Neurosciences Commons^™

Insulin Resistance As A Mediator Of Physical Activity's Effects On Beta-Amyloid Accumulation And Tau Phosphorylation: A Scoping Review, Michael G. Slee, Joanne Scotney, Stephanie R. Rainey-Smith, Kirk I. Erickson, Hamid R. Sohrabi, Giuseppe Verdile, Belinda M. Brown

Research outputs 2022 to 2026

Background Type 2 diabetes is associated with increased Alzheimer’s disease risk and brain beta amyloid (Aβ) burden, suggesting an underlying mechanistic relationship between Alzheimer’s disease and type 2 diabetes. Animal studies show exercise reduces levels of brain Aβ and tau, and while human studies are somewhat limited, some studies have reported physical activity is associated with lower brain Aβ and tau levels. Exercise has well established links to reductions in insulin resistance; thus, as physical activity can impact both insulin resistance and Alzheimer’s disease pathology and/or biomarkers, it is reasonable to hypothesise that a mediating relationship may exist. The objective …

Plasma Aβ42/40 Predicts Progression From Aβ-Amyloid Negative To Positive Pet Scans, Azadeh Feizpour, Vincent Doré, Pierrick Bourgeat, James D. Doecke, Rodrigo Canovas, Simon M. Laws, Tenielle Porter, Kun Huang, Christopher Fowler, Ralph N. Martins, Paul Maruff, Hamid R. Sohrabi, Michael W. Weiner, John C. Morris, Tammie L.S. Benzinger, Suzanne E. Schindler, Randall J. Bateman, Yan Li, Ovod Vitaliy, Larry Ward, Jurgen Mejan-Fripp, Colin L. Masters, Victor L. Villemagne, Christopher C. Rowe

Research outputs 2022 to 2026

Background The agreement between plasma Aβ42/40 and Aβ positron emission tomography (PET) is approximately 75 %, with ∼85 % of discrepancies due to positive plasma but negative PET results. It is unclear whether this reflects Aβ changes in plasma before PET-detectable. Objectives To assess the influence of Aβ42/40 positivity on risk of progression to Aβ PET positivity, and feasibility of using plasma Aβ42/40 tests to enrich a primary prevention trial. Design A prospective longitudinal cohort study. Setting Participants of Australian Imaging, Biomarkers and Lifestyle study (AIBL), Alzheimer’s Disease Neuroimaging Initiative (ADNI), and Open Access Series of Imaging Studies 3 (OASIS3). …

Educational Attainment And Symptom Improvement In Treatment-Resistant Depression: A Longitudinal Cohort Analysis Across Treatment Modalities, Marjorie Harrison, Giselli Scaini Msc, Phd, Aspen Viamontes

Summer Research Program Abstracts

No abstract provided.

Neurodevelopmental Outcomes After Posthemorrhagic Hydrocephalus Of Prematurity, Mekal S. Mathew, Rene Leal, Caroline L. Hanan, David J. Sun, Hasan K. Mubarak, Amelie D. Perrier, William E. Johnson, Micolette R. Mardik, Trevor R. Alwell, Christian Amezquita Contreras, Chance E. Hatfield, Peter H. Yang

Summer Research Program Abstracts

No abstract provided.

Sarcopenia, Obesity, Sarcopenic Obesity And Dementia Risk: A Systematic Review And Meta-Analysis Of Cohort Studies, Uraiporn Booranasuksakul, Zhongyang Guan, Leticia Radin Pereira, Kostas Tsintzas, Ian Macdonald, Ellise Stirling, Sana Farzam, Lorenzo M. Donini, Alexandra M. Johnstone, Marc Sim, Blossom Stephan, Mario Siervo

