Neuroscience and Neurobiology Commons^™

Testing A Structural Equation Model Of Language-Based Cognitive Fitness, Elizabeth Ann Moxley-Paquette

Walden Dissertations and Doctoral Studies

The normative development of language is often taken for granted, yet problems with language development can result in stress for the individual and family. A challenge with these language development problems lies within the contemporary education system, which assumes that children have appropriate skills when they begin school. The purpose of the study was to test a theoretical model of language readiness known as language-based cognitive fitness, which includes measures associated with structural concepts of language involving receptive language, expressive language, spontaneous narrative speech, and writing fluency. The sample included children from a private school who received an extensive battery …

An Environmental Toxic Model Of Parkinson's Disease: The Fruit Fly, Jennene Lyda

Graduate Student Theses, Dissertations, & Professional Papers

Parkinson’s disease (PD) is the second most common neurodegenerative disorder with no known specific cause; although genetic risk factors and/or environmental exposure are thought to be involved. The etiology of PD is currently unknown, although the combination of non-genetic components such as environmental exposures, the accumulation of exposure, and gene-environment interactions are thought to play a major role. However, despite this knowledge it is important to develop better models that parallel PD pathophysiology to further understand the mechanisms underlying dopaminergic neuron (DaN) damage. The use of mammalian models to study the degenerative processes in PD has been the most common …

Quantifying Cognitive Function In Concussed Athletes Before And After Acute Exercise Using A Choice Reaction Time Task, Stephanie A. Ramautar M.Sc., Michael E. Cinelli Ph.D.

Theses and Dissertations (Comprehensive)

Following a concussion, cognitive deficits have been shown to last longer than symptom resolution. Currently clinicians rely heavily on symptom emergence following the fundamental exercises of the return to play (RTP) protocol, which may leave athletes at risk of returning to play too early if cognitive deficits have not been detected. The purpose of this study was to assess the effects of exercise on choice reaction time (CRT) both at rest and following an acute exercise in 3 populations: non-concussed (NC), recently concussed (RC), and post-concussion syndrome (PCS) individuals. A CRT task in the form of an iPad application measured …

A Bittersweet Investigation Of Availability And Nutritive Value As Determinants Of Volitional Sucrose Consumption, Milan D. Valyear

Theses and Dissertations (Comprehensive)

Rats given ~24 h access to a 4% sucrose solution every 3^rd day (E3DA) consume about 100 g more solution than rats with continuous, everyday access (EDA). Under the same EDA-E3DA conditions rats will consume similar amounts of a more concentrated 8 or 16% sucrose solutions (Eikelboom, Hewitt, & Adams, Unpublished). It maybe that with these more concentrated solutions rats hit a satiety limit that prevents a difference between EDA and E3DA consumption from being evident. Experiment 1 was conducted to investigate the effect of adding quinine to 4% and 8% sucrose solutions with the intention of reducing consumption …

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

Open Access Theses & Dissertations

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

The Neural Substrates Of Natural Reading: A Comparison Of Normal And Nonword Text Using Eyetracking And Fmri, W. Choi, Rutvik Desai, J. M. Henderson

Faculty Publications

Most previous studies investigating the neural correlates of reading have presented text using serial visual presentation (SVP), which may not fully reflect the underlying processes of natural reading. In the present study, eye movements and BOLD data were collected while subjects either read normal paragraphs naturally or moved their eyes through “paragraphs” of pseudo-text (pronounceable pseudowords or consonant letter strings) in two pseudo-reading conditions. Eye movement data established that subjects were reading and scanning the stimuli normally. A conjunction fMRI analysis across natural- and pseudo-reading showed that a common eye-movement network including frontal eye fields (FEF), supplementary eye fields (SEF), …

The Processing Of Amyloid Precursor Protein In The Central Nervous System Of Humans And Rhesus Macaques, Justyna Anna Dobrowolska

All Theses and Dissertations (ETDs)

