Neuroscience and Neurobiology Commons^™

Synaptic Properties Of Parabigeminal Circuits., Kyle Whyland

Electronic Theses and Dissertations

Subcortical structures of the visual system have been the subject of intense study in recent years, but there remain some important unanswered questions regarding the synaptic relationships linking the nuclei that comprise this important sensory network within the brain. In these studies, we use several modern and traditional approaches, including viral tract tracing, in vitro slice physiology, immunohistochemistry, optogenetics, and electron microscopy to characterize the circuits linking the superior colliculus (SC), parabigeminal nucleus (PBG), and lateral geniculate nucleus (LGN), with particular focus on GABAergic and cholinergic cell types. We found that the SC, an important visuomotor structure with connections to …

Perineuronal Nets Are Not Required To Close The Critical Period For Ocular Dominance Plasticity., Emily Crouse

Electronic Theses and Dissertations

In the developing visual system, a transient critical period demarcates when neural circuits are most sensitive to visual experience. In the mouse, the critical period occurs between approximately postnatal day(P) 19 to 32. Closing one eye (monocular deprivation, MD) within the critical period shifts ocular dominance (OD) to be more responsive to the open eye. Nogo-66 Receptor 1 (NGR1) limits OD plasticity to the critical period yet it remains unknown how OD plasticity propagates through primary visual cortex or by which mechanisms NGR1 utilizes to confine said plasticity. In primary studies, NGR1 was selectively deleted in different cortical layers to …

Supraspinal Reorganization After Pediatric-Onset Spinal Cord Injury., Luis Alvarado

Electronic Theses and Dissertations

Pediatric spinal cord injury (SCI) disrupts the efferent and afferent flow of the developing brain, leading to devastating functional impairments below the injury site, yet our understanding of its impact on the brain remains limited. This study examines supraspinal reorganization in children with SCI using electrophysiology and neuroimaging techniques to understand the relationship between residual spinal transmission and supraspinal reorganization. Chapter 2 discusses the development of a child-centric approach using ‘learn, play, and practice’ to foster a trusting relationship with each child and increase compliance with experimental protocols. Chapter 3 evaluates the residual neural transmission of three spinal pathways in …

Chemosensory Processing By The Mediodorsal Thalamus., Kelly Fredericksen

Electronic Theses and Dissertations

The mediodorsal thalamus (MD) is thought to be key component of the network that processes chemosensory information to guide our consummatory choices. Previous studies show that the mediodorsal thalamus receives projections from both the piriform cortex (PC) and gustatory cortex (GC), suggesting that it may process chemosensory information from both areas. Although the mediodorsal thalamus has been shown to respond to odors detected by sniffing, it remains unknown how its neurons represent experienced odors, tastes, and odor-taste mixtures originating from the mouth. Importantly, humans and animals with mediodorsal thalamic lesions do not suffer from anosmia, but experience deficits in odor …

Neural Correlates Of Sub-Clinical Grandiose Cluster B Personality Disorders, Adriana Lavarco

Theses, Dissertations and Culminating Projects

The Cluster B personality disorders (PDs) include antisocial personality disorder (ASPD), borderline personality disorder (BPD), narcissistic personality disorder (NPD), and histrionic personality disorder (HPD). With impulsivity being a commonly shared symptom across the cluster B personality disorders, specifically in BPD, the right and left dorsolateral prefrontal cortex (DLPFC) was targeted for TMS. Since these personality disorders are grouped together due to their shared ‘dramatic’ characteristics, the current study aimed to investigate the effects of transcranial magnetic stimulation (TMS) on the presence of cluster B personality disorder traits in 13 healthy participants. We found that there is a significant decrease in …

Psychopathy In Society: Understanding The Neural Mechanisms That Give Rise To Psychopathic Traits, Phoebe Zalenski

Psychological Science Undergraduate Honors Theses

Psychopathy is characterized as an individual exhibiting callousness, grandiosity, lack of empathy, and manipulative behavior towards others over a long period of time. Given these symptoms, psychopathy is associated with a markedly increased risk of arrest and imprisonment. Together, these findings highlight the importance of understanding the cause(s) of psychopathy, as doing so may help to develop treatments or preventative interventions. Prior work has suggested that structural abnormalities in the amygdala may play a role in clinical psychopathy; however, it is less clear whether amygdala abnormalities exist on a continuum of psychopathic traits. In this study, I aimed to determine …

Does State Of Mind Predict Prototype-Based Category Learning In Older Adults?, Kana Kimura

