Neuroscience and Neurobiology Commons^™

The Rhesus Macaque Corticospinal Connectome, Sydney Talmi

CMC Senior Theses

The corticospinal tract (CST), which carries commands from the cerebral cortex to the spinal cord, is vital to fine motor control. Spinal cord injury (SCI) often damages CST axons, causing loss of motor function, most notably in the hands and legs. Our preliminary work in rats suggests that CST circuitry is complex: neurons whose axons project to the lower cervical spinal cord, which directly controls hand function, also send axon collaterals to other locations in the nervous system and may engage parallel motor systems. To inform research into repair of SCI, we therefore aimed to map the entire projection pattern, …

Ethnicity, Perceptions Of Stress, And Depressive Symptoms Among Female Undergraduate Students, Claudia Priscilla Cobos

Walden Dissertations and Doctoral Studies

Individuals have suffered from depression for decades. Although depression is under diagnosed, it is one of the most common disorders seen by psychiatrists. The purpose of this research study was to understand whether students' perceived stress level was a significant predictor of students' depressive symptoms. The study explored social cognitive theory to assist in understanding the relationship between depressive symptoms and perceived stress in female minority students. Although depressive symptoms and perceived stress in students have been explored exhaustively, these variables had not been explored specifically among minority students and then compared to nonminority students. Using the Center for Epidemiologic …

Regulator Of G Protein Signaling-12 (Rgs12) In Dopaminergic And Kappa Opioid Receptor-Dependent Signaling And Behavior, Joshua David Gross

Graduate Theses, Dissertations, and Problem Reports (ETD)

Dopaminergic neurotransmission is critically involved in the etiology and treatment of many psychiatric and neurological disorders. One modulator of dopaminergic neurotransmission is the kappa opioid receptor (KOR) -- a G protein-coupled receptor (GPCR) that is densely expressed within dopaminergic neurons and circuits. GPCRs are tightly regulated by a variety of intracellular signaling molecules, including Regulator of G Protein Signaling (RGS) proteins. Canonically, RGS proteins act as GTPase accelerating proteins (GAPs) on GTP-bound Ga subunits following GPCR activation, thereby hastening the rate at which GPCR-mediated G protein signaling is terminated. However, some RGS proteins exhibit more complex mechanisms of action on …

Discrimination And Behavioral Responses To Communication Signals Compared Across Apteronotids., Danielle Leigh Dillon-Seeger

Graduate Theses, Dissertations, and Problem Reports (ETD)

Sensory systems are often uniquely tailored to encode behaviorally relevant signals and comparative studies across species can thus reveal how evolutionary changes shape sensory functions. The structure of communication signals varies widely between ghost knifefish species. Recent findings suggest that the nervous system co-adapted to the various signal structures observed across species to support different sensory behaviors. The aim for this thesis was to compare the sensory behavior of 3 species of ghost knifefish to contrast their behavioral performance with the known differences in neurophysiology. We hypothesize that for the different signal types and species, the ability to discriminate small …

Glial Cell Expansion And Intercellular Signaling In The Developing Medial Nucleus Of The Trapezoid Body (Mntb), Ashley N. Brandebura

Graduate Theses, Dissertations, and Problem Reports (ETD)

Neural circuit formation is a complex process involving coordinated communication between neurons, glia and vascular-associated cells (VACs). Each cell type is responsible for a unique transcriptional and translational contribution to tissue maturation. Deciphering the intercellular signaling patterns which guide neural circuit formation during normal development is thus an essential step in understanding which components of neural circuit formation go awry in neurodevelopmental disorders. The medial nucleus of the trapezoid body (MNTB), located in the auditory brainstem, was used as a model system to study the dynamics of neural circuit formation because it contains a mostly homogeneous population of postsynaptic neurons …

Role Of Extracellular Vesicles In Neuroinflammatory Progression And Mitochondrial Functional Alterations, Ashley E. Russell

Graduate Theses, Dissertations, and Problem Reports (ETD)

