Medical Neurobiology Commons^™

Investigating Conserved Mechanisms For Embryonic Eye Regrowth In Xenopus Laevis, Cindy Kha

UNLV Theses, Dissertations, Professional Papers, and Capstones

Regeneration is a complex process to replace or restore tissue after damage. However, animals vary in their ability to regenerate tissue, and humans are limited in their abilities. Understanding how regeneration occurs in highly regenerative vertebrates, such as in Xenopus laevis frogs will lead to defining common regeneration mechanisms. In recent years, eye regeneration research in Xenopus laevis tadpoles provided new promising insight into the mechanisms necessary for repair of damaged eye tissue. Much progress has been made towards understanding the regenerative capability of the complex eye since Xenopus tadpoles can regenerate mature eye tissues, including: the optic nerve, retina, …

Macrophage Migration Inhibitory Factor (Mif) Makes Complex Contributions To Pain-Related Hyperactivity Of Nociceptors After Spinal Cord Injury, Alexis Bavencoffe, Emily A Spence, Michael Y Zhu, Anibal Garza-Carbajal, Kerry E Chu, Ona E Bloom, Carmen W Dessauer, Edgar T Walters

Faculty, Staff and Student Publications

Neuropathic pain is a major, inadequately treated challenge for people with spinal cord injury (SCI). While SCI pain mechanisms are often assumed to be in the CNS, rodent studies have revealed mechanistic contributions from primary nociceptors. These neurons become chronically hyperexcitable after SCI, generating ongoing electrical activity that promotes ongoing pain. A major question is whether extrinsic chemical signals help to drive ongoing electrical activity after SCI. People living with SCI exhibit acute and chronic elevation of circulating levels of macrophage migration inhibitory factor (MIF), a cytokine implicated in preclinical pain models. Probable nociceptors isolated from male rats and exposed …

The Role Of Microglia In Neuroinflammation Of The Spinal Cord After Peripheral Nerve Injury, Tana S. Pottorf, Travis M. Rotterman, William M. Mccallum, Zoë A. Haley-Johnson, Francisco J. Alvarez

Neuroscience, Cell Biology & Physiology Faculty Publications

Peripheral nerve injuries induce a pronounced immune reaction within the spinal cord, largely governed by microglia activation in both the dorsal and ventral horns. The mechanisms of activation and response of microglia are diverse depending on the location within the spinal cord, type, severity, and proximity of injury, as well as the age and species of the organism. Thanks to recent advancements in neuro-immune research techniques, such as single-cell transcriptomics, novel genetic mouse models, and live imaging, a vast amount of literature has come to light regarding the mechanisms of microglial activation and alluding to the function …

Connectomic Analysis Of The Drosophila Lateral Neuron Clock Cells Reveals The Synaptic Basis Of Functional Pacemaker Classes, Orie T. Shafer, Gabrielle J. Gutierrez, Kimberly Li, Amber Mildenhall, Daphna Spira, Jonathan Marty, Aurel A. Lazar, Maria De La Paz Fernandez

Advanced Science Research Center

The circadian clock orchestrates daily changes in physiology and behavior to ensure internal temporal order and optimal timing across the day. In animals, a central brain clock coordinates circadian rhythms throughout the body and is characterized by a remarkable robustness that depends on synaptic connections between constituent neurons. The clock neuron network of Drosophila, which shares network motifs with clock networks in the mammalian brain yet is built of many fewer neurons, offers a powerful model for understanding the network properties of circadian timekeeping. Here, we report an assessment of synaptic connectivity within a clock network, focusing on the …

Meta-Analysis Of 175 Patients With Covid-19 And Seizures, Status Epilepticus, Or Cortical Myoclonus: An Individual Patient Data Analysis, Aditi Kappagantu Bs, Helena A. Brantz Ms, Amman Bhasin Ba, Cristina Jageka Bs, Rooqash Ali Md, Izzy Saef Md, Brittany M. Stopa Mph, Ayaz Khawaja Md

Medical Student Research Symposium

Objective

To characterize management and outcomes of seizures, status epilepticus, and cortical myoclonus in COVID-19, with individual patient data analysis of published literature.

Methods

Systematic literature review was conducted in accordance with PRISMA guidelines. Criteria included new-onset seizures, status epilepticus, and/or cortical myoclonus with concomitant COVID-19. COVID-19 severity was dichotomized into mild and severe cases. Good outcome was defined as discharge without severe deficits, and/or return to baseline.

