Molecular and Cellular Neuroscience Commons^™

Cannabinoid Receptor Interacting Protein Suppresses Agonist-Driven Cb1 Receptor Internalization And Regulates Receptor Replenishment In An Agonist-Biased Manner, Lawrence C. Blumes, Sandra Leone-Kabler, Deborah J. Luessen, Glenn S. Marrs, Erica Lyons, Caroline E. Bass, Rong Chen, Dana E. Selley, Allyn C. Howlett

Neurology Publications

Cannabinoid receptor interacting protein 1a (CRIP1a) is a CB1 receptor (CB1R) distal C-terminus-associated protein that modulates CB1R signaling via G proteins, and CB1R down-regulation but not desensitization (Blume et al. [2015] Cell Signal., 27, 716-726; Smith et al. [2015] Mol. Pharmacol., 87, 747-765). In this study, we determined the involvement of CRIP1a in CB1R plasma membrane trafficking. To follow the effects of agonists and antagonists on cell surface CB(1)Rs, we utilized the genetically homogeneous cloned neuronal cell line N18TG2, which endogenously expresses both CB1R and CRIP1a, and exhibits a well-characterized endocannabinoid signaling system. We developed stable CRIP1a-over-expressing and CRIP1a-siRNA-silenced knockdown …

Early Neurodevelopment: Notch Signaling, Axial Differentiation, Brain Patterning, And Neurogenesis, Adrian M. Bebenek '17

Independent Study

The vastly complex, delicate nature of the nervous system calls for a highly effective development system. The development of the nervous system begins early in embryogenesis and is one of the last systems to be completed after birth. Deemed to be one of the most important steps in the evolutionary progression towards sophisticated life, the pathways regulating neurodevelopment are highly specialized and conserved. Embryonic neurodevelopment is an important starting point for the understanding of brain anatomy, function, and its neurobiology. The past few decades have brought about numerous technological advancements allowing for the study of the earliest stages of embryonic …

Vitamin D Clinical Relevance In The Recovery From Traumatic Brain Injury Among The Military Population, Yuisa M. Colón

Honors Undergraduate Theses

Background: Traumatic brain injury (TBI) still remains a difficult disorder to treat. TBI has been associated to chronic neuroinflammation and a high risk for neurodegenerative disorders. Since 2001 between ten to twenty percent of all deployed military members have suffered a combat-related TBI. Nearly twenty to thirty percent of those will experience chronic cognitive, behavioral and somatic symptoms after suffering a TBI.
Methods: The objective of this review is to evaluate current literature examining vitamin D as a neurosteroid with protective properties and its clinical relevance after traumatic brain injury. Vitamin D is known to participate in neurobiological …

Role Of The Chondroitin Sulfate Proteoglycan, Neurocan, In Inhibition Of Sensory Neurite Regeneration, Madison Klump, Umang Khandpur, Chris Calulot, Adrian Centers, Diane M. Snow

Lewis Honors College Capstone Collection

In the adult mammalian brain and spinal cord, neuronal injury results in failed neurite regeneration, in part due to the up-regulation of chondroitin sulfate proteoglycans (CSPGs). CSPGs are molecules consisting of a protein core with covalently bound glycosaminoglycans (GAGS), specifically, chondroitin sulfate side-chains. The majority of CSPGs produced after injury originate from reactive astrocytes found in the glial scar surrounding the injury site. Although this milieu is very complex and involves more than just CSPGs, axonal regrowth may be improved if the expression of specific, highly inhibitory CSPGs produced after injury were attenuated selectively. Neurocan is one type of CSPG …

Probing The Functional Relevance Of Reactive Hippocampal Neurogenesis In A Model Of An Alcohol Use Disorder, Chelsea Rhea Geil Nickell

Theses and Dissertations--Pharmacy

Alcoholism, or alcohol use disorders (AUDs), represent a major public health concern both locally and globally. Critically, excessive alcohol consumption results in neurodegeneration in brain regions such as the hippocampus which is known for its role in learning and memory. Recovery of hippocampal volume loss has been observed after prolonged abstinence, but the mechanisms underlying this process are not well understood. Adult neurogenesis is thought to contribute to this recovery since after alcohol exposure a reactive increase in adult neurogenesis is observed. This reactive neurogenesis (the process by which brain insult results in a compensatory increase in neurogenesis) may represent …

The Effect Of Caffeine On Migraine Headaches, Deborah Shimshoni

Honors Undergraduate Theses

As the most widely consumed drug around the globe, there is a vast array of contradicting research available on caffeine. One of the most debated and researched topics on caffeine is its effect on the brain. Meanwhile, the data on the neurological condition of migraine has information scattered throughout countless research articles and experiments.

