progenitor type and developmental time point that thereby specifies a particular cell fate at that stage of development. The nervous system is an important setting for understanding developmental timing because different cell types are produced in a certain order and the switch from stem cells to progenitors requires precise timing and regulation. Notable examples of such regulatory molecules include the RNA-binding …

Gender- And Region-Specific Changes In Estrogen Signaling In Aging Rat Brain Mitochondria, Christopher M. Evola, Tanner L. Hudson, Luping Huang, Adrian M. Corbett, Debra A. Mayes

Neuroscience, Cell Biology & Physiology Faculty Publications

Recently epidemiological studies suggest females lose neuroprotection from neurodegenerative diseases as they go through menopause. It has been hypothesized that this neuroprotection is hormone‐dependent. The current study characterized cell signaling molecules downstream of estrogen receptor beta that are known to play a role in memory, PKC, ERK, and connexin‐43, in regions of the brain associated with memory decline in an attempt to elucidate significant changes that occur post‐estrus. Total whole cell lysates were compared to isolated mitochondrial protein because mitochondrial function is known to be altered during aging. As hypothesized, protein concentrations differed depending on age, gender, and brain region. …

An Evaluation Of Alzheimer's Disease-Related Pathology In Two Different Models Of Diabetes In Immune-Challenged Mice, Andrew Scott Murtishaw

UNLV Theses, Dissertations, Professional Papers, and Capstones

Obesity, type 2 diabetes mellitus (T2DM), and metabolic syndrome are related disorders with wide-ranging and devastating effects that can be observed throughout the body. One important and understudied organ of damage is the brain. Clinical and epidemiological studies have found that T2DM, and more specifically hyperinsulinemia, significantly increases the risk of cognitive decline and increases the likelihood of Alzheimer’s disease (AD) and other forms of dementia in the elderly. Insulin has slightly different functions in the peripheral body than in the central nervous system and the dysregulation of these functions may contribute to the onset and progression of late-life neurodegenerative …

Predicting Gains With Visuospatial Training After Stroke Using An Eeg Measure Of Frontoparietal Circuit Function, Robert J. Zhou, Hossein M. Hondori, Maryam Khademi, Jessica M. Cassidy, Katherine M. Wu, Derek Z. Yang, Nikhita Kathuria, Fareshte R. Erani, Lucy Dodakian, Alison Mckenzie, Cristina V. Lopes, Walt Scacchi, Ramesh Srinivasan, Steven C. Cramer

Physical Therapy Faculty Articles and Research

The heterogeneity of stroke prompts the need for predictors of individual treatment response to rehabilitation therapies. We previously studied healthy subjects with EEG and identified a frontoparietal circuit in which activity predicted training-related gains in visuomotor tracking. Here we asked whether activity in this same frontoparietal circuit also predicts training-related gains in visuomotor tracking in patients with chronic hemiparetic stroke. Subjects (n = 12) underwent dense-array EEG recording at rest, then received 8 sessions of visuomotor tracking training delivered via home-based telehealth methods. Subjects showed significant training-related gains in the primary behavioral endpoint, Success Rate score on a standardized test …

Volitional Down-Regulation Of The Primary Auditory Cortex Via Directed Attention Mediated By Real-Time Fmri Neurofeedback, Matthew Sherwood, Jason G. Parker, Emily E. Diller, Subhashini Ganapathy, Kevin B. Bennett, Jeremy T. Nelson

Neuroscience, Cell Biology & Physiology Faculty Publications

The present work assessed the efficacy of training volitional down-regulation of the primary auditory cortex (A1) based on real-time functional magnetic resonance imaging neurofeedback (fMRI-NFT). A1 has been shown to be hyperactive in chronic tinnitus patients, and has been implicated as a potential source for the tinnitus percept. 27 healthy volunteers with normal hearing underwent 5 fMRI-NFT sessions: 18 received real neurofeedback and 9 sham neurofeedback. Each session was composed of a simple auditory fMRI followed by 2 runs of A1 fMRI-NFT. The auditory fMRI alternated periods of no auditory with periods of white noise stimulation at 90 dB. A1 …

Defining The Radioresponse Of Mossy Cells, Devon Ivy

Electronic Theses, Projects, and Dissertations

Clinical radiotherapy is used to treat a variety of brain tumors within the central nervous system. While effective, it can result in progressive and debilitating cognitive impairment that can diminish quality of life. These impairments have been linked to hippocampal dysfunction and corresponding deficits in spatial learning and memory. Mossy cells are a major population of excitatory neurons located within the dentate hilus and highly involved in hippocampal circuitry. They play critical roles in spatial navigation, neurogenesis, memory, and are particularly vulnerable to a variety of neurotoxic insults. However, their sensitivity to ionizing radiation has yet to be investigated in …

