Molecular and Cellular Neuroscience Commons^™

Metabolism As A Regulator Of Sleep And Cortical Activity In Health And Alzheimer’S Disease, Nicholas J. Constantino

Theses and Dissertations--Neuroscience

Metabolic flexibility is essential for maintaining normal physiological function, enabling an organism to sense, flux, utilize, and switch fuel sources in response to changing energetic availability, demand, and cellular needs. Energetic demands are state-dependent, with wake and sleep exhibiting distinct metabolic profiles. Sleep is highly sensitive to changes in metabolism and requires metabolic flexibility to both transition into and maintain sleep stability. Alzheimer’s disease (AD) is increasingly recognized as a disease of altered metabolism yet is often framed as a disease of energetic failure. We instead define AD as a disease of metabolic inflexibility, characterized not by insufficient energy availability, …

Design And Advancement Of Analytical Frameworks For In Vivo Single-Photon Calcium Imaging To Characterize Temporal- And Treatment-Dependent Neural Adaptations To Opioid Exposure And Withdrawal In The Medial Prefrontal Cortex, Alexia R. Alsum Dr.

Theses and Dissertations--Pharmacy

Despite the availability of several approved medications for opioid use disorder (OUD), it remains a significant public health concern characterized by persistent neurobiological adaptations that drive relapse and impede successful recovery. The medial prefrontal cortex (mPFC), a region critical for executive control and decision-making, undergoes pronounced functional changes during chronic opioid exposure and withdrawal, yet the cellular mechanisms underlying these adaptations remain poorly understood. This dissertation aims to investigate longitudinal alterations in mPFC neural activity across opioid exposure and withdrawal using in vivo single-photon calcium imaging and newly developed computational frameworks.

Following standard preprocessing to extract and normalize calcium traces, …

Microglial Apoe Across Alzheimer’S Disease-Relevant Pathologies, Georgia Nolt

Theses and Dissertations--Physiology

APOE exists as three common alleles (APOE2, APOE3, APOE4) that encode their corresponding protein isoforms (apoE2, apoE3, apoE4). Despite differing by only one or two single-amino acid substitutions, each APOE allele confers a distinct AD risk profile with APOE4 increasing risk by 28% and APOE2 decreasing risk by 14% compared to the most commonly expressed APOE3 allele. While traditionally considered “neutral,” APOE3 still accounts for ~36% of AD cases while APOE4 contributes ~57%, indicating that the majority of AD cases would not occur in the absence of the APOE3 and APOE4 alleles. Microglia, the resident phagocytic immune cells …

Disrupted Circadian Rhythms Affect Hallmark Pathologies In Alzheimer’S Disease-Related Mouse Models, Valeria Buzinova

Theses and Dissertations--Molecular and Cellular Biochemistry

Alzheimer’s Disease (AD) is a complex neurodegenerative disease with two hallmark pathologies: extracellular amyloid-b (Ab) and intracellular neurofibrillary tangles (NFTs). Ab is proteolytically processed from amyloid precursor protein (APP) by b-secretase and g-secretase as a monomeric peptide prone to aggregation. Eventually, the aggregate-prone monomers will form dense plaques that are difficult to break down and remove. These plaques begin to deposit into the cortex decades prior to the formation of NFTs and the onset of cognitive decline. NFTs are comprised of hyper-phosphorylated tau. Tau is a protein that serves to promote and stabilize the formation of microtubules. The formation of …

Plasma S100Β Is A Predictor For Pathology And Cognitive Decline In Alzheimer’S Disease, Geetika Nehra, Bryan J. Maloney, Rebecca Smith, Wijitra Chumboatong, Erin L. Abner, Peter T. Nelson, Björn Bauer, Anika M. S. Hartz

UK CARES Faculty Publications

Background Blood–brain barrier dysfunction is one characteristic of Alzheimer’s disease (AD) and is recognized as both a cause and consequence of the pathological cascade leading to cognitive decline. The goal of this study was to assess markers for barrier dysfunction in postmortem tissue samples from research participants who were either cognitively normal individuals (CNI) or diagnosed with AD at the time of autopsy and determine to what extent these markers are associated with AD neuropathologic changes (ADNC) and cognitive impairment.

