Molecular and Cellular Neuroscience Commons^™

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. …

Exosomes As Systemic Mediators Of Nanotube Induced Neurotoxicity, Christopher G. Canal

Theses and Dissertations

Extra-pulmonary effects of nanoparticle inhalation have been well documented; however, mechanisms for conveying peripheral bioactivity remain elusive. Recent studies point to indirect molecular mediators shed into the circulation. Protein and lipid alternatives to cytokines or chemokines have been proposed, yet the diversity among responses suggests a broader assemblage of factors. Recently we have proposed proteolytic fragment peptides as an additional source of bioactivity, which interestingly were significantly associated with exosomal proteins after enrichment analysis. Here we tested whether modeled exposure to multi-walled carbon nanotubes (MWCNT) could alter the composition and bioactivity of circulating exosomes. Male C57BL/6 mice were exposed by …

Role Of Astrocyte-Derived Extracellular Vesicles In Neuroinflammation Mediated By Drug Abuse, Ke Liao

Theses & Dissertations

Neuronal damage and neuroinflammation is a hallmark feature of HIV-associated neurological disorders (HANDs). Opioids abuse accelerates the incidence and progression of HAND; however, the mechanisms underlying the potentiation of neuropathogenesis by these drugs remain elusive. Extracellular vesicles (EVs) are essential conduits in HIV and drug abuse-mediated synaptodendritic injury and neuroinflammation. Findings from our group have demonstrated that astrocyte-derived EV (ADEV)-miRNA-29b mediates HIV Tat and morphine-induced neuronal injury, thus underscoring the importance of such interactions in NeuroHIV.

Besides, HIV Tat and morphine-mediated synaptodendritic injury via ADEVs, we are also interested in whether ADEVs contributes to neuroinflammation. Microglia are critical players in …

Novel Antiviral Effect Of A Small Molecule Onc201 And Its Potential Application In Hiv-1 Eradication, Runze Zhao

Theses & Dissertations

Despite the success of antiretroviral therapy (ART), eradication of HIV-1 from brain reservoirs remains elusive. HIV-1 brain reservoirs include perivascular macrophages that are behind the blood-brain barrier and difficult to access by ART. Macrophages express transcription factor FOXO3a and the TNF superfamily cytokine TRAIL, which are known to target HIV-1-infected macrophages for viral suppression. ONC201 is a novel and potent FOXO3a activator capable of inducing TRAIL. It can cross the blood-brain barrier, and has shown an antitumor effect in clinical trials. We hypothesized that activation of FOXO3a/TRAIL by ONC201 will reduce the size of HIV-1 brain reservoirs. Using primary human …

Effects Of Chronic Ethanol Exposure On Stress Coping Style And Genetic States Of Zebrafish (Danio Rerio), Alexander Goodman

UNO Student Research and Creative Activity Fair

Neurotransmitter systems are important in regulating the stress response. If a behavioral response is disproportional to a stressor it is characterized as anxiety-like behavior. Many anxiolytic compounds, such as ethanol, increase stressor engagement, but how these compounds interact with an organism on a neurogenetic level is less understood. In this study, I assessed the impact of chronic ethanol treatment on behavior and gene expression of GABA_Areceptors subunits on two strains of zebrafish. Each strain was selectively bred to display the proactive or reactive stress coping style where proactive individuals will actively engage a stressor more than reactive individuals. …

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 …

Structure-Activity Relationship Studies Of Synthetic Cathinones And Related Agents, Rachel A. Davies

Theses and Dissertations

Synthetic cathinones and related agents represent an international drug abuse problem, and at the same time an important class of clinically useful compounds. Structure-activity relationship studies are needed to elucidate molecular features underlying the pharmacology of these agents. Illicit methcathinone (i.e., MCAT), the prototype of the synthetic cathinone class, exists as a racemic mixture. Though the differences in potency and target selectivity between the positional and optical isomers of synthetic cathinones and related agents have been demonstrated to have important implications for abuse and therapeutic potential, the two MCAT isomers have never been directly compared at their molecular targets: the …

Molecular Targets Of Psychedelics And Their Role In Behavioral Models Of Hallucinogenic Action, Hiba Z. Vohra

Theses and Dissertations

Psychedelics are a subset of hallucinogenic drugs that exert their characteristic effects through agonist activity at the serotonin receptor 2A (5-HT_2A). In this study, I aimed to characterize the modulatory role of the metabotropic glutamate subtype 2 receptor (mGluR2) in the 5-HT_2A-specific rodent model of hallucinogenic action, head-twitch response (HTR). Secondly, I aimed to explore if 5-HT_2A agonist-induced deficits in prepulse inhibition (PPI) of the startle response, an additional model of hallucinogenic action, could be produced in mice. Though 5-HT_2A agonist-induced PPI deficits, which represent interruptions in normal sensorimotor gating, have been described in …

An Investigation On The Role Of Β-Arrestin 2, Protein Kinase C And Sex On The Mechanism Of Morphine Tolerance In The Mouse Ileum, Karan Hitesh Muchhala

Theses and Dissertations

Opioids such as morphine are frequently used in the clinic to treat pain. However, the perennial bane of chronic opioid use is the rapid development of tolerance to the analgesic effects but delayed development of tolerance to the respiratory depressant and constipating effects. As constipation is one of the most common opioid-related adverse effects in humans, it is important to delineate mechanisms that drive opioid tolerance in the ileum and lack of it in the colon. The overarching goal of this thesis was to investigate mechanisms of morphine tolerance in the ileum by comparing the mechanism of morphine tolerance in …

The Role Of Perivascular Fibrosis In Post-Stroke Glymphatic Impairment And Cerebral Amyloid Angiopathy, Matthew D. Howe

Dissertations and Theses (Open Access)

In healthy brain tissue, toxic amyloid-β (Aβ) proteins are transported by the pulsatile flow of cerebrospinal fluid (CSF) along perivascular drainage pathways. Ischemic stroke may disrupt this process, leading to a perivascular build-up of Aβ, termed cerebral amyloid angiopathy (CAA). I hypothesize that an abnormal pattern of extracellular matrix deposition within the vascular basement membrane, termed fibrosis, impairs Aβ drainage from the aged brain after stroke. I further hypothesize that inhibition of astrocytic transforming growth factor-β (TGF-β) signaling can reverse these phenotypes. Finally, I also hypothesize that serum biomarkers of perivascular fibrosis can be used to diagnose CAA following intracerebral …

An Aged Canid With Behavioral Deficits Exhibits Blood And Cerebrospinal Fluid Amyloid Beta Oligomers, Clare Rusbridge, Francisco J. Salguero, Monique Antoinette David, Kiterie M. E. Faller, Jose T. Bras, Rita J. Guerreiro, Angela C. Richard-Londt, Duncan Grainger, Elizabeth Head, Sebastian G. P. Brandner, Brian Summers, John Hardy, Mourad Tayebi

Pharmacology and Nutritional Sciences Faculty Publications

Many of the molecular and pathological features associated with human Alzheimer disease (AD) are mirrored in the naturally occurring age-associated neuropathology in the canine species. In aged dogs with declining learned behavior and memory the severity of cognitive dysfunction parallels the progressive build up and location of Aβ in the brain. The main aim of this work was to study the biological behavior of soluble oligomers isolated from an aged dog with cognitive dysfunction through investigating their interaction with a human cell line and synthetic Aβ peptides. We report that soluble oligomers were specifically detected in the dog's blood and …

Molecular Brain Adaptations To Ethanol: Role Of Glycogen Synthase Kinase-3 Beta In The Transition To Excessive Consumption, Andrew D. Van Der Vaart

Theses and Dissertations

Alcoholism is a complex neuropsychiatric disease that is characterized by compulsive alcohol use and intensifying cravings and withdrawals, often culminating in physiologic dependency. Fundamental alterations in brain chemistry underlie the transition from initial ethanol exposure to repetitive excessive use. Key mediators of this adaptation include changes in gene expression and signal transduction. Here we investigated gene expression pathways in prefrontal cortex and nucleus accumbens following acute or chronic ethanol treatment, to identify genes with potentially conserved involvement in the long-term response of the corticolimbic system to repeated ethanol exposure. We investigated Gsk3b, which encodes glycogen synthase kinase 3-beta, as a …

