Physiology Commons^™

Effect Of Jet Lag And Nighttime Shifts On The Circadian Rhythm Of Humans, Mahd Adrees

Williams Honors College, Honors Research Projects

This project reviews the circadian rhythm and its disruption by jet lag and nighttime shifts. It discusses the effects on melatonin, sleep quality, and physiological symptoms using articles from Google Scholar. Key studies, mechanisms, and statistics will support these points. A discussion follows, comparing and contrasting the various literature sources. This review aims to raise awareness and summarize strategies to reduce jet lag and nighttime shift effects, improving wellbeing.

Physiological Development Of Hypertension As A Result Of High-Fat Diet Induced Obesity, Michael Nguyen

Williams Honors College, Honors Research Projects

This literature review focuses on the physiological development of obesity due to the consumption of diets rich in fats and the resulting pathophysiological development of hypertension. This review aims to identify causes of obesity and hypertension as well as current treatments to propose future areas of study. The literature review analyzed a wide variety of literature sources on obesity and hypertension published between the years 1995 and 2025. The review identifies high-fat diets as a cause of obesity and the resulting health effects of elevated leptin, insulin, and nervous system activity as contributors to the development of hypertension. Future areas …

Toadally Not A Frog: A Neuromuscular Physiology Study, Iris Renna

Williams Honors College, Honors Research Projects

Upper-level physiology labs in undergraduate education use freshly isolated bullfrog and/or leopard frog tissue to teach core concepts in nerve and muscle physiology. Sourcing live animals for routine educational use raises ethical and conservation concerns. Cane toads (Rhinella marina) are an invasive species that are routinely culled, can provide a potential source of laboratory animals which would remove pressure to native amphibian populations. This study tested the hypothesis that cane toads can serve as a functional substitute for bullfrogs and/or leopard frogs in the muscle and nerve physiology lab. Isolated sciatic nerve and gastrocnemius muscle preparations from cane …

Bmal1 Mediates Sex-Specific Circadian Regulation Of Cardiac Ion Channels And Temporal Arrhythmia Vulnerability, Brian P. Delisle, Ezekiel Rozmus, Abhilash Prabhat, Spencer B. Procopio, Xiping Zhang, Emilia Entcheva, Karyn A. Esser, Elizabeth Schroder

Physiology Faculty Publications

No abstract provided.

C/Ebpα Is Essential For Gonadal But Not Inguinal White Adipose Tissue Formation In Mice, Krista Y. Hu, Yu-Lin Ma, Esme A. Dodge, Olivia A. B. Maguire, Caio V. Matias, Ryan K. Barney, Hector S. Himede, Juliana Gomez Pardo, Miriam Cepeda, Scott M. Gordon, Robert C. Bauer

Physiology Faculty Publications

Objective: The distribution of excess white adipose tissue (WAT) in obesity correlates with risk for comorbidities. Thus, understanding depot-specific WAT developmental mechanisms is translationally relevant. SNPs near the gene CEBPA associate with waist to hip ratio, and while C/EBPα is a recognized regulator of adipogenesis, there is no previously known role for C/EBPα in regulating adipose distribution.

Methods: We crossed Cebpa floxed mice to the AdipoQ-Cre transgenic mouse strain, generating mice with adipocyte-specific knockout of Cebpa (Cebpa_ASKO). Mice were phenotyped on a chow diet and after prolonged high-fat diet (HFD) feeding.

Results: Cebpa_ASKO mice almost entirely lack gonadal …

Dim Light At Night Worsens Cardiac Autonomic Dysregulation In Female Diabetic Mice, Abhilash Prabhat, Shrishti Naidu, Isabel G. Stumpf, Tanya S. Seward, Elizabeth A. Schroder, Brian P. Delisle

Physiology Faculty Publications

Cardiovascular autonomic neuropathy (CAN) is a common complication of diabetes mellitus. CAN is characterized by impaired cardiovascular autonomic control and is associated with increased mortality, especially among women with type 2 diabetes. Identifying environmental factors that exacerbate the CAN-associated phenotype may reveal modifiable strategies to reduce cardiovascular risk.

Nighttime light exposure is a novel cardiovascular risk factor. Among ∼90,000 individuals, greater nighttime light exposure correlated with increased atrial fibrillation and heart failure risk. Light at night disrupts sympathovagal balance and elevates nocturnal heart rate in humans. Dim light at night similarly disrupts autonomic regulation of heart rate in mice. We …

Early Microglial Response To Amyloid Plaques Drives Sleep Loss In Alzheimer’S Disease, Nicholas J. Constantino, Riley E. Irmen, Matthew J. Lanning, Sierra M. Turner, Clair C. Ashley, Caitlin M. Carroll, Evan M. Neary, Dave Rubinow, J. Andy Snipes, Shannon L. Macauley

Physiology Faculty Publications

Introduction: Sleep disruption is an early feature of Alzheimer's disease (AD), but the cellular mechanisms linking amyloid pathology to sleep loss remain unclear.

