Life Sciences Commons^™

Neural Responses To Magnetic Orientation Information In Songbirds, Madeleine Ir Brodbeck

Electronic Thesis and Dissertation Repository

Effective navigation and orientation is essential for animals to survive. The study of migratory birds provides insights into these processes, particularly through mechanisms like the geomagnetic compass, which uses Earth's magnetic field for directional information. A brain region in songbirds relevant to this is cluster N, known for its potential role in processing geomagnetic information. Notably, cluster N appears exclusive to nocturnally migratory birds, being active solely at night, and lesion studies reveal that an intact cluster N is necessary for geomagnetic compass orientation. However, given the scarcity of empirical data concerning cluster N, substantial questions persist regarding its function. …

The Modulation Of Lfp Characteristics In The Freely Moving Common Marmoset, William Jm Assis

Electronic Thesis and Dissertation Repository

The hippocampus is a neural structure critical for navigation. Neurons in this region, along with others, create a functional network which generates large-amplitude modulations known as local field potential (LFP) activity. Prior LFP research has predominantly used rodent animal models, however recent studies have shown that frequencies associated with navigation in other mammals do not correlate to those of the rodent. We hypothesized that LFP characteristics in the common marmoset are modulated by the speed and axis of travel of the animal. Two marmosets were placed in a free moving 3-dimensional environment where movement and neurological activity were recorded. Results …

Withdrawal From Voluntary Oral Methamphetamine Reveals Female Specific Susceptibilities To Behavioral Deficits And Neurochemical Perpetuators Of Neurotoxicity And Drug Seeking Behavior, Nicoletta K. Memos

Dissertations, Theses, and Capstone Projects

MA is a potent, highly addictive psychomotor stimulant known to produce neurotoxic effects on the brain leading to neurological impairments^1-6 characterized by neurodegeneration of dopaminergic fibers, cell bodies and pathways, as well as brain regions such as the hippocampus, frontal cortex, and midbrain^1,5.

In MA addiction, women are more vulnerable to the behavioral and cognitive effects of MA compared to men. Adult human literature reveals gender differences in usage patterns and women demonstrate increased vulnerability to the neurotoxic effects and health effects of MA use. Women begin drug use at an earlier age, escalate drug use quicker, …

The Effects Of Astrocytic Derived Insulin-Like Growth Factor (Igf-1) On Cognition And Astrocytes, Destiny Wilson

Honors Theses

Insulin-like growth factor 1 (IGF-1) is a neuroendocrine signaling hormone that plays a vital role in growth and development, as well as learning and memory. Inhibition of this hormone results in cognitive impairments like those seen with age-related decline. While a majority of research has focused on the role of IGF-1 on neurons, the role of astrocytes still needs to be explored. Our research investigates how astrocytes and cognition are affected as a result of direct regulation of localized IGF-1 production in early development and after puberty. Preliminary studies in our laboratory established a connection between IGF-1 and glial fibrillary …

Voluntary Oral Methamphetamine Reveals Susceptibilities To Spatial Memory Deficits, Decreased Dopamine Marker Expression And Increased Neuroinflammation In The Hippocampus Of Male And Female Mice, Jorge A. Avila

Dissertations, Theses, and Capstone Projects

Methamphetamine is an addictive illicit psychostimulant that produces lasting neurochemical and behavioral changes. The mechanisms underlying these deficits have been characterized in animal models using extremely high doses. Currently, better translational models are needed to understand the onset and progression of these deficits that more accurately reflect the gradual and voluntary dosing parameters as chosen by an abuser. To that end, a new model of methamphetamine administration, labeled Voluntary Oral Methamphetamine Administration (VOMA), offers a means to examine the progression of neurotoxicity, behavioral deficits, and the addiction process through a voluntary consumption framework.

Female populations show consistent vulnerabilities to methamphetamine, …

Interhemispheric Communication And Lateralization In The Mouse Hippocampus, Jake Jordan

Dissertations, Theses, and Capstone Projects

The hippocampus is essential for memory and spatial navigation. Many theories have been proposed to explain how the hippocampus contributes to cognition; however, none has fully explained relevant neurophysiological and behavioral data. Hemispheric lateralization of hippocampal function has been reported in humans and in rodents, and lateralization of hippocampal neural circuitry has been reported in rodents. Most theories of hippocampal function fail to consider the hippocampus as a bilateral structure with hemispheric differences. Further, proposed theories of hippocampal lateralization have their own limitations in explaining empirical data concerning left/right function. Little is known about communication between the hippocampi across hemispheres. …

Exploring The Role Of Insulin Receptor Signaling In Hippocampal Learning And Memory, Neuronal Calcium Dysregulation, And Glucose Metabolism, Hilaree N. Frazier

Theses and Dissertations--Pharmacology and Nutritional Sciences

In the late 90’s, emerging evidence revealed that the brain is insulin-sensitive, highlighted by broad expression of brain-specific insulin receptors and reports of circulating brain insulin. Contemporary literature robustly supports the role of insulin signaling in normal brain function and suggests that insulin-related processes diminish with aging, evidenced by decreased signaling markers, reduced insulin receptor density, and lower levels of insulin transport across the blood-brain barrier. In the context of pathological cognitive decline, clinical trials using intranasal insulin delivery have reported positive outcomes on memory and learning in patients with mild cognitive decline or early-stage Alzheimer’s disease. However, while the …

Object Processing In The Medial Temporal Lobe: Influence Of Object Domain, Anna Blumenthal

Electronic Thesis and Dissertation Repository

We live in a rich visual world, surrounded by many different kinds of objects. While we may not often reflect on it, our ability to recognize what an object is, detect whether an object is familiar or novel, and bring to mind our general knowledge about an object, are all essential components of adaptive behavior. In this dissertation, I investigate the neural basis of object representations, focusing on medial temporal lobe (MTL) structures, namely, perirhinal cortex, parahippocampal cortex, and hippocampus. I use what type of thing an object is, or more specifically, the broader category (e.g., “face” or “house”) or …

Short-Term Activity-Dependent Changes In Schaffer Collateral Axon Function, Benjamin Michael Owen

Theses, Dissertations and Capstones

Schaffer collaterals are the unmyelinated axons of pyramidal neurons in the CA3 area of the hippocampus, a brain structure essential for memory formation. Schaffer collateral axons conduct electrical signals in the form of action potentials from CA3 pyramidal cells to synaptic terminals in area CA1. The fidelity with which these axons conduct action potentials determines the nature of the information which can be transmitted between areas CA3 and CA1. Conduction fidelity may be affected by both normal and abnormal patterns of firing, fluctuations in ion concentration, and some drugs and toxins. In this dissertation, I examined the function of Schaffer …