Neuroscience and Neurobiology Commons^™

Origins Of Thalamic And Cortical Projections To The Posterior Auditory Field In Congenitally Deaf Cats., Blake E Butler, Nicole Chabot, Andrej Kral, Stephen G Lomber

Psychology Publications

Crossmodal plasticity takes place following sensory loss, such that areas that normally process the missing modality are reorganized to provide compensatory function in the remaining sensory systems. For example, congenitally deaf cats outperform normal hearing animals on localization of visual stimuli presented in the periphery, and this advantage has been shown to be mediated by the posterior auditory field (PAF). In order to determine the nature of the anatomical differences that underlie this phenomenon, we injected a retrograde tracer into PAF of congenitally deaf animals and quantified the thalamic and cortical projections to this field. The pattern of projections from …

Toric Ideals, Polytopes, And Convex Neural Codes, Caitlin Lienkaemper

HMC Senior Theses

How does the brain encode the spatial structure of the external world?

A partial answer comes through place cells, hippocampal neurons which

become associated to approximately convex regions of the world known

as their place fields. When an organism is in the place field of some place

cell, that cell will fire at an increased rate. A neural code describes the set

of firing patterns observed in a set of neurons in terms of which subsets

fire together and which do not. If the neurons the code describes are place

cells, then the neural code gives some information about the …

Resting State Functional Network Disruptions In A Kainic Acid Model Of Temporal Lobe Epilepsy., Ravnoor Singh Gill, Seyed M Mirsattari, L Stan Leung

Physiology and Pharmacology Publications

We studied the graph topological properties of brain networks derived from resting-state functional magnetic resonance imaging in a kainic acid induced model of temporal lobe epilepsy (TLE) in rats. Functional connectivity was determined by temporal correlation of the resting-state Blood Oxygen Level Dependent (BOLD) signals between two brain regions during 1.5% and 2% isoflurane, and analyzed as networks in epileptic and control rats. Graph theoretical analysis revealed a significant increase in functional connectivity between brain areas in epileptic than control rats, and the connected brain areas could be categorized as a limbic network and a default mode network (DMN). The …

Self, Death, And Suicide: Does An Animal Know Of These?, Carolyn A. Ristau

Animal Sentience

Peña-Guzmán makes a strong case, using examples from the media and scientific literature, that many captive animals suffer severely. In examining the possibility of animal suicide, he dismisses the need for “reflective self-subjectivity” and “intent” in suicidal behavior. He claims that at least some animals understand “death,” citing examples of behavior he deems to be death “rituals.” But these can be more simply interpreted. The possibility of animal suicide remains more dubious than Peña-Guzmán suggests.

Changes In Behavior And Emotion Under Chicken Domestication, Martin Johnsson

Animal Sentience

Marino’s target article provides an overview of chickens’ cognition, emotion, and personality, with the aim of changing how people view chickens. In this commentary, I will agree that chickens deserve better than their reputation, but contend with a statement about the lack of behavioral change under chicken domestication.

Error Rate On The Director’S Task Is Influenced By The Need To Take Another’S Perspective But Not The Type Of Perspective, Edward W. Legg, Laure Olivier, Steven Samuel, Robert Lurz, Nicola S. Clayton

Publications and Research

Adults are prone to responding erroneously to another’s instructions based on what they themselves see and not what the other person sees. Previous studies have indicated that in instruction-following tasks participants make more errors when required to infer another’s perspective than when following a rule. These inference-induced errors may occur because the inference process itself is error-prone or because they are a side effect of the inference process. Crucially, if the inference process is error-prone, then higher error rates should be found when the perspective to be inferred is more complex. Here, we found that participants were no more error …

Alpha-Synuclein: Insight Into The Hallmark Of Parkinson's Disease As A Target For Quantitative Molecular Diagnostics And Therapeutics, Baggio A. Evangelista

Honors Undergraduate Theses

Parkinson’s disease (PD) is the second-most common neurodegenerative disease after Alzheimer’s disease. With 500,000 individuals currently living with Parkinson’s and nearly 60,000 new cases diagnosed each year, this disease causes significant financial burden on the healthcare system - amassing to annual expenditures totaling 200 billion dollars; predicted to increase through 2050. The disease phenotype is characterized by a combination of a resting tremor, bradykinesia, muscular rigidity, and depression due to dopaminergic neuronal death in the midbrain. The cause of the neurotoxicity has been largely discussed, with strong evidence suggesting that the protein, alpha-Synuclein, is a key factor. Under native conditions, …

The Relationship Between Sleep, Working Memory, And Decision Making In Young And Old Adult Populations, Melissa G. Merz

Honors Undergraduate Theses

Sleep is known to influence basic tasks concerning working memory, reaction time and executive functioning (Silva, Wang, Ronda, Wyatt, & Duffy, 2010; Nebes, Buysse, Halligan, Houck, & Monk, 2009). However, the amount that sleep influences these functions varies from study to study possibly due to differences in age and task design. Aim 1A of this study is to determine if sleep quality affects working memory. Aim 1B of this study is to determine if age affects sleep quality and working memory in comparison of young and old adult populations. Finally, Aim 2 of this study is to determine if there …

Verbal Behaviors During Employment Interviews Of College Students With And Without Asd, Dennis James Bublitz, Katherine Fitzgerald, Maria Alarcon, Joanne D'Onofrio, Kristen Gillespie-Lynch

Publications and Research

BACKGROUND: Even well-educated people with ASD struggle with obtaining employment, partially due to social difficulties during interviews. Although increasing numbers of individuals with ASD are entering college, little research focuses on this population. Particularly little is known about how to help college students with ASD obtain jobs.

OBJECTIVE: This study attempts to identify challenges with verbal communication during employment interviews that are specific to college students with ASD.

METHODS: We administered mock employment interviews to 16 college students with ASD and 14 college students without disabilities. Responses to interview questions were coded for content and timing.

RESULTS: Students with ASD …

Transposon-Mediated Stable Suppression Of Gene Expression In The Developing Chick Retina, Masaru Nakamoto, Chizu Nakamoto

Biology Faculty Publications

The embryonic chick has long been a favorite model system for in vivo studies of vertebrate development. However, a major technical limitation of the chick embryo has been the lack of efficient loss-of-function approaches for analyses of gene functions. Here, we describe a methodology in which a transgene encoding artificial microRNA sequences is introduced into embryonic chick retinal cells by in ovo electroporation and integrated into the genome using the Tol2 transposon system. We show that this methodology can induce potent and stable suppression of gene expression. This technique therefore provides a rapid and robust loss-of-function approach for studies of …

Aβ Vaccination In Combination With Behavioral Enrichment In Aged Beagles: Effects On Cognition, Aβ, And Microhemorrhages, Paulina R. Davis, Ginevra Giannini, Karin Rudolph, Nathaniel Calloway, Christopher M. Royer, Tina L. Beckett, M. Paul Murphy, Frederick Bresch, Dieter Pagani, Thomas Platt, Xiaohong Wang, Amy Skinner Donovan, Tiffany L. Sudduth, Wenjie Lou, Erin L. Abner, Richard J. Kryscio, Donna M. Wilcock, Edward G. Barrett, Elizabeth Head

Sanders-Brown Center on Aging Faculty Publications

Beta-amyloid (Aβ) immunotherapy is a promising intervention to slow Alzheimer’s disease (AD). Aging dogs naturally accumulate Aβ and show cognitive decline. An active vaccine against fibrillar Aβ 1–42 (VAC) in aged beagles resulted in maintenance but not improvement of cognition along with reduced brain Aβ. Behavioral enrichment (ENR) led to cognitive benefits but no reduction in Aβ. We hypothesized cognitive outcomes could be improved by combining VAC with ENR in aged dogs. Aged dogs (11–12 years) were placed into 4 groups: (1) control/control (C/C); (2) control/VAC (C/V); (3) ENR/control (E/C); (4) ENR and VAC (E/V) and treated for 20 months. …

Endocytic Vesicle Rupture In The Pathogenesis And Propagation Of Neurodegenerative Proteinopathies, William P. Flavin

Dissertations

Numerous pathological amyloid proteins spread from cell-to-cell during neurodegenerative disease, facilitating the propagation of cellular pathology and disease progression. Understanding the mechanism by which disease-associated amyloid protein assemblies enter target cells and induce cellular dysfunction is therefore key to understanding the progressive nature of such neurodegenerative proteinopathies. In this study, we utilized an imaging-based assay to monitor the ability of disease-associated amyloid assemblies to induce the rupture of intracellular vesicles following endocytosis, as well as to elucidate the cellular consequences of this damaging mechanism of invasion. We observed that the ability to induce vesicle rupture is a conserved feature of …

The Application Of Half-Life In Clinical Decision Making: Comparison Of The Pharmacokinetics Of Extended-Release Topiramate (Usl255) And Immediate-Release Topiramate, Barry E. Gidal, Annie M. Clark, Bob Anders, Frank Gilliam

Neuroscience Faculty Publications

Objective: For extended-release drugs with multi-compartment kinetics, such as topiramate, effective half-life (t_1/2eff) may be a more clinically relevant parameter than elimination half-life (t_1/2z). Using topiramate as a real-life example, the objective was to compare these half-life values for immediate- and extended-release topiramate (TPM-IR and USL255, respectively) to understand how drug pharmacokinetics may impact drug dosing recommendations.