Role Of C121a In Mglur2 Homodimeric Expression And Function, Jong M. Shin

Theses and Dissertations

The group II metabotropic glutamate receptors are known for their involvement in various psychiatric disorders. The mGluR2 in particular is linked with etiology of schizophrenia especially in the context of crosstalk with 5-HT2A. Thus, the mGluR2 has attracted attentions for its potential therapeutic applications. Despite numerous physiological evidences on the actions of mGluR2, its mechanism is still unclear to this day. It is partially due to the lack of understanding in characteristics of mGluR2 homodimer which is its functionally active form. Therefore, the characterization of dimeric interaction serves as a foundation to advanced understanding of the role of mGluR2. On …

Metabotropic Glutamate Receptor 2 Activation: Computational Predictions And Experimental Validation, Amr Ellaithy

Theses and Dissertations

G protein-coupled receptors (GPCRs) are the largest family of signaling proteins in animals and represent the largest family of druggable targets in the human genome. Therefore, it is of no surprise that the molecular mechanisms of GPCR activation and signal transduction have attracted close attention for the past few decades. Several stabilizing interactions within the GPCR transmembrane (TM) domain helices regulate receptor activation. An example is a salt bridge between 2 highly conserved amino acids at the bottom of TM3 and TM6 that has been characterized for a large number of GPCRs. Through structural modeling and molecular dynamics (MD) simulations, …

Thiamine Deficiency And Neurodegeneration: The Interplay Among Oxidative Stress, Endoplasmic Reticulum Stress, And Autophagy, Dexiang Liu, Zunji Ke, Jia Luo

Pharmacology and Nutritional Sciences Faculty Publications

Thiamine (vitamin B1) is an essential nutrient and indispensable for normal growth and development of the organism due to its multilateral participation in key biochemical and physiological processes. Humans must obtain thiamine from their diet since it is synthesized only in bacteria, fungi, and plants. Thiamine deficiency (TD) can result from inadequate intake, increased requirement, excessive deletion, and chronic alcohol consumption. TD affects multiple organ systems, including the cardiovascular, muscular, gastrointestinal, and central and peripheral nervous systems. In the brain, TD causes a cascade of events including mild impairment of oxidative metabolism, neuroinflammation, and neurodegeneration, which are commonly observed in …

The Effects Of The Hiv-1 Tat Protein And Morphine On The Structure And Function Of The Hippocampal Ca1 Subfield, William D. Marks

Theses and Dissertations

HIV is capable of causing a set of neurological diseases collectively termed the HIV Associated Neurocognitive Disorders (HAND). Worsening pathology is observed in HIV+ individuals who use opioid drugs. Memory problems are often observed in HAND, implicating HIV pathology in the hippocampus, and are also known to be exacerbated by morphine use. HIV-1 Tat was demonstrated to reduce spatial memory performance in multiple tasks, and individual subsets of CA1 interneurons were found to be selectively vulnerable to the effects of Tat, notably nNOS+/NPY- interneurons of the pyramidal layer and stratum radiatum, PV+ neurons of the pyramidal layer, and SST+ neurons …

Exploring The Effect Of Novel Small Molecules On Oligodendrocyte Precursor Proliferation, Sagune Sakya

University Scholar Projects

Gliomas, a type of brain tumor, can be difficult to treat and have a poor survival rate. One pathway that leads to glioma formation is excessive signaling by platelet derived growth factors (PDGF) through PDGF receptor α (PDGFRα). Through this research, I found that novel compounds that downregulate PDGFRα decrease proliferation of Oli-neu cells, an oligodendrocyte precursor cell model, and identified signaling pathways through which these compounds may exert their effect. Further investigation may identify targets for development of glioma treatments.