Inflammation within the central nervous system (CNS), termed neuroinflammation, is a defining characteristic of many neuropathological conditions, including Alzheimer’s disease (AD) and stroke. Certain inflammatory mediators activate the transcription factor NF-κB, which induces transcription of many pro-inflammatory genes, including miR-34a and miR-146a. Several target candidate genes of these miRNAs encode for proteins of the mitochondrial electron transport chain. In our studies, we demonstrate that in response to inflammatory stimuli, such as TNF-α, the expression of miR-34a and -146a is significantly increased in several CNS cell types, and in their secreted extracellular vesicles (EVs). Exposure to TNF-α-derived EVs significantly increases cellular …

Sodium Channel Distribution In The Apical Dendrites Of Pyramidal Cells Vary In The Hindbrain Of Apteronotus Leptorhynchus., Sree Indrani Motipally

Graduate Theses, Dissertations, and Problem Reports (ETD)

Apteronotid weakly electric fish heavily rely on their electrosensory system for behaviors like spatial navigation, communication and prey capture. Since the behaviorally important information about their environment is contained in the spatial and temporal modulations of the electrosensory signal, efficient mechanisms to process this information with great fidelity are of the utmost importance. Efficient sensory processing often involves having multiple parallel processing streams so that each stream can specialize to treat signals with different properties. This strategy requires the response properties and neural dynamic to be adjusted in each pathway to implement different neural coding strategies. One of the neural …

Amazon Nights Ii: Electric Boogaloo-Neural Adaptations For Communication In Three Species Of Weakly Electric Fish, Kathryne M. Allen

Graduate Theses, Dissertations, and Problem Reports (ETD)

Sensory systems have to extract useful information from environments awash in noise and confounding input. Studying how salient signals are encoded and filtered from these natural backgrounds is a key problem in neuroscience. Communication is a particularly tractable tool for studying this problem, as it is a ubiquitous task that all organisms must accomplish, easily compared across species, and is of significant ethological relevance. In this chapter I describe the current knowledge of what is both known and still unknown about how sensory systems are adapted for the challenges of encoding conspecific signals, particularly in environments complicated by conspecific-generated noise. …

Design, Synthesis And Pharmacological Characterization Of Potential Mu Opioid Receptor Selective Ligands, Abhishek S. Kulkarni

Theses and Dissertations

Selective Mu Opioid Receptor (MOR) antagonists possess immense potential in the treatment of opioid abuse/addiction. Utilizing the “message-address” concept, our laboratory reported a novel, reversible, non-peptide MOR selective antagonist 17-cyclopropylmethyl-3,14β-dihydroxy-4,5α-epoxy-6β-[(4՛-pyridyl)carboxamido]morphinan (NAP). Molecular modeling studies revealed that the selectivity of NAP for the MOR is because of a π-π stacking interaction of its pyridine ring with the Trp318residue in theMOR. Pharmacological characterization showed that NAP is a P-glycoprotein substrate, thereby limiting its use in the treatment of opioid abuse/addiction. Thus, to modify NAP, we replaced the pyridine ring with its isosteric counterpart thiophene. Isosteric replacement …

Resilience Building In Biracial And Multiracial, Bisexual Adults: An Interpretative Phenomenological Analysis, Melissa Gale Swartz

Walden Dissertations and Doctoral Studies

Until recently, society and science often ignored, erased, and avoided bisexual women and men and individuals with biracial and multiracial identities, and rarely considered these identities simultaneously. Prior research has shown that some lesbians and gay people of color exhibit resilience against sexual minority stress due in part to an inoculating effect of exposure to racism earlier in life. However, little is known about the lived experience of thriving, resilient bisexual multiracial individuals. In the tradition of positive psychology and context of intersectionality theory, this qualitative study explored how multiracial bisexual individuals develop and maintain flourishing well-€being despite sociocultural factors …

Testosterone Replacement Therapy For The Recovery From Chronic Vestibular Dysfunction Following Repeat Mild Traumatic Brain Injury In Male Long-Evans Hooded Rats, Arthur Segismundo