Methods We used postmortem brain tissue and plasma samples from 19 participants: 9 CNI and 10 AD dementia patients who …

Leveraging Clinical Standards To Improve The Translational Relevance Of Therapies For Experimental Spinal Cord Injury, Aaron L. Silverstein

Theses and Dissertations--Neuroscience

Efforts to improve treatment of spinal cord injury (SCI) often use animals to develop effective therapeutics, intending to improve the survival and the quality of life of persons with SCI. Over half of all SCIs in the United States occur at the cervical level and often cause locomotor deficits and life-threatening breathing dysfunction. Thus, my dissertation is focused on this important patient population.

After beginning with a description of translational research and surveying SCI from a clinical standpoint, I turned to describe experimental models of cervical SCI and more detailed neuroimmunological findings relevant to my work. Then, I conducted a …

Investigating The Role Of Dynamic Signaling Of Nrg3-Erbb4 In The Prefrontal Cortex In Mediating Nicotine Withdrawal Phenotypes, Emily Prantzalos

Theses and Dissertations--Pharmacy

While several pharmacotherapies are currently available for nicotine use disorder (NUD), smoking cessation success rates remain below 10% each year. The molecular mechanisms underlying failed quit attempts continue to represent a critical gap in our knowledge. However, recent advances in understanding the genetic contributions to nicotine dependence offer a promising avenue for developing more effective cessation therapies. Prior research has identified genetic variation in Neuregulin 3 (Nrg3) and its cognate receptor ErbB4 as potential contributors to affective nicotine withdrawal (WD) phenotypes and cessation outcomes. Therefore, this dissertation aims to systematically investigate the region-specific, functional role of the Neuregulin Signaling Pathway …

A 40-Week Phase 2b Randomized, Multicenter, Double-Blind, Placebo-Controlled Study Evaluating The Safety And Efficacy Of Memantine In Amyotrophic Lateral Sclerosis, Salman Bhai, Todd Levine, Dan Moore, Robert Bowser, Andrew J. Heim, Maureen Walsh, Aziz Shibani, Zachary Simmons, James Grogan, Namita A. Goyal, Raghav Govindarajan, Yessar Hussain, Tania Papsdorf, Tiffany Schwasinger-Schmidt, Nick Olney, Kim Goslin, Michael Pulley, Edward J. Kasarskis, Michael Weiss, Susan W. Katz, Suzan Moser, Duaa Jabari, Omar Jawdat, Jeffrey Statland, Mazen M. Dimachkie, Richard Barohn, Neuromuscular Study Group And Western Als Consortium Memantine Als Study Group

Neurology Faculty Publications

Introduction: Amyotrophic lateral sclerosis (ALS) is a rapidly progressive neurodegenerative disease with no known cure, limited treatment options with minimal benefits, and significant unmet need for disease modifying therapies.

Aims: This study investigated memantine's impact on ALS progression, with an additional focus on the effects of memantine on cognitive and behavioral changes associated with the disease.

Methods: A randomized, double-blind, placebo-controlled clinical trial was conducted from December 2018 to September 2020. ALS patients were enrolled in-person and remotely across 13 sites in the United States. Participants were randomized to memantine (20 mg twice daily) or placebo in a 2:1 ratio …

Blood Biomarkers In Down Syndrome: Facilitating Alzheimer’S Disease Detection And Monitoring, Melissa E. Petersen, Lisi Flores-Aguilar, Elizabeth Head, Laia Montoliu-Gaya, Andre Strydom, Sarah E. Pape, Juan Fortea, Nicholas J. Ashton, Chinedu Udeh-Momoh, Sid E. O’Bryant, Dwight German, Florin Despa, Mark Mapstone, Henrik Zetterberg