Methods: The t_1/2z and t_1/2eff for USL255 and TPM-IR were compared using data from a phase I study (N = 36) of 200 mg USL255 administered once daily (QD) or TPM-IR twice daily (BID); effect of sampling duration …

Cx43 Expression Increases In Response To Increased Temperature Incubation In The Developing Chicken Embryonic Brain, Erick A. Barrios

Browse all Theses and Dissertations

We used the chicken embryo model to examine whether altered incubation temperature during chicken embryo development would alter the protein expression of heat shock protein 70 (hsp70), hsp90, and connexin 43 (cx43) in the brain. We incubated eggs in either optimal (37.6° C, Con), increased (39.6° C, +2), or decreased (35.6° C, -2) temperature conditions until they reached embryonic day 16 (E16). The -2 condition significantly increased incidence of embryonic mortality. As shown in the literature, the development of the eggs was accelerated or decelerated due to increased or decreased temperature respectively. To control for this, we incubated eggs at …

N-Alkyl 4-Methylamphetamine Enantiomers And The Implication For Potential Modulation Of Abuse Liability And Enhancement Of Psychoactive Drug Targeting., Ramsey Sitta

Theses and Dissertations

Drugs of abuse have a long history in humanity. Currently however, a subject of great interest is the phenylalkylamine family of drugs. Not only is the abuse liability of interest but also the potential therapeutic expansion of the capabilities of this family of drugs by utilizing the unique stereospecific effects of the newly discovered hybrid compounds. Based upon prior data of N-Alkyl 4-MA the enantiomers of N-Methyl, N-Ethyl, and N-Propyl were analyzed in hDAT, hNET, and hSERT. It was found that there was a negative correlation between chain length and potency and dopaminergic component. In agreement with the currently established …

Integrating Genetics And Neuroimaging To Study Subtypes Of Binge Drinkers, Megan E. Cooke

Theses and Dissertations

Risky alcohol use is a major health concern among college students, with 40.1% reporting binge drinking (5 or more drinks in one occasion) and 14.4% reporting heavy drinking (binge drinking on 5 or more occasions) in the past month. Risky alcohol use is thought to be the result of a complex interplay between genes, biological processes, and other phenotypic characteristics. Understanding this complex relationship is further complicated by known phenotypic heterogeneity in the development of alcohol use. Developmental studies have suggested two pathways to risky alcohol use, characterized by externalizing and internalizing characteristics, respectively. However, the underlying biological processes that …

The Effects Of The Hiv-1 Tat Protein And Morphine On The Structure And Function Of The Hippocampal Ca1 Subfield, William D. Marks

Theses and Dissertations

HIV is capable of causing a set of neurological diseases collectively termed the HIV Associated Neurocognitive Disorders (HAND). Worsening pathology is observed in HIV+ individuals who use opioid drugs. Memory problems are often observed in HAND, implicating HIV pathology in the hippocampus, and are also known to be exacerbated by morphine use. HIV-1 Tat was demonstrated to reduce spatial memory performance in multiple tasks, and individual subsets of CA1 interneurons were found to be selectively vulnerable to the effects of Tat, notably nNOS+/NPY- interneurons of the pyramidal layer and stratum radiatum, PV+ neurons of the pyramidal layer, and SST+ neurons …

Metabolic And Morphologic Shifts In Neuro2a Cells Cultured In Galactose Medium, Leah Welker

Masters Theses

It has been observed that highly-proliferating cells, such as cancer cells, rely mainly on glycolysis for ATP production, regardless of presence of oxygen. This effect, however, can be reversed by changing the main energy substrate in the medium from glucose to galactose. The oxidation of galactose in glycolysis yields less net ATP, presumably forcing the cell into OXPHOS. This has been established in many cell lines, including HeLA, HepG2, and skeletal muscle cells. As of yet, this has not been reproduced in neuronal cells. Using Neuro2a, a murine neuroblastoma cell line, this study exposes neuronal cells to galactose medium, and …

Effects Of Asiatic Acid On Neurite Outgrowth In Neuro-2a Cells, Aishah Asiri

Masters Theses

Recently, medicinal plants from ancient Ayurvedic medicine have provided clues to the discovery of novel therapeutics for various diseases. In Ayurvedic medicine, a common Indian plant, Centella asiatica is highly regarded as a "rasayana" or nerve tonic. The Centella extract is used to ward off age-related dementia and to increase memory and intelligence. The mechanism by which Centella improves memory and learning and reduces the risk of dementia is unclear.