Methods: Electroencephalography/electromyography (EEG/EMG) recordings, quantitative EEG analysis, and sleep deprivation were performed in APPswe/PSEN1dE9 (APP/PS1) mice at different stages of pathology relative to normal aging. Amyloid burden and microglial density were quantified with whole-brain light-sheet microscopy. CSF1R-mediated microglial depletion explored effects of microglia on sleep loss.

Results: Amyloid plaques caused non–rapid eye movement (NREM) sleep loss that did not worsen with increased plaque burden. Aging reduced REM sleep and eliminated sleep rebound. Amyloid pathology was associated with …

Ultrasound-Derived Liver Composition And Metabolic Flexibility Under Exercise Stress, Rhodes Van Houten

All Master's Theses

Metabolic Associated Fatty Liver Disease (MAFLD) is characterized by abnormal liver fat accumulation in conjunction with metabolic syndromes. MAFLD affects 33% of individuals worldwide, though little is known about how increased liver fat impacts physiological responses to exercise. This study aimed to analyze the relationship between liver composition and metabolic flexibility during a graded exercise test.  Body composition was analyzed via dual-energy X-ray absorptiometry. Liver ultrasound was evaluated for echogenicity, where elevated mean gray volume (MGV) indicates abnormal liver tissue. Rates of fat (FATox) and carbohydrate (CHOox) oxidation (g/min), respiratory exchange ratio (RER), and blood lactate concentrations ([LA^-], …

Low Energy Availability And Dietary Factors In High School Runners, Natalie E. Allik

All Master's Theses

Context: Low energy availability (LEA) is associated with adverse health and performance outcomes in athletes and may be particularly concerning during adolescence when growth and bone development are ongoing. Although inadequate carbohydrate (CHO) intake has been proposed as a contributor to LEA, limited research has examined this relationship in adolescent endurance athletes. Objective: To examine dietary intake, bone mineral density (BMD), and eating disorder (ED) risk in adolescent distance runners with and without LEA. Methods: Eighteen adolescent distance runners (15.7 ± 1.2 years; 7 males, 11 females) completed baseline assessments including anthropometrics, dual-energy X-ray absorptiometry (DXA), a 24-hour dietary recall, …

Human Plasma Extracellular Vesicles As An Exercise Mimetic To Preserve Skeletal Muscle Plasticity During Disuse, Alexander M. Fliflet, Yanqi Tan, Takeshi M. Barnes, Ane Nishitha Vijayan, Sung Jun Choi

Kinesiology & Sport Management Scholarship

The purpose of this study was to determine the extent to which extracellular vesicles (EVs) circulating in blood after exercise training act as an effective mimetic to maintain skeletal muscle mass during unloading and/or accelerate recovery after disuse. Ten healthy males (27.7 ± 7.1 y) were recruited for a 6-week progressive resistance and endurance training program. EVs were isolated from blood before (EVs) or immediately after training (ExerVs). EVs were intraperitoneally injected into male mice (4×; 3 × 108 particles/injection) during 14 days of hindlimb unloading (HU), then the muscles were collected immediately or 7 days after HU. ExerVs did …

How Effective Is Online Teaching Of Physiology Modules? Perception Of Rwandan Health Sciences Students, Abdullateef Isiaka Alagbonsi, Mojeed Akorede Gbadamosi, Mathieu Nemerimana, Makinde V. Olubiyi, Olufunke Onaadepo, Akaninyene Ubong Ime, Abdul-Rahuf Aderemi Feyitimi, Ruth Wanjiru Mungai, Florent Rutagarama, Simiat Elias

Biomedical Sciences, East Africa

Background: While blended teaching is approved in Rwandan medical education, the perceived effectiveness of online-only delivery for physiology modules remains unclear. This uncertainty limits its continued use. The present study assessed Rwandan health sciences students’ perceptions of the effectiveness of online teaching for physiology modules.