Although neither migraine or caffeine are completely understood by the medical world, this analysis attempts to give a more coherent understanding of the relationship between the two. This is done by first understanding the known and theorized mechanisms of caffeine as well as the pathologies of …

The Role Of Sox4 In Regulating Choroid Fissure Closure And Retinal Neurogenesis, Wen Wen

Theses and Dissertations--Biology

The development of the vertebrate eye is tightly controlled by precise genetic regulations. From a single ocular primordium to bilateral eyes with complex structures and cell types, it requires intensive proliferation and migration for cells in both the ectoderm and mesoderm to accomplish ocular morphogenesis, and during this process cell differentiation and interaction takes place to establish the complex composition of ocular cell types and cellular connections. Genetic defects can lead to severe abnormalities in eye morphogenesis and cell differentiation during ocular development. A tremendous amount of work has been done to identify both intrinsic and extrinsic factors that regulate …

The Role Of Astrocytic Calcineurin Activation And Downstream Signaling In Neurodegenerative Diseases, Melanie M. Pleiss

Theses and Dissertations--Pharmacology and Nutritional Sciences

Calcineurin (CN) is a calcium (Ca²⁺)-sensitive serine/threonine protein phosphatase that plays a significant role in several cell signaling pathways, and has been implicated in many neurodegenerative diseases including Alzheimer’s disease (AD) and vascular cognitive impairment and dementia (VCID). Although normally found in neurons, CN also appears at high levels in activated astrocytes under conditions of injury and disease. To elucidate the role of astrocytic calcineurin signaling in neurodegenerative diseases, our lab has used primary rat astrocytes, transgenic and diet-induced mouse models of dementia, and human tissue biospecimens from confirmed AD and VCID cases.

To better understand mechanisms for …

Assessing The Expression Of Astrocytic Markers In Retinal Ganglion Cell Projection Of Lcr/Hcr Rats, Isabella K. Bartholomew, Samuel Crish, James Holda, Jordan Renna, Gina Wilson

Williams Honors College, Honors Research Projects

Metabolic Syndrome is a human condition that presents with various metabolic issues such as abnormal distribution of body fat, high blood pressure, and a prothrombotic state, among other problems (Alberti,et al, 2005). This syndrome is a risk factor for visual disorders, such as glaucoma, and is often associated with increased levels of neuroinflammation. Currently, the animal model used to replicate this syndrome is The Low Capacity Runner and High Capacity Runner Rat Model. These rats have been bred based on their running capacities for 30+ generations to have drastic metabolic differences. We assessed key areas of the retinal ganglion cell …

Overlapping Signatures Of Chronic Pain In The Dna Methylation Landscape Of Prefrontal Cortex And Peripheral T Cells, Renaud Massart, Sergiy Dymov, Magali Millecamps, Matthew Suderman, Stephanie Gregoire, Kevin Koenigs, Sebastian Alvarado, Maral Tajerian, Laura S. Stone, Moshe Szyf

Publications and Research

We tested the hypothesis that epigenetic mechanisms in the brain and the immune system are associated with chronic pain. Genome-wide DNA methylation assessed in 9 months post nerve-injury (SNI) and Sham rats, in the prefrontal cortex (PFC) as well as in T cells revealed a vast difference in the DNA methylation landscape in the brain between the groups and a remarkable overlap (72%) between differentially methylated probes in T cells and prefrontal cortex. DNA methylation states in the PFC showed robust correlation with pain score of animals in several genes involved in pain. Finally, only 11 differentially methylated probes in …

Intrinsic And Extrinsic Regulation Of Pineal Melatonin Rhythms, Ye Li

Theses and Dissertations--Biology

Circadian rhythm is a biological rhythm with period of about 24 hours. Circadian rhythm is universal in phyla from bacteria to mammals and exists in different level from gene expression to behavior. Circadian system consists of three components: 1) a self-sustained oscillator; 2) an input pathway which can alter the phase of the oscillator; and 3) an output such as gene expression, enzyme activity, hormone production, heart rate, body temperature or locomotor activities. The way the oscillator regulates its outputs is complicated, in that on one hand usually the oscillator is not the only factor affecting the outputs, and on …

Sleep Alterations In Mouse Genetic Models Of Human Disease, Mansi Sethi

Theses and Dissertations--Biology

Sleep is a process essential for the well-being of an animal and in humans as much as one-third of our life is spent in sleep. Yet, the biological need for sleep still remains a conundrum. Our knowledge of the genes influencing sleep and the mechanisms regulating the process can be advanced with the utilization of genetic and genomic approaches which, in turn, may inform us about the functions of sleep as well. With this goal, I have investigated and examined sleep-wake phenotypes for a variety of transgenic and knock out animals.

