Neuroscience and Neurobiology Commons^™

Investigating Mechanisms In Nociceptors Driving Ongoing Activity And Ongoing Pain, Elia Lopez

Dissertations and Theses (Open Access)

Ongoing (apparently spontaneous) pain at rest is a major complaint of patients suffering from many forms of acute and chronic pain, including acute and persistent postsurgical pain. Accumulating evidence suggests ongoing activity in nociceptors is a major driver of ongoing pain. Ongoing activity can be generated in sensory neurons in the absence of sensory generator potentials if one or more of three neurophysiological alterations occur – prolonged depolarization of resting membrane potential (RMP), hyperpolarization of action potential (AP) threshold, and/or increased amplitude of depolarizing spontaneous fluctuations of membrane potential (DSFs) to bridge the gap between RMP and AP threshold. Cellular …

The Effects Of Acute Exercise On Retrieval Induced Forgetting, Walter Simpson

Honors Theses

Retrieval Induced Forgetting (RIF) is a type of active forgetting that may play beneficial and detrimental roles in long-term memory. The benefit of the retrieval of certain information is that information will become more readily available following subsequent retrieval; a concept termed the retrieval practice effect (RP). The detrimental effect of RIF may be that, upon the subsequent recall of certain information, related information may be inhibited from recall. The effects and mechanisms of RIF have remained a topic of debate among neuroscientists, psychologists, and other related scholars. The goal of this study was to evaluate the effects of acute …

The Effects Of Myelin On Macrophage Activation Are Phenotypic Specific Via Cpla2 In The Context Of Spinal Cord Injury Inflammation, Timothy J. Kopper, Bei Zhang, William M. Bailey, Kara E. Bethel, John C. Gensel

Physiology Faculty Publications

Spinal cord injury (SCI) produces chronic, pro-inflammatory macrophage activation that impairs recovery. The mechanisms driving this chronic inflammation are not well understood. Here, we detail the effects of myelin debris on macrophage physiology and demonstrate a novel, activation state-dependent role for cytosolic phospholipase-A2 (cPLA₂) in myelin-mediated potentiation of pro-inflammatory macrophage activation. We hypothesized that cPLA₂ and myelin debris are key mediators of persistent pro-inflammatory macrophage responses after SCI. To test this, we examined spinal cord tissue 28-days after thoracic contusion SCI in 3-month-old female mice and observed both cPLA₂ activation and intracellular accumulation of lipid-rich myelin …

Extracellular Vesicles From Uvb Irradiated Keratinocytes Contain Cyclobutane Pyrimidine Dimers, Meghana Reddy Ginugu

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Ultraviolet (UV) radiation induces the formation of cyclobutane pyrimidine dimers (CPDs) in genomic DNA, which are normally removed by nucleotide excision repair. However, the fate of these adducts remain largely unexplored. Detection of these photoproducts in body fluids could act as a predictor of UV exposure and enable a better understanding of the pathogenesis of photosensitive skin diseases, such as lupus. Using cultured human keratinocytes exposed to UVB radiation in vitro, ultracentrifugation of cell culture supernatants, and immunodot blot analysis of isolated DNA, we have found that a small fraction of CPDs is released from cells in a dose- and …

Open Neuroscience Initiative, Austin Lim

College of Science and Health Full Text Publications

The Open Neuroscience Initiative is a free-to-use textbook

This project began as a means to overcoming the financial burden that face undergraduate neuroscience students when buying textbooks. By compiling and writing a completely free-to-access textbook that covers the foundations of a typical college introduction to neuroscience course, students would have one less obstacle to overcome in their educational career, allowing them to focus their valuable time and attention on learning rather than finances. To make this project a reality, I began with a humble tweet in May 2019 that managed to gain a tiny bit of traction among the neuroscience …

Muscarinic Excitation Of Dopamine Neurons In The Ventral Tegmental Area Via Activation Of A Trpc-Like Cation Conductance, Yu Tzu Chen

Theses and Dissertations

Dopaminergic (DA) neurons in the ventral tegmental area (VTA) play a crucial role in reward and motivational behaviors, including the development of drug addictions. VTA DA neurons receive excitatory cholinergic inputs from the mesopontine tegmentum. Blockage of the M5 muscarinic receptor in DA neurons has been shown to attenuate drug-induced DA release and abuse-related behaviors, but the molecular mechanism is unknown. In this study, experiments were designed to identify the electrophysiological effects of muscarinic agonism in the modulation of action potential kinetics and firing patterns in VTA DA neurons of mice. Pharmacology of the muscarinic receptor-evoked current was also characterized. …