Methods: A total of 528 students from medicine and surgery (n = 300), pharmacy (n = 99), dentistry (n = 89), and clinical psychology (n = 40) programs at the University of Rwanda completed an online questionnaire. Data were analyzed using multivariable logistic regression and non-parametric tests (Mann-Whitney U, Kruskal-Wallis) with corresponding effect …

Eeg And Imu Gait Signal Processing: A Comparative Assessment Of The "Reza" Exponential Filter And Classic Filters, Reza Pousti, Daniel M. Russell, Derek C. Monroe, Christopher K. Rhea

Rehabilitation Sciences Faculty Publications

Noise degrades both EEG and gait signals, and classical IIR filters (Butterworth, Chebyshev, elliptic) involve trade-offs between passband flatness, ripple, and roll-off. This study compared a novel exponential "Reza" filter with these designs for neural and locomotor data. We analyzed an open-source mobile brain-body imaging dataset with EEG and gait data from 49 healthy adults (EEG: 256-channel, 512 Hz; IMUs: six APDM Opals, 128 Hz). EEG channels were grand-averaged and band-pass filtered at 0.5-50 Hz, while IMU axes were averaged and band-pass filtered at 0.5-5 Hz. The outcomes were signal-to-noise ratio SNR (dB) and band-integrated Welch PSD (EEG:0.5-50 Hz; IMU:0.5-5 …

The Sequence (S) Index As A Marker Of Diminished Step-To-Step Transition Efficiency In Older Adults, Elham Alijanpour, Ashwini Kulkarni, Peter G. Adamczyk, Daniel M. Russell

Rehabilitation Sciences Faculty Publications

Introduction: Age-related declines in walking efficiency are often attributed to musculoskeletal and neuromuscular changes, yet the mechanisms underlying these inefficiencies remain poorly understood. One key contributor is the step-to-step transition (STST), during which the center of mass (CoM) is redirected between limbs. The Sequence (S) index quantifies the temporal overlap between push-off and collision forces during STST, with higher values indicating greater mechanical energy loss. This study investigated whether aging affects STST efficiency, as quantified by the S index, and examined the timing and impulse characteristics underlying observed differences.

Methods: Thirteen young and eleven older healthy adults walked at five …

Ultrasound-Based Assessment Of Talar Cartilage In Individuals With Chronic Ankle Instability: A Systematic Review, Amin Mohammadi, Saeed Eshghi, Iman Mohammadi, Patrick Wilson, Ryan Mccann

Rehabilitation Sciences Faculty Publications

Purpose

To systematically synthesize ultrasound (US) evidence on talar cartilage morphology and load-induced deformation in individuals with chronic ankle instability (CAI), and to map methodological approaches (acquisition, outcome definitions, loading paradigms, and normalization) to inform protocol standardization.

Methods

PubMed, Web of Science, and EBSCO were searched (March 31, 2025). Eligible studies reported quantitative US-derived talar cartilage morphology (e.g., thickness, cross-sectional area [CSA]) and/or deformation following standardized loading in CAI and comparison groups. Due to heterogeneity in imaging protocols, loading tasks, and outcome definitions, findings were synthesized narratively and organized by outcome domain.

Results

Across available cohorts, load-induced deformation was the …

Spiders In The World Of Pesticides: A Review, Jackson L. Mendillo

Williams Honors College, Honors Research Projects

Pesticides and other agrochemicals have varying effects on spiders depending on their mechanism of action and dosage, ranging from behavioral changes and ataxia, to reproductive changes and physiological stress, to lethal non-target effects. Additionally, peptide Hv1a has promising effects as a more narrow-spectrum pesticide.

Manuka Honey Modulates Oxidative Stress In Neuro2-A Cells Through Mitochondrial Regulation, Rachel Abramovici

Honors Undergraduate Theses

Manuka honey is known for its vital usage in wound healing, being an agonist towards fighting infections, and is an acting antioxidant [32]. Its main constituents are flavonoids and phenolic compounds, with methyl syringate (MSYR) being a major active ingredient. The specific compounds responsible for these antioxidant effects, particularly in the CNS, remain unclear. It is hypothesized that pre-treatment of mouse neuroblastoma cells with MSYR followed by hydrogen peroxide exposure will activate the AMPK/SIRT1/PGC-1a pathway, due to MSYR’s phenolic structure, and thus reduce oxidative stress and improve mitochondrial biogenesis. Hydrogen peroxide is a standard reactive oxygen species (ROS) treatment to …

Feeding Mode Is Associated With Infant Night Sleep Trajectories During The First Postnatal Year, Magdalena Olson, Li Liu, Elizabeth Reifsnider, Dean V. Coonrod, Sarada S. Panchanathan, Megan E. Petrov, Corrie M. Whisner