Research outputs 2022 to 2026

Sarcopenia and obesity, characterised respectively by reduced muscle mass and function and increased adiposity, may co-occur as sarcopenic obesity (SO). This systematic review summarises cohort evidence linking these body composition phenotypes to dementia risk. MEDLINE, EMBASE, Cochrane Database and PsycINFO were searched from inception to February 2026. Outcomes included incident all-cause dementia (ACD) and subtypes. Pooled hazard ratios were calculated for each phenotype using random-effects models. Fourteen publications were included for sarcopenia, 72 for obesity, and four for SO. Late-life obesity (≥65 years) was protective for ACD (HR 0.83, 95% CI 0.76–0.89), whereas mid-life obesity (<65 years) modestly increased risk (HR 1.09, 95% CI 1.01–1.16). Sarcopenia was associated with increased risk (HR 1.42, 95% CI 1.26–1.58). SO showed no significant association (HR 1.43, 95% CI 0.87–1.99). These findings highlight age-dependent effects of obesity and an elevated dementia risk with sarcopenia; the predictive role of SO requires further research.

Refining Aicardi Syndrome Diagnostic Criteria: An Expert-Based Consensus Using A Modified Delphi Approach, Silvia Masnada, Valentina De Giorgis, Umberto Carugo, Nadia Bahi-Buisson, Mara Cavallin, Mark Corbett, Manuela Formica, Jozef Gecz, Natalia Petros, Emilio Perucca, Anna Pichiecchio, Paolo Fusar Poli, Elliott H Sherr, Ignatia B Van Den Veyver, Federico Zara, Martin Geroldinger, Pierangelo Veggiotti, Alexis Arzimanoglou

Duncan NRI Faculty and Staff Publications

Background and objectives: Aicardi syndrome (AIC) is a rare neurodevelopmental disorder historically characterised by the presence of chorioretinal lacunae, corpus callosum agenesis, infantile spasms and several supporting features that aid in diagnosis. However, the unclear aetiology and evolving diagnostic tools have led to ongoing reconsideration of the criteria, based on individual approaches. Our study aimed to establish, for the first time, an expert-based consensus on diagnostic criteria for AIC by integrating both existing and novel ones.

Methods: A geographically diverse and multidisciplinary group of expert physicians was invited to participate in a modified Delphi study, to achieve consensus on major, …

Beta-Band Modulation Reveals The Cortical Dynamics Of Auditory Statistical Learning In Children, Jarrad A.G Lum, Christine N. Moreau, Li Ann Leow, Welber Marinovic, Sarah J. Lum, Marc F. Joanisse, Laura J. Batterink

Research outputs 2022 to 2026

Children's ability to extract statistical regularities from speech is considered fundamental to lexical, syntactic, and grammatical development. However, the neural oscillatory mechanisms supporting this process in childhood remains poorly understood. While beta-band oscillations have been linked to statistical learning in visual and motor domains, it is unclear whether similar dynamics support auditory statistical learning in children. In this study, we recorded electroencephalography (EEG) from children aged 8–12 years as they listened to a continuous stream of trisyllabic nonwords (e.g., dapiku), where syllable order within each nonword was fixed (high predictability), but transitions between nonwords were variable (low predictability). Beta power …

Unraveling The Significance Of Fecal Microrna Profile In Alzheimer’S Disease, Kavisha Katuwawala, Prashant Bharadwaj, Ian Martins, B. G.D.N.K. De Silva, Vincent Ho, Asiri Dissanayake, Ralph N. Martins, W. M.A.D.Binosha Fernando

Research outputs 2022 to 2026

Alzheimer’s disease (AD), a complex neurodegenerative disorder characterised by progressive cognitive decline, affects millions globally. With no current cure, treatment focuses on symptom management and slowing disease progression. Early identification is therefore crucial. Fecal microRNA (miRNA) analysis is emerging as a promising non-invasive diagnostic tool. Evidence suggests that miRNAs present in fecal samples may regulate gene expression linked to AD pathology, impacting cellular functions and disease progression. Dietary factors critically influence gut microbiota composition and diversity, affecting brain health via the gut brain axis. Macronutrients such as carbohydrates, proteins, and fats modulate miRNA expression and gut microbiota, influencing AD risk. …

