Neuroscience and Neurobiology Commons^™

Explaining The Staircase Gelb Illusion, Simultaneous Contrast, And Perceptual Fading Of Stabilized Images With A Neural Model Driven By Fixational Eye Movements, Michael E. Rudd

MODVIS Workshop

A neural model of lightness computation driven by fixational eye movements is described and used to simulate various lightness phenomenon, including the Staircase Gelb illusion and its variants, simultaneous contrast, the Chevreul illusion, and perceptual fading of stabilized images. The model provides a precise account of the lightness matches from several experiments, with an overall error of only 1.5%. In the model, spatial maps of transient ON and OFF cell activations—produced as the eyes traverse the visual scene—are sorted by eye movement direction in visual cortex. At a subsequent processing stage, the activations within these maps are summed across space …

Comparing Executive Control: Bilingualism's Cognitive Advantage, Malcolm Jasmin, Tonya Buchanan Ph.D.

Symposium Of University Research and Creative Expression (SOURCE)

The Stroop Task is a widely used method for studying executive control. It helps to understand cognitive processes like inhibition and attentional regulation to examine how reading text and naming colors can interfere with each other. The study intends to use the Stroop Task to explore the executive control abilities of both bilingual and monolingual individuals. Previous research has shown that bilingual individuals perform better in the Stroop test compared to those who only speak one language (Bialystok et al., 2010). The impact of this advantage is believed to be due to the need to switch between languages and prevent …

Age-Related Brain Atrophy And The Positive Effects Of Behavioral Enrichment In Middle-Aged Beagles., Jessica A Noche, Hamsanandini Radhakrishnan, Margo F. Ubele, Kathy Boaz, Jennifer L Mefford, Erin D Jones, Hollie Y Van Rooyen, Jessica A Perpich, Katie Mccarty, Beverly Meacham, Jeffrey R. Smiley, Stasia A Bembenek Bailey, László G Puskás, David K. Powell, Lorena Sordo, Michael J Phelan, Christopher M. Norris, Elizabeth Head, Craig E L Stark

Neuroscience Faculty Publications

Aging dogs serve as a valuable preclinical model for Alzheimer's disease (AD) due to their natural age-related development of β-amyloid (Aβ) plaques, human-like metabolism, and large brains that are ideal for studying structural brain aging trajectories from serial neuroimaging. Here we examined the effects of chronic treatment with the calcineurin inhibitor (CNI) tacrolimus or the nuclear factor of activated T cells (NFAT)-inhibiting compound Q134R on age-related canine brain atrophy from a longitudinal study in middle-aged beagles (36 females, 7 males) undergoing behavioral enrichment. Annual MRI was analyzed using modern, automated techniques for region-of-interest-based and voxel-based volumetric assessments. We found that …

Inflammaging In The Alzheimer’S Brain And Beyond: Insights From A Transgenic Mouse Model On The Sex-Specific Pathophysiology Of Alzheimer’S Disease, Alicia Jeanne Barber

Dartmouth College Ph.D Dissertations

Aging and sex are major risk factors for developing late-onset Alzheimer’s disease. Compared to men, women experience worse neuropathological burden and cognitive decline despite living longer with the disease. Similarly, male 3xTg-AD mice, developed to model Alzheimer’s disease, no longer consistently exhibit standard Alzheimer’s neuropathology yet experience higher rates of mortality - providing a unique opportunity to further elucidate this dichotomy. We hypothesized that sex differences in the biological aging process yield distinct pathological and molecular Alzheimer’s disease signatures in males and females, which could be harnessed for therapeutic and biomarker development.