We recently tested the effects of asiatic acid, the main active component of Centella, on neuronal growth. We hypothesized that asiatic acid will promote neuronal growth and neurite network …

Stretch Activated Channels In Proprioceptive Organs Of Crab And Crayfish Are Sensitive To Gadolinium But Not Amiloride, Ruthenium Red Or Low Ph, Viresh Dayaram, Cole A. Malloy, Sarah Martha, Brenda Alvarez, Ikenna Chukwudolue, Nadera Dabbain, Dlovan D.Mahmood, Slavina Goleva, Tori Hickey, Angel Ho, Molly King, Paige Kington, Matthew Mattingly, Samuel Potter, Landon Simpson, Amanda Spence, Henry Uradu, Jacob Van Doorn, Robin L. Cooper

Biology Faculty Publications

The type of stretch activated receptors (SARs) in the chordotonal organs in the crab walking leg and of the muscle receptor organ (MRO) in the crayfish abdomen have not yet been classified as to their molecular or pharmacological profile. The purpose of this study is to examine the pharmacological profile of SARs in the proprioceptive neurons in the crab and crayfish models. Since many SARs share the pharmacological profile of displaying low pH or being proton sensitive (i.e. being more active) or blocked by the diuretic amiloride or ruthenium red as well as being blocked by the broad stretch activated …

Developmental Toxicity Of Nicotine: A Transdisciplinary Synthesis And Implications For Emerging Tobacco Products, Lucinda J. Enland, Kjersti Aagaard, Michele Bloch, Kevin Conway, Kelly Cosgrove, Rachel Grana, Thomas J. Gould, Dorothy Hatsukami, Frances Jensen, Denise Kandel, Bruce Lanphear, Frances Leslie, James R. Pauly, Jenae Neiderhiser, Mark Rubinstein, Theodore A. Slotkin, Eliot Spindel, Laura Stroud, Lauren Wakschlag

Pharmaceutical Sciences Faculty Publications

While the health risks associated with adult cigarette smoking have been well described, effects of nicotine exposure during periods of developmental vulnerability are often overlooked. Using MEDLINE and PubMed literature searches, books, reports and expert opinion, a transdisciplinary group of scientists reviewed human and animal research on the health effects of exposure to nicotine during pregnancy and adolescence. A synthesis of this research supports that nicotine contributes critically to adverse effects of gestational tobacco exposure, including reduced pulmonary function, auditory processing defects, impaired infant cardiorespiratory function, and may contribute to cognitive and behavioral deficits in later life. Nicotine exposure during …

Octopamine In Sexual Behavior, Ana Isabel Fernandez

Open Access Theses & Dissertations

Octopamine is a biogenic amine neuromodulator present in neuronal and non-neuronal tissues in invertebrates (Roeder, 1999). It modulates numerous physiological processes such as motivation, pheromone response, olfaction, ovulation, learning and memory. Octopamine together with its precursor tyramine have roles restricted only to invertebrates (Roeder, 1999). It is believed that octopamine is the invertebrate homolog of norepinephrine, a catecholamine present in mammals that acts as a neuromodulator in the sympathetic and central nervous systems. Both octopamine and norepinephrine are derived from the same amino acid tyrosine and are monoamine neurotransmitters. The main objective of this study is to understand the role …

Variations In Crowding, Saccadic Precision, And Spatial Localization Reveal The Shared Topology Of Spatial Vision, John A. Greenwood, Martin Szinte, Bilge Sayim, Patrick Cavanagh

Dartmouth Scholarship

Visual sensitivity varies across the visual field in several characteristic ways. For example, sensitivity declines sharply in peripheral (vs. foveal) vision and is typically worse in the upper (vs. lower) visual field. These variations can affect processes ranging from acuity and crowding (the deleterious effect of clutter on object recognition) to the precision of saccadic eye movements. Here we examine whether these variations can be attributed to a common source within the visual system. We first compared the size of crowding zones with the precision of saccades using an oriented clock target and two adjacent flanker elements. We report that …