Neurology Faculty Publications

Blood-based biomarkers continue to be explored for disease detection, monitoring of progression, and therapeutic outcomes as the diagnostic determination of Alzheimer’s Disease in Down Syndrome (DS-AD) remains challenging in clinical settings. This perspective highlights the current status of this effort. Overall, amyloid (A), tau (T), and neurodegeneration (AT[N]) blood-based biomarkers have been shown to increase with disease pathology for individuals with DS. Phosphorylated tau biomarkers (p-tau217, p-tau181) have been consistently shown to track disease progression for DS-AD and are likely good candidates for use in clinical settings. Biomarkers of inflammation (glial fibrillary acidic protein) also show promise; however, additional work …

Targeted Long-Read Sequencing To Quantify Methylation Of The C9orf72 Repeat Expansion, Evan Udine, Nicole Finch, Mariely Dejesus-Hernandez, Jazmyne L. Jackson, Matthew C. Baker, Siva Arumugam Saravanaperumal, Eric Wieben, Mark T. W. Ebbert, Jaimin Shah, Leonard Petrucelli, Rosa Rademakers, Björn Oskarsson, Marka Van Blitterswijk

Neurology Faculty Publications

Background The gene C9orf72 harbors a non-coding hexanucleotide repeat expansion known to cause amyotrophic lateral sclerosis and frontotemporal dementia. While previous studies have estimated the length of this repeat expansion in multiple tissues, technological limitations have impeded researchers from exploring additional features, such as methylation levels.

Methods We aimed to characterize C9orf72 repeat expansions using a targeted, amplification-free long-read sequencing method. Our primary goal was to determine the presence and subsequent quantification of observed methylation in the C9orf72 repeat expansion. In addition, we measured the repeat length and purity of the expansion. To do this, we sequenced DNA extracted from …

Parallel Electrophysiological Abnormalities Due To Covid-19 Infection And To Alzheimer’S Disease And Related Dementia, Yang Jiang, Jennifer Neal, Pradoldej Sompol, Görsev Yener, Xianghong Arakaki, Christopher M. Norris, Francesca R. Farina, Agustin Ibanez, Susanna Lopez, Abdulhakim Al-Ezzi, Voyko Kavcic, Bahar Güntekin, Claudio Babiloni, Mihály Hajós

Neurology Faculty Publications

Many coronavirus disease 2019 (COVID-19) positive individuals exhibit abnormal electroencephalographic (EEG) activity reflecting “brain fog” and mild cognitive impairments even months after the acute phase of infection. Resting-state EEG abnormalities include EEG slowing (reduced alpha rhythm; increased slow waves) and epileptiform activity. An expert panel conducted a systematic review to present compelling evidence that cognitive deficits due to COVID-19 and to Alzheimer’s disease and related dementia (ADRD) are driven by overlapping pathologies and neurophysiological abnormalities. EEG abnormalities seen in COVID-19 patients resemble those observed in early stages of neurodegenerative diseases, particularly ADRD. It is proposed that similar EEG abnormalities in …

Novel Psychoplastogen Dm506 Reduces Cue-Induced Heroin-Seeking And Inhibits Tonic Gaba Currents In The Prelimbic Cortex, Kassandra Looschen, Shailesh N. Khatri, Malabika Maulik, Colin Salisbury, Alaina F. Carman, Katilyn Corriveau, Colton Smith, Dina Manetti, Maria Novella Romanelli, Hugo R. Arias, Cassandra D. Gipson, Swarup Mitra

Markey Cancer Center Faculty Publications

Opioid use disorder is a major public health crisis that is manifested by persistent drug-seeking behavior and high relapse frequency. Most of the available treatments rely on targeting opioid receptors using small molecules that do not provide sustained symptom alleviation. Psychoplastogens are a novel class of non-opioid drugs that produce rapid and sustained effects on neuronal plasticity, intended to produce therapeutic benefits. Ibogalogs are synthetic derivatives of iboga alkaloids that lack hallucinogenic or adverse side effects. In the current study, we examine the therapeutic potential of DM506, a novel ibogalog lacking any cardiotoxic or hallucinogenic effects, in cue-induced seeking behavior …

Cerebrovascular Reactivity Mri As A Biomarker For Cerebral Small Vessel Disease–Related Cognitive Decline: Multi-Site Validation In The Markvcid Consortium, Peiying Liu, Zixuan Lin, Kaisha Hazel, George Pottanat, Cuimei Xu, Dengrong Jiang, Jay J. Pillai, Emma Lucke, Christopher E. Bauer, Brian T. Gold, Steven M. Greenburg, Karl G. Helmer, Kay Jann, Gregory Jicha, Joel Kramer, Pauline Maillard, Rachel M. Mulavelil, Pavel Rodriguez, Claudia L. Satizabal, Kristin Schwab, Sudha Seshadri, Herpreet Singh, Ángel G. Velarde Dediós, Danny J. J. Wang, Rita R. Kalyani, Abhay Moghekar, Paul B. Rosenberg, Sevil Yasar, Marilyn Albert, Hanzhang Lu

Neurology Faculty Publications

INTRODUCTION: Vascular contributions to cognitive impairment and dementia (VCID) represent a major factor in cognitive decline in older adults. The present study examined the relationship between cerebrovascular reactivity (CVR) measured by magnetic resonance imaging (MRI) and cognitive function in a multi-site study, using a predefined hypothesis.

METHODS: We conducted the study in a total of three analysis sites and 263 subjects. Each site performed an identical CVR MRI procedure using 5% carbon dioxide inhalation. A global cognitive measure of Montreal Cognitive Assessment (MoCA) and an executive function measure of item response theory (IRT) score were used as outcomes.

RESULTS: CVR …

Decentralized Clinical Trials For Medications To Reduce The Risk Of Dementia: Consensus Report And Guidance, Leanne Howard, Carla Abdelnour, Erin Abner, Ricardo F. Allegri, Hiroko H. Dodge, Serge Gauthier, Camilla M. Hoyos, Gregory Jicha, Patrick G. Kehoe, Catherine J. Mummery, Adesola Ogunniyi, Nikolaos Scarmeas, Xiaoying Chen, Jodie R. Titiner, Christopher R. Weber, Ruth Peters

Neurology Faculty Publications

INTRODUCTION: Recent growth in the functionality and use of technology has prompted an increased interest in the potential for remote or decentralized clinical trials in dementia. There are many potential benefits associated with decentralized medication trials, but we currently lack specific recommendations for their delivery in the dementia field.

METHODS: A modified Delphi method engaged an expert panel to develop recommendations for the conduct of decentralized medication trials in dementia prevention. A working group of researchers and clinicians with expertise in dementia trials further refined the recommendations.

RESULTS: Overall, the recommendations support the delivery of decentralized trials in dementia prevention …

A Pathologic Study Of Perivascular Ptdp-43 Lin Bodies In Late-Nc, Ryan K. Shahidehpour, Peter T. Nelson, Adam D. Bachstetter

Neurology Faculty Publications

Background TAR DNA-Binding Protein 43 (TDP-43) pathological inclusions are a distinctive feature in dozens of neurodegenerative pathologies, including limbic-predominant age-related TDP-43 encephalopathy neuropathologic change (LATE-NC). Prior investigations identified vascular-associated TDP-43-positive micro-lesions, known as “Lin bodies,” located on or near the brain capillaries of some individuals with LATE-NC. This study aimed to investigate the relationship between the accumulation of Lin bodies and glial cells in LATE-NC and the potential co-localization with ferritin, a protein associated with iron storage. Using multiplexed immunohistochemistry and digital pathology tools, we conducted pathological analyses to investigate the relationship between Lin bodies and glial markers (GFAP for …

