Neuroscience and Neurobiology Commons^™

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

Dissertations & 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 …

Distinct Phenotypes In Zebrafish Models Of Human Startle Disease, Lisa R. Ganser, Qing Yan, Victoria M. James, Robert Kozol, Maya Topf, Robert J. Harvey, Julia E. Dallman

Faculty Articles

Startle disease is an inherited neurological disorder that causes affected individuals to suffer noise- or touch-induced non-epileptic seizures, excessive muscle stiffness and neonatal apnea episodes. Mutations known to cause startle disease have been identified in glycine receptor subunit (GLRA1 and GLRB) and glycine transporter (SLC6A5) genes, which serve essential functions at glycinergic synapses. Despite the significant successes in identifying startle disease mutations, many idiopathic cases remain unresolved. Exome sequencing in these individuals will identify new candidate genes. To validate these candidate disease genes, zebrafish is an ideal choice due to rapid knockdown strategies, accessible embryonic stages, and stereotyped behaviors. The …

Neural Correlates Of Audiovisual Speech Perception In Aphasia And Healthy Aging, Sarah H. Baum

Dissertations & Theses (Open Access)

Understanding speech in face-to-face conversation utilizes the integration of multiple pieces of information, most importantly the auditory vocal sounds and visual lip movements. Prior studies of the neural underpinnings of audiovisual integration in the brain have provided converging evidence to suggest that neurons within the left superior temporal sulcus (STS) provide a critical neural hub for the integration of auditory and visual information in speech. While most studies of audiovisual processing focus on neural mechanisms within healthy, young adults, we currently know very little about how changes to the brain can affect audiovisual integration in speech. To examine this further, …

Mtorc1 Signaling In Memory Formation And Dysfunction, Natalia S. Rozas De O'Laughlin

Dissertations & Theses (Open Access)

The mechanistic Target of Rapamycin Complex 1 (mTORC1) pathway integrates cellular availability of growth factors, energy and amino acids to regulate protein synthesis and autophagy. The mTORC1 pathway has also been shown to be required for memory consolidation, and its dysregulation is associated with many neurological disorders. MTORC1 is negatively regulated by the tuberous sclerosis complex (TSC1/2). When ATP and growth factors are available, TSC1/2 is inhibited and mTORC1 activity can be restored. In a complementary regulatory pathway, amino acids signal to mTORC1 through the Rag GTPases and Ragulator complex, which modulate the translocation of mTORC1 from the cytoplasm to …

Short Duration Waveforms Recorded Extracellularly From Freely Moving Rats Are Representative Of Axonal Activity, Ashlee A. Robbins, Steven E. Fox, Gregory L. Holmes, Rod C. Scott, Jeremy M. Barry

Dartmouth Scholarship

While extracellular somatic action potentials from freely moving rats have been well characterized, axonal activity has not. We report direct extracellular tetrode recordings of putative axons whose principal feature is a short duration waveform (SDW) with an average peak-trough length less than 179 μs. While SDW recordings using tetrodes have previously been treated as questionable or classified as cells, we hypothesize that they are representative of axonal activity. These waveforms have significantly shorter duration than somatic action potentials, are triphasic and are therefore similar to classic descriptions of microelectrode recordings in white matter and of in vitro action potential propagation …

A Novel Signal Processing Method For Intraoperative Neurophysiological Monitoring In Spinal Surgeries, Krishnatej Vedala

FIU Electronic Theses and Dissertations

Intraoperative neurophysiologic monitoring is an integral part of spinal surgeries and involves the recording of somatosensory evoked potentials (SSEP). However, clinical application of IONM still requires anywhere between 200 to 2000 trials to obtain an SSEP signal, which is excessive and introduces a significant delay during surgery to detect a possible neurological damage. The aim of this study is to develop a means to obtain the SSEP using a much less, twelve number of recordings. The preliminary step involved was to distinguish the SSEP with the ongoing brain activity. We first establish that the brain activity is indeed quasi-stationary whereas …

Progressive Levels Of Physical Dependence To Tobacco Coincide With Changes In The Anterior Cingulum Bundle Microstructure, Wei Huang, Joseph R. Difranza, David N. Kennedy, Nanyin Zhang, Douglas M. Ziedonis, W. W. Sanouri A. Ursprung, Jean A. King

Douglas M. Ziedonis

BACKGROUND: The tobacco withdrawal syndrome indicates the development of neurophysiologic dependence. Clinical evidence indicates that neurophysiologic dependence develops through a set sequence of symptom presentation that can be assessed with a new 3-item survey measure of wanting, craving, and needing tobacco, the Level of Physical Dependence (PD). This study sought to determine if advancing neurophysiologic dependence as measured by the Level of PD correlates with characteristics of white matter structure measured by Fractional Anisotropy (FA).

