Physiology Commons^™

Investigation Of Cardiac Electrophysiology In Human Ventricular Tissue, Kathleen Brownson

Theses and Dissertations--Biomedical Engineering

Individuals with cardiomyopathy are at higher risk to die from sudden cardiac arrest than those with non-failing (NF) hearts. This study examined the differences in electrical properties of failing and NF human hearts in terms of cardiac memory through explicit control of diastolic intervals in a sinusoidal fashion, restitution of action potential duration (APD) through standard and dynamic pacing protocols, maximum rate of depolarization and APD alternans. Recordings of transmembrane potentials were made in tissues extracted from patients with heart failure and one donor NF heart. Computational simulations were performed using the O’Hara Rudy model for generating surrogates of control …

Renal Humoral, Genetic And Genomic Mechanisms Underlying Spontaneous Hypertension, Jason A. Collett

Theses and Dissertations--Biology

In spite of significant progress in our knowledge of mechanisms that control blood pressure, our understanding of the pathogenesis of hypertension, its genetics, and population efforts to control blood pressure, hypertension remains the leading risk factor for mortality worldwide. It’s estimated that 1 out of every 3 adults has hypertension. Hypertension is a major risk factor for cardiovascular disease and stroke, and is considered a primary or contributing cause of death to more than 2.4 million US deaths each year. Although spontaneous hypertension has been the subject of substantial research, many critical questions remain unanswered.

To investigate mechanisms underlying spontaneous …

Trpa1 Channels In Cochlear Supporting Cells Regulate Hearing Sensitivity After Noise Exposure, Alejandra C. Velez-Ortega

Theses and Dissertations--Physiology

TRPA1 channels are sensors for noxious stimuli in a subset of nociceptive neurons. TRPA1 channels are also expressed in cells of the mammalian inner ear, but their function in this tissue remains unknown given that Trpa1^–/– mice exhibit normal hearing, balance and sensory mechanotransduction. Here we show that non-sensory (supporting) cells of the hearing organ in the cochlea detect tissue damage via the activation of TRPA1 channels and subsequently modulate cochlear amplification through active cellshape changes.

We found that cochlear supporting cells of wild type but not Trpa1^–/– mice generate inward currents and robust long-lasting Ca²⁺ responses …

Transmural Heterogeneity Of Cellular Level Cardiac Contractile Properties In Aging And Heart Failure, Premi Haynes

Theses and Dissertations--Physiology

The left ventricle of the heart relaxes when it fills with blood and contracts to eject blood into circulation to meet the body’s metabolic demands. Dysfunction in either relaxation or contraction of the left ventricle can lead to heart failure. Transmural heterogeneity is thought to contribute to normal ventricular wall motion but it is not well understood how transmural modifications affect the failing left ventricle. The overall hypothesis of this dissertation is that normal left ventricles exhibit transmural heterogeneity in cellular level contractile properties and with aging and heart failure there are region-specific changes in cellular level contractile mechanisms.

Age …

Β-Amyloid Deposition Is Shifted To The Vasculature And Memory Impairment Is Exacerbated When Hyperhomocysteinemia Is Induced In App/Ps1 Transgenic Mice, Tiffany L. Sudduth, