Neuroscience and Neurobiology Commons^™

Multichannel Characterization Of Brain Activity In Neurological Impairments, Yalda Shahriari

Biomedical Engineering Theses & Dissertations

Hundreds of millions of people worldwide suffer from various neurological and psychiatric disorders. A better understanding of the underlying neurophysiology and mechanisms for these disorders can lead to improved diagnostic techniques and treatments. The objective of this dissertation is to create a novel characterization of multichannel EEG activity for selected neurological and psychiatric disorders based on available datasets. Specifically, this work provides spatial, spectral, and temporal characterizations of brain activity differences between patients/animal models and healthy controls, with focus on modern techniques that quantify cortical connectivity, which is widely believed to be abnormal in such disorders. Exploring the functional brain …

Development Of A Practical Visual-Evoked Potential-Based Brain-Computer Interface, Nicholas R. Waytowich

Biomedical Engineering Theses & Dissertations

There are many different neuromuscular disorders that disrupt the normal communication pathways between the brain and the rest of the body. These diseases often leave patients in a `locked-in" state, rendering them unable to communicate with their environment despite having cognitively normal brain function. Brain-computer interfaces (BCIs) are augmentative communication devices that establish a direct link between the brain and a computer. Visual evoked potential (VEP)- based BCIs, which are dependent upon the use of salient visual stimuli, are amongst the fastest BCIs available and provide the highest communication rates compared to other BCI modalities. However. the majority of research …

Adolescent Crash Rates And School Start Times In Two Central Virginia Counties, 2009-2011: A Follow-Up Study To A Southeastern Virginia Study, 2007-2008, Robert Daniel Vorona, Mariana Szklo-Coxe, Rajan Lamichhane, J. Catesby Ware, Ann Mcnallen, David Leszczyszyn

Community & Environmental Health Faculty Publications

Background and Objective: Early high school start times (EHSST) may lead to sleep loss in adolescents ("teens"), thus resulting in higher crash rates. (Vorona et al., 2011). In this study, we examined two other adjacent Virginia counties for the two years subsequent to the above-mentioned study. We again hypothesized that teens from jurisdictions with EHSST (versus later) experience higher crash rates.

Methods: Virginia Department of Motor Vehicles supplied de-identified aggregate data on weekday crashes and time-of- day for 16-18 year old (teen) and adult drivers for school years 2009-2010 and 2010-2011 in Henrico and Chesterfield Counties (HC and CC, respectively). …

Nocturnal Diaphoresis Secondary To Mild Obstructive Sleep Apnea In A Patient With A History Of Two Malignancies, Robert Daniel Vorona, Mariana Szklo-Coxe, Mark Fleming, J. Catesby Ware

Community & Environmental Health Faculty Publications

Numerous medical disorders, including obstructive sleep apnea, may cause nocturnal diaphoresis. Previous work has associated severe obstructive sleep apnea with nocturnal diaphoresis. This case report is of import as our patient with severe nocturnal diaphoresis manifested only mild sleep apnea, and, for years, his nocturnal diaphoresis was ascribed to other causes, i.e., first prostate cancer and then follicular B-cell lymphoma. Additionally, it was the nocturnal diaphoresis and not more common symptoms of obstructive sleep apnea, such as snoring, that led to the definitive diagnosis of his sleep apnea and then to treatment with a gratifying resolution of his onerous symptom.

Novel Report Of Expression And Function Of Cd97 In Malignant Gliomas: Correlation With Wilms Tumor 1 Expression And Glioma Cell Invasiveness Laboratory Investigation, Archana Chidambaram, Helen L. Fillmore, Timothy E. Van Meter, Catherine I. Dumur, William C. Broaddus

Division of Research and Economic Development Faculty & Staff Publications

Object. The Wilms tumor 1 (WT1) protein—a developmentally regulated transcription factor—is aberrantly expressed in gliomas and promotes their malignant phenotype. However, little is known about the molecular allies that help it mediate its oncogenic functions in glioma cells.

Methods. The authors used short interfering RNA (siRNA) to suppress WT1 expression in glioblastoma (GBM) cells and evaluated the effect of this on GBM cell invasiveness. Gene expression analysis was then used to identify the candidate genes that were altered as a result of WT1 silencing. One candidate target, CD97, was then selected for further investigation into its role by suppressing …

Brain-Computer Interfaces In Medicine, Jerry J. Shih, Dean J. Krusienski, Johnathan R. Wolpaw