Role Of The Calcium Plateau In The Neuronal Injury And Behavioral Morbidities Following Organophosphate Intoxication, Laxmikant S. Deshpande, Robert E. Blair, Kristin F. Phillips, Robert J. Delorenzo

Neurology Publications

Organophosphate (OP) chemicals include nerve agents and pesticides, and there is a growing concern of OP based chemical attacks against civilians. Current antidotes are essential in limiting immediate mortality associated with OP exposure. However, further research is needed to identify molecular mechanisms underlying long-term neurological deficits following survival of OP toxicity in order to develop effective therapeutics. We have developed rat survival models of OP induced status epilepticus (SE) that mimic chronic mortality and morbidity following OP intoxication. We have observed significant elevations in hippocampal calcium levels after OP SE that persisted for weeks following initial survival. Drugs inhibiting intracellular …

High Affinity Block Of Icl,Swell By Thiol-Reactive Small Molecules, Sung H. Park

Theses and Dissertations

Ebselen (Ebs) is considered as a glutathione peroxidase (GPx) mimetic and primarily thought to function by scavenging intracellular reactive oxygen species (ROS). Previous to our work, Deng et al. (2010a) demonstrated complete block of I_Cl,swell with 15 microM Ebs following endothelin-1 (ET-1) induced activation of the current in cardiomyocytes. This block was presumed to take effect mainly via the quenching of ROS. Nonetheless, our work with DI TNC1 astrocytes strongly emphasizes that Ebs might function by an alternative mechanism based on its kinetic profile in blocking I_Cl,swell. Our experiments showed that 45 nM Ebs can fully block …

The Role Of Oxidative Stress In The Mechanisms Of Ammonia-Induced Brain Swelling And Tolerance In The Goldfish (Carassius Auratus), David F. Jones Lisser Mr.

Theses and Dissertations (Comprehensive)

Toxic build-ups of ammonia can cause potentially fatal brain swelling in mammals, but such swelling is reversible in the anoxia- and ammonia-tolerant goldfish (Carassius auratus). The mechanisms of ammonia-induced brain swelling and tolerance remain elusive, but several studies have suggested a role for reactive oxygen species (ROS), which may damage proteins and lipids in the plasma membrane of astrocytes in the brain. As a result, osmotic gradients across cell membranes may be altered leading to water uptake by astrocytes and swelling. While a role for ROS has been proposed in mammals, no studies have addressed this question in …

An Environmental Toxic Model Of Parkinson's Disease: The Fruit Fly, Jennene Lyda

Graduate Student Theses, Dissertations, & Professional Papers

Parkinson’s disease (PD) is the second most common neurodegenerative disorder with no known specific cause; although genetic risk factors and/or environmental exposure are thought to be involved. The etiology of PD is currently unknown, although the combination of non-genetic components such as environmental exposures, the accumulation of exposure, and gene-environment interactions are thought to play a major role. However, despite this knowledge it is important to develop better models that parallel PD pathophysiology to further understand the mechanisms underlying dopaminergic neuron (DaN) damage. The use of mammalian models to study the degenerative processes in PD has been the most common …

Characterizing A Novel Monoclonal Ampa Receptor 1/2/3 Antibody In The Hippocampus And Prefrontal Cortex Of Rat, Monkey, And Human, Sebastian Aguiar

Pitzer Senior Theses

The excitatory, ionotropic glutamatergic AMPA receptor is the most common membrane-bound receptor in the central nervous system. AMPARs and the NMDA receptors are central to synaptic plasticity, memory, and mechanisms of neurodegeneration. The AMPAR is an obligate heterotetramer, composed of subunits GluA1-4. Subunit permutation determines ion conductance, trafficking and other functional characteristics. Few available antibodies are subunit-specific, disabling researchers from accurately visualizing differential AMPAR subunit distribution in the nervous system. This study sought to visualize a novel monoclonal GluA1/2/3 antibody with functional avidity for three of four receptor subunits and to characterize the ultrastructural localization of these receptors using confocal …

Flavonoids With Novel Nicotinic Activity As Potential Pharmacotherapies To Treat Ethanol-Induced Neurotoxicity, Joseph A. Lutz