Master's Theses

Repeat mild traumatic brain injury (rmTBI) is a major public health concern leading to both chronic hypogonadism and vestibular impairment. Following rmTBI, vestibular symptoms are one of the most common complaints and hypogonadism occurs in a majority of patients. Gonadal hormones have a well-established role in neuroplasticity and axonal regeneration. The loss of gonadal hormones due to rmTBI may delay recovery. A clinically relevant closed-headed rmTBI male rodent model was utilized to examine the role of testosterone replacement therapy on chronic vestibular dysfunction. This is the first study to demonstrate both hypogonadism and vestibular dysfunction in the acute and chronic …

Neurobehavioral Measurements Of Natural And Opioid Reward Value, Aaron Paul Smith

Theses and Dissertations--Psychology

In the last decade, (non)prescription opioid abuse, opioid use disorder (OUD) diagnoses, and opioid-related overdoses have risen and represent a significant public health concern. One method of understanding OUD is as a disorder of choice that requires choosing opioid rewards at the expense of other nondrug rewards. The characterization of OUD as a disorder of choice is important as it implicates decision- making processes as therapeutic targets, such as the valuation of opioid rewards. However, reward-value measurement and interpretation are traditionally different in substance abuse research compared to related fields such as economics, animal behavior, and neuroeconomics and may be …

Spag17 Deficiency Impairs Neuronal Cell Differentiation In Developing Brain, Olivia J. Choi

Theses and Dissertations

The development of the nervous system is a multi-level, time-sensitive process that relies heavily on cell differentiation. However, the molecular mechanisms that control brain development remain poorly understood. We generated a knockout (KO) mouse for the cilia associated gene Spag17. These animals develop hydrocephalus and enlarged ventricles consistent with the role of Spag17 in the motility of ependymal cilia. However, other phenotypes that cannot be explained by this role were also present. Recently, a mutation in Spag17 has been associated with brain malformations and severe intellectual disability in humans. Therefore, we hypothesized that Spag17 plays a crucial role in …

Characterizing The Cellular Nature Of The Physical Interactions Necessary For Collective Neuron Migration, Rebecca Vareed

Theses and Dissertations

Neuronal migration is an essential process in the development of the nervous system. Neurons are born in one location and migrate sizable distances to their final location. In many other developmental processes, cells migrate as collectives, where the migration of one cell influences the migration of another cell; this process has yet to be shown in the developing central nervous system. Using the conserved tangential migration of facial branchiomotor neurons (FBMNs), I aim to determine the nature of the collective migration in the developing nervous system. Here, two models of FBMN collective migration are tested: the “Pioneer” model, where following …

The Role Of Mindfulness In Self-View Investment: Neural And Subjective Indicators, Hadley Rahrig

Theses and Dissertations

Self-concept is strongly influenced by beliefs about one’s personal psychological attributes, and these beliefs are held with varying degrees of confidence and consequence. Hence, it is investment in self-views of those attributes that helps to regulate and maintain stable self-concept. Self-view investment is relevant to numerous self-related functions, but high self-view investment can also contribute to maladaptive self-views. Theory suggests that mindfulness cultivates a less personal, more objective perception of one’s thoughts, emotions and behaviors, and training in mindfulness has been shown to alter self-referential processing. The current pilot study (N=21) investigates the possible role of dispositional mindfulness in two …

Structure-Activity Relationship Studies Of Synthetic Cathinones And Related Agents, Rachel A. Davies

Theses and Dissertations

Synthetic cathinones and related agents represent an international drug abuse problem, and at the same time an important class of clinically useful compounds. Structure-activity relationship studies are needed to elucidate molecular features underlying the pharmacology of these agents. Illicit methcathinone (i.e., MCAT), the prototype of the synthetic cathinone class, exists as a racemic mixture. Though the differences in potency and target selectivity between the positional and optical isomers of synthetic cathinones and related agents have been demonstrated to have important implications for abuse and therapeutic potential, the two MCAT isomers have never been directly compared at their molecular targets: the …

Illumination Of The Golgi Apparatus Of Pathogenic And Nonpathogenic Naegleria Species, Tyler M. Poe