Electrical & Computer Engineering Faculty Publications

Brain-computer interfaces (BCIs) acquire brain signals, analyze them, and translate them into commands that are relayed to output devices that carry out desired actions. BCIs do not use normal neuromuscular output pathways. The main goal of BCI is to replace or restore useful function to people disabled by neuromuscular disorders such as amyotrophic lateral sclerosis, cerebral palsy, stroke, or spinal cord injury. From initial demonstrations of electroenceph-alography-based spelling and single-neuron-based device control, researchers have gone on to use electroenceph-alographic, intracortical, electrocorticographic, and other brain signals for increasingly complex control of cursors, robotic arms, prostheses, wheelchairs, and other devices. Brain-computer interfaces …

Group Ii Metabolic Glutamate Receptors In The Basal Amygdala Regulate Sleep And Fear-Induced Alterations In Sleep, Enheng Dong

Theses and Dissertations in Biomedical Sciences

Glutamate is a major excitatory neurotransmitter in the brain and it has been recognized as playing an essential role in activating and maintaining arousal. Group II metabotropic glutamate (mGlu II) receptors are expressed in the amygdala, a brain structure important in the regulation of stress and anxiety as well as in the regulation of sleep and arousal. Our lab has found that the central nucleus of the amygdala (CNA) is involved in the emotional modulation of sleep. The basal amygdala (BA), which has direct connections with the CNA, is involved in conditioned fear and fear extinction. However, the potential role …

Cellular Immunity In Mouse Models Of Viral Encephalitis, Christina Dawn Steel

Theses and Dissertations in Biomedical Sciences

Evidence is presented herein that intranasal application of vesicular stomatitis virus (VSV) caused acute infection of the murine central nervous system (CNS) with associated morbidity and significant mortality in mice. However, VSV encephalitis was not invariably fatal, suggesting that the CNS contained a professional antigen-presenting cell (APC) capable of inducing or propagating a protective antiviral immune response. To examine this possibility, we administered VSV via the intranasal route and then characterized the cellular elements that infiltrate the brain as well as the activation status of resident microglia, cells widely believed to represent the major APC population in the CNS. To …

Sleep Well To Stay Safe: Ready For Primetime?, Mihai C. Teodorescu, Mariana Szklo-Coxe

Community & Environmental Health Faculty Publications

Commentary on Kling et al. Sleep problems and workplace injuries in Canada. Sleep 2010;33:611-618.

A Smart-Phone Application For Improving Communication Skills In Children With Autism, Lakshmi Padmaja Battagiri

Electrical & Computer Engineering Theses & Dissertations

The prevalence of autism, a complex neurobiological disorder, has grown at a staggering rate in the recent past. Today, one out of 150 American children is diagnosed with autism. Generally, the disorder appears during an individual's first three years of life of and persists through his/her entire life span. The individual faces various social interaction, communication and behavioral problems. Developmental disabilities, extreme withdrawal, lack of social behaviour, severe language and attention deficits, repetitive behaviours and limited interests are the characteristics of this disorder. There is no verified cure yet, but several therapies and intervention systems especially focused on the early …

Analysis Of Electroencephalogram Signals For The Identification Of Mental Tasks, My Thy Thi Tran

Electrical & Computer Engineering Theses & Dissertations

Electroencephalogram (EEG) signals can be used for implicit communication such as to control robots or medical equipment by brain activity or to detect an individual's intentions of committing premeditated crimes. An EEG based brain-computer interface allows paralyzed patients to express their thoughts. However, biological and technical artifacts heavily interfered with EEG signals due to blinking of the eyes, muscle activities and line noise. Sometimes the noise interference due to signal artifacts becomes more prominent than the information content. This thesis investigates novel feature extraction methodologies in EEG signals to represent different thought processes and employs neural network-based pattern classification techniques …

Effects Of Hze Irradiation On Chemical Neurotransmission In Rodent Hippocampus, Mayumi Machida

Theses and Dissertations in Biomedical Sciences

Space radiation represents a significant risk to the CNS (central nervous system) during space missions. Most harmful are the HZE (high mass, highly charged (Z), high energy) particles, e.g. ⁵⁶Fe, which possess high ionizing ability, dense energy deposition pattern, and high penetrance.

Accumulating evidence suggests that radiation has significant impact on cognitive functions. In ground-base experiments, HZE radiation induces pronounced deficits in hippocampus dependent learning and memory in rodents. However, the mechanisms underlying these impairments are mostly unknown.

Exposure to HZE radiation elevates the level of oxidation, resulting in cell loss, tissue damage and functional deficits through direct ionization …

Resting State Default-Mode Network Connectivity In Early Depression Using A Seed Region-Of-Interest Analysis: Decreased Connectivity With Caudate Nucleus, Robyn Bluhm, Peter Williamson, Ruth Lanius, Jean Théberge, Maria Densmore, Robert Bartha, Richard Neufeld, Elizabeth Osuch

Philosophy Faculty Publications

Aim: Reports on resting brain activity in healthy controls have described a default-mode network (DMN) and important differences in DMN connectivity have emerged for several psychiatric conditions. No study to date, however, has investigated resting-state DMN in relatively early depression before years of medication treatment. The objective of the present study was, therefore, to investigate the DMN in patients seeking help from specialized mental health services for the first time for symptoms of depression.