Cdk5 Inhibition Resolves Pka/Camp-Independent Activation Of Creb1 Signaling In Glioma Stem Cells, Subhas Mukherjee, Carol Tucker-Burden, Emily Kaissi, Austin Newsam, Hithardhi Duggireddy, Monica Chau, Changming Zhang, Bhakti Diwedi, Manali Rupji, Sandra Seby, Jeanne Kowalski, Jun Kong, Renee Read, Daniel J. Brat

Neurology Faculty Publications

Cancer stem cells promote neoplastic growth, in part by deregulating asymmetric cell division and enhancing self-renewal. To uncover mechanisms and potential therapeutic targets in glioma stem cell (GSC) self-renewal, we performed a genetic suppressor screen for kinases to reverse the tumor phenotype of our Drosophila brain tumor model and identified dCdk5 as a critical regulator. CDK5, the human ortholog of dCdk5 (79% identity), is aberrantly activated in GBMs and tightly aligned with both chromosome 7 gains and stem cell markers affecting tumor-propagation. Our investigation revealed that pharmaceutical inhibition of CDK5 prevents GSC self-renewal in vitro and in xenografted tumors, at …

Treating Adhd With Suggestion: Neurofeedback And Placebo Therapeutics, Robert T. Thibault, Samuel Vassière, Jay A. Olson, Amir Raz

Psychology Faculty Articles and Research

Objective: We propose that clinicians can use suggestion to help treat conditions such as ADHD. Methods: We use EEG neurofeedback as a case study, alongside evidence from a recent pilot experiment utilizing a sham MRI scanner to highlight the therapeutic potential of suggestion-based treatments. Results: The medical literature demonstrates that many practitioners already prescribe treatments that hardly outperform placebo comparators. Moreover, the sham MRI experiment showed that, even with full disclosure of the procedure, suggestion alone can reduce the symptomatology of ADHD. Conclusion: Non-deceptive suggestion-based treatments, especially those drawing on accessories from neuroscience, may offer a safe complement and potential …

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 …

Post-Traumatic Stress Disorder: Review Of Dsm Criteria And Functional Neuroanatomy, Cornelius W. Thomas

Marshall Journal of Medicine

The Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria for post-traumatic stress disorder (PTSD) consist of over twenty possible symptoms that can be divided into six broad categories. These categories correlate with specific brain networks that regulate emotions, behaviors, and autonomic function. Normal functioning of these networks depends on two key regions; the prefrontal cortex and the amygdala. The prefrontal cortex provides top-down executive control over amygdala, whereas the amygdala is critical for threat detection and activation of the ‘fight or flight’ response. Events that trigger extreme and/or prolonged fear can cause persisting dysregulation within the prefrontal-amygdala circuit; resulting …

Bilateral Facial Spasm Following Guillain-Barré Syndrome, Zain Guduru, John Morgan, Kapil Sethi

Neurology Faculty Publications

Background: We report a patient who developed lower facial muscle spasm at rest and bilateral facial synkinesis several months after treatment of Guillain–Barré syndrome (GBS); this finding, to our knowledge, is hitherto unreported.

Phenomenology Shown: Bilateral synkinesis, facial muscles spasm at rest, bilateral postparalytic facial syndrome.

Educational Value: Aberrant regeneration of nerve fibers post GBS, resulting in facial muscles spasm at rest, bilateral synkinesis.

Network Specialization During Adolescence: Hippocampal Effective Connectivity In Boys And Girls, Jeffrey D. Riley, E. Elinor Chen, Jessica Winsell, Elyssia Poggi Davis, Laura M. Glynn, Tallie Z. Baram, Curt A. Sandman, Steven L. Small, Ana Solodkin

Psychology Faculty Articles and Research

Adolescence is a complex period of concurrent mental and physical development that facilitates adult functioning at multiple levels. Despite the growing number of neuroimaging studies of cognitive development in adolescence focusing on regional activation patterns, there remains a paucity of information about the functional interactions across these participating regions that are critical for cognitive functioning, including memory. The current study used structural equation modeling (SEM) to determine how interactions among brain regions critical for memory change over the course of adolescence. We obtained functional MRI in 77 individuals aged 8–16 years old, divided into younger (ages 8–10) and older (ages …

The Role Of Reactive Astrocitose In The Chronological Evolution Of Traumatic Brain Injury, Roxana M. Duncea-Borca, Vladimir Belis, Mihnea Costescu, Relu G. Calota, Reka Kutasi, Cosmin A. Moldovan

Journal of Mind and Medical Sciences

Introduction and objectives. This study aims to investigate whether the cerebral modifications of posttraumatic reactive astrocitose can be considered an objective criterion for determining the age of traumatic cranio-cerebral lesions.

Materials and methods. The present study consists of a series of 23 medico-legal cases that underwent autopsy inTeleormanCounty(Romania) Department of Forensic Medicine during 2007–2016, with full immune-histochemical microscopic examination using GFAP staining. The study consists of two groups, a series of 13 cases with cranio-cerebral trauma with different posttraumatic survival periods and 9 cases as a control group.