Theses and Dissertations

In this study, Naegleria fowleri, a pathogenic amoeba and the causative agent of Primary Amebic Meningoencephalitis (PAM), was utilized to determine the presence or absence of classically conserved Golgi molecules featured in the expression of a Golgi apparatus. Previous studies concluded no Golgi expression via light microscopy and transmission electron microscopy, but a recent report on Naegleria gruberi indicated the presence of dispersed Golgi tubules. Non-pathogenic species of the Naegleria genus such as Naegleria gruberi 30540 and Naegleria lovaniensis 30569 were utilized in Western immunoblot analysis compared to reduced whole-cell lysate proteins of two strains of N. fowleri and …

Molecular Targets Of Psychedelics And Their Role In Behavioral Models Of Hallucinogenic Action, Hiba Z. Vohra

Theses and Dissertations

Psychedelics are a subset of hallucinogenic drugs that exert their characteristic effects through agonist activity at the serotonin receptor 2A (5-HT_2A). In this study, I aimed to characterize the modulatory role of the metabotropic glutamate subtype 2 receptor (mGluR2) in the 5-HT_2A-specific rodent model of hallucinogenic action, head-twitch response (HTR). Secondly, I aimed to explore if 5-HT_2A agonist-induced deficits in prepulse inhibition (PPI) of the startle response, an additional model of hallucinogenic action, could be produced in mice. Though 5-HT_2A agonist-induced PPI deficits, which represent interruptions in normal sensorimotor gating, have been described in …

An Investigation On The Role Of Β-Arrestin 2, Protein Kinase C And Sex On The Mechanism Of Morphine Tolerance In The Mouse Ileum, Karan Hitesh Muchhala

Theses and Dissertations

Opioids such as morphine are frequently used in the clinic to treat pain. However, the perennial bane of chronic opioid use is the rapid development of tolerance to the analgesic effects but delayed development of tolerance to the respiratory depressant and constipating effects. As constipation is one of the most common opioid-related adverse effects in humans, it is important to delineate mechanisms that drive opioid tolerance in the ileum and lack of it in the colon. The overarching goal of this thesis was to investigate mechanisms of morphine tolerance in the ileum by comparing the mechanism of morphine tolerance in …

Dna Methylation Of The Clusterin Promoter: Associations With Alzheimer’S Disease Risk And Related Phenotypes, Madeline Peretti

Theses: Doctorates and Masters

Background

In 2017 approximately 50 million people worldwide were living with dementia. With Alzheimer’s disease (AD), accounting for 50-70% of dementia cases making this debilitating disease, with no current effective prevention, treatment or cure, a critical healthcare concern. Genome wide association studies (GWAS) have identified a number of risk genes for late onset AD (LOAD); Apolipoprotein E (APOE), a gene involved in the cholesterol/lipid pathway is considered the gene with the greatest risk. The third most associated AD risk gene is Clusterin (CLU), is also involved in the cholesterol/lipid pathway. CLU has been implicated in both …

Improving Dopamine Monitoring With Ncam And The Effects Of Intranasal Oxytocin On Dopamine Signaling In The Rat Brain, Darren Earl Ginder

EWU Masters Thesis Collection

Dopamine (DA) is a neurohormone highly involved in learning and memory. Oxytocin (OXT), another neurohormone, has also been implicated in learning and memory. Fast-scan cyclic voltammetry (FSCV) is a method used for the real-time examination of DA neurotransmission in the brain. Implanting FSCV electrodes is an invasive technique that likely results in an inflammatory response (i.e. gliosis) that can restrict FSCV recording of DA signals. Neural cell adhesion molecule (NCAM) may reduce gliosis and potentially improve the ability of FSCV electrodes to monitor DA signaling. Chapter 1 Methods: FSCV electrodes were coated with NCAM and implanted in the rat brain. …

The Progression Of Aβ Proteins In The Retrosplenial Cortex Using An App/Ps1 Alzheimer’S Disease Transgenic Rodent Model, Maha H. Rashid