Widespread Tau Seeding Activity At Early Braak Stages, Jennifer L. Furman, Jaime Vaquer-Alicea, Charles L. White, Nigel J. Cairns, Peter T. Nelson, Marc I. Diamond

Pathology and Laboratory Medicine Faculty Publications

Transcellular propagation of tau aggregates may underlie the progression of pathology in Alzheimer's disease (AD) and other tauopathies. Braak staging (B1, B2, B3) is based on phospho-tau accumulation within connected brain regions: entorhinal cortex (B1); hippocampus/limbic system (B2); and frontal and parietal lobes (B3). We previously developed a specific and sensitive assay that uses flow cytometry to quantify tissue seeding activity based on fluorescence resonance energy transfer (FRET) in cells that stably express tau reporter proteins. In a tauopathy mouse model, we have detected seeding activity far in advance of histopathological changes. It remains unknown whether individuals with AD also …

A Laser-Pulse Photolysis Study Of The Mechanism Of Potentiation Of The Glua2qflip Ampa Receptors By Cx546, Yu-Chuan Shen

Legacy Theses & Dissertations (2009 - 2024)

Insufficient activity of the α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-type glutamate ion channels is involved in neurological disorders and developmental problems, such as schizophrenia, one of the most serious psychiatric diseases. Use of regulatory agents to enhance AMPA receptor activity under the circumstance has been shown therapeutically beneficial. Specifically, small-molecule compounds generally termed as potentiators or positive modulators of AMPA receptors have long been pursued as drug candidates for a potential treatment of these neurological disorders and diseases. The goal of my MS thesis work is to investigate the mechanism of potentiation on AMPA receptor by a classic potentiator known as CX546. The …

Elucidating The Transcriptional Regulation Underlying Neural Induction, Sarah E. Hirsch

Legacy Theses & Dissertations (2009 - 2024)

The brain is one of the most complicated structures in the human body and its development is also elusive. Great strides have been made in expounding some of the complex mechanisms of neural development, which allows for the creation of innovative, less invasive, and more effective treatments for neurodevelopmental and neurodegenerative disorders. The advent of stem cell technology has brought therapy development for these disorders closer to a reality, as stem cells provide a platform to model early stages of human neural development. This is of great importance, as only through studying neurodevelopment will the various transcriptional and molecular components …

Disease In A Dish : Modeling Tau Pathology For Future Antibody Testing, Leneea Toyisha Warner

Legacy Theses & Dissertations (2009 - 2024)

ABSTRACT

Analysis Of Candidate Genes For Seizure Susceptibility In Epileptogenesis, Brittany O'Brien

Legacy Theses & Dissertations (2009 - 2024)

The occurrence of recurrent spontaneous seizures is the hallmark of epilepsy. The key to understanding how a normal brain can develop epilepsy through a process known as epileptogenesis is identifying susceptibility factors. Previously, various strains of inbred mice from the hybrid mouse diversity panel were subjected to multiple seizures via the repeated flurothyl model (RFM) for epileptogenesis. The results demonstrated differences in kindling among the inbred strains; specifically two main trends in the generalized seizure threshold (GST) data were kindling-sensitive and kindling-resistant strains. In addition, genome wide association studies done from these mice demonstrated a quantitative trait locus (QTL) on …

Retinal Disease Modeling And Drug Screening Using Stem Cell Derived Retinal Pigment Epithelium, Janmeet Singh Saini

Legacy Theses & Dissertations (2009 - 2024)

The eye is an intricate organ, possessing sensory receptors in the retina that are involved in visual perception. The retina consists primarily of the neural layer, referred to as the neural retina, and the pigmented layer, referred to as the retinal pigment epithelium (RPE). The neural retina and RPE develop and mature in a coordinated manner, and depend on each other for survival. In a mature healthy retina, the retinal photoreceptor outer segments interdigitate with the RPE monolayer, and they co-exchange key supportive factors. RPE cells are indispensable for the health of the retina as they are involved in a …

Harnessing Electrocorticographic Signals For Neuroscience And Neurosurgery, Adriana De Pesters

Legacy Theses & Dissertations (2009 - 2024)

Daily human activities, such as speaking, driving or listening to music, are produced by activations of neurons in the brain. Where, when and how these activations occur has been the subject of intense debate for the last decades. Traditional techniques to image the human brain, such as functional magnetic resonance imaging (fMRI) or electroencephalography (EEG), only provide limited information regarding where and when these activations take place. For that reason, critical information is currently missing regarding how neurons from different parts of the brain interact and coordinate their activity to implement behavior. This information is critical to understand human behavior …