We aged male and female, 3xTg-AD and B6129 …

Analysis And Computation Of Constrained Sparse Coding On Emerging Non-Von Neumann Devices, Kyle Henke

Mathematics & Statistics ETDs

This dissertation seeks to understand how different formulations of the neurally inspired Locally Competitive Algorithm (LCA) represent and solve optimization problems. By studying these networks mathematically through the lens of dynamical and gradient systems, the goal is to discern how neural computations converge and link this knowledge to theoretical neuroscience and artificial intelligence (AI). Both classical computers and advanced emerging hardware are employed in this study. The contributions of this work include:

1. Theoretical Work: A comprehensive convergence analysis for networks using both generic Rectified Linear Unit (ReLU) and Rectified Sigmoid activation functions. Exploration of techniques to address the binary …

Integrating Higher-Order Cognition With Sensory Experience: Insights From Cue-Based Expectations Across Diverse Domains, Heejung Jung

Dartmouth College Ph.D Dissertations

Higher-order cognition, such as expectations about the future, cannot be studied in isolation from sensory representations. This thesis explores the dynamic interplay of higher-order cognition and sensory experiences, examining the important role of expectations across multiple domains: sensory, cognitive, and affective. First, a systematic review outlines the origins of higher-order cognitive functions – e.g., social interaction, memory, and attentional control – and how they arise at the convergence of hierarchically organized gradients that extend from primary sensory areas. These convergence zones are rich in information crucial for the human capacity for making projections, such as thinking about another person’s mental …

Unveiling The Nexus Of Cellular Quality Control: Exploring The Interplay Between Ribosome-Associated Protein Quality Control And Mitochondrial Quality Control Pathways, Foozhan Tahmasebinia

Biological Sciences Theses and Dissertations

In eukaryotic cells, the intricate interplay between cellular quality control mechanisms is crucial for maintaining homeostasis and safeguarding the integrity of vital processes, spanning from macromolecule synthesis to the renewal of entire cellular organelles.

Disruption of these networks can lead to severe diseases such as metabolic disorders, underscoring the interconnected nature and feedback control mechanisms inherent in biological systems, including cellular quality control systems. This interconnectedness extends to the intricate communication between organelles, enabling coordinated functioning and adaptation to changing cellular conditions, particularly in response to stressors.

While the exact mechanisms governing these communications within cellular quality control systems remain …

Screen For Beneficial Genetic And Chemical Modifiers In Drosophila Models Of Als And Traumatic Brain Injury, Will Bonderer

Biological Sciences Theses and Dissertations

The underlying molecular processes of aberrant protein expression in neurodegeneration are intricate and multifaceted, with ribosome-associated quality control (RQC) emerging as a promising avenue of exploration. Ribosome-associated quality control is integral to cellular function. Its evolutionarily conserved pathway encompasses a network of mechanisms designed to ensure the fidelity of protein synthesis, folding, and degradation within the cells of all eukaryotes. The ribosome, central to protein synthesis, plays a pivotal role in this quality control network, and its malfunction can lead to the accumulation of misfolded or aberrant proteins. In the context of neurodegenerative disorders, this dysfunction can have dire consequences. …

Early Developmental Exposure To Δ9-Tetrahydrocannabinol Causes Latent Behavioral, Growth, And Bioenergetic Effects In Danio Rerio, Astra Hahm

Honors Theses

Early developmental exposure to Δ9-tetrahydrocannabinol causes latent behavioral, growth, and bioenergetic effects in Danio rerio

(Under the direction of Dr. Kristine Willett)

Δ9-tetrahydrocannabinol (Δ9-THC) is used during pregnancy to mitigate symptoms such as nausea, pain, and insomnia. It is established that Δ9-THC exposure early in life causes adverse effects in children’s development including behavioral disorders. Our goal was to determine the latent and generational impacts on growth, behavior, and mitochondrial bioenergetics following exposure to Δ9-THC. Wildtype (5D) zebrafish were exposed to 0 (0.05% DMSO), 0.08, 0.4, or 1 µM Δ9-THC from 6-96 hours post-fertilization (hpf), then subsequently raised in clean …

Neuroscience Educational Interventions For Mental Health Management Within The Neurodiverse Population: A Working Model, Kadi Rae Smith, C.K. Miller, Bill Griesar, Jeff Leake

Student Research Symposium

Sociological and environmental factors such as economic disparity and cultural marginalization hinder access to educational and medical resources and must be taken into account to ensure accurate diagnoses, effective self-regulation and mental health management for neurodiverse individuals, and offset disparities in access to healthcare and education. Arbitrary attachment of stigma to traits commonly associated with neurodivergence perpetuate neuro-myths1 that have dire consequences when internalized, informing individuals’ development and sense of self. Neuroscience outreach done by NW Noggin is an active model for engaging communities with limited resources and a greater need for services to offset economic disparity. Integrated arts programming …