Exploring The Mechanisms Of Tanshinone Iia In The Treatment Of Intracranial Aneurysm Based On Network Pharmacology And Machine Learning, Wanqi Wang, Lois Balmer, Shaotao Weng

Research outputs 2022 to 2026

Background Intracranial aneurysm (IA) is a cerebrovascular disease with high mortality and limited treatment options. Tanshinone IIA (Tan IIA), a bioactive compound from Salvia miltiorrhiza , has shown vascular protective effects, but its mechanism in the treatment of IA remains unclear. Methods The GSE75436 dataset was used to identify differentially expressed genes (DEGs). Weighted gene co-expression network analysis (WGCNA) was performed to identify disease-related modules. IA targets were obtained from GeneCards and the Comparative Toxicogenomics Database (CTD). Potential targets of Tan IIA were predicted using TCMSP, SwissTargetPrediction, and SymMap. KEGG enrichment analysis was conducted for DEGs, WGCNA modules, disease-related genes, …

Gut Microbial Composition And Short-Chain Fatty Acid Metabolism In Cognitively Unimpaired Adults Stratified By Amyloid-Β Status, D. M.Sithara Dissanayaka, Thilini N. Jayasinghe, Hamid R. Sohrabi, Stephanie R. Rainey-Smith, Kevin Taddei, Colin L. Masters, Ralph N. Martins, W. M.A.D.Binosha Fernando

Research outputs 2022 to 2026

Short-chain fatty acids (SCFAs) produced by gut microbial fermentation influence host metabolism and neuroinflammatory processes implicated in Alzheimer’s disease (AD). However, the relationship between fecal SCFAs, microbial taxa, and cerebral amyloid-β (Aβ) burden in cognitively unimpaired individuals remains unclear. Fecal SCFAs were quantified using GC-MS, and microbial species were profiled by shotgun metagenomics in 87 participants. Associations between SCFAs, demographics, APOE ε4 status, and Aβ burden were tested using nonparametric statistics and multivariable regression. Microbial–SCFA links were evaluated using Spearman correlations and multivariate ordinations, with mediation analysis exploring potential indirect pathways. Acetate was the predominant SCFA and demonstrated the most …

Prevalence Of Dementia In Selected Middle East And North Africa (Mena) Countries: A Systematic Review And Meta-Analysis, Mohsen Sedighi, Mohammad Hasan Shahabi, Alireza Amanollahi, Khurshid Alam, Soudabeh Shemehsavar, Zahra Shirzadi, Serena Sabatini, Ahmad R. Khatoonabadi, Matthew Prina, Akram A. Hosseini, Claire V. Burley, Jennifer Dunne, Simin Mahinrad, Iman Dajani, Ralph N. Martins, Blossom C.M. Stephan, Ali Chaari, Hamid R. Sohrabi

Research outputs 2022 to 2026

Data on dementia epidemiology in the Middle East and North Africa (MENA) region is limited. This systematic review and meta-analysis examined dementia prevalence across MENA. Databases were searched up to October 2024. Analyses were stratified by country and sex. Pooled prevalence was estimated using a random-effects model with a 95% confidence interval (CI). Fifty-two studies on the selected countries met inclusion criteria, covering 87,219 individuals with dementia from a total population of 1,045,908. The pooled prevalence was 12.16% (95% CI: 9.61–14.96) for the region and the Israel had the highest prevalence (17.00%), followed by Iran (13.20%), Turkey (11.40%), Saudi Arabia …

Neural Correlates Of Cognitive Fatigue In Regular Cannabis Users And Non-Users: A Pilot Fnirs Study, Mariia Vistyzenko

Theses and Dissertations (Comprehensive)

Background: Cognitive fatigue impairs performance across multiple domains, yet how regular cannabis use affects fatigue responses remains unclear. This pilot study investigated neural and behavioural correlates of cognitive fatigue in abstinent cannabis users versus non-users.

