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Therapeutic Implications Of The Gut-Cns Axis In Promoting Recovery Following Cervical Spinal Cord Injury, Jessica Wilson

Theses and Dissertations--Neuroscience

Nearly 60% of all spinal cord injuries (SCI) occur at the cervical level. These high-level injuries can interrupt the descending respiratory pathways required for breathing. Indeed, therapies in animal studies have been successful at restoring breathing after SCI; however, these interventions appear to be more effective at chronic time points. One potential cause for this observation is the impact of the injury on the gut microbiome. Neurotrauma can induce gut dysbiosis, an imbalance of pathogenic and beneficial gut microbiota, which has previously been shown to negatively impact the central nervous system (CNS) and impair recovery. We aimed to build upon …

Peripheral And Central Glucose Flux In Type I Diabetes, Jelena Anna Juras

Theses and Dissertations--Neuroscience

Diabetes is a complex metabolic disorder, of which high blood glucose concentration is the primary hallmark. Type I diabetes mellitus (T1DM) is characterized by the lack of insulin production, due to a poorly understood autoinflammatory cascade. In the words of historian Barnett “Diabetes may no longer be a death sentence, but for more and more people in the 21st century, it will become a life sentence”, making it the focal point of many research groups. It is estimated that around 20 million individuals worldwide live with T1DM.

Effects of long-term chronically elevated blood glucose are not only seen in micro/macro-vascular …

Examining Human Apoe Genotype And Sex As Modulators Of Respiratory Plasticity In The Presence And Absence Of Spinal Cord Injury, Lydia Ella Strattan

Theses and Dissertations--Neuroscience

There are over 17,000 new spinal cord injuries (SCIs) every year in the Unites States alone. Almost 60% of these injuries occur at the cervical level, potentially leading to loss of function in a variety of sensory and motor systems including upper and lower limbs, respiratory, and autonomics. In addition to the physical and emotional costs, individuals who experience these higher level injuries also face a massive financial burden, incurring over $1 million in expenses during the first year after injury in addition to substantial yearly costs for the rest of their lifetime. A myriad of therapeutic approaches targeting plasticity …

Tgf-Β, Wnt, And Fgf Signaling Pathways During Axolotl Tail Regeneration And Forelimb Bud Development, Qingchao Qiu

Theses and Dissertations--Neuroscience

Tgf-β, Wnt, and Fgf signaling pathways are required for many developmental processes. Here, I investigated the requirement of these signaling pathways during tail regeneration and limb development in the Mexican axolotl (Ambystoma mexicanum).

Using small chemical inhibitors during tail regeneration, I found that the Tgf-β signaling pathway was required from 0-24 and 48-72 hours post tail amputation (hpa), the Wnt signaling pathway was required from 0-120 hpa, and the Fgf signaling pathway was required from 0-12hpa. Tgf-β1 was upregulated after amputation and thus may mediate Tgf-β signaling pathway during tail regeneration. Both Smad-mediated and non-Smad mediated Tgf-β signaling …

Autologous Peripheral Nerve Grafts To The Brain For The Treatment Of Parkinson's Disease, Andrew Welleford

Theses and Dissertations--Neuroscience

Parkinson’s disease (PD) is a disorder of the nervous system that causes problems with movement (motor symptoms) as well as other problems such as mood disorders, cognitive changes, sleep disorders, constipation, pain, and other non-motor symptoms. The severity of PD symptoms worsens over time as the disease progresses, and while there are treatments for the motor and some non-motor symptoms there is no known cure for PD. Thus there is a high demand for therapies to slow the progressive neurodegeneration observed in PD. Two clinical trials at the University of Kentucky College of Medicine (NCT02369003, NCT01833364) are currently underway that …

Neuroprotective Strategies Following Experimental Traumatic Brain Injury: Lipid Peroxidation-Derived Aldehyde Scavenging And Inhibition Of Mitochondrial Permeability Transition, Jacqueline Renee Kulbe

