Physiology Commons^™

Prefrontal Coding Of Naturalistic Working Memory: Mechanisms During Normal Maintenance And Modelled Disease, Megan P. Roussy

Electronic Thesis and Dissertation Repository

Neural activity in the primate lateral prefrontal cortex (LPFC) has been causally linked to working memory (WM) ⁠— the brief maintenance and mental manipulation of information. Primates use WM to perform tasks in complex contexts; however, neural mechanisms of WM and the pathophysiology related to WM deficits have traditionally been studied using simple tasks that deviate from naturalistic conditions. This raises the question, how is WM processed in naturalistic conditions? To explore this, I trained two macaque monkeys on a spatial WM task set in a naturalistic virtual environment. During the task, a target was presented in 1 of 9 …

Cortisol Receptor Sensitivity As A Risk Factor For Depression, Michela Michielli

Honors Theses

In 2020, the World Health Organization reported over 264 million people across the world were suffering from depression. Studies have demonstrated that one source of depression is a hormonal imbalance involved in the stress response. Cortisol is a stress hormone regulated by the Hypothalamic-Anterior-Pituitary (HPA) Axis. Its effects on the stress response and other metabolic activities in the body are exerted through the glucocorticoid and mineralocorticoid receptors (GR and MR respectively).

Our research has examined mutations known as single-nucleotide-polymorphisms (SNPs) relating to cortisol-receptor sensitivity and the behavior of cortisol in the body to investigate the link between cortisol activity and …

On The Roles Of Trait Anxiety And Toll Like Receptor 4 In Amphetamine Sensitization In Adolescent Male Rats, Corey A. Calhoun

Graduate Doctoral Dissertations

Mammalian adolescence can be a difficult transition from childhood to adulthood, where increases in impulsivity and novelty- and risk-seeking are combined with heightened affect and elevated sensitivity to stress. Indeed, during adolescence, first drug use patterns emerge and in the continental United States, increasing misuse of amphetamines has been observed in adolescent youth. Myriad neural mechanisms underlie this shift in adolescence, including the dynamic remodeling of the mesocorticolimbic (MCL) pathway. Repeated drug administration affects neuroimmune substrates within the MCL circuit including toll-like receptor 4 (TLR4)Advances in addiction neuroscience indicate that drugs of abuse activate neural TLR4 and implicate glial TLR4 …

Linking Spinal Cord Circuits With Upper Limb Sensorimotor Control In Adults With Cerebral Palsy, Saihari Dukkipati

Theses & Dissertations

Cerebral palsy (CP) is the most common neurological disorder originating in childhood, but most of the people living with CP are currently adults. While people with CP continue to get older, the amount of research focused on adults has been rather limited. The early childhood insults leading to CP are thought to originate in the brain, but the effects on the entire neuromuscular system across the lifespan have only recently started to be explored. Of note, recent neuroimaging evidence suggests that the cervical spinal cord structure is atypical in adults with CP. However, it is largely unclear how the neurophysiological …

The Effects Of Acute Exercise Intensity On Retrieval-Induced Forgetting, Geoffrey Reliquias

Honors Theses

Previous research has indicated that aspects of cognitive inhibition may be enhanced after engaging in acute exercise. Notably, cognitive inhibition has been theorized as a potential mechanism for a form of active forgetting known as retrieval-induced forgetting (RIF). Given that cognitive inhibition may explain the RIF phenomenon, and is also influenced by exercise, it is plausible that acute exercise may directly influence RIF. To our knowledge, only one study has examined whether acute exercise has an effect on RIF. The findings of that study did not find a statistically significant effect for RIF; however, we believe that the rather small …

Neural Substrates Of Homing Pigeon Spatial Navigation: Results From Electrophysiology Studies, Gerald E. Hough

Faculty Scholarship for the College of Science & Mathematics

Over many centuries, the homing pigeon has been selectively bred for returning home from a distant location. As a result of this strong selective pressure, homing pigeons have developed an excellent spatial navigation system. This system passes through the hippocampal formation (HF), which shares many striking similarities to the mammalian hippocampus; there are a host of shared neuropeptides, interconnections, and its role in the storage and manipulation of spatial maps. There are some notable differences as well: there are unique connectivity patterns and spatial encoding strategies. This review summarizes the comparisons between the avian and mammalian hippocampal systems, and the …

New Treatment For Multiple Sclerosis Could Halt Disease Progression Without Weakening Immune System, Carter Helquist, Dario Mizrachi

Library/Life Sciences Undergraduate Poster Competition 2022

• Multiple Sclerosis (MS) is a debilitating neurological and autoimmune disease in which immune cells cause demyelination of axons in nervous tissue.
• Current treatments for the disease are principally aimed at weakening the immune system to therefore weaken the autoimmune attack on the brain. This leaves patients prone to other sicknesses.
• We seek a treatment that prevents the immune cells from entering the central nervous system (CNS) thereby protecting its cells.
• We can prevent immune cells from entering the CNS by strengthening the blood brain barrier through targeting claudin 5 proteins in the tight junctions.
• This new treatment could mean increased …

The Neurobiological Underpinnings Of Depression-Related Maternal Behavior Deficits, Sarah B. Winokur