Methods: Twenty-six participants (18 non-users, 8 regular cannabis users after 24-hour abstinence) completed cognitive tasks before and after a 60-minute Sustained Attention to Response Task (SART) designed to induce fatigue. Tasks assessed working memory (N-Back), cognitive flexibility (Wisconsin Card Sorting), psychomotor speed (Digit Symbol Substitution), sustained attention (Continuous Performance Task), inhibition (Stroop, Stop Signal), and motion perception. Functional near-infrared spectroscopy (fNIRS) continuously monitored prefrontal cortex …

Circulating Metabolite Signatures Associated With Amyloid Positivity, Cognitive Performance And Plasma P-Tau181 Levels In Cognitively Unimpaired Older Adults, Tahmida Sharmin, James D. Doecke, Pratishtha Chatterjee, Hamid R. Sohrabi, Henrik Zetterberg, Nicholas J. Ashton, Manohar L. Garg, Kaj Blennow, Ralph N. Martins

Research outputs 2022 to 2026

Emerging evidence suggests altered circulating metabolite levels in individuals with Alzheimer’s disease (AD) and/or mild cognitive impairment (MCI) compared to healthy controls; how these metabolites alter with early cortical amyloidosis—before symptom onset—remains unclear. This cross-sectional study aimed to investigate plasma metabolites obtained through targeted profiling using the Biocrates AbsoluteIDQ® p400 HR kit. The study cohort comprises 100 cognitively unimpaired (CU) older adults, stratified into CU Aβ− (negative positron emission tomography [PET]-amyloid-beta [Aβ]) and CU Aβ+ (positive PET-Aβ) groups. Significantly altered metabolites were further analysed for associations across amyloid plaque deposition, cognitive performance and plasma tau phosphorylated at threonine 181 (P-tau181) …

Loss Of The Maternal Effect Gene Nlrp2 Impairs Embryonic And Extra-Embryonic Development, Revealing A Novel Genetic Cause Of Congenital Anomalies†, Momal Sharif, Zahra Anvar, Imen Chakchouk, Sara H El-Dessouky, Roni Zemet, Eric C Kao, Wessam E Sharaf-Eldin, Ying-Wooi Wan, Zhandong Liu, Pengfei Liu, Michael Jochum, Ignatia B Van Den Veyver

Duncan NRI Faculty and Staff Publications

Maternal-effect genes (MEGs) play a crucial role in early mammalian development, and their dysfunction can lead to severe embryonic and extra-embryonic abnormalities. NLRP2, a MEG that encodes a subcortical maternal complex (SCMC) protein, has been implicated in preimplantation development, but its role after implantation remains underexplored. In this study, we investigated the developmental consequences of maternal Nlrp2 loss-of-function in a maternal knockout (KO) mouse model at embryonic day 11.5. Embryos derived from Nlrp2-KO females have abnormal yolk sac vasculature, increased embryonic resorption, craniofacial abnormalities, neural tube defects, and congenital heart defects. Placental architecture is disrupted with an altered junctional zone …

Exploring The Role Of Astrocyte System Xc– In Excitatory/Inhibitory Balance, Samantha Olivia Sutton

Theses - ALL

Astrocytes play a central role in maintaining excitatory/inhibitory (E/I) balance in the central nervous system by supporting intracellular glutathione (GSH) synthesis and regulating extracellular glutamate. System xc– (Sxc–), an obligate cystine/glutamate antiporter encoded by SLC7a11, couples the import of L-cystine with the export of L-glutamate. It is highly expressed throughout the cortex, hippocampus, striatum, and cerebellum, where its activity provides cystine—the rate-limiting substrate for cysteine-dependent GSH production—and contributes to ambient glutamatergic tone. Although global loss of Sxc– alters seizure threshold and redox homeostasis, whether these effects arise specifically from the loss of astrocytic Sxc– has remained unresolved. This thesis examined …

Abnormalities In Sensorimotor Brain Function Are Related To Chronicity Of Low Back Pain, Jo Armour Smith, Rongwen Tain, Kelli G. Sharp, Laura M. Glynn, Linda R. Van Dillen, Jesse V. Jacobs, Steven C. Cramer