Ellmer School of Nursing Faculty Publications

Background: Short sleep and formula feeding during infancy are associated with increased risk of childhood obesity. Feeding practices and sleep arrangements vary during infancy and may also be dynamic, yet their impact on infant night sleep duration remains unclear. Understanding these relationships is crucial for formulating recommendations to support breastfeeding and address sleep concerns. Objective: We examined the association between feeding mode and parent-reported infant night sleep duration during the first postnatal year, while additionally evaluating night-weaning and bedsharing as contextual sleep-related practices. Methods: Infants in the Phoenix Metropolitan Area (n = 193) were followed up at 3, 8, 13, …

Estrogen Deprivation During Primate (Papio Anubis) Pregnancy: Impact On Systemic Microvascular Flow And Cardiovascular Development And Function After Birth In Offspring, Sifa Turan, Jeffery S. Babischkin, Graham W. Aberdeen, Gerald J. Pepe, Eugene D. Albrecht

Department of Biomedical and Translational Sciences Faculty Publications

Background

Suppressing estradiol (E₂) during baboon pregnancy lowers offspring skeletal muscle capillary density, vital for insulin-mediated glucose uptake, and induces insulin resistance. We examined whether E₂ deprivation also impairs microvascular flow and cardiac function.

Methods

Offspring of untreated baboons, letrozole-treated baboons, or letrozole plus E₂ (maternal s.c. injections during the second half of gestation) underwent contrast-enhanced microbubble ultrasonography to quantify microvessel flow and echocardiography to assess cardiac performance.

Results

Letrozole reduced maternal serum E₂ by 95% (p <  0.01). In letrozole offspring, microbubble flux rate (β) fell 55% (p <  0.02), replenishment was 5 s slower (p <  0.03), and microvessel flow declined 40% (p = 0.05); all were restored by added E₂. Indices of systolic (isovolumic contraction), diastolic (isovolumic relaxation), global performance (Tei index), and cardiac output were unchanged.

Conclusion

Prolonged gestational E₂ deprivation programs a reduction in microvascular flow without altering cardiac function; maternal E₂ prevents this, supporting E₂'s role in …

Comparative Mass Spectrometry Analysis Of High And Low Centrifugation Extracellular Vesicle (Ev) Pellets From Healthy Urine Following Tamm-Horsfall Protein Removal, Dana Bielopolski, Luca Musante, Henrik Molina, Douglas Barrows, Samantha Upson, Lifang Yang, Thomas Carrol, Jonathan N. Tobin, Rhonda G. Kost, U. Erdbrügger

Department of Biomedical and Translational Sciences Faculty Publications

Objectives

Urinary extracellular vesicles (uEVs) are potential biomarkers for renal physiology and disease. Their isolation is challenged by Tamm-Horsfall protein (THP) contamination, particularly in high-speed ultracentrifugation (P100) fractions. Low-speed (P20) fractions contain biologically relevant uEVs, yet their proteomic composition is underexplored. This study evaluates strategies for THP removal to optimize mass spectrometry analysis and characterizes P20 and P100 uEV proteomes and its combination in healthy urine.

Methods

Urine from a healthy volunteer was processed via sequential centrifugation at 21,200 g (P20) and 164,244 g (P100). THP removal was performed using low ionic strength buffer (P20) and size-exclusion chromatography (P100). Western …

Prolonged Qt Interval In Hiv-1 Infected Humanized Mice Treated Chronically With Dolutegravir/Tenofovir Disoproxil Fumarate/Emtricitabine, Ali Namvaran, Julian V. Garcia, Mahendran Ramasamy, Kayla Nguyen, Farzaneh Tavakkoli Ghazani, Bryan T. Hackfort, Prasanta Dash, Reagan E. Fisher, Benson J. Edagwa, Santhi Gorantla, Keshoer R. Bidasee

Journal Articles: Cellular & Integrative Physiology

The REPRIEVE Trial recently reported high rates of sudden cardiac death (SCD) middle-aged people living with HIV-1 infection (PWH) using the WHO/NIH-recommended two nucleoside reverse transcriptase inhibitors (NRTIs)/one integrase strand inhibitor (INSTI) regimen to manage HIV-1 viremia. To date, clinically relevant animal models to delineate underlying causes for this remain limited. Here, we assessed if HIV-1-infected NOD.Cg-Prkdc^scidIl2rg^tm1Wjl/SzJ humanized mice (Hu-mice) treated with the WHO/NIH-recommended antiretroviral regimen, dolutegravir (DTG, INSTI)/tenofovir disoproxil fumarate (TDF, NRTIs)/emtricitabine (FTC, NRTIs), can recapitulate abnormalities in the ECG and subclinical structural heart disease that serve as harbingers of SCD in middle-aged PWH. …