Methods: Fourteen depressed subjects and 15 matched controls were scanned using 4-T functional magnetic resonance imaging while resting with eyes closed. All but one subject was …

Examining Neurophysiological Evidence Of Age-Related Interactions Of Sensory And Cognitive Processes During Speech Processing, Cady Kristen Block

Psychology Theses & Dissertations

The present study sought to examine the contribution of sensory and cognitive factors on speech processing as evidenced by ERP measures and to find support for the Sensory Cognitive Interaction Theory (SCIT) and the Effortfulness Hypothesis in that older adults. who experience sensory deficits with normal aging. must put forth increased effort during early sensory stages of speech processing that may compromise subsequent semantic performance and recall of information. In the present investigation. younger and older adults performed a sentence verification task at low and high presentation levels (PL). Accuracy and response time to sentence verifications were assessed along with …

Optimization Of Biomathematical Model Predictions For Cognitive Performance Impairment In Individuals: Accounting For Unknown Traits And Uncertain States In Homeostatic And Circadian Processes, Hans P. A. Van Dongen, Christopher G. Mott, Jen-Kuang Huang, Daniel J. Mollicone, Frederic D. Mckenzie, David F. Dinges

Mechanical & Aerospace Engineering Faculty Publications

Current biomathematical models of fatigue and performance do not accurately predict cognitive performance for individuals with a priori unknown degrees of trait vulnerability to sleep loss, do not predict performance reliably when initial conditions are uncertain, and do not yield statistically valid estimates of prediction accuracy, These limitations diminish their usefulness for predicting the performance of individuals in operational environments. To overcome these 3 limitations, a novel modeling approach was developed, based on the expansion of a statistical technique called Bayesian forecasting. The expanded Bayesian forecasting procedure was implemented in the two-process model of sleep regulation, which has been used …

Confidence Intervals For Individualized Performance Models, Hans P. A. Van Dongen, Christopher G. Mott, Jen-Kuang Huang, Daniel J. Millicone, Frederic D. Mckenzie, David F. Dinges

Mechanical & Aerospace Engineering Faculty Publications

Commentary on Reifman J; Rajaraman S; Gribok AV. Moving Towards Individualized Performance Models. Sleep 2007;30(9):1081-82.

Art Therapy With Adults With Autism, Kimberly Dennler

EVMS School of Health Professions Theses & Dissertations

Research regarding art therapy with adults with autism is limited. The objective of this study was to understand the effect of a specific art therapy intervention upon social interaction and communication of the adults with autism. The hypothesis was that by participating in this intervention, the participants’ communication and socialization would increase and their maladaptive behaviors would decrease. Over a series of nine sessions, the five participants from Bittersweet Farms were introduced to basic techniques for working with clay.

Results were based on qualitative analysis of data from staff surveys, through the use of pre and post questionnaires; observations made …

Effects Of Gesture+Verbal Treatment For Noun And Verb Retrieval In Aphasia, Anastasia M. Raymer, Floris Singletary, Amy Rodriguez, Maribel Ciampitti, Kenneth M. Heilman, Leslie J. Gonzalez Rothi

Communication Disorders & Special Education Faculty Publications

Links between verbs and gesture knowledge suggest that verb retrieval may be particularly amenable to gesture+verbal training (GVT) in aphasia compared to noun retrieval. This study examines effects of GVT for noun and verb retrieval in nine individuals with aphasia subsequent to left hemisphere stroke. Participants presented an array of noun and verb retrieval deficits, including impairments of semantic and/or phonologic processing. In a single-participant experimental design, we investigated effects of GVT for noun and verb retrieval in two counterbalanced treatment phases. Effects were evaluated in spoken naming and gesture production to pictured objects and actions. Spoken naming improvements associated …

Theta Activity During Navigation In Virtual Environments, Colleen Margaret Moore

Psychology Theses & Dissertations

Human navigation has gone through many different stages, from guidance by stars to guidance by technology. Theories for performance differences range from differences between individuals, to experience with the environment. Researchers turn to virtual environments during experimentation which are easy to manipulate and easier to measure during navigation. However, fidelity is an issue with regard to transfer of learning to a real world environment. We examined differences in theta activity during navigation in low and high fidelity virtual environments. The researchers recruited thirty-two students between the ages of 18-40 from the university subject pool for voluntary participation. We measured EEG …