Evaluation Of Sleep Outcomes After Traumatic Brain Injury In Children Using Questionnaires And Actigraphy, Connie Tran, Sydney Weese, Cydni Williams Md

Student Research Symposium

Traumatic brain injuries are the result of a sudden external blunt force to the brain and can result in long-term complications or death. In pediatrics, it is the leading cause of acute and chronic sleep wake disturbances, as well as cognitive deficits, which can lead to a reduction in the quality of life. These impairments can later result in lowered performance in work and school settings or decreased psychosocial function. Although there is sufficient evidence that traumatic brain injuries contribute to is that it is unknown whether or not sleep wake disturbances contribute to an increase in the mentioned cognitive …

Understanding The Importance Of Social Emotional Learning In Children And The Link Between Mental Health, Lynette Marie Lubiak

Student Research Symposium

I will examine how very important it is to society to teach structured Social Emotional Learning (SEL) programs to children in school. It can bring mental wellbeing and the ability to have healthy relationships, non addictive behaviors and being able to emotionally regulate themselves. Since we have pushed on only academia and not SEL for our children, mental illness has skyrocketed. This problem started after the SEL part of school was taken out of schools and then the division between rich and poor became wider and wider as time went on. If we were to bring back SEL into school, …

Immunopathogenesis Of Post-Infectious Hydrocephalus, Sascha Powers Bernier

Honors Scholar Theses

Hydrocephalus is characterized by the abnormal accumulation of cerebrospinal fluid (CSF) within the brain ventricles. In post-infectious hydrocephalus (PIH) cases, the condition presents challenges in understanding the immune response. PIH is a complex condition, often persisting after the initial infection is treated and thus requiring a deeper understanding of the immune mechanisms involved in its development. This thesis will explore the immunopathogenesis of PIH, elucidating the relationship between the immune response and neurological complications that would succeed infection. The immune response of PIH includes a series of events, beginning with the activation of immune cells and finishing with the release …

Investigating The Antibacterial And Immunomodulatory Effects Of Resolvin D2 On Monocytes And Macrophages, Cristina Maria Padovani

Theses and Dissertations

In the late phase of sepsis, immunosuppression occurs, where the host is unable to clear the pre-existing infection and is susceptible to secondary infections. It is believed that the ideal treatments for sepsis should attenuate immunosuppression so that the host can get back to homeostasis. Specialized Pro-resolving Mediators (SPMs) are endogenously- produced fatty acids that resolve infectious inflammation without being immunosuppressive. We hypothesize that an SPM – Resolvin D2 (RvD2) – can augment exhausted macrophage function during the immunosuppressive phase of sepsis. We developed a two-hit model to establish macrophage exhaustion in vitro, and found that RvD2 increased NF-κB activity, …

Compensatory Changes In The Visual System As A Result Of Neurodegeneration, Liz Bierlein

Theses & Dissertations

The brain has the remarkable ability to compensate for damage and maintain physiological set points. In the visual system where even after significant damage has been done, the brain fills in visual gaps because of this compensation. This thesis attempts to understand several components of visual changes after damage in disorders such as glaucoma. This was accomplished by using several models of vision loss in mice including the DBA/2J (D2) and silicone oil (SO) models of glaucoma, the RD10 model of retinitis pigmentosa, and a retina-specific knockout of brain-derived neurotrophic factor (BDNF)— the Chx10-cre; BDNF^fl/fl mouse. Through these models …

The Relationship Between Amygdala And Orbitofrontal Cortex Volume In The Context Of Oppositional Defiant Disorder, Rahul Alla

Honors Scholar Theses

Disobedient and rebellious attitude in children is on the rise and this type of behavior is categorized as Oppositional Defiant Disorder (ODD). ODD in children can be identified as a persistent pattern of angry or irritable mood, argumentative or defiant behavior or vindictiveness toward others according to the Diagnostic and Statistical Manual (DSM-5, Fifth Edition) of Mental Disorders.1 Children with ODD typically have difficulty regulating and processing their emotions. Issues with regulating emotions is defined as the process by which individuals “influence which emotions they have, when they have them, and how they experience and express them”.2 Dysregulation of emotions …