METHODS: Diffusion-MRI based FA and diffusion tensor imaging probabilistic tractography were used to evaluate 11 smokers and 10 nonsmokers. FA was also examined in relation …

Multiple Sclerosis, Physical Therapy, And Quality Of Life Insights, Claire Simon

Sound Neuroscience: An Undergraduate Neuroscience Journal

Multiple sclerosis (MS) is a progressive and irreversible neurological disease. Current medications and therapies only help alleviate symptoms, but physical therapy (PT) can be a promising treatment option for MS patients to increase quality of life. Observations of on-site PT sessions at the University of Puget Sound and interviews with MS patients provide further evidence for the unique benefits of PT for treating disease and improving quality of life.

The Temporal Relationship Between Daily Stress And Delayed Modulation Of Chronic Headache Pain, Chelsea Clark

Sound Neuroscience: An Undergraduate Neuroscience Journal

Headache pain affects a large portion of the population and significantly reduces quality of life. Stress has been implicated as a cause in many headache disorders, and this study investigates how stressful events affect subjects with chronic headache pain. Ten days after a stressful event, there was a significant change in perceived headache pain, though pain increased for some and decreased for others. Stress-related release of the hormone thyroxine may be a mediator for chronic pain states.

Social Compass Curriculum: Three Descriptive Case Studies Of Social Skills Outcomes For Students With Autism, Louanne E. Boyd, Deborah M. Ward

Engineering Faculty Articles and Research

The Social Compass Curriculum (SCC) was investigated for its effectiveness in improving core social skills in three descriptive case studies of students with autism. Treatment fidelity of the SCC was also measured in the school setting. The Social Responsiveness Scale and the Autism Social Skills Profile were completed by parents to measure pre- and postintervention social skills for three students aged 8 to 11 years who participated in the present multisite pilot study. Fidelity of implementation data were collected via a checklist during observations for three educators who implemented the intervention. Results indicate that the SCC improved core social deficits …

Sex Differences In White Matter Development During Adolescence: A Dti Study, Yingying Wang, Chris Adamson, Weihong Yuan, Mekibib Altaye, Anna W. Byars, Scott K. Holland

Center for Brain, Biology, and Behavior: Faculty and Staff Publications

Adolescence is a complex transitional period in human development, composing physical maturation, cognitive and social behavioral changes. The objective of this study is to investigate sex differences in white matter development and the associations between intelligence and white matter microstructure in the adolescent brain using diffusion tensor imaging (DTI) and tract-based spatial statistics (TBSS). In a cohort of 16 typically-developing adolescents aged 13 to 17 years, longitudinal DTI data were recorded from each subject at two time points that were one year apart. We used TBSS to analyze the diffusion indices including fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity …

Prolactin And Fmri Response To Skf38393 In The Baboon, Brad D. Miller, Lauren A. Marks, Jonathan M. Koller, Blake J. Newman, G Larry Bretthorst, Kevin J. Black

Kevin J. Black, MD

Background: This study’s goal was to provide dose-response data for a dopamine agonist in the baboon using standard methods (replicate measurements at each dose, across a range of doses), as a standard against which to subsequently validate a novel pharmacological MRI (phMRI) method. Dependent variables were functional MRI (fMRI) data from brain regions selected a priori, and systemic prolactin release. Necessary first steps included estimating the magnitude and time course of prolactin response to anesthesia alone and to various doses of agonist. These first steps (“time course studies”) were performed with three agonists, and the results were used to select …

Welcome To The Journal Of Evolution And Health, Aaron Blaisdell, Paul Jaminet, David C. Pendergrass

Aaron P Blaisdell

Welcome to the first issue of the Journal of Evolution and Health! The Journal of Evolution and Health is the peer-reviewed, open-access journal of the Ancestral Health Society, a community of scientists, healthcare professionals, and laypersons who collaborate to understand health challenges from an evolutionary perspective.

Effects Of Hearing Aid Amplification On Robust Neural Coding Of Speech, Jonathan Daniel Boley

Open Access Dissertations

Hearing aids are able to restore some hearing abilities for people with auditory impairments, but background noise remains a significant problem. Unfortunately, we know very little about how speech is encoded in the auditory system, particularly in impaired systems with prosthetic amplifiers. There is growing evidence that relative timing in the neural signals (known as spatiotemporal coding) is important for speech perception, but there is little research that relates spatiotemporal coding and hearing aid amplification.

This research uses a combination of computational modeling and physiological experiments to characterize how hearing aids affect vowel coding in noise at the level of …

Combined Erp/Fmri Evidence For Early Word Recognition Effects In The Posterior Inferior Temporal Gyrus, Joseph Dien, Eric S. Brian, Dennis L. Molfese, Brian T. Gold

Center for Brain, Biology, and Behavior: Faculty and Staff Publications

Two brain regions with established roles in reading are the posterior middle temporal gyrus and the posterior fusiform gyrus. Lesion studies have also suggested that the region located between them, the posterior inferior temporal gyrus (pITG), plays a central role in word recognition. However, these lesion results could reflect disconnection effects since neuroimaging studies have not reported consistent lexicality effects in pITG. Here we tested whether these reported pITG lesion effects are due to disconnection effects or not using parallel ERP/fMRI studies. We predicted that the Recognition Potential (RP), a left-lateralized ERP negativity that peaks at about 200–250 ms, might …

Differential Joint-Specific Corticospinal Tract Projections Within The Cervical Enlargement, Curtis O. Asante, John H. Martin

Publications and Research

The motor cortex represents muscle and joint control and projects to spinal cord interneurons and–in many primates, including humans–motoneurons, via the corticospinal tract (CST). To examine these spinal CST anatomical mechanisms, we determined if motor cortex sites controlling individual forelimb joints project differentially to distinct cervical spinal cord territories, defined regionally and by the locations of putative last-order interneurons that were transneuronally labeled by intramuscular injection of pseudorabies virus. Motor cortex joint-specific sites were identified using intracorticalmicrostimulation. CST segmental termination fields from joint-specific sites, determined using anterograde tracers, comprised a high density core of terminations that was consistent between animals …

Cholinergic Enhancement Of Brain Activation In Mild Cognitive Impairment During Episodic Memory Encoding, Shannon L. Risacher, Yang Wang, Heather A. Wishart, Laura A. Rabin, Laura A. Flashman, Brenna C. Mcdonald, John D. West, Robert B. Santulli, Andrew J. Saykin

Publications and Research

Objective: To determine the physiological impact of treatment with donepezil (Aricept) on neural circuitry supporting episodic memory encoding in patients with amnestic mild cognitive impairment (MCI) using functional magnetic resonance imaging (fMRI).

Methods: Eighteen patients with MCI and 20 age-matched healthy controls (HC) were scanned twice while performing an event-related verbal episodic encoding task. MCI participants were scanned before treatment and after approximately 3 months on donepezil; HCwere untreated but rescanned at the same interval.Voxel-level analyses assessed treatment effects on activation profiles in MCI patients relative to retest changes in non-treated HC. Changes in task-related connectivity in medial temporal circuitry …

The Flexible Fairness: Equality, Earned Entitlement, And Self-Interest, Chunliang Feng, Yi Luo, Ruolei Gu, Lucas S. Broster, Xueyi Shen, Tengxiang Tian, Yue-Jia Luo, Frank Krueger

Behavioral Science Faculty Publications

The current study explored whether earned entitlement modulated the perception of fairness in three experiments. A preliminary resource earning task was added before players decided how to allocate the resource they jointly earned. Participants' decision in allocation, their responses to equal or unequal offers, whether advantageous or disadvantageous, and subjective ratings of fairness were all assessed in the current study. Behavioral results revealed that participants proposed more generous offers and showed enhanced tolerance to disadvantageous unequal offers from others when they performed worse than their presumed "partners," while the reverse was true in the better-performance condition. The subjective ratings also …

Brain Activity And Medical Diagnosis: An Eeg Study, Laila M. Ribas, Fábio T. Rocha, Neli R. Ortega, Armando F. Rocha, Eduardo Massad

Armando F Rocha

Despite new brain imaging techniques that have improved the study of the underlying processes of human decision-making, to the best of our knowledge, there have been very few studies that have attempted to investigate brain activity during medical diagnostic processing.The main purpose of this paper was to investigate brain electroencephalography (EEG) activity associated with diagnostic decision-making in the realm of veterinary medicine using X-rays as a fundamental auxiliary test. The principal component analysis revealed four patterns that accounted for 85% of the total variance in the EEG activity recorded while veterinary doctors read a clinical history, examined an X-ray image …