The Effects Of Estrogen On Dorsal Root Ganglion Neurons, Sheila A. Scoville

Theses and Dissertations in Biomedical Sciences

Skin sensation is mediated by dorsal root ganglion (DRG) neurons. Data indicates that skin sensitivity in female rats is estrogen-dependent. Some DRG neurons have estrogen receptors (ERs) which are regulated by estrogen. In these cells, nerve growth factor (NGF) and estrogen receptors colocalize. Regulation of NGF receptors and neuronal sensitivity to NGF may allow estrogen to regulate NGF-dependent genes. The goals of the present study were to determine which DRG neurons express the ER gene and to analyze the effects of long-term estrogen administration on the interrelated expression of tyrosine kinase A (trkA), preprotachykinin (PPT), and 68kD neurofilament (NF) genes …

F Response Frequency For The Median And Ulnar Nerves In A Normal Population, Patricia J. Killea

Rehabilitation Sciences Theses & Dissertations

The F wave or F response results form the recurrent discharge of antidromically activated anterior horn cells. F response latency represents an impulse which travels to and from the spinal cord through the central segment of a nerve. Study of the F wave is commonly done to assess proximal conduction in motor nerves, to measure motor nerve conduction velocity over a longer pathway than in orthodromic motor studies, and to assess motor neuron excitability. F response characteristics less commonly studied include duration, chronodispersion, shape, amplitude, and frequency. The primary purpose of this study was to determine F response frequencies of …

The Functional Role Of Peripheral Nerves In Ige-Mediated Inflammation, Gary Wright Miller

Biological Sciences Theses & Dissertations

IgE-mediated inflammation was measured in mouse footpads with and without sciatic innervation. Mice were passively sensitized with IgE anti-dinitrophenol, a monoclonal antibody. Antigen-induced swelling was reduced by 26% by sciatic nerve transection. Whether transection occurred 10 days prior or immediately prior to antigen challenge did not affect the swelling response. The full inflammatory response was restored by antidromic stimulation of the distal portion of the cut nerve, but only in the freshly cut nerve. Antigen-induced swelling was unaffected by rhizotomy or spinal nerve transection. Pre-treatment with capsaicin reduced the swelling to a level similar to sciatic nerve transection. Treatment with …

The Role Of Gaba In Reproductive Neuroendocrine Systems, Robert Carter Mcree

Theses and Dissertations in Biomedical Sciences

Local gamma-amino butyric acid (GABA) neurons in the hypothalamus can modulate the luteinizing hormone releasing hormone (LHRH) pulse generating system.

Two animal models (intact and ovariectomized rats) were used to determine the nature of modulation of LHRH release by GABA. The experiment determined the release of LHRH, serotonin (5-HT), and 5-hydroxyindole acetic acid (5-HIAA) during two hormonal states with each model. In the intact rat the proestrus and estrus states were examined, and in the ovariectomized rat in-vitro release was determined with (OVX₂) and without (OVX) estradiol treatment.

In-vivo experiments studied the effect of stimulation of GABA receptors …

Evidence Of A Neurogenic Component During Ige-Mediated Inflammation In Murine Skin, Victoria Jean Cavanaugh

Biological Sciences Theses & Dissertations

The direct stimulation of sensory nerves or the intradermal injection of neuropeptides triggers a cutaneous inflammatory response that involves the degranulation of mast cells. These neurogenic inflammatory reactions are physiologically similar to IgE-mediated hypersensitivity responses, which also depend on mast cells. Although non-antigenic stimuli distinguish neurogenic from IgE-mediated inflammation, the similarity of their effector stages suggested that peripheral nerves may also participate in lgE-mediated responses. To examine this hypothesis, IgE responses were elicited in denervated skin. A murine model was developed where the footpad was denervated by surgically removing a 2 mm segment of the sciatic nerve, proximal to the …

Simultaneous Determination Of 3-Methoxy-4-Hydroxyphenyl-Glycol, Homovanillic Acid, And 5-Hydroxyindoleacetic Acid In Plasma By High Performance Liquid Chromatography, Yung-Te Tseng

Chemistry & Biochemistry Theses & Dissertations

A rapid, reliable, and sensitive method for simultaneous determination of 3-methoxy-4-hydroxyphenylglycol (MHPG), Homovanillic acid (HVA), and 5-hydroxyindoleacetic acid (5- HIAA) in plasma is described. The method is based on high performance liquid chromatography with electrochemical detection. Samples were filtered with Amicon Centrifree micropartition systems and extracted with organic solvent before chromatography. Chromatographic separation of sample components was achieved isocratically in a C18 reverse-phase column. Quantitation was performed by measuring the peak height ratios of the sample components to an internal standard. Analytical recoveries ranged from 50.78 (SD 4.2%) to 67.94 (SD 3.28). Within-run coefficient of variations (CVs) ranged from 3.78 …