Physical Therapy Faculty Articles and Research

Maladaptive plasticity in the brain may contribute to chronic low back pain (LBP) and underlie the altered postural control of the lumbopelvic musculature that is evident in some individuals with LBP. We recently described an MRI-compatible leg-raise paradigm to measure brain activity associated with lumbopelvic postural control. The objective of this study was to compare brain function in young adults with and without a history of LBP and to determine relationships between brain function, pain, and postural control characteristics. We recruited 55 participants with a history of LBP, who were asymptomatic when studied, and 30 healthy controls. Postural control during …

Metabolomic Profiling Reveals Brain Lipid Alterations In Pex7-Deficient Models Of Rhizomelic Chondrodysplasia Punctata, Riya Sankhe, Meredith I Williams, Wedad Fallatah, Laura Mackay, Mary Layne Brown, Pranjali Bhagwat, Sarah H Elsea, Nancy Braverman, Michael F Wangler

Duncan NRI Faculty and Staff Publications

Rhizomelic chondrodysplasia punctata type 1 (RCDP1) is a peroxisomal disorder characterized by skeletal shortening, intellectual disability, seizures, cataracts, and reduced lifespans. RCDP1 is caused by biallelic loss-of-function variants in PEX7, which encodes a protein required for importing select enzymes into the peroxisome matrix, including those essential for ether lipid synthesis (e.g., plasmalogens) and the branched-chain fatty acid catabolism. Plasmalogen deficiency is a hallmark of RCDP1 and other peroxisomal disorders, including RCDP types 2-5 (RCDP2-5) and Zellweger spectrum disorders (ZSD). Here, we performed comprehensive metabolomic profiling of clinical samples from RCDP patients and Pex7-deficient mouse models. We identified profound …

Acute And Chronic Effects Of Neuroinflammation On Hippocampus And Anterior Cingulate Cortex Network Dynamics, Lauren A. Crew

UNLV Theses, Dissertations, Professional Papers, and Capstones

Neuroinflammation has emerged as a critical modulator of cognitive function and neural circuit dynamics, yet the distinct contributions of acute and chronic neuroinflammation to brain function remain poorly defined. This dissertation examines how inflammation independently alters large-scale neural activity and behavior, focusing on interactions between the hippocampus (HPC) and anterior cingulate cortex (ACC), regions essential for memory and executive processes. Using in vivo electrophysiological techniques in a rodent model, this study compares the effects of short-term (acute) and prolonged (chronic) neuroinflammatory states, induced via Poly I:C, on neural oscillations, regional coherence, and spatial coding. Findings reveal that even transient inflammation …

Seizures In Camp Settings, Sandra Shapiro, Taylor Gilman, Tamar Sternfield, Jolie Skivington

CompassPoint

Managing seizures in the summer camp environment presents unique challenges, requiring not only medical attention but also empathy and understanding from both peers and caregivers. Approximately 0.5–5% of children and adolescents will experience at least one afebrile seizure by adolescence and there is a 3.6% risk of experiencing at least one seizure in an 80-year-lifespan (Murphy et al., 1995 as cited in Wilfong, 2025). Recognizing how to support a child with seizures during the camp season is essential to promoting their safety and well-being while also ensuring they have a positive and inclusive camp experience.

Spike Timing Depended Plasticity Produces Unsupervised Learning Of Synergistic Muscle Feedback In A Synthetical Neural Network, Mark Allen Pupkiewicz

Dissertations and Theses

This study investigates how type Ia feedback from muscle spindles can be organized into groups representing agonistic muscle pairs through Spike Timing Dependent Plasticity (STDP). A single degree of freedom joint is actuated with four biologically modeled muscles forming two agonistic pairs. In order to emulate the sensory dynamics of biological muscle spindles, sensors in the model record the active length and velocity states of each muscle, the two primary factors eliciting type Ia afferent responses. In biological networks, synapses from Ia sensory neurons frequently activate interneurons representing agonistic muscle sources. This research investigates whether this organization can emerge in …