Doctoral Dissertations

Maternal caregiving is a dynamic process that requires extensive cognitive, motivational, and affective processing. World-wide, approximately 17% of mothers are diagnosed with postpartum depression yearly (Wang et al., 2021). Untreated, mothers with postpartum depression experience deficits in cognition, motivation, affect, and parenting (Arteche et al., 2011; Dix and Meunier, 2009; Lovejoy et al., 2000). Although postpartum depression is related to compromised parenting, to date, few studies have examined the neurobiological mechanisms by which maternal behavior is compromised in postpartum depression (Field, 2010; Murray et al., 1996)_. This dissertation aims to examine how depression neurobiologically disrupts parenting abilities. These studies …

Strong Inferences About Pain In Invertebrates Require Stronger Evidence, Edgar T. Walters

Animal Sentience

Evidence for sentience in animals distantly related to humans is often sought in observations of behavioral and neural responses to noxious stimuli that would be painful in humans. Most proposed criteria for painful sentience in “lower” animals such as decapod crustaceans have no necessary links to the affective (“suffering”) component of pain. The best evidence for painful affect in animals is learned aversion to stimuli associated with noxious experience, and conditioned preference for contexts associated with relief from aversive consequences of noxious experience, as expressed in voluntary behavior. Such evidence is currently lacking for any invertebrate except octopus.

Characterizing And Investigating The Electrophysiological Properties Of The Plastic Cricket Auditory System In Response To Cooling, Hannah Tess Scotch

Honors Projects

The auditory system of the Mediterranean field cricket (Gryllus bimaculatus) is capable of profound compensatory plasticity. Following deafferentation due to the loss of an auditory organ, the dendrites of intermediate auditory neuron Ascending Neuron 2 (AN-2) grow across the midline and functionally connect to contralateral afferents. The loss of the auditory organ can be mimicked with reversible cold-deactivation, in which cooled Peltier elements silence the auditory organ and its afferents. Though this would presumably prevent AN-2 from firing, cooling instead induces a novel firing pattern called DOPE (delayed-onset, prolonged-excitation). In this study, intracellular physiological recordings were completed before, …

Mechanistic Insight Into Chronic Stress-Induced Cerebrovascular Dysfunction, Emily Nicole Burrage

Graduate Theses, Dissertations, and Problem Reports

Despite decades of research psychological stress remains a prevalent problem in society, often diminishing quality of life and increasing the risk of developing dementia. The brain plays a central role in the response to stress and as it is unable to store energy substrates, the brain relies heavily on dynamically regulated blood flow. Therefore, it is important that there is a tight coupling between neural activity and cerebral blood flow to meet metabolic demands and maintain critical brain function. It has been established that chronic psychological stress has detrimental effects on cerebrovascular function, potentially through increased superoxide anion production through …

Microglia Distribution In The Lateral Ventricles Following Treatment Of Lysolecithin Model Of Multiple Sclerosis, Spencer James Wilson

Browse all Theses and Dissertations

Multiple sclerosis (MS) affects an estimated one million people in the US alone (Wallin et al., 2019). We modeled MS in rats using lysolecithin injection into the corpus callosum to diminish motor function unilaterally through demyelination, meanwhile treating the injury with Fluoxetine, Ibuprofen, and ascorbic acid (FIAA) to increase neurogenesis and oligodendrogenesis. Motor function was assessed using the Montoya Staircase test pre- and post-surgery. Motor capabilities recovered in the contralateral limb, but not in the ipsilateral, and recovery was not significantly affected by treatment. We identified microglia by CX3CR1 and examined its distribution in the adult neurogenic niche, the SVZ …

Evaluation Of A Monosynaptic Spinal Circuit In Multiple Mouse Models Of Amyotrophic Lateral Sclerosis, Maura A. Curran

Browse all Theses and Dissertations

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease. To date, there are no significant disease-modifying treatments, and one limiting factor in treatment is the amount of time it takes for a patient to receive a diagnosis of ALS. This study examined multiple mouse models before symptom onset to help identify early changes in a reflex circuit of ALS mice. Dorsal root stimulation of the sacral spinal cord in multiple models ALS mouse models showed changes in the resulting ventral root compound action potential amplitude, latency, and ability to maintain synaptic depression. These data also suggest that a mouse model …

Use Of Forelimb Asymmetry In The Analysis Of Cns Recovery From A Demyelination Event, Joseph C. Hinkle

Browse all Theses and Dissertations

Using forelimb asymmetry analysis along with Montoya Staircase methodology we tested how a fluoxetine simvastatin ascorbic acid drug cocktail would affect recovery from a demyelinating event in a rat model, with the hypothesis that if administered then it would help female recovery but hinder male recovery. It was found that a fluoxetine simvastatin and ascorbic acid drug cocktail did not significantly enhance recovery from a demyelination model injury in female rats, and that the same drug cocktail significantly slowed male rat recovery from the same type of injury. It was also apparent that the more effective methodology for investigating this …

Examining The Diverse Effects Of Pi4ks On Synaptic Transmission And Morphology Phenotypes In Drosophila Melanogaster, Claire Richter Gorey

Electronic Theses and Dissertations

Phosphoinositides (PI) are lipid molecules reversibly phosphorylated by kinases at the 3’, 4’ and 5’ -OH groups of their myoinositol ring, producing seven PI species. PIs act in a dynamic and acute manner at the synapse, facilitated by multiple kinases that synthesize their respective PI species at the precise location and time. There are three phosphatidylinositol 4-kinase (PI4K) genes that encode three different PI4K enzymes (PI4KII, PI4KIIIβ (fwd) and PI4KIIIα) to synthesize PI4P (converted to PIP2), serving vital functions at the synapse. PIs participate in signaling events, protein recruitment, marking membrane identity, regulating channels and transporters, synaptic growth, …