Myelin, Cpla2, And Azithromycin: Modulation Of Macrophage Activation In Spinal Cord Injury Inflammation, Timothy J. Kopper

Theses and Dissertations--Physiology

Spinal cord injury (SCI) produces a chronic inflammatory state primarily mediated by macrophages consisting of resident microglia and infiltrating monocytes. These chronically activated SCI macrophages adopt a pro-inflammatory, pathological state that continues to cause additional damage after the initial injury and inhibits recovery. While the roles of macrophages in SCI pathophysiology are well documented, the factors contributing to this maladaptive response are poorly understood. Here, we identify the detrimental effects of myelin debris on macrophage physiology and demonstrate a novel, activation state-dependent role for cytosolic phospholipase-A2 (cPLA₂) in myelin- mediated potentiation of pro-inflammatory macrophage activation. Macrophage- mediated inflammatory …

Estrogen Disruption Of Hypothalamic Neural Activity, Princess Dickson

Cal Poly Humboldt theses and projects

The brain is highly dependent on the endocrine system for proper neurodevelopment, as it plays a key role in many biological processes. Bisphenol A is a chemical found in plastics that has the potential to mimic the effects of Estrogen in the body, at least weakly. People interact with plastic that contains BPA regularly, and people are at risk for exposure even before being born. The abundance of BPA, along with other exogenous estrogens, makes examining the relationship between early exposure and changes in brain activity imperative. The current study aims to establish a relationship between disrupted estrogen function and …

Opioid Use Disorder: The Timeline For Medication Assisted Therapy, Alexander Cristofori

Capstone Showcase

Opioid Use Disorder is patterns of opioid use leading to withdrawal, giving up important life events in order to use opioids, and excessive time spent using opioids, to name a few diagnostic criteria. The clinical progression of the disorder involves periods of acute exacerbation and remission that are cyclic in nature. Treatment is most effective when it includes both pharmacological and psychosocial modalities, referred to as medication assisted therapy (MAT). Three drugs used commonly in MAT-based treatment for OUD from oldest to newest include Methadone, Buprenorphine-naloxone, and Naltrexone. Treatment program models that prioritize total abstinence from the addictive substance attached …

Effects Of Fluoxetine/Simvastatin/Ascorbic Acid Combination Treatment On Neurogenesis And Functional Recovery In A Model Of Multiple Sclerosis, Olivia Cameron Webb

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Whereas immune modulation has proven beneficial in multiple sclerosis (MS), we hypothesized that targeting down-stream modulators of neurogenesis and subsequent remyelination may offer an additional, if not superior, point of intervention in an attempt to repair damage and recover lost function. As such, the present study assessed the effectiveness of 30-day administration of the drug combination fluoxetine (5 mg/kg), simvastatin (1 mg/kg), and ascorbic acid (50 mg/kg) (FSA) on an early marker of neurogenesis, doublecortin (DCX), and functional recovery using the Montoya Staircase following lysolecithin-induced focal demyelination of the corpus callosum in middle-aged (10-11 month) male and female rats. Lysolecithin …

A Novel Method For Analysis Of Proprioceptor Sensory Neuron Subtypes In The Mouse Dorsal Root Ganglia, Delaney C. Grant

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Proprioceptive sensory neurons encode critical mechanosensory information that helps determine how the body interacts with the outside world and monitors the proper execution of motor movements. Housed in skeletal muscles lie specialized mechanoreceptors that are critical to this feedback loop: muscle spindles supplied by group Ia & group II afferents, and Golgi tendon organs supplied by group Ib afferents relay information regarding changes in muscle force, length, and tension. All three afferent subtypes originate in the muscle and travel to the dorsal root ganglia, relaying information to the central nervous system. GTO and MS proprioceptive afferent subtypes have been identified, …

Potential Involvement Of Micro Vesicle Particles In The Synergistic Effects Of Ultraviolet-B Radiation And Platelet -Activating Factor Receptor Agonists On Cytokine Production, Shweta Bhadri