Results

A total of 105 studies reporting 176 patients (male 56.3%;mean age 47.8,SD 25.6) were included. Status epilepticus occurred in 47 patients (26.7%) and myoclonus in 41 (23.3%). Severe COVID-19 occurred in …

Intrabody-Mediated Postsynaptic Recruitment Of Camkiiα Improves Memory, Anthony Chifor, Jeongyoon Choi Dr., Joongkyu Park Dr.

Medical Student Research Symposium

Long-term potentiation (LTP), the selective strengthening of specific synapses based on recent activity, has widely been accepted as the biological mechanism responsible for learning and memory. N-methyl-D-aspartate receptors (NMDARs) play a critical role in LTP, which when activated, result in a surge of postsynaptic intracellular calcium levels. The calcium rise during LTP results in the activation of Ca²⁺/calmodulin-dependent kinase II alpha (CaMKIIa), which consequently enacts multiple cellular effects that ultimately result in the strengthening of synaptic connections. Previous work has examined the effects of CaMKIIa overexpression in rat hippocampi on spatial memory, however, significant but limited improvement in …

Il-10 And Tgf-Β Increase Connexin-43 Expression And Membrane Potential Of Hl-1 Cardiomyocytes Coupled With Raw 264.7 Macrophages, Cora B. Cox, Mike Castro, Thomas L. Brown, Nancy J. Bigley

Neuroscience, Cell Biology & Physiology Faculty Publications

Cardiac resident macrophages facilitate electrical conduction by interacting with cardiomyocytes via connexin-43 (Cx43) hemichannels. Cx43 is critical for impulse propagation and coordination between muscle contractions. Cardiomyocyte electrophysiology can be altered when coupled with noncardiomyocyte cell types such as M2c tissue-resident macrophages. Using cocultures of murine HL-1 cardiomyocytes and RAW 264.7 macrophages, we examined the hypothesis that cytokine signals, TGF-β1 and IL-10, upregulate Cx43 expression at points of contact between the two cell types. These cytokine signals maintain the macrophages in an M2c anti-inflammatory phenotype, mimicking cardiac resident macrophages. The electrophysiology of cardiomyocytes was examined using di-8-ANEPPS potentiometric dye, which reflects …

Ciliogenesis Mechanisms Mediated By Pak2-Arl13b Signaling In Brain Endothelial Cells Is Responsible For Vascular Stability, Karthikeyan Thirugnanam, Shubhangi Prabhudesai, Emma Van Why, Amy Pan, Ankan Gupta, Koji Foreman, Rahima Zennadi, Kevin R. Rarick, Surya M. Nauli, Sean P. Palacek, Ramani Ramchandran

Pharmacy Faculty Articles and Research

In the developing vasculature, cilia, microtubule-based organelles that project from the apical surface of endothelial cells (ECs), have been identified to function cell autonomously to promote vascular integrity and prevent hemorrhage. To date, the underlying mechanisms of endothelial cilia formation (ciliogenesis) are not fully understood. Understanding these mechanisms is likely to open new avenues for targeting EC-cilia to promote vascular stability. Here, we hypothesized that brain ECs ciliogenesis and the underlying mechanisms that control this process are critical for brain vascular stability. To investigate this hypothesis, we utilized multiple approaches including developmental zebrafish model system and primary cell culture systems. …

Computational Analysis Of Memory Consolidation Following Inhibitory Avoidance (Ia) Training In Adult And Infant Rats: Critical Roles Of Camkiia And Mecp2, Yili Zhang, Paul Smolen, Cristina M Alberini, Douglas A Baxter, John H Byrne

Faculty, Staff and Student Publications

Key features of long-term memory (LTM), such as its stability and persistence, are acquired during processes collectively referred to as consolidation. The dynamics of biological changes during consolidation are complex. In adult rodents, consolidation exhibits distinct periods during which the engram is more or less resistant to disruption. Moreover, the ability to consolidate memories differs during developmental periods. Although the molecular mechanisms underlying consolidation are poorly understood, the initial stages rely on interacting signaling pathways that regulate gene expression, including brain-derived neurotrophic factor (BDNF) and Ca²⁺/calmodulin-dependent protein kinase II α (CaMKIIα) dependent feedback loops. We investigated the ways …

Co-Transmitting Neurons In The Lateral Septal Nucleus Exhibit Features Of Neurotransmitter Switching, Patrick J Hunt, Mikhail Kochukov, Brandon T Pekarek, Benjamin D W Belfort, Juan M Romero, Jessica L Swanson, Benjamin R Arenkiel