Senior Independent Study Theses

Alzheimer’s disease is the most common form of dementia in the world with a new case of dementia diagnosed every 3.2 seconds. For over 25 years the amyloid cascade hypothesis has existed as a mechanism of understanding and diagnosing Alzheimer’s Disease. The amyloid cascade hypothesis suggests that Alzheimer’s Disease is sequential in protein progression and proliferative from the medial temporal lobe to the rest of the brain. Hypometabolism of brain regions has also been correlated to plaque deposition and hypometabolism is observed in brain regions that make up the default mode network, specifically the retrosplenial cortex, which is not accounted …

Intelligence, Complexity, And Individuality In Sheep, Lori Marino, Debra Merskin

Animal Sentience

Domestic sheep (Ovis aries) are among the earliest animals domesticated for human use. They are consumed worldwide as mutton, hogget, and lamb, kept as wool and milk producers, and used extensively in scientific research. The popular stereotype is that sheep are docile, passive, unintelligent, and timid, but a review of the research on their behavior, affect, cognition, and personality reveals that they are complex, individualistic, and social.

Sacrificial Lambs, Clive Phillips

Animal Sentience

Sheep evolved from the mouflon as mountain animals, able to escape predation by leaping between rock ledges. Their defense was their agility. Humans brought them to the plains, where the agility was less useful, but their lack of aggression, speed or weaponry against predators made them a prime target to become one of man’s meat providers. A perfect animal in many ways, with extraordinary perceptive powers and some remarkable cognitive skills, they are often treated with complete disregard for their welfare. Yet sheep themselves won’t tell us this, for a sheep that alerted others to its weakness really would be …

Pulling The Wool From Our Eyes, Jennifer Vonk

Animal Sentience

Marino & Merskin review evidence of the complexity of sheep cognition, concluding that researchers ought to feel sheepish about misrepresenting ovine cognitive capacities. However, the failure to situate the data in critical context risks pulling the wool over readers’ eyes.

Is Knowing Enough To Change Human Attitudes And Actions?, Liv Baker

Animal Sentience

Marino & Merskin present evidence on key aspects of cognition, such as theory of mind, learning, emotional valence, and sociality, to make a convincing argument that sheep are due consideration as individual sentient beings. With this information, what will it take to produce a real, meaningful shift in our attitudes and actions towards other animals, including a species as disadvantaged as sheep? What else do we need to know?

Reflections On Sheep Rearing, Joyce D'Silva

Animal Sentience

Sheep rearing has an incredibly long history. Sometimes this alone can give credibility and status to a human practice. In the twenty-first century, it may be time to reassess our treatment of sheep and their place in nature. “Just because we’ve always done it” no longer has validity by itself. There are many other human practices which used to be accepted widely in certain societies and which we now may find abhorrent. With sheep intelligence now rightly regarded as an acceptable area of research within the academic community, it is a good time to reflect on our treatment of these …

Casting A Sheep’S Eye On Science, David M. Peña-Guzmán

Animal Sentience

Marino & Merskin review evidence that sheep are not just passive and reactive creatures. They have personalities that vary from individual to individual and endure over time. It follows that we must rethink what it means to study them scientifically.

Far More To Sheep Than Meets The Casual Eye, Bernard Rollin

Animal Sentience

Marino & Merskin’s survey of the cognitive and social capacities of sheep is an eye-opener about the individuality and emotionality of this most maligned of all farm animals. My own eyes had already been opened by an adopted orphaned lamb, so much more like a dog as a companion animal than the mindless robot I had been conditioned to expect. I am morally certain that Marino & Merskin’s survey will have a similar effect on readers open to changing their minds.

Sentient Animals Do Not Just Live In The Present, John Webster

Animal Sentience

Sheep are particularly well-equipped with the cognitive and emotional skills appropriate to their phenotype and natural environment. These include spatial memory, the benefits of safety in numbers, and the ability to recognise special individuals in large flocks by sight and by sound. Marino & Merskin’s target article reviews convincing evidence on whether sheep are more or less clever than other mammalian species. Sheep are very good at being sheep. But sentient animals do not just live in the present. Their emotional state is not simply dictated by events of the moment. If they learn, they can cope; if not, they …