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Cytokines play a pivotal role in regulating inflammation, which is a condition that makes the tissue vulnerable to different pathological and physiological conditions. Thus, how cytokines are regulated is an important area of study. Skin that receives ultraviolet B radiation (UVB), a major pro-oxidative stressor, results in the release of multiple cytokines and chemokines like tumor necrosis factor (TNF)-alpha and interleukin (IL)-8. Previous studies from our group and others have demonstrated synergistic release of TNF-alpha when UVB is combined with IL-1 or the lipid mediator Platelet-activating factor (PAF). Of interest, subcellular microvesicle particles (MVP) have been proposed to play an …

Morphological Changes In Dorsal Root Ganglia Macrophages Associated With Neuropathic Pain Mechanisms Suggest A Novel Target For Chronic Pain Therapy, Emily Kussick

CMC Senior Theses

The present study examined morphological changes in the dorsal root ganglia (DRG) following an innate immune stimulus. The importance of the DRG has increasingly become recognized in pain processing as more than just the home of primary afferent cell bodies. All sensory information passes through the DRG via the primary afferents, and on to the spinal cord. The primary afferents synapse with second-order neurons in the spinal cord that ascend towards the brain, where they transmit the pain signal to the limbic forebrain and/or the somatosensory cortex for processing. The DRG is an interesting niche to study at as it …

Prenatal Alcohol Exposure Alters Transcriptional Expression Of Stress And Tlr4-Related Immune Signaling Factors In The Brain Following Early Life Stress, Chaselyn D. Ruffaner-Hanson

Biomedical Sciences ETDs

Background: Depression and anxiety disorders, believed to be caused by stress-related neuropeptides and pro-inflammatory molecules in the brain, are prevalent comorbidities of fetal alcohol spectrum disorders (FASD).

Methods: Brain tissue was collected following a 4-hour maternal separation stress during the early postnatal period, postnatal days 10 and 12, from mice subjected to 1^st and 2^nd trimester prenatal alcohol exposure (PAE).

Hypothesis: We hypothesized that PAE leads to glucocorticoid receptor insensitivity, stress molecule overexpression, and potentiated toll-like receptor 4 (TLR4) pathway inflammatory responses in the brain following early life stress.

Results: PAE and stress increased mRNA expression of TLR4 …

Sexually Dimorphic Oxytocin Receptor-Expressing Neurons In The Anteroventral Periventricular Nucleus Regulates Maternal Behavior, Kaustubh Sharma

LSU Doctoral Dissertations

The neurohypophysial hormone oxytocin is involved in the regulation of social behaviors, including social recognition, pair bonding, and sex-specific parental behaviors in a variety of species. Oxytocin triggers these social behaviors by binding to oxytocin receptors (OXTR) in various parts of the brain. Oxytocin-induced sex-typical behavior, therefore, suggests a sexual dimorphic distribution of OXTR in the brain. In recent years, the oxytocin system in the brain received tremendous attention as a potential pharmacological target for treatment of many psychiatric disorders, such as anxiety, autism spectrum disorders, and even sex-specific psychiatric disorder like postpartum depression (PPD). An important problem and a …

Mathematical Modelling Of Temperature Effects On The Afd Neuron Of Caenorhabditis Elegans, Zachary Mobille, Rosangela Follmann, Epaminondas Rosa

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.

Effect Of Ambient Temperature On Recovery Of Surgically Instrumented Sprague-Dawley Rats, Gianna Mangone

Senior Honors Projects, 2020-current

Based on current guidelines for housing rodents after surgical instrumentation, rodents may be housed at temperatures that hinder surgical recovery and cause thermal stress– room temperature (21°C) being one of them. Rodents are often housed at room temperature since this temperature is easy for humans to be caring for them. However, if recovering rodents are thermally stressed, experimental results will be confounded. To address this issue, Sprague-Dawley rats were surgically instrumented with radiotelemtry thermoprobes (Data Sciences, #TA-10F40) to monitor their core temperatures, then housed at one of five temperatures to assess the effect ambient temperature had on multiple aspects of …

Amygdala And Neocortical Structural Volume Analysis In The Shank3b Mutant Mouse Model Of Autism Spectrum Disorder, Preet Sawhney

Honors Scholar Theses

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder that is characterized by abnormal social behavior, deficits in communication, and motor stereotypy. The SHANK3 gene, responsible for the generation of a scaffolding protein that is integral for the development of synapses, has been identified as one of the primary candidate genes implicated in the disorder. Shank3B is the rodent homolog for this gene. Research has shown that when this gene is disrupted in rodent models (e.g., via knock-out (KO)), ASD-like behaviors result. These include deficits in social interaction, increased anxiety, and repetitive self-grooming. The current study aimed to identify a physiological …