Theses and Dissertations--Neuroscience

Traumatic brain injury (TBI) represents a significant health crisis. To date there are no FDA-approved pharmacotherapies available to prevent the neurologic deficits caused by TBI. Following TBI, dysfunctional mitochondria generate reactive oxygen and nitrogen species, initiating lipid peroxidation (LP) and the formation of LP-derived neurotoxic aldehydes, which bind mitochondrial proteins, exacerbating dysfunction and opening of the mitochondrial permeability pore (mPTP), resulting in extrusion of mitochondrial sequestered calcium into the cytosol, and initiating a downstream cascade of calpain activation, spectrin degradation, neurodegeneration and neurologic impairment.

As central mediators of the TBI secondary injury cascade, mitochondria and LP-derived neurotoxic aldehydes make promising …

The Default Mode Network And Executive Function: Influence Of Age, White Matter Connectivity, And Alzheimer’S Pathology, Christopher A. Brown

Theses and Dissertations--Neuroscience

The default mode network (DMN) consists of a set of interconnected brain regions supporting autobiographical memory, our concept of the self, and the internal monologue. These processes must be maintained at all times and consume the highest amount of the brain’s energy during its baseline state. However, when faced with an active, externally-directed cognitive task, the DMN shows a small, but significant, decrease in activity. The reduction in DMN activity during the performance of an active, externally-directed task compared to a baseline state is termed task-induced deactivation (TID), which is thought to ‘free-up’ resources required to respond to external demands. …

Target-Directed Biosynthetic Evolution: Redirecting Plant Evolution To Genomically Optimize A Plant’S Pharmacological Profile, Dustin Paul Brown

Theses and Dissertations--Neuroscience

The dissertation describes a novel method for plant drug discovery based on mutation and selection of plant cells. Despite the industry focus on chemical synthesis, plants remain a source of potent and complex bioactive metabolites. Many of these have evolved as defensive compounds targeted on key proteins in the CNS of herbivorous insects, for example the insect dopamine transporter (DAT). Because of homology with the human DAT protein some of these metabolites have high abuse potential, but others may be valuable in treating drug dependence. This dissertation redirects the evolution of a native Lobelia species toward metabolites with greater activity …

The Intranasal Delivery Of Dnsp-11 And Its Effects In Animal Models Of Parkinson's Disease, Mallory J. Stenslik

Theses and Dissertations--Neuroscience

A major challenge in developing disease altering therapeutics for the treatment of Parkinson’s disease (PD) has been the delivery of compounds across the blood-brain barrier (BBB) to the central nervous system (CNS). While direct surgical infusion has been utilized to deliver compounds to the brain that don’t cross the BBB, issues of poor biodistribution in the CNS due in part to properties of the molecules being delivered and/or infusion device protocols have limited the widespread success of this invasive approach. To avoid the issues of surgically delivering compounds to the CNS, numerous studies have examined the use of intranasal administration …

Calpain 5: A Non-Classical Calpain Highly Expressed In The Cns And Localized To Mitochondria And Nuclear Pml Bodies, Ranjana Singh

Theses and Dissertations--Neuroscience

Calpain 5 (CAPN5) is a non-classical member of the calpain family. It lacks the EF-hand motif characteristic of the classical calpains, calpain 1 and 2, but retains catalytic and Ca²⁺ binding non EF domains. Tra-3, an ortholog of CAPN5, is involved in necrotic cell death in C.elegans; although specific role of CAPN5 has not been investigated in the mammalian CNS. I compared relative mRNA levels of calpains in rat CNS, which revealed that CAPN5 is the second most highly expressed calpain. We examined relative levels of CAPN5 from late embryonic day 18 to postnatal day 90 and …

Effects Of Intranasally Administered Dnsp-11 On The Central Dopamine System Of Normal And Parkinsonian Fischer 344 Rats, James H. Sonne

Theses and Dissertations--Neuroscience

Due to the blood-brain barrier, delivery of many drugs to the brain has required intracranial surgery which is prone to complication. Here we show that Dopamine Neuron Stimulating Peptide 11 (DNSP-11), following non-invasive intranasal administration, protects dopaminergic neurons from a lesion model of Parkinson’s disease in the rat. A significant and dose-dependent increase in an index of dopamine turnover (the ratio of DOPAC to dopamine) was observed in the striatum of normal young adult Fischer 344 rats by whole-tissue neurochemistry compared to vehicle administered controls.