Sensory-Specific Appetition: Postingestive Detection Of Glucose Rapidly Promotes Continued Consumption Of A Recently Encountered Flavor, Kevin P. Myers, Marisa S. Taddeo, Emily K. Richards

Faculty Journal Articles

It is generally thought that macronutrients stimulate intake when sensed in the mouth (e.g., sweet taste) but as food enters the GI tract its effects become inhibitory, triggering satiation processes leading to meal termination. Here we report experiments extending recent work (see [1]) showing that under some circumstances nutrients sensed in the gut produce a positive feedback effect, immediately promoting continued intake. In one experiment, rats with intragastric (IG) catheters were accustomed to consuming novel flavors in saccharin daily while receiving water infused IG (5 ml/15 min). The very first time glucose (16% w/w) was infused IG instead of water, …

Investigation Of Auditory Encoding And The Use Of Auditory Feedback During Speech Production, Laura E. Beamish

Electronic Thesis and Dissertation Repository

Responses to altered auditory feedback during speech production are highly variable. The extent to which auditory encoding influences this varied use is not well understood. Thirty-nine normal hearing adults completed a first formant (F1) manipulation paradigm where F1 of the vowel /ε/ was shifted upwards in frequency towards an /æ/–like vowel in real-time. Frequency following responses (FFRs) and envelope following responses (EFRs) were used to measure neuronal activity to the same vowels produced by the participant and a prototypical talker. Cochlear tuning, measured by SFOAEs and a psychophysical method, was also recorded. Results showed that average F1 production changed to …

Functional Analysis Of Corazonin And Its Receptor In Drosophila Melanogaster, Kai Sha

Doctoral Dissertations

Corazonin (Crz) is an amidated undecapeptide originally isolated from the American cockroach. It has been shown to affect diverse physiological functions in a species-specific manner. However, the functionality of Crz in Drosophila melanogaster has not yet been determined. To gain insight into the role of Crz signaling in vivo, Crz and CrzR null alleles were obtained by transposable element mobilization. Flies carrying a deficiency uncovering Crz and pr-set7 loci were generated via P-element excision, and the latter was rescued by wild-type pr-set7 transgene. A mutation of Crz receptor (CrzR) was generated by Minos-element mobilization from …

Kisspeptin Receptor Agonist (Ftm080) Increased Plasma Concentrations Of Luteinizing Hormone In Anestrous Ewes, Brian K. Whitlock, Kelly A. Chameroy, Rebecca R. Payton, Shinya Oishi, Nobutaka Fujii, Joseph A. Daniel

Brian K Whitlock, PhD, DVM, DACT

Kisspeptin (KP) and the KP receptor (Kiss1r) are integral to central regulation of the gonadotropic-axis. The demonstration that intravenous infusion of KP can stimulate gonadotropin secretion and ovulation in seasonally anestrous female sheep offers a means of manipulating the reproductive axis. However, KP may be of limited clinical use because of the short circulating half-life. Kiss1r agonists with increased half-life and similar efficacy to KP in vitro potentially may provide beneficial applications in breeding management of many species. However, many of these agonists have not been tested in vivo. This study was designed to test and compare the effects of …

Network Dynamics Of Visual Naming, Christopher R. Conner

Dissertations & Theses (Open Access)

Recognition and naming of objects and actions are fundamental components of language. They involve several different systems working in coordination to accomplish a complex behavior. During visual naming, sensory and semantic processing are carried out by dedicated cortical substrates in the temporal and occipital lobes, while response selection and articulatory planning are handled by prefrontal cortex. Despite decades of research using lesion analysis, functional MRI and electro-encephalography, the precise dynamics involved remain unknown due to the inadequate spatio-temporal resolution of these methodologies. Of particular interest is the organization of semantic knowledge and the degree of serial and parallel organization of …

Alternations Of Nmda And Gabab Receptor Function In Development: A Potential Animal Model Of Schizophrenia, Monica Bolton

UNLV Theses, Dissertations, Professional Papers, and Capstones

Schizophrenia is a debilitating mental disorder that affects up to 3% of the world population. The behavioral symptoms are categorized into positive and negative symptoms, which appear during late adolescence/early adulthood. Unfortunately, the underlying cellular and molecular mechanisms of the disease are poorly understood. Several hypotheses exist to explain mechanisms contributing to these behavioral alterations. One model proposes that a reduced function of the NMDA glutamate receptor on specific GABAergic interneurons may be responsible for deficits in schizophrenia. Post-mortem investigations provide evidence of reductions in both glutamate and GABA-related proteins in patients with schizophrenia. Further, GABAergic interneurons that are activated …

