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Growth Factor Delivery From Fibrin Matrics Containing Affinity-Based Delivery Systems To Treat Peripheral Nerve Injury, Matthew Wood
Growth Factor Delivery From Fibrin Matrics Containing Affinity-Based Delivery Systems To Treat Peripheral Nerve Injury, Matthew Wood
All Theses and Dissertations (ETDs)
This thesis work sought to develop a biomaterial to further the understanding of affinity-based delivery and to serve as a potential treatment for peripheral nerve injury. The use of an affinity-based delivery system: ABDS) with growth factors in a nerve guidance conduit: NGC) was hypothesized to promote nerve regeneration and functional recovery following a critical nerve defect. Evaluation of affinity-based delivery using peptides with varying binding affinity for heparin determined that peptide binding affinity for heparin affected the release rate and biological activity of nerve growth factor: NGF) in vitro. The ABDS presented biologically active NGF, which promoted neurite extension …
Dissecting The Molecular Mechanisms Underlying Synpase Development And Neuronal Functions In Caenorhabditis Elegans, Shuo Luo
All Theses and Dissertations (ETDs)
The development and function of the nervous system is under delicate regulation of diverse tissue-derived signals in multi-cellular organisms. In Dr. Nonet's lab, I am using the model organism Caenorhabditis elegans to ask two basic questions: 1) How do different tissues in an organism coordinate to regulate neural functions and behaviors? 2) What controls the development of synapse, the basic unit of the nervous system? These questions divide my dissertation into three parts, with the first two parts related to the first question and the third part to the second question. In the first part of this dissertation, I present …
Mechanisms Of Feedback In The Visual System, Adam Eggebrecht
Mechanisms Of Feedback In The Visual System, Adam Eggebrecht
All Theses and Dissertations (ETDs)
Feedback is an ubiquitous feature of neural systems though there is little consensus on the roles of mechanisms involved with feedback. We set up an in vivo preparation to study and characterize an accessible and isolated feedback loop within the visual system of the leopard frog, Rana pipiens. We recorded extracellularly within the nucleus isthmi, a nucleus providing direct topographic feedback to the optic tectum, a nucleus that receives the vast majority of retinal output. The optic tectum and nucleus isthmi of the amphibian are homologous structures to the superior colliculus and parabigeminal nucleus in mammals, respectively. We formulated a …
A Quest For Meaning In Spontaneous Brain Activity - From Fmri To Electrophysiology To Complexity Science, Biyu He
All Theses and Dissertations (ETDs)
The brain is not a silent, complex input/output system waiting to be driven by external stimuli; instead, it is a closed, self-referential system operating on its own with sensory information modulating rather than determining its activity. Ongoing spontaneous brain activity costs the majority of the brain's energy budget, maintains the brain's functional architecture, and makes predictions about the environment and the future. I have completed three separate studies on the functional significance and the organization of spontaneous brain activity. The first study showed that strokes disrupt large-scale network coherence in the spontaneous functional magnetic resonance imaging: fMRI) signals, and that …
The Role Of Astrocyte Activation In Infantile Neuronal Ceroid Lipofuscinosis, Shannon Macauley-Rambach
The Role Of Astrocyte Activation In Infantile Neuronal Ceroid Lipofuscinosis, Shannon Macauley-Rambach
All Theses and Dissertations (ETDs)
Infantile neuronal ceroid lipofuscinoses: INCLs), or Batten Disease, is an inherited neurodegenerative lysosomal storage disorder affecting the central nervous system: CNS) during infancy or childhood. Hallmark pathological changes include accumulation of autofluorescent material, neuronal loss, cortical thinning, and brain atrophy, which ultimately lead to cognitive deficits, motor dysfunction, seizure activity, and blindness. INCL is the result of mutations in the CLN1 gene leading to a deficiency in the lysosomal enzyme, palmitoyl protein thioesterase 1: PPT1). A mouse model of INCL, the PPT1-deficient: PPT1-/-) mouse, was recently created by a targeted disruption in the CLN1 gene. The phenotype of the PPT1-/- …
The Mechanisms And Roles Of Feedback Loops For Visual Processing, Jing Shao
The Mechanisms And Roles Of Feedback Loops For Visual Processing, Jing Shao
All Theses and Dissertations (ETDs)
Signal flow in the brain is not unidirectional; feedback represents a key element in neural signal processing. To address the question on how do neural feedback loops work in terms of synapses, microcircuitry, and systems dynamics, we developed a chick midbrain slice preparation to study and characterize one important feedback loop within the avian visual system: isthmotectal feedbackloop. The isthmotectal feedback loop consists of the optic tectum: OT) and three nucleus isthmi: Imc, Ipc and SLu. The tectal layer 10 neurons project to ipsilateral Imc, Ipc and SLu in a topographic way. In turn Ipc and SLu send back topographical: …
Medial Temporal Lobe Structure And Function, Meghana Karnik
Medial Temporal Lobe Structure And Function, Meghana Karnik
All Theses and Dissertations (ETDs)
Medial Temporal Lobe Structure and Function by Meghana Sunil Karnik Doctor of Philosophy in Biology and Biomedical Sciences: Neuroscience) Washington University in St. Louis, 2009 Professor John G. Csernansky, Chairperson My main goal was to examine the relationship between brain structure and function, specifically medial temporal lobe structure and episodic memory, in various groups of subjects who had schizophrenia, were at risk for schizophrenia because of genetic and disease influences, or who were healthy, in order to explore the influence of genetic and disease influences on brain structure-function relationships. Most of what is known about the neural structures thought to …
Aggregation & Localization Of A Disease-Associated Prion Protein (Prp) Mutant, Andrea Rhonda Medrano
Aggregation & Localization Of A Disease-Associated Prion Protein (Prp) Mutant, Andrea Rhonda Medrano
All Theses and Dissertations (ETDs)
ABSTRACT OF THE DISSERTATION Aggregation & Localization of a Disease-Associated Prion Protein: PrP) Mutant by Andrea Rhonda Zaragoza Medrano Doctor of Philosophy in Biology and Biomedical Sciences: Genetics) Washington University in St. Louis, 2009 Professor David A. Harris, Chairperson Prion protein: PrP) is a GPI-anchored sialoglycoprotein involved in the pathogenesis of infectious and inherited forms of transmissible spongiform encephalopathies: TSEs). A nine-octapeptide insertional mutation in the prion protein: PrP) causes a fatal neurodegenerative disorder in both humans and transgenic mice. To determine the precise cellular localization of this mutant PrP: designated PG14), we have generated transgenic mice expressing PG14-EGFP, a …
Feature Topography And Sound Intensity Level Encoding In Primary Auditory Cortex, Paul Watkins
Feature Topography And Sound Intensity Level Encoding In Primary Auditory Cortex, Paul Watkins
All Theses and Dissertations (ETDs)
The primary auditory cortex: A1) in mammals is one of the first areas in the neocortex that receives auditory related spiking activity from the thalamus. Because the neocortex is implicated in regulating high-level brain phenomena, such as attention and perception, it is therefore important in regards to these high-level behaviors to understand how sounds are represented and transformed by neuronal circuits in this area. The topographic organization of neuronal responses to auditory features in A1 provides evidence for potential mechanisms and functional roles of this neural circuitry. This dissertation presents results from models of topographic organization supporting the notion that …