Alzheimer's disease: AD) is the most common dementia, currently afflicting 30 million people worldwide, with prevalence steadily increasing. Over 99% of AD cases are classified as sporadic, in which the major risk factors are age: greater than 65 years) and the ApoE-ε4 allele: in a gene dose dependent manner). The minority of AD cases: less than 1%) are caused by autosomal dominant inheritance of a genetic mutation in one of three genes: Amyloid Precursor Protein: APP), Presenilin-1: PSEN1), or Presenilin-2: PSEN2). Mutation carriers will generally notice cognitive decline starting at a relatively young age, anytime between their 30s-50s, and eventually …

The Effects Of Chronic Simvastatin Treatment On The Expression Of Behavioral Symptoms In A Transgenic Mouse Model Of Huntington’S Disease, Ashley Whitmarsh

LSU New Orleans Theses and Dissertations

Huntington’s disease (HD) is a heritable, neurodegenerative disorder characterized by motor, cognitive, and psychiatric disturbances. An unstable CAG expansion within the gene normally encoding for the Huntingtin protein is responsible. The expanded mutant form of Huntingtin and the putative protein co-factor Rhes interact and cause cell death within the striatum. We hypothesized chronic treatment with simvastatin, a cholesterol lowering drug, would disrupt the biosynthetical pathway which gives both Rhes and its target cells binding sites and render Rhes inactive. Healthy and HD mice were treated with simvastatin or a vehicle. Animals’ motor behavior was assessed with three separate tests over …

Enrichment And Training Improve Cognition In Rats With Cortical Malformations, Kyle R. Jenks, Marcella M. Lucas, Ben A. Duffy, Ashlee A. Robbins, Barjor Gimi, Jeremy M. Barry, Rod C. Scott

Dartmouth Scholarship

Children with malformations of cortical development (MCD) frequently have associated cognitive impairments which reduce quality of life. We hypothesized that cognitive deficits associated with MCD can be improved with environmental manipulation or additional training. The E17 methylazoxymethanol acetate (MAM) exposure model bears many anatomical hallmarks seen in human MCDs as well as similar behavioral and cognitive deficits. We divided control and MAM exposed Sprague-Dawley rats into enriched and non-enriched groups and tested performance in the Morris water maze. Another group similarly divided underwent sociability testing and also underwent Magnetic Resonance Imaging (MRI) scans pre and post enrichment. A third group …

Field Effects And Ictal Synchronization: Insights From In Homine Observations, Shennan A. Weiss, Guy Mckhann Jr., Robert Goodman, Ronald G. Emerson, Andrew Trevelyan, Marom Bikson, Catherine A. Schevon

Publications and Research

It has been well established in animal models that electrical fields generated during inter-ictal and ictal discharges are strong enough in intensity to influence action potential firing threshold and synchronization. We discuss recently published data from microelectrode array recordings of human neocortical seizures and speculate about the possible role of field effects in neuronal synchronization. We have identified two distinct seizure territories that cannot be easily distinguished by traditional EEG analysis. The ictal core exhibits synchronized neuronal burst firing, while the surrounding ictal penumbra exhibits asynchronous and relatively sparse neuronal activity. In the ictal core large amplitude rhythmic ictal discharges …

Acceleration Of Image Analyst Training With Transcranial Direct Current Stimulation, R. Andy Mckinley, Lindsey Mcintire, Nathaniel Bridges, Charles Goodyear, Michael Patrick Weisend

Wright State Research Institute Publications

Humans today are routinely and increasingly presented with vast quantities of data that challenge their capacity for efficient processing. To restore the balance between man and machine, it is worthwhile to explore new methods for enhancing or accelerating this capacity. This study was designed to investigate the efficacy of transcranial DC stimulation (tDCS) to reduce training time and increase proficiency in spatial recognition using a simulated synthetic aperture radar (SAR) task. Twenty-seven Air Force active duty members volunteered to participate in the study. Each participant was assigned to 1 of 3 stimulation groups and received two, 90-min training sessions on …