Results and discussions. We discovered GFAP+ reactive astrocytes even when death occurred …

Single Session Low Frequency Left Dorsolateral Prefrontal Transcranial Magnetic Stimulation Changes Neurometabolite Relationships In Healthy Humans, Matthew Sherwood, Richard A. Mckinley, Danielle Boeke, Jason G. Parrker, Lindsey K. Mcintire, Justin M. Nelson, Catherine Fletchall, Natasha Alexander, Amanda Mcconnell, Chuck Goodyear, Jeremy T. Nelson, Nathaniel R. Bridges

Neuroscience, Cell Biology & Physiology Faculty Publications

Background: Dorsolateral prefrontal cortex (DLPFC) low frequency repetitive transcranial magnetic stimulation (LF-rTMS) has shown promise as a treatment and investigative tool in the medical and research communities. Researchers have made significant progress elucidating DLPFC LF-rTMS effects—primarily in individuals with psychiatric disorders. However, more efforts investigating underlying molecular changes and establishing links to functional and behavioral outcomes in healthy humans are needed. Objective: We aimed to quantify neuromolecular changes and relate these to functional changes following a single session of DLPFC LF-rTMS in healthy participants. Methods: Eleven participants received sham-controlled neuronavigated 1 Hz rTMS to the region most activated by a …

Variant Intestinal-Cell Kinase In Juvenile Myoclonic Epilepsy, J. N. Bailey, L. De Nijs, D. Bai, T. Suzuki, H. Miyamoto, M. Tanaka, C. Patterson, Y.-C. Lin, M. T. Medina, M. E. Alonso, J. M. Serratosa, R. M. Durón, Viet-Hong Nguyen, J. E. Wight, I. E. Martínez‑Juárez, A. Ochoa, A. Jara-Prado, L. Guilhoto, Y. Molina, E. M. Yacubian, M. López‑Ruiz, Y. Inoue, S. Kaneko, S. Hirose, M. Osawa, H. Oguni, S. Fujimoto, T. M. Grisar, J. M. Stern, K. Yamakawa, B. Lakaye, A. V. Delgado-Escueta

Pharmacy Faculty Articles and Research

BACKGROUND

In juvenile myoclonic epilepsy, data are limited on the genetic basis of networks promoting convulsions with diffuse polyspikes on electroencephalography (EEG) and the subtle microscopic brain dysplasia called microdysgenesis.

METHODS

Using Sanger sequencing, we sequenced the exomes of six members of a large family affected with juvenile myoclonic epilepsy and confirmed cosegregation in all 37 family members. We screened an additional 310 patients with this disorder for variants on DNA melting-curve analysis and targeted real-time DNA sequencing of the gene encoding intestinal-cell kinase (ICK). We calculated Bayesian logarithm of the odds (LOD) scores for cosegregating variants, odds …

Amperometric Self-Referencing Ceramic Based Microelectrode Arrays For D-Serine Detection, Diana Campos-Beltrán, Åsa Konradsson-Geuken, Jorge E. Quintero, Lisa Marshall

Neuroscience Faculty Publications

D-serine is the major D-amino acid in the mammalian central nervous system. As the dominant co-agonist of the endogenous synaptic NMDA receptor, D-serine plays a role in synaptic plasticity, learning, and memory. Alterations in D-serine are linked to neuropsychiatric disorders including schizophrenia. Thus, it is of increasing interest to monitor the concentration of D-serine in vivo as a relevant player in dynamic neuron-glia network activity. Here we present a procedure for amperometric detection of D-serine with self-referencing ceramic-based microelectrode arrays (MEAs) coated with D-amino acid oxidase from the yeast Rhodotorula gracilis (RgDAAO). We demonstrate in vitro D-serine recordings with a …

Aging Exacerbates Development Of Cerebral Microbleeds In A Mouse Model, Rachita K. Sumbria, Mher Mahoney Grigoryan, Vitaly Vasilevko, Annlia Paganini-Hill, Kelley Kilday, Ronald Kim, David H. Cribbs, Mark J. Fisher

Pharmacy Faculty Articles and Research

Background: Cerebral microhemorrhages (CMH) are commonly found in the aging brain. CMH are also the neuropathological substrate of cerebral microbleeds (CMB), demonstrated on brain MRI. Recent studies demonstrate the importance of systemic inflammation in CMH development, but the relationships among inflammation, aging, and CMH development are not well-defined. In the current study, we hypothesized that the pathogenesis of inflammation-induced CMH in mice differs by age.

Methods: We studied young (3 months, n = 20) and old (18 months, n = 25) C57BL/6 mice injected with low-dose lipopolysaccharide (LPS; 1 mg/kg, i.p.) or saline at 0, 6, and 24 …