Theses and Dissertations--Pharmacy

Ethanol causes neurotoxicity via several mechanisms at different points in the cycle of dependence, including neuroinflammation and oxidative stress during ethanol exposure as well as excitotoxicity during ethanol withdrawal. The primary therapeutic implication is that ethanol-induced neurotoxicity requires multifunctional pharmacotherapies which reduce all mechanisms. Using an innovative pharmacological high throughput screening method on a large plant extract library we discovered flavonoids with alpha7 nicotinic acetylcholine receptor (nAChR) activity. In addition to their well-known anti-inflammatory and antioxidant properties, this novel activity means they can potentially reduce excitotoxicity and therefore makes them ideal for inhibition of ethanol-induced neurotoxicity. Rhamnetin, the candidate compound, …

Repeated Asenapine Treatment Produces A Sensitization Effect In Two Preclinical Tests Of Antipsychotic Activity, Rongyin Qin, Yingzhu Chen, Ming Li

Department of Psychology: Faculty Publications

Among several commonly used atypical antipsychotic drugs, olanzapine and risperidone cause a sensitization effect in the conditioned avoidance response (CAR) and phencyclidine (PCP)- induced hyperlocomotion paradigms – two well established animal tests of antipsychotic drugs, whereas clozapine causes a tolerance effect. Asenapine is a novel antipsychotic drug recently approved for the treatment of schizophrenia and manic disorders. It shares several receptor binding sites and behavioral features with other atypical antipsychotic drugs. However, it is not clear what type of repeated effect (sensitization or tolerance) asenapine would induce, and whether such an effect is transferrable to other atypicals. In this study, …

Modulation Of Synaptic Transmission By Adenosine In Layer 2/3 Of The Rat Visual Cortex In Vitro, Nicholas M. Bannon

Master's Theses

No abstract provided.

Olanzapine Sensitization And Clozapine Tolerance: From Adolescence To Adulthood In The Conditioned Avoidance Response Model, Jing Qiao, Hong Li, Ming Li

Department of Psychology: Faculty Publications

Disruption of conditioned avoidance response (CAR) in rodents is one trademark feature of many antipsychotic drugs. In adult rats, repeated olanzapine (OLZ) treatment causes an enhanced disruption of avoidance response (sensitization), whereas repeated clozapine (CLZ) treatment causes a decreased disruption (tolerance). The present study addressed (1) whether OLZ sensitization and CLZ tolerance can be induced in adolescent rats, and (2) the extent to which OLZ sensitization and CLZ tolerance induced in adolescence persists into adulthood. Male adolescent Sprague–Dawley rats (approximate postnatal days (BP) 43–47) were first treated with OLZ (1.0 or 2.0 mg/kg, subcutaneously (sc)) or CLZ (10 or 20 …

Diet-Induced Obesity: Dopaminergic And Behavioral Mechanisms As Outcomes And Predictors, Vidya Narayanaswami

Theses and Dissertations--Pharmacy

Obesity and drug abuse share common neural circuitries including the mesocoticolimbic and striatal dopamine reward system. In the current study, a rat model of diet-induced obesity (DIO) was used to determine striatal dopamine function, impulsivity and motivation as neurobehavioral outcomes and predictors of obesity. For the outcome study, rats were randomly assigned a high-fat (HF) or a low-fat (LF) diet for 8 wk. Following the 8-wk HF-diet exposure, rats were segregated into obesity-prone and obesity-resistant groups based on maximum and minimum body weight gain, respectively, and neurobehavioral outcomes were evaluated. For the predictor study, neurobehavioral antecedents were evaluated prior to …

Effects Of Maternal Low Protein Diet On Expression Of Drug Transporters In The Blood-Brain Barrier Of Adult Offspring, Bonnie L. Hastings

Senior Theses

Adverse uterine environment, manifested as low birth weight (LBW), has been shown to predispose individuals to hypertension, diabetes, and obesity by mechanisms that are just beginning to be understood. One of the mechanisms is the dysregulation of the expression or function of drug transport proteins, such as the organic anion transporter (OAT) family, which are crucial for the transport of various endogenous and exogenous compounds into and out of all organs, especially the brain. Hence, we examined the status of select drug transporters in the blood-brain barrier (BBB), using a LBW rat model. Maternal low protein diet (LPD) during gestation …