For the first part of my research (Chapter 3), …

Axon Initial Segment Loss Is Not Observed In The Hippocampus Of A Experimental Autoimmune Encephalomyelitis Mouse Model, Praveen Mohanraju

UROP Posters

The axon initial segment (AIS) is fundamental for neuronal communication and action potential initiation, a characteristic which has been shown to be disrupted in inflammatory diseases such as Multiple Sclerosis (MS). Previous work from our lab has shown AIS breakdown in layer 5 of the cortex in a mouse model of MS known as experimental autoimmune encephalomyelitis (EAE). Moreover, it was shown that AIS breakdown was independent of demyelination but temporally correlated with microglial inflammatory reactivity. In order to determine if this pathology is specific to the cortex or affects other regions of the brain, we exploited these EAE induced …

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 …

A Neural Circuit Of Appetite Control In C. Elegans, Kristen C. Davis

Theses and Dissertations

Feeding behavior and its associated neural circuitry is complex and intricate in mammalian systems, however, a simple model organism, such as C. elegans provides a more basic approach to understand factors and molecules involved. The fruit-dwelling nematode provides a unique set of resources; it only consists of 959 cells, 302 of which are neurons. In addition, each neuron’s connectivity and position within the worm is known and consistent between animals. Conservation of neurotransmitters and biochemical processes add to this impressive list. These resources provide an excellent background to address feeding behavior and the neural structures governing it.

Feeding behavior in …

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 …

Neuron Morphology Influences Axon Initial Segment Plasticity, Allan T. Gulledge, Jaime J. Bravo

Dartmouth Scholarship

In most vertebrate neurons, action potentials are initiated in the axon initial segment (AIS), a specialized region of the axon containing a high density of voltage-gated sodium and potassium channels. It has recently been proposed that neurons use plasticity of AIS length and/or location to regulate their intrinsic excitability. Here we quantify the impact of neuron morphology on AIS plasticity using computational models of simplified and realistic somatodendritic morphologies. In small neurons (e.g., dentate granule neurons), excitability was highest when the AIS was of intermediate length and located adjacent to the soma. Conversely, neurons having larger dendritic trees (e.g., pyramidal …

Reactive Oxygen Species-Mediated Neurodegeneration Is Independent Of The Ryanodine Receptor In Caenorhabditis Elegans, Lyndsay E.A. Young, Daniel C. Williams

Journal of the South Carolina Academy of Science

Despite the significant impacts on human health caused by neurodegeneration, our understanding of the degeneration process is incomplete. The nematode Caenorhabditis elegans is emerging as a genetic model organism well suited for identification of conserved cellular mechanisms and molecular pathways of neurodegeneration. Studies in the worm have identified factors that contribute to neurodegeneration, including excitotoxicity and stress due to reactive oxygen species (ROS). Disruption of the gene unc-68, which encodes the ryanodine receptor, abolishes excitotoxic cell death, indicating a role for calcium (Ca²⁺) signaling in neurodegeneration. We tested the requirement for unc-68 in ROS-mediated neurodegeneration using the …

Characterizing The Rogfp2-Orp1 Fluorescent Biosensor For Detecting Oxidative Stress In Mammalian Cells, Sara A. Doan, Stevie Norcross, Mathew Tantama

The Summer Undergraduate Research Fellowship (SURF) Symposium

Parkinson’s disease is a neurodegenerative disease involving the death of neurons in the substantia nigra and loss of the neurotransmitter, dopamine. The disease leads to progressive loss of motor control. Exact causes and mechanisms by which Parkinson’s disease proceeds are unknown, however, previous experiments determine oxidative stress in mitochondria as a factor that results in cell death. Strategies have been implemented to generate fluorescent biosensors to monitor reactive oxygen species (ROS) concentrations while simultaneously measuring the spatiotemporal distribution and correlation between the ROS, cellular function and organelle. Orp1, an enzyme found in yeast, is a sensitive oxidizing species and when …

Characteristics Of Exocytosis And Endocytosis In Photoreceptors, Karlene M. Cork

Theses & Dissertations

Photoreceptors signal changes in light intensity to downstream retinal neurons through the exocytosis of glutamate-containing synaptic vesicles. The maintenance of the vesicle exocytosis and endocytosis process is essential for ongoing synaptic signaling. This study investigated the properties of exocytosis and endocytosis in photoreceptors and their role in ongoing neurotransmission.

I used electrophysiology and imaging techniques to study the properties of vesicle exocytosis and endocytosis in photoreceptors. First, we examined baseline release in photoreceptors that occurs in the absence of depolarizing stimulation. We measured mEPSCs in whole cell patch clamp recordings from horizontal cells. After inhibiting Ca²⁺ influx and efflux …