Safe Sleep: Developmental Implications For Hospitalized Infants, Katherine Kohlsaat

Senior Honors Projects

The rate at which an infant develops both physically and cognitively is significant during sleep, as this is the time when the entire body can dedicate its efforts to this cause. Parents of healthy infants follow the guidelines set by the American Academy of Pediatrics (AAP) relating to safe sleep, and since their introduction in 1992, the rate of Sudden Infant Death Syndrome (SIDS) has decreased by 40% (Center for Disease Control and Prevention, 2016). However, if an infant has been hospitalized since birth due to necessary invasive procedures such as open-heart surgery, these protocols cannot be initially implemented. Common …

Microglia-Neuron Interactions In A Mouse Model Of Low Grade Neuroepithelial Tumors, Veolette Hanna

Honors Scholar Theses

Microglia are the macrophages of the brain and spinal cord, playing an important role in the immune response to disease states of the nervous system. This study conducts an investigation on the activity of microglia in response to low grade neuroepithelial tumors. Using mouse models and microglial markers, a qualitative and quantitative analysis of microglia activation, migration, and invasion within the brain cortex during early stages of tumor development was conducted. It was found that the presence of a low grade neuroepithelial tumor in the cortex of one hemisphere of the brain causes significant microglia activation in comparison to the …

The Effect Of Physical Activity And S-Equol On Neurogenesis In The Hiv-1 Transgenic Rat, Jeremy M. Lapointe

Senior Theses

The aim of this thesis is to investigate the effect of physical activity and the administration of s-equol on rates of neurogenesis in HIV-1 transgenic rats. HIV-1 is a neurodegenerative disease that leads to the wide range of cognitive impairment described as HAND. Neurogenesis is a newly discovered process that involves the birth of new neurons during our adult life within the dentate gyrus of the hippocampus. Therefore, inducing neurogenesis may be a proper therapeutic that can mitigate some of the cognitive destruction seen as a result of HIV-1 infection. Physical activity has shown to increase the rate of neurogenesis …

Protocol Development And Optimization For Rnls Mouse Characteristic Assessment, Hasan Farid

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Protocol development and optimization are vital in the scientific method process. By having accurate protocols, one can properly assess the characteristics of their animal model for any given experiment. One animal newly adopted in our lab was the novel regulatable nuclear localization sequence (rNLS) mouse model. This novel mouse model displays symptoms of Amyotrophic Lateral Sclerosis (ALS) and Frontotemporal dementia (FTD), after the accumulation of the hTDP-43 (TAR DNA-binding protein 43) aggregate in the central nervous system. The expression of this protein occurs after the removal of deoxycycline from the mouse’s food source. Once the removal of the drug, this …

Focal Augmentation Of Somatostatin Interneuron Function And Subsequent Circuit Effects In Developmentally Malformed, Epileptogenic Cortex, Nicole Ekanem

Theses and Dissertations

Drug-resistant epilepsy (DRE) is a common clinical sequela of developmental cortical malformations such as polymicrogyria. Unfortunately, much remains unknown about the aberrant GABA-mediated circuit alterations that underlie DRE's onset and persistence in this context. To address this knowledge gap, we utilized the transcranial freeze lesion model in optogenetic mice lines (Somatostatin (SST)-Cre or Parvalbumin (PV)-Cre x floxed channelrhodopsin-2) to dissect features of the SST, PV, and pyramidal neuron microcircuit that are potentially associated with DRE. Investigations took place within developmental microgyria’s known pathological substrate, the adjoined and epileptogenic paramicrogyral region (PMR). As well, microcircuit relationships within the previously unexplored range …

The Role Of Melatonin In Biological Rhythms Of Songbirds, Clifford E. Harpole

Theses and Dissertations--Biology

In vertebrates, melatonin is a hormone that is produced and secreted at night and inhibited by light. This unique “darkness-only” expression profile makes it an intellectually appealing candidate for a means of transmitting temporal information to an individual, both time of day and time of year.