The Effect Of Repetitive Transcranial Magnetic Stimulation On Brain And Cognitive Variables In Patients With Amnestic Mild Cognitive Impairment, Connor J. Phipps

Theses & Dissertations

Healthy and pathological aging processes can impact human memory. Current interventions for clinical memory impairment offer little opportunity for restoration of memory ability. Fortunately, a novel therapy in the form of repetitive transcranial magnetic stimulation (rTMS) has exhibited promise in this regard. In healthy adults, rTMS of the angular gyrus (AG) has been reported to improve memory. The current study sought to determine the generalizability of these findings to individuals with clinical memory impairment by administering a clinical trial replicating an rTMS protocol reported to improve hippocampal-dependent memory in healthy individuals to individuals with amnestic mild cognitive impairment (aMCI). Individuals …

Individual Differences In Age And Testosterone Are Uniquely Associated With Neural Oscillatory Activity Serving Verbal Working Memory In Children And Adolescents, Abraham D. Killanin

Theses & Dissertations

During the sensitive period of adolescence, the human brain undergoes dynamic changes in structure and function resulting in vast executive function gains. Verbal working memory (VWM) is one executive function that serves as a foundation to language acquisition, reading, and learning. Many have examined the development of VWM in youth, but few have probed age-related changes in the underlying neural oscillatory dynamics, and none have examined testosterone-related changes. We recorded magnetoencephalography during a modified Sternberg VWM task in 82 youth participants aged 6 – 14 years old and collected salivary testosterone samples. Significant oscillatory responses were identified and imaged using …

Interactions Between Repetitive Mild Traumatic Brain Injury And Methylphenidate Administration On Catecholamine Transporter Protein Levels Within The Rodent Prefrontal Cortex, Anna Abrimian, Eleni Papadopoulos, Christopher P. Knapp, J. Loweth, Barry Waterhouse, Rachel Navarra

Rowan-Virtua Research Day

It is theorized that low concentrations of dopamine (DA) and norepinephrine (NE) within in the prefrontal cortex (PFC) following traumatic brain injury (TBI) leads to increased risky behavior. Our lab has shown that repeated mild TBI (rmTBI) sex-differentially increases risky behavior in a rodent model. Methylphenidate (MPH) is a psychostimulant drug used to treat symptoms of Attention-Deficit Hyperactivity Disorder (ADHD), also driven by a hypo-catecholaminergic PFC. MPH elevates catecholamine levels by blocking DA and NE transporters, DAT and NET. While the potential of psychostimulants to treat post-TBI symptoms have been explored, the effects of sub-chronic MPH on transporter levels following …

A Preliminary Report On The Role Of Lipoxin A4 In Reinstating The Blood-Brain Barrier Integrity In A Rodent Model Of Acute Inflammation With Impaired Cerebrovasculature, Minjal Patel, Shruti Varshney, Ananya Nethikunta, George G. Godsey, Mary C. Kosciuk, Ana Rodriguez, Bernd Spur, Kingsley Yin, Randel L. Swanson, Venkat Venkataraman, Robert G. Nagele, Nimish Acharya

Rowan-Virtua Research Day

Background: The blood-brain barrier (BBB) is responsible for maintaining brain homeostasis and ultimately proper neuronal function. Disruption of the BBB, leading to increased BBB permeability, has been reported in several neurodegenerative diseases, including Alzheimer’s disease (AD) and traumatic brain injury (TBI). Lipoxins (LXs) are a class of arachidonate-derived eicosanoids, which are a class of specialized pro-resolving lipid mediators (SPMs). SPMs are known to inhibit immune response through inhibition of cellular infiltration, downregulation of pro-inflammatory mediators and upregulation of anti-inflammatory mediators. Hence, LXs are recognized as “breaking signals” in the inflammatory process. One form of LXs, Lipoxin A4 (LXA4) …