Faculty, Staff and Students Publications

The lateral septal nucleus (LSN) is a highly interconnected region of the central brain whose activity regulates widespread circuitry. As such, the mechanisms that govern neuronal activity within the LSN have far-reaching implications on numerous brain-wide nuclei, circuits, and behaviors. We found that GABAergic neurons within the LSN express markers that mediate the release of acetylcholine (ACh). Moreover, we show that these vGATLSN neurons release both GABA and ACh onto local glutamatergic LSN neurons. Using both short-term and long-term neuronal labeling techniques we observed expression of the cholinergic neuron marker Choline Acetyltransferase (ChAT) in vGATLSN neurons. These findings provide evidence …

Full- Versus Sub-Regional Quantification Of Amyloid-Beta Load On Mouse Brain Sections, Yuu Ohno, Riley Murphy, Matthew Choi, Weijun Ou, Rachita K. Sumbria

Pharmacy Faculty Articles and Research

Extracellular accumulation of amyloid-beta (Aβ) plaques is one of the major pathological hallmarks of Alzheimer's disease (AD), and is the target of the only FDA-approved disease-modifying treatment for AD. Accordingly, the use of transgenic mouse models that overexpress the amyloid precursor protein and thereby accumulate cerebral Aβ plaques are widely used to model human AD in mice. Therefore, immunoassays, including enzyme-linked immunosorbent assay (ELISA) and immunostaining, commonly measure the Aβ load in brain tissues derived from AD transgenic mice. Though the methods for Aβ detection and quantification have been well established and documented, the impact of the size of the …

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 …

The Role Of Corticothalamic Projections (Prelimbic Cortex To Nucleus Reuniens) In Working Memory, Phillip Kumpf, Paul C. Kumpf, S. D. Dunn, Evan Ciacciarelli, T. Gohar, Timothy Sloand, Mark Niedringhaus, Elizabeth West

Rowan-Virtua Research Day

Working memory (WM) is the ability to store information for short periods of time and is used to execute tasks

WM has been understood to work via the medial prefrontal cortex (mPFC) and dorsal hippocampus (dHPC), but they do not directly project to each other

The nucleus reuniens of the thalamus (Re) is a “middle man” between the mPFC and dHPC

There are projections between the prelimbic cortex (PrL) and Re that may be used during WM

To test the connection of the PrL to Re, a delayed nonmatch to position (DNMTP) task was performed

Neuronal Activity Within The Ventral Tegmental Area Is Correlated With Cocaine-Seeking Behavior In Male, But Not Female, Rats, Colton D. Spencer, Nicole M. Hinds, Ireneusz D. Wojtas, Desta M. Pulley, Daniel Manvich

Rowan-Virtua Research Day

The objective of this study was to begin to determine the neurobiological underpinnings of psychosocial stress-induced cocaine seeking. Social defeat stress, achieved using the well-established resident-intruder procedure, is an ecologically-valid psychosocial stressor in rodents that may more closely recapitulate those psychosocial experiences that elicit cocaine craving and relapse in human cocaine users. Our laboratory has developed a model of psychosocial stress-induced relapse in rats in which extinguished cocaine seeking is reinstated by re-exposure to a discrete cue that signals impending social defeat stress. We previously reported that an individual rat’s predilection towards the display of active coping behaviors during prior …

A Preliminary Report: The Hippocampus And Surrounding Temporal Cortex Of Patients With Schizophrenia Have Impaired Blood-Brain Barrier, Eric L. Goldwaser, Randel L. Swanson, Edgardo J. Arroyo, Venkat Venkataraman, Mary C. Kosciuk, Robert G. Nagele, L. Elliot Hong, Nimish K. Acharya

Rowan-Virtua Research Day

Schizophrenia (SZ) is one of the most severe forms of mental illness, yet mechanisms remain unclear. A widely established brain finding in SZ is hippocampal atrophy, and a coherent explanation similarly is lacking. Epidemiological evidence suggests increased cerebrovascular and cardiovascular complications in SZ independent of lifestyle and medication, pointing to disease-specific pathology. Endothelial cell contributions to blood-brain barrier (BBB) compromise may influence neurovascular unit and peripheral vascular function, and we hypothesize that downstream functional and structural abnormalities may be explained by impaired BBB.