Neural Mechanisms Of Respiratory Interoception, Pei-Ying Sarah Chan, Lu-Yuan Lee, Paul W. Davenport

UK CARES Faculty Publications

Respiratory interoception is one of the internal bodily systems that is comprised of different types of somatic and visceral sensations elicited by different patterns of afferent input and respiratory motor drive mediating multiple respiratory modalities. Respiratory interoception is a complex system, having multiple afferents grouped into afferent clusters and projecting into both discriminative and affective centers that are directly related to the behavioral assessment of breathing. The multi-afferent system provides a spectrum of input that result in the ability to interpret the different types of respiratory interceptive sensations. This can result in a response, commonly reported as breathlessness or dyspnea. …

Comprehensive Assessment Of Tdp‑43 Neuropathology Data In The National Alzheimer’S Coordinating Center Database, Davis C. Woodworth, Katelynn M. Nguyen, Lorena Sordo, Kiana A. Scambray, Elizabeth Head, Claudia H. Kawas, María M. Corrada, Peter T. Nelson, S. Ahmad Sajjadi

Neurology Faculty Publications

TDP-43 proteinopathy is a salient neuropathologic feature in a subset of frontotemporal lobar degeneration (FTLD-TDP), in amyotrophic lateral sclerosis (ALS-TDP), and in limbic-predominant age-related TDP-43 encephalopathy neuropathologic change (LATE-NC), and is associated with hippocampal sclerosis of aging (HS-A). We examined TDP-43-related pathology data in the National Alzheimer’s Coordinating Center (NACC) in two parts: (I) availability of assessments, and (II) associations with clinical diagnoses and other neuropathologies in those with all TDP-43 measures available. Part I: Of 4326 participants with neuropathology data collected using forms that included TDP-43 assessments, data availability was highest for HS-A (97%) and ALS (94%), followed by …

Alzheimer’S Disease And Inflammatory Biomarkers Positively Correlate In Plasma In The Uk-Adrc Cohort, Kate E. Foley, Zachary Winder, Tiffany L. Sudduth, Barbara J. Martin, Peter T. Nelson, Gregory Jicha, Jordan P. Harp, Erica M. Weekman, Donna M. Wilcock

Neurology Faculty Publications

INTRODUCTION: Protein-based plasma assays provide hope for improving accessibility and specificity of molecular diagnostics to diagnose dementia. METHODS: Plasma was obtained from participants (N = 837) in our community-based University of Kentucky Alzheimer’s Disease Research Center cohort. We evaluated six Alzheimer’s disease (AD)- and neurodegeneration-related (Aβ40, Aβ42, Aβ42/40, p- tau181, total tau, and NfLight) and five inflammatory biomarkers (TNF𝛼, IL6, IL8, IL10, and GFAP) using the SIMOA-based protein assay platform. Statistics were performed to assess correlations. RESULTS: Our large cohort reflects previous plasma biomarker findings. Relationships between biomarkers to understand AD–inflammatory biomarker correlations showed significant associations between AD and inflammatory …

Hiv-1 Mrna Knockdown With Crispr/Cas9 Enhances Neurocognitive Function, Kristen A. Mclaurin, Hailong Li, Kamel Khalili, Charles F. Mactutus, Rosemarie M. Booze

Neurology Faculty Publications

Mixed glia are infiltrated with HIV-1 virus early in the course of infection leading to the development of a persistent viral reservoir in the central nervous system. Modification of the HIV-1 genome using gene editing techniques, including CRISPR/Cas9, has shown great promise towards eliminating HIV-1 viral reservoirs; whether these techniques are capable of removing HIV-1 viral proteins from mixed glia, however, has not been systematically evaluated. Herein, the efficacy of adeno-associated virus 9 (AAV9)-CRISPR/Cas9 gene editing for eliminating HIV-1 messenger RNA (mRNA) from cortical mixed glia was evaluated in vitro and in vivo. In vitro, a within-subjects experimental design was …

Nalfurafine Promotes Myelination In Vitro And Facilitates Recovery From Cuprizone + Rapamycin-Induced Demyelination In Mice, Ross Van De Wetering, Rabia Bibi, Andy Biggerstaff, Sheein Hong, Bria Pengelly, Thomas E. Prisinzano, Anne C. La Flamme, Bronwyn M. Kivell

Markey Cancer Center Faculty Publications

The kappa opioid receptor has been identified as a promising therapeutic target for promoting remyelination. In the current study, we evaluated the ability of nalfurafine to promote oligodendrocyte progenitor cell (OPC) differentiation and myelination in vitro, and its efficacy in an extended, cuprizone-induced demyelination model. Primary mouse (C57BL/6J) OPC-containing cultures were treated with nalfurafine (0.6–200 nM), clemastine (0.01–100 μM), T3 (30 ng/mL), or vehicle for 5 days. Using immunocytochemistry and confocal microscopy, we found that nalfurafine treatment increased OPC differentiation, oligodendrocyte (OL) morphological complexity, and myelination of nanofibers in vitro. Adult male mice (C57BL/6J) were given a diet con- taining …

Caenorhabditis Elegans Rapgef Promotes Synaptic Development Through A Small G Protein Signaling Cascade, Reagan Em Lamb

Theses and Dissertations--Neuroscience

Synaptic dysfunction is a major contributor toward the development of many neurological disorders. For proper development, synapses require a series of signaling pathways to guide them, but not all the mechanisms underlying these processes are understood. Here, we used the neuromuscular junction of Caenorhabditis elegans as a model circuitry for examining underlying pathways that mediate proper development of synapses. We hypothesized that the C. elegans RapGEF2 and RapGEF6 orthologue, PXF-1, contributed toward development of cholinergic synapses at the neuromuscular junction. Using behavioral assays and fluorescence microscopy, we found that pxf-1 mutant animals had decreased neuromuscular junction function and decreased synaptic …

Characterizing Age-Associated Cd19+ B Cells After Stroke In Aged Male And Female Mice Reveals Sex-Dependent Functional Recovery, Katie Colson

Theses and Dissertations--Neuroscience

Age-Associated B cells (ABCs) are atypical memory B cells commonly expressing CD11b, CD11c, and T-bet. We hypothesized that aged female mice would have worse functional outcomes after stroke due to higher brain-localized ABCs. We identified 6 ABC subsets expressed in the brain, with higher levels in uninjured animals versus 3 weeks after stroke. Contradictory to my hypothesis, aged uninjured males with higher numbers of Classical ABCs (CD11bhighCXCR5+/CXCR5-) in the brain exhibited better motor function, though with limited differences by injury or sex for other classical ABC subsets. Rare CD11b+CXCR5+ populations from uninjured mice secreted more IFN-γ when exposed to TLR7/9 …

The Differential Proteomic Response To Ischemic Stroke In Appalachian Subjects Treated With Mechanical Thrombectomy, Christopher J. Mclouth, Benton Maglinger, Jacqueline A. Frank, Kristin J. Hazelwood, Jordan P. Harp, Will Cranford, Shivani Pahwa, David Dornbos Iii, Amanda L. Trout, Ann M. Stowe, Justin F. Fraser, Keith R. Pennypacker

Neurology Faculty Publications

Introduction The Appalachia region of North America is known to have significant health disparities, specifically, worse risk factors and outcomes for stroke. Appalachians are more likely to have comorbidities related to stroke, such as diabetes, obesity, and tobacco use, and are often less likely to have stroke interventions, such as mechanical thrombectomy (MT), for emergent large vessel occlusion (ELVO). As our Comprehensive Stroke Center directly serves stroke subjects from both Appalachian and non-Appalachian areas, inflammatory proteomic biomarkers were identified associated with stroke outcomes specific to subjects residing in Appalachia. Methods There were 81 subjects that met inclusion criteria for this …

Astrocytic Stress Response Is Induced By Exposure To Astrocyte-Binding Antibodies Expressed By Plasmablasts From Pediatric Patients With Acute Transverse Myelitis, Chad Smith, Kiel M. Telesford, Sara G. M. Piccirillo, Yamhilette Licon‑Munoz, Wei Zhang, Key M. Tse, Jacqueline R. Rivas, Chaitanya Joshi, Dilan S. Shah, Angela X. Wu, Ritu Trivedi, Scott Christley, Yu Qian, Lindsay G. Cowell, Richard H. Scheuermann, Ann M. Stowe, Linda Nguyen, Benjamin M. Greenberg, Nancy L. Monson

Neurology Faculty Publications

Background Pediatric acute transverse myelitis (ATM) accounts for 20–30% of children presenting with a first acquired demyelinating syndrome (ADS) and may be the first clinical presentation of a relapsing ADS such as multiple sclerosis (MS). B cells have been strongly implicated in the pathogenesis of adult MS. However, little is known about B cells in pediatric MS, and even less so in pediatric ATM. Our lab previously showed that plasmablasts (PB), the earliest B cell subtype producing antibody, are expanded in adult ATM, and that these PBs produce self‑reactive antibodies that target neurons. The goal of this study was to …

Different Cohort, Disparate Results: Selection Bias Is A Key Factor In Autopsy Cohorts, Kathryn Gauthreaux, Walter A. Kukull, Karin B. Nelson, Charles Mock, Yen-Chi Chen, Kwun C. G. Chan, David W. Fardo, Yuriko Katsumata, Erin L. Abner, Peter T. Nelson

Neurology Faculty Publications

INTRODUCTION: Research-oriented autopsy cohorts provide critical insights into dementia pathobiology. However, different studies sometimes report disparate findings, partially because each study has its own recruitment biases. We hypothesized that a straightforward metric, related to the percentage of research volunteers cognitively normal at recruitment, would predict other inter-cohort differences.

METHODS: The National Alzheimer’s Coordinating Center (NACC) provided data on N = 7178 autopsied participants from 28 individual research centers. Research cohorts were grouped based on the proportion of participants with normal cognition at initial clinical visit.

RESULTS: Cohorts with more participants who were cognitively normal at recruitment contained more individuals who …

Cognitive Decline, Aβ Pathology, And Blood–Brain Barrier Function In Aged 5xfad Mice, Geetika Nehra, Sasivimon Promsan, Ruedeemars Yubolphan, Wijitra Chumboatong, Pornpun Vivithanaporn, Bryan J. Maloney, Anusorn Lungkaphin, Bjoern Bauer, Anika M. S. Hartz

Markey Cancer Center Faculty Publications

Background

Patients with Alzheimer’s disease (AD) develop blood–brain barrier dysfunction to varying degrees. How aging impacts Aβ pathology, blood–brain barrier function, and cognitive decline in AD remains largely unknown. In this study, we used 5xFAD mice to investigate changes in Aβ levels, barrier function, and cognitive decline over time.

Methods

5xFAD and wild-type (WT) mice were aged between 9.5 and 15.5 months and tested for spatial learning and reference memory with the Morris Water Maze (MWM). After behavior testing, mice were implanted with acute cranial windows and intravenously injected with fluorescent-labeled dextrans to assess their in vivo distribution in the …

Oxidative Stress Alters Mitochondrial Homeostasis In Isolated Brain Capillaries, Gopal V. Velmurugan, Hemendra J. Vekaria, Anika M. S. Hartz, Björn Bauer, William Brad Hubbard

Markey Cancer Center Faculty Publications

Background

Neurovascular deficits and blood-brain barrier (BBB) dysfunction are major hallmarks of brain trauma and neurodegenerative diseases. Oxidative stress is a prominent contributor to neurovascular unit (NVU) dysfunction and can propagate BBB disruption. Oxidative damage results in an imbalance of mitochondrial homeostasis, which can further drive functional impairment of brain capillaries. To this end, we developed a method to track mitochondrial-related changes after oxidative stress in the context of neurovascular pathophysiology as a critical endophenotype of neurodegenerative diseases.

Methods

To study brain capillary-specific mitochondrial function and dynamics in response to oxidative stress, we developed an ex vivo model in which …

Impacts Of Xylazine On Fentanyl Demand, Body Weight, And Acute Withdrawal In Rats: A Comparison To Lofexidine, Safiyah M. Sadek, Shailesh N. Khatri, Zachary A. Kipp, Kelly E. Dunn, Joshua S. Beckmann, William W. Stoops, Terry D. Hinds, Jr., Cassandra D. Gipson

Markey Cancer Center Faculty Publications

The opioid use landscape has recently shifted to include xylazine, a veterinary anesthetic, as an adulterant in the fentanyl supply. The health impacts of xylazine as an emerging fentanyl adulterant has raised alarm regarding xylazine as a public health threat, warranting research on the impacts of xylazine on fentanyl’s behavioral effects. No prior studies have evaluated the effects of xylazine on fentanyl consumption at various unit doses, fentanyl demand, or withdrawal as compared to the Food and Drug Administration-approved opioid withdrawal medication, lofexidine (Lucemyra®). This is important because lofexidine and xylazine are both adrenergic α2a (A2aR) agonists, however, lofexidine is …

Oxycodone Withdrawal Is Associated With Increased Cocaine Self-Administration And Aberrant Accumbens Glutamate Plasticity In Rats, Shailesh N. Khatri, Hanaa Ulangkaya, Erin E. Maher, Safiyah M. Sadek, Mei Hong, Andrea M. Woodcox, William W. Stoops, Cassandra D. Gipson

Markey Cancer Center Faculty Publications

Individuals with opioid use disorder (OUD) frequently use other substances, including cocaine. Opioid with- drawal is associated with increased likelihood of cocaine use, which may represent an attempt to ameliorate opioid withdrawal effects. Clinically, 30% of co-using individuals take opioids and cocaine exclusively in a sequential manner. Preclinical studies evaluating mechanisms of drug use typically study drugs in isolation. However, polysubstance use is a highly prevalent clinical issue and thus, we established a novel preclinical model of sequential oxycodone and cocaine self-administration (SA) whereby rats acquired oxycodone and cocaine SA in an A-B-A-B design. Somatic signs of withdrawal were evaluated …

A Blunted Th17 Cytokine Signature In Women With Mild Cognitive Impairment: Insights From Inflammatory Profiling Of A Community-Based Cohort Of Older Adults, Adam D. Bachstetter, Jenny Lutshumba, Edric D. Winford, Erin L. Abner, Barbra J. Martin, Jordan P. Harp, Linda J. Van Eldik, Frederick A. Schmitt, Donna M. Wilcock, Ann M. Stowe, Gregory A. Jicha, Barbara S. Nikolajczyk

Markey Cancer Center Faculty Publications

People with dementia have an increase in brain inflammation, caused in part by innate and adaptive immune cells. However, it remains unknown whether dementia-associated diseases alter neuro-immune reflex arcs to impact the systemic immune system. We examined peripheral immune cells from a community-based cohort of older adults to test if systemic inflammatory cytokine signatures associated with early stages of cognitive impairment. Human peripheral blood mononuclear cells were cultured with monocyte or T-cell-targeted stimuli, and multiplex assays quantitated cytokines in the conditioned media. Following T-cell-targeted stimulation, cells from women with cognitive impairment produced lower amounts of TH17 cytokines compared with cells …