Among animals challenged with a moderate, unilateral 6-hydroxy-dopamine (6-OHDA) lesion of the substantia nigra, those …

Post-Traumatic Sleep Following Diffuse Traumatic Brain Injury, Rachel K. Rowe

Theses and Dissertations--Neuroscience

Traumatic brain injury (TBI) is a major cause of death and disability throughout the world with few pharmacological treatments available for individuals who suffer from neurological morbidities associated with TBI. Cellular and molecular pathological processes initiated at the time of injury develop into neurological impairments, with chronic sleep disorders (insomnia, hypersomnolence) being among the somatic, cognitive and emotional neurological impairments. Immediately post-injury, TBI patients report excessive daytime sleepiness, however, discordant opinions suggest that individuals should not be allowed to sleep or should be frequently awoken following brain injury. To provide adequate medical care, it is imperative to understand the role …

Dynamic L-Glutamate Signaling In The Prefrontal Cortex And The Effects Of Methylphenidate Treatment, Catherine Elizabeth Mattinson

Theses and Dissertations--Neuroscience

The prefrontal cortex (PFC) is an area of the brain that is critically important for learning, memory, organization, and integration, and PFC dysfunction has been associated with pathologies including Alzheimer’s disease, schizophrenia, and drug addiction. However, there exists a paucity of information regarding neurochemical signaling in the distinct sub-regions of the PFC, particularly the medial prefrontal cortex (mPFC). The mPFC receives glutamatergic input from a number of brain areas, and functional glutamate signaling is essential for normal cognitive processes. To further understand glutamate neurotransmission, in vivo measurements of glutamate were performed in the cingulate cortex, prelimbic cortex, and infralimbic cortex …

Role Of Calcium And Nitric Oxide Synthase (Nos) In Brain Mitochondrial Dysfunction, Vidya Nag Nukala

Theses and Dissertations--Neuroscience

Mitochondria are essential for promoting cell survival and growth through aerobic metabolism and energy production. Mitochondrial function is typically analyzed using mitochondria freshly isolated from tissues and cells because they yield tightly coupled mitochondria, whereas those from frozen tissue can consist of broken mitochondria and membrane fragments. A method, utilizing a well-characterized cryoprotectant such as dimethyl sulfoxide (DMSO), is described. Such mitochondria show preserved structure and function that presents us with a possible strategy to considerably expand the time-frame and the range of biochemical, molecular and metabolic studies that can be performed without the constraints of mitochondrial longevity ex vivo …

Functional Properties Of L-Glutamate Regulation In Anesthetized And Freely Moving Mice, Kevin N. Hascup

Theses and Dissertations--Neuroscience

L-glutamate (Glu) is the predominant excitatory neurotransmitter in the mammalian central nervous system with involvement encompassing learning and memory, cognition, plasticity, and motor movement. Dysregulation of the glutamatergic system is implicated in several neurological disorders including Parkinson’s disease, Alzheimer’s disease, Huntington’s disease and amyotrophic lateral sclerosis. The mechanisms underlying these neurological disorders are not clear, but evidence suggests that abnormal Glu neurotransmission plays a role. Elevated levels of Glu in the synaptic cleft overstimulate the N-methyl-Daspartate receptor leading to excitotoxicity, which causes neuronal loss in chronic neurological diseases. What is less understood is the source for the elevated Glu levels. …