Theses and Dissertations

Category learning plays an important role in day-to-day lives across all ages, allowing us to organize related experiences, develop expectations, and determine how we behave given those expectations. Despite its importance, the current body of literature on category learning in older adults is much smaller than that of other memory domains. Thus, little is known about how well older adults learn new concepts and what factors best promote learning novel categories. One factor that may affect category learning abilities is an individual’s state of mind. A number of studies demonstrate the effects of sleep, stress, affect, and motivation on cognition, …

P120-Catenin Subfamily Members Have Distinct As Well As Shared Effects On Dendrite Morphology During Neuron Development In Vitro, Maxsam Donta

Dissertations & Theses (Open Access)

Proper dendrite morphology is essential for neuronal connectivity and function, and abnormal dendrite morphology is seen in many neurological pathologies. This study characterizes and compares the effects of a group of four proteins – the p120-catenin subfamily – that regulate cytoskeletal remodeling and dendrite morphology. To do this, I tracked the endogenous localization of each p120-subfamily catenin during neuron development, and I determined how altering the expression of each p120-subfamily catenin affects dendrite morphology. I find that all catenins are expressed in dendritic processes and the soma, ARVCF-catenin is expressed at relatively high proportions in the nucleus, and p120-catenin and …

The Reinforcement Enhancing Effects Of Delta-9-Tetrahyrdrocannabinol (Thc) In Male And Female Rats, Kynah Walston

Electronic Theses and Dissertations

Cannabis is widely consumed by humans for pharmacological effects that are mediated by THC, though there is little evidence that THC is a primary reinforcer in non-human animal models. We hypothesized that THC may have potent reinforcement enhancing effects, comparable to other drugs (e.g., nicotine and caffeine) which are also widely consumed by humans, but difficult to establish as primary reinforcers in non-humans. In three experiments with male and female rats saccharin (SACC) or a visual stimulus (VS) served as reinforcers for operant behavior. We explored several pharmacological parameters of THC on responding for SACC or VS, including THC dose, …

Validating A New In Vivo Model To Study Als, Izabela J. Cimachowska

Student Theses and Dissertations

Buildup of oxidative stress and mitochondrial dysfunction are well known characteristics of both sporadic and hereditary amyotrophic lateral sclerosis (ALS). While both forms of the disease seem to arise from common cellular dysfunction, the genetic disease is studied to a much greater extent. Engineering novel animal models of the sporadic form of the disease is crucial for development of druggable targets to treat ALS and understand the underlying mechanisms. Interestingly, accumulation of oxidative stress by exacerbated emission of reactive oxygen species (ROS) from presynaptic mitochondria is a hallmark of both hereditary and sporadic ALS. Previous work by our laboratory showed …

Social Exclusion : How Inhibition And Excitation Of The Dorsal Lateral Prefrontal Cortex (Dlpfc) Influences Feelings Of Social Exclusion, Anthony Minervini

Theses, Dissertations and Culminating Projects

Social exclusion refers to the experience of rejection by one or more people during a social event. Cyberball, a computer program, is one of the most common tools for analyzing social exclusion. Cyberball simulates a game of catch in which any number of individuals or computer- generated players can pass a virtual ball to one another. Regions of the brain that underlies pain perception include networks lined to the Dorsal Lateral Prefrontal Cortex (DLPFC). Direct manipulation of this area may provide a better understanding of how the DLPFC can influence the perception of social exclusion. Transcranial magnetic stimulation (TMS) was …

Artificial Dendritic Neuron: A Model Of Computation And Learning Algorithm, Zachary Hutchinson

Electronic Theses and Dissertations

Dendrites are root-like extensions from the neuron cell body and have long been thought to serve as the predominant input structures of neurons. Since the early twentieth century, neuroscience research has attempted to define the dendrite’s contribution to neural computation and signal integration. This body of experimental and modeling research strongly indicates that dendrites are not just input structures but are crucial to neural processing. Dendritic processing consists of both active and passive elements that utilize the spatial, electrical and connective properties of the dendritic tree.