Issues Related To Development Of New Antiseizure Treatments, Karen S. Wilcox, Tracy Dixon-Salazar, Graeme J. Sills, Elinor Ben-Menachem, H. Steve White, Roger J. Porter, Marc A. Dichter, Solomon L. Moshe, Jeffrey L. Noebels, Michael D. Privitera, Michael A. Rogawski

Michael A. Rogawski

This report represents a summary of the discussions led by the antiseizure treatment working group of the International League Against Epilepsy (ILAE)/American Epilepsy Society (AES) Working Groups joint meeting in London (London Meeting). We review here what is currently known about the pharmacologic characteristics of current models of refractory seizures, both for adult and pediatric epilepsy. In addition, we address how the National Institute of Neurological Disorders and Stroke (NINDS)-funded Anticonvulsant Screening Program (ASP) is evolving to incorporate appropriate animal models in the search for molecules that might be sufficiently novel to warrant further pharmacologic development. We also briefly address …

Enhanced Nicotine Self-Administration And Suppressed Dopaminergic Systems In A Rat Model Of Diabetes, Laura O'Dell

Laura Elena O'Dell

Patients with diabetes display a heightened propensity to use tobacco; however, it is unclear whether they experience enhanced rewarding effects of nicotine. Thus, this study examined the reinforcing effects of nicotine in a rodent model of diabetes involving administration of streptozotocin (STZ), a drug that is toxic to pancreatic insulin-producing cells. The first study compared STZ- and vehicle-treated rats that had 23-hour access to intravenous self-administration (IVSA) of nicotine or saline and concomitant access to food and water. In order to examine the contribution of dopamine to our behavioral effects, dopamine transporter (DAT), D1 and D2 receptor levels were compared …

Prefrontal Cortical Microcircuits Bind Perception To Executive Control, Ioan Opris, Lucas Santos, Greg A. Gerhardt, Dong Song, Theodore W. Berger, Robert E. Hampson, Sam A. Deadwyler

Neuroscience Faculty Publications

During the perception-to-action cycle, our cerebral cortex mediates the interactions between the environment and the perceptual-executive systems of the brain. At the top of the executive hierarchy, prefrontal cortical microcircuits are assumed to bind perceptual and executive control information to guide goal-driven behavior. Here, we tested this hypothesis by comparing simultaneously recorded neuron firing in prefrontal cortical layers and the caudate-putamen of rhesus monkeys, trained in a spatial-versus-object, rule-based match-to-sample task. We found that during the perception and executive selection phases, cell firing in the localized prefrontal layers and caudate-putamen region exhibited similar location preferences on spatial-trials, but less on …

Effect Of Meloxicam On Gain And Inflammatory Response Of Calves Castrated By Banding Post-Weaning, Brian K. Whitlock, Peter D. Krawczel, Jeff A. Carroll, Nicole C. Burdick Sanchez, Jeff W. Dailey, Joseph A. Daniel, Johann F. Coetzee

Brian K Whitlock, PhD, DVM, DACT

Castration may detrimentally affect the health and performance of weaned calves, and painful procedures are increasingly becoming a public concern. The objective of this study was to determine the effects of castration (by banding) with or without administration of meloxicam, a non-steroid anti-inflammatory, on performance and inflammatory response in weaned beef calves. Forty-eight (weaned) beef calves [10.0±0.2 mo old; 304±6 kg BW] were blocked by age, BW, wither height, scrotal circumference, and source, then randomly assigned to 1 of 3 treatments (n=16 calves per treatment: 1) intact bulls (BULL), 2) castration by banding (BAN), or 3) castration by banding with …

Effect Of Meloxicam On Gain And Behavior Of Calves Castrated By Banding Pre-Weaning, Joseph A. Daniel, Peter D. Krawczel, Brian K. Whitlock

Brian K Whitlock, PhD, DVM, DACT

The objective was to determine if oral meloxicam (M; a non-steroid anti-inflammatory) administered at castration of pre-weaning calves affected ADG or behavior. Prior to castration (14 d), Angus bulls were assigned to bull (BULL; n = 7; age 106 ± 6 d; BW = 174.2 ±7.7 kg; scrotal circumference 17.7 ± 0.4 cm), castrated (BAN; n = 12; age = 105 ± 5 d; BW = 144.5 ± 7.6 kg; scrotal circumference = 16 ± 0.4 cm) or castrated with meloxicam (BAN+M; n = 13; age = 121 ± 6 d; BW = 145.8 ± 6 kg; scrotal circumference = …