Repeated Asenapine Treatment Produces A Sensitization Effect In Two Preclinical Tests Of Antipsychotic Activity, Rongyin Qin, Yingzhu Chen, Ming Li

Department of Psychology: Faculty Publications

Among several commonly used atypical antipsychotic drugs, olanzapine and risperidone cause a sensitization effect in the conditioned avoidance response (CAR) and phencyclidine (PCP)- induced hyperlocomotion paradigms – two well established animal tests of antipsychotic drugs, whereas clozapine causes a tolerance effect. Asenapine is a novel antipsychotic drug recently approved for the treatment of schizophrenia and manic disorders. It shares several receptor binding sites and behavioral features with other atypical antipsychotic drugs. However, it is not clear what type of repeated effect (sensitization or tolerance) asenapine would induce, and whether such an effect is transferrable to other atypicals. In this study, …

Iptakalim Attenuates Self-Administration And Acquired Goal-Tracking Behavior Controlled By Nicotine, S. Charntikov, N. Swalve, Steven T. Pittenger, K. Fink, S. Schepers, G. C. Hadlock, A. E. Fleckenstein, G. Hu, Ming Li, Rick A. Bevins

Department of Psychology: Faculty Publications

Iptakalim is an ATP-sensitive potassium channel opener, as well as an a4b2-containing nicotinic acetylcholine receptor (nAChR) antagonist. Pretreatment with iptakalim diminishes nicotine-induced dopamine (DA) and glutamate release in the nucleus accumbens. This neuropharmacological profile suggests that iptakalim may be useful for treatment of nicotine dependence. Thus, we examined the effects of iptakalim in two preclinical models. First, the impact of iptakalim on the interoceptive stimulus effect of nicotine was evaluated by training rats in a discriminated goal-tracking task that included intermixed nicotine (0.4 mg/kg, SC) and saline sessions. Sucrose was intermittently presented in a responseindependent manner only on nicotine sessions. …

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

Dissertations and Theses (Open Access)

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

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

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

Dissertations and 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 …

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

Dissertations and 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, …

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 …

The Development Of A Traumatic Brain Injury Bioreactor, Zachery Heller

Graduate Theses and Dissertations

Approximately 1.7 million Americans experience a traumatic brain injury (TBI) each year. Concussive injuries are a subset of TBI in which blows to the head cause the brain to collide against the interior of the skull. Damage to the neurons, supporting cells, and surrounding extra cellular matrix resulting from these collisions can lead to permanent physical, cognitive, and psychological impairment. We believe the prevalence and clinical significance of concussive injures warrants research investment. To study brain injury following TBI, in vivo models have been the gold standard for TBI experiments. Although a valuable research alternative, animals are expensive, raise ethical …

Neuroscience, Memory And Art: Deborah Aschheim, Sara Gevurtz

SWITCH

This article recounts a discussion with artist Deborah Aschheim and explores the intersections of neuroscience, memory, and art. Aschheim’s work investigates memory, memory loss, and place through interactive sculptures and installations, often incorporating sound and collaboration with musicians and scientists.

On The Evolution Of The Serotonin Transporter Linked Polymorphic Region (5-Httlpr) In Primates, Seth D. Dobson, Lauren J.N Brent

Dartmouth Scholarship

Some allelic variants of the serotonin transporter linked polymorphic region (5-HTTLPR) result in lower levels of expression of the serotonin transporter gene (SLC6A4). These low-expressing (LE) alleles are associated with mental-health disorders in a minority of humans that carry them. Humans are not the only primates that exhibit this polymorphism; other species, including some monkeys, also have LE and high-expressing (HE) variants of 5-HTTLPR. We propose a behavioral genetic framework to explain the adaptive evolution of this polymorphism in primates, including humans. We hypothesize that both LE and HE alleles are maintained by balancing selection in species characterized …