The Brodmann Area 39/40 Of The Brain In Alzheimer’S, Mild Cognitive Impairment, And No Cognitive Impairment Subjects At Advanced Age Demonstrate Comparable Levels Of Blood-Brain Barrier Breach, Dhara Rana, Forum Mangrola, Randel L. Swanson, Venkat Venkataraman, David A. Bennett, Zoe Arvanitakis, David Libon, Robert Nagele, Nimish Acharya

Rowan-Virtua Research Day

• Alzheimer’s disease (AD) is one of the most common form of dementia

• Mild cognitive impairment (MCI), specifically amnestic subtype, more likely to progress to AD

• Pathogenesis Theories:

• o Accumulation of amyloid-beta peptides and neurofibrillary tangles containing hyperphosphorylated neuronal tau protein
• o Blood Brain Barrier (BBB) dysfunction is associated with AD pathogenesis

• Brodmann area 39/40: regions of parietal cortex are responsible for language, spatial cognition, memory retrieval, attention, phonological processing, and emotional processing

• Hypothesis: An increased BBB permeability in Brodmann area 39/40 of AD and age-matched MCI and no cognitive impairment (NCI) subjects

Plasmalogen Deficiency: A Risk Factor For Dementias And Potential Treatment Target, Mitchel A. Kling, Mallika Mendu, Rima F. Kaddurah-Daouk, Sheldon Jordan, Dayan B. Goodenowe

Rowan-Virtua Research Day

Altered lipid metabolism is implicated in the risk of sporadic Alzheimer’s disease (AD) and related dementias (ADRD); however, the precise mechanisms accounting for findings from observational studies remains to be fully elucidated.

Plasmalogens are a subclass of integral membrane phospholipids with unique properties that appear to play important roles relevant to the pathophysiology of AD and ADRD, including vesicle fusion necessary for synaptic neurotransmitter release, modulation of membrane fluidity and microdomain dynamics, membrane antioxidant functions, and neuroprotection. Like the more familiar phosphatides, plasmalogens are synthesized on a 3-carbon glycerol backbone; however, they differ from phosphatides by the presence of a …

Morphine-Induced Hyperactivity Is Attenuated By Intra-Accumbens Administration Of The Highly-Selective Dopamine D3 Receptor Antagonist Vk4-40, Mansi Patel, Desta M. Pulley, Daniel Manvich

Rowan-Virtua Research Day

Opioids exert their abuse-related effects by enhancing dopamine (DA) neurotransmission within the brain’s mesolimbic reward system, a neural projection involving DA neurons in the ventral tegmental area (VTA) that project to medium spiny neurons within the nucleus accumbens (NAc). Mu (MOR) are expressed by several populations of GABAergic neurons that tonically inhibit VTA DA neurons. By inhibiting these GABAergic neurons in a MOR-dependent manner, opioids indirectly enhance DA neurotransmission via disinhibition of DAergic neurons. Accumulating evidence indicates that selective pharmacological antagonism of the dopamine D3 receptor (D3R) attenuates the abuse-related effects of several opioids, but the neurobiological mechanisms mediating this …

Early Detection Of Atypical Motor And Neurobehavior Of Infants At Risk Secondary To Opioid Exposure: A Prospective Study, Kara Boynewicz

Electronic Theses and Dissertations

Prenatal opioid exposure has been studied in relation to infants' medical outcomes. However, large gaps exist in the literature supporting early identification of atypical neurobehavior and motor development of infants with prenatal opioid exposure. The purpose of the study was to investigate whether prenatal opioid exposure has a negative influence on a newborn infant’s neurobehavior and motor development to aid in the early identification of potential delays. Using a prospective quasi experimental design, infants motor development using the Test of Infant Motor Performance (TIMP) and neurobehavior using the NICU Neonatal Network Scale (NNNS) was assessed on 58 infants in a …

The Impact Of Volume Of Tissue Activation On Cortical-Striatal Networks And Verbal Fluency Declines In Post-Deep Brain Stimulation Parkinson's Disease Patients., Alexander Luke Alley

Electronic Theses and Dissertations

This study investigated the cortical-striatal networks of verbal fluency declines in 6-month, post-operative, deep brain stimulation Parkinson’s Disease patients. Nine Parkinson’s disease participants with implanted STN or GPi DBS systems were recruited for this study. Verbal fluency data was obtained from each patient preoperatively and 6- months post implantation. The stimulation-based volume of tissue activated area (VTA) of each target site (STN or GPi) was analyzed using Lead-DBS and Lead-Group. The white matter tracks intersecting each patient’s VTA, terminating in the pre-SMA, SMA, caudate nucleus, and anterior cingulate were investigated and correlated with verbal fluency declines. We found statistically significant …