This work presents a neuron model based around the structure and properties of dendrites. …

Early Life Stress Predicts Future Conduct Disorder In Adolescents, Savannah Ellis

Biological Sciences Undergraduate Honors Theses

Early Life Stress (ELS) and adversity increase people’s risk for developing mental, social, or emotional dysregulation and disorders later in life. The objective of this study was to test whether ELS in adolescents could prospectively predict future conduct disorder. The study additionally tested potential neural mediators of the effect of ELS on future conduct disorder, and specifically targeted the structural connections from the anterior insula and medial prefrontal cortex to the Nucleus Accumbens (NAcc). Data for the project came from the Adolescent Brain Cognitive Development Study (ABCD study), which is a longitudinal multi-site consortium funded by the National Institutes of …

Immobilization And Its Effects On Functional Recovery After Spinal Cord Injury., William H. Gregory

College of Arts & Sciences Senior Honors Theses

Recovery, or rather the failure to recover, is a perplexing issue of spinal cord injury that is currently being investigated. This issue becomes more puzzling when investigating models in which spinal cord injury (SCI) is studied. There appears to be greater functional recovery experienced by animals within these models after injury as compared to patients in the clinical setting. While many things could contribute to this disparity, one difference that stands out when comparing the basic research model and clinical experience of SCI is the inactivity and limb disuse after the injury. This same level of immobility is rarely accounted …

The Effects Of Loss Of Orexin Neurons On Attention, Alejandra Eceizabarrena Sainz

Undergraduate Honors Theses

Attention is the ability to process stimuli in the environment and select relevant cues amongst distractors. It is a crucial aspect of the nervous system that engages multiple brain circuits. Neurons that release the neuropeptide orexin are implicated in attention. These neurons originate in the lateral hypothalamus and send projections widely throughout the brain. Evidence suggests orexins modulate attentional mechanisms through interactions with ascending neuromodulatory systems such as the basal forebrain. Experiments manipulating orexin receptors have found a subsequent effect on attention-demanding tasks, with infusions of orexin A enhancing attention in the presence of distractors. In contrast, the blockade of …

Adolescents With Family History Of Alcohol-Use Disorders Have Reduced Structural Coherence Of Anterior Insula To Nucleus Accumbens Tract, Grace Wood

Psychological Science Undergraduate Honors Theses

Genetics play a significant role in predisposition towards alcohol use disorders. Analyzing the neural phenotypes related to alcohol use disorder development could allow researchers to predict one’s predisposition. The anterior insula (AIns) contributes to binge drinking tendencies while exhibiting downstream signaling towards the nucleus accumbens (NAcc). Recent research has examined this relationship simultaneously with alcohol consumption, but the genetic effect of the AIns and NAcc functional relationship prior to alcohol consumption has yet to be examined. In this study, we used data from the Adolescent Brain Cognitive Development (ABCD) study to analyze the structural coherence of the AIns to NAcc …

Aggression In And Out Of The Surrounding Space, Marissa Incer

Undergraduate Honors Theses

Social isolation is a type of punishment used to address misbehavior in individuals, such as children with time-outs and prisoners in solitary confinement. It was thought to be an effective method for teaching good behavior or alleviating tense situations. However, this type of punishment may worsen the punished individual’s aggression depending on the environment of isolation. The current study was divided into two experiments. In the first experiment, participants were isolated in a small (2x2 feet) or large (6x6 feet) space to observe if the space alone affected their aggression. In the second experiment, a frustration-inducing task was given to …

Analysis Of Genes Responsible For Neuronal Morphological Changes In Down Syndrome Hipsc-Derived Neurons, Juhi Patel

Senior Theses

Down syndrome (DS) is a complex neurodevelopmental disorder caused by the trisomy of chromosome 21. DS is the largest genetic cause of intellectual disability, which occurs in varying severity among affected individuals. It is associated with a variety of developmental and cognitive defects, including reduced brain size, impaired synaptic function, and altered neuronal morphology. A number of genes have been identified to play critical roles in the development and maintenance of neuronal morphology, and alterations in the expression of some of these genes are implicated in the morphological changes observed in DS. Knocking out or altering their expression leads to …

The Effects Or Practicing A Golf Putting Task In Virtual Reality, Zoya Amer, Logan T. Markwell, Andrew J. Strick, Jared M. Porter

Chancellor’s Honors Program Projects

No abstract provided.

Gaze During Turning In Older Adults, Kalina Mavrov

Theses/Capstones/Creative Projects

To navigate complex environments, our gaze needs to attenuate to locomotor tasks, such as walking and turning. Shifting gaze (i.e., rotation of the eyes and head), is important when moving through different environments. The aim of this study was to compare gaze anticipation during clinical tests and complex real-world locomotion. I hypothesized that older adults would shift their gaze in a new heading direction in anticipation of turns. I further predicted increased gaze anticipation in tasks that have a high demand for spatial orientation. Participants were asked to complete clinical tasks consisting of a 2-minute walk, figure-8, and 360-turning in …