Neuroscience and Neurobiology Commons^™

A Flight Sensory-Motor To Olfactory Histamine Circuit Mediates Olfactory Processing Of Ecologically And Behaviorally Natural Stimuli, Samual P. Bradley

Graduate Theses, Dissertations, and Problem Reports (ETD)

Environmental pressures have conferred species specific behavioral and morphological traits to optimize reproductive success. To optimally interact with their environment, nervous systems have evolved motor-to-sensory circuits that mediate the processing of its own reafference. Moth flight behavioral patterns to odor sources are stereotyped, presumably to optimize the likelihood of interacting with the odor source. In the moth Manduca sexta wing beating causes oscillatory flow of air over the antenna; because of this, odorant-antennal interactions are oscillatory in nature. Electroantennogram recordings on antennae show that the biophysical properties of their spiking activity can effectively track odors presented at the wing beat …

Neuroimaging Of Real-World Audio-Visual Sensory Integration In High-Functioning Autism, Paula J. Webster

Graduate Theses, Dissertations, and Problem Reports (ETD)

Sensory processing differences are a prevalent aspect of autism spectrum disorder (ASD) that may contribute to core deficits of ASD such as repetitive behaviors as well as comorbidities including anxiety disorders. The ability to integrate information among our senses is required to comprehend the world around us and is crucial for the development of language, motor skills, and social communication. Prior studies have shown that individuals with autism differ from individuals without autism when presented with simple, non-natural audio-visual stimuli such as basic shapes accompanied by pure tones. Because the human brain processes non-natural and natural stimuli differently, more recent …

Automated And Standardized Tools For Realistic, Generic Musculoskeletal Model Development, Trevor Rees Moon

Graduate Theses, Dissertations, and Problem Reports (ETD)

Human movement is an instinctive yet challenging task that involves complex interactions between the neuromusculoskeletal system and its interaction with the surrounding environment. One key obstacle in the understanding of human locomotion is the availability and validity of experimental data or computational models. Corresponding measurements describing the relationships of the nervous and musculoskeletal systems and their dynamics are highly variable. Likewise, computational models and musculoskeletal models in particular are vitally dependent on these measurements to define model behavior and mechanics. These measurements are often sparse and disparate due to unsystematic data collection containing variable methodologies and reporting conventions. To date, …

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 …

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 …

Aptamer Functionalized Zinc Oxide Field Effect Transistors For Odor Detection, Michael D. Aldridge

Graduate Theses, Dissertations, and Problem Reports (ETD)

Odor detection and identification are complex processes, and tasks that currently only animals do well. There is a pressing need for an electronic nose, or eNose, with good sensitivity, selectivity, and speed that mimics that ability. Food quality control operations, environmental sensing, occupational safety, and the defense sectors all require systems that can rapidly and reliably detect trace levels of volatile organic compounds. The goal of this work is to create a biologically inspired device which can accurately detect and identify odors at concentrations consistent with the most sensitive biological systems.

In order to mimic a natural olfactory system, we …

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 …

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. …

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 …

Induction Of Cerebral Hyperexcitability By Peripheral Viral Challenge: Role Of Cxcl10 Chemokine, Tiffany J. Petrisko

Graduate Theses, Dissertations, and Problem Reports (ETD)

Peripheral viral infections are po­tent comorbid factors that exacerbate neuro­degene­ration. Although the under­lying mecha­nisms have not been defined, neuronal hyperexcitability has been established as an underlying feature. Our lab has developed a preclinical model in which a viral mimetic, poly­inosinic-poly­cytidylic acid (PIC) is injected in­tra­peritoneally to induce an anti-viral acute phase response (APR). APR in turn elicits robust neuronal hyperexcitability. The present study was undertaken to characterize molecular mechanisms that mediate the development of hyperexcitability in response to PIC challenge. The analysis of brain tissue after PIC challenge revealed a robust elevation of CXCL10 chemokine, indicating its putative role in …

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 …

Polarity And Competition In The Development Of The Calyx Of Held Terminal In The Medial Nucleus Of The Trapezoid Body In The Mouse, Paul Steven Holcomb

Graduate Theses, Dissertations, and Problem Reports (ETD)

In the auditory brainstem, the connection between globular bushy cells of the anteroventral cochlear nucleus and principal cells (PCs) of the medial nucleus of the trapezoid body (MNTB) is created by one of the largest nerve terminals in the central nervous system, the calyx of Held (CH). The characteristics of the CH:MNTB connection—a short developmental period (48-72 hours), accessibility for recording from pre- and postsynaptic components, and clear monoinnervated end point—make this system an ideal model system for studying nervous system development. Model systems undergo stereotyped stages of development, including exuberant overinnervation, competition between terminals, and a refinement of innervation …

The Integration Of Extrinsic And Intrinsic Neuromodulators In The Olfactory System, Kristyn M. Lizbinski

Graduate Theses, Dissertations, and Problem Reports (ETD)

Neuromodulation is a ubiquitous feature of neural systems, allowing flexible, context specific control over network dynamics by adjusting the biophysical and synaptic properties of neurons. Neuromodulation was first described in invertebrate motor systems and early work established a basic dichotomy for neuromodulation as having either an intrinsic origin (i.e. neurons that participate in network coding) or an extrinsic origin (i.e. neurons from independent networks). Although this dichotomy has been thoroughly considered in motor systems, it has received far less attention in sensory systems. Furthermore, nervous systems are continually subject to a dynamic cocktail of both intrinsic and extrinsic modulators. However, …