In passerine birds, “time of day” information is certainly transmitted via melatonin secretion. The primary producer of systemic melatonin in this family of birds is the pineal gland, and surgical removal of it causes a bird to become arrhythmic in constant conditions. I find that as pinealectomized house sparrows (Passer domesticus) become …

Divergence In Neuronal Calcium Dysregulation In Brain Aging And Animal Models Of Ad, Adam Ghoweri

Theses and Dissertations--Pharmacology and Nutritional Sciences

Neuronal calcium dysregulation first garnered attention during the mid-1980’s as a key factor in brain aging, which led to the formulation of the Ca²⁺ hypothesis of brain aging and dementia. Indeed, many Ca²⁺-dependent cellular processes that change with age, including an increase in the afterhyperpolarization, a decrease in long-term potentiation, an increased susceptibility to long-term depression, and a reduction in short-term synaptic plasticity, have been identified. It was later determined that increased intracellular Ca²⁺ with age was due to increased Ca²⁺ channel density, elevated release from intracellular Ca²⁺ stores, and decreased Ca²⁺ buffering …

Neuroanatomy Of The Blackspotted Rockskipper, Entomacrodus Striatus, Pooja Dayal

Williams Honors College, Honors Research Projects

Here I characterized the central neuroanatomy of the Blackspotted Rockskipper, Entomacrodus striatus, native to French Polynesia. The neuroanatomy of E. striatus has not been studied prior to this paper. I used several histology and antibody staining techniques to accomplish this, including Crystal Violet, immunohistochemistry, immunofluorescence, and Bielschowsky’s Silver Nitrate staining. This paper describes the most successful techniques used, identifies major structures in the species’ neuroanatomy, and also explains why studying E. striatus is important in the future of vertebrate research.

Divalent Metal Cation Entry And Cytotoxicity In Jurkat T Cells: Role Of Trpm7 Channels, Alayna N. Mellott

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Humans are exposed daily to a variety of metals that can be harmful to our immune system. Although certain divalent metal cations are essential for numerous cellular functions and are critical trace elements in humans, the uptake mechanisms of these ions remain mostly unknown. Transient receptor potential melastatin 7 (TRPM7), which is expressed in a variety of human cell types, including lymphocytes and macrophages, conducts many divalent metal cations. TRPM7 channels are largely inactive under normal physiological conditions due to cytoplasmic magnesium acting as a channel inhibitor. Magnesium is a cofactor for many biochemical reactions. Low serum levels of magnesium, …

Non-Invasive Method For Leptin Supplementation In Zebrafish (Danio Rerio), Regan Mcnamara

Williams Honors College, Honors Research Projects

I tested the hypothesis that recombinant leptin protein can be introduced to zebrafish in vivo through non-invasive soaking in a solution containing the protein. One way to study various molecules’ effects in vivo is through intraperitoneal or intracerebroventricular injections during the embryonic or larval stage, which is invasive, difficult to administer, and can have a high mortality rate. 48 hours post fertilization (hpf) zebrafish were soaked in a His-tagged recombinant leptin protein solution at 10 nM and 100 nM concentrations (produced by Genscript). After soaking, zebrafish larvae were washed extensively to remove all recombinant protein on their exterior before homogenization. …

Artificially-Generated Scenes Demonstrate The Importance Of Global Properties During Early Scene Perception, Mavuso Wesley Mzozoyana

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During scene perception, studies have shown the importance of the global distribution of a scene. Electrophysiological studies have found these global effects concentrated corresponding to the second positive and first negative peaks (P2 and N1, respectively) of the Event-related potential (ERP) during the first 600 ms of scene perception. We sought to understand in Experiment 1, to what extent early responses to scenes were driven by mid-level global information such as the degree of naturalness or openness in a scene image in the absence of specific low-and high-level information (color and semantic object detail). This was done using artificially-generated stimuli …

Exploring The Impact Of Affective Processing On Visual Perception Of Large-Scale Spatial Environments, Auroabah S. Almufleh

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This thesis explores the interaction between emotions and visual perception using large scale spatial environment as the medium of this interaction. Emotion has been documented to have an early effect on scene perception (Olofsson, Nordin, Sequeira, & Polich, 2008). Yet, most popularly-used scene stimuli, such as the IAPS or GAPED stimulus sets often depict salient objects embedded in naturalistic backgrounds, or “events” which contain rich social information, such as human faces or bodies. And thus, while previous studies are instrumental to our understanding of the role that social-emotion plays in visual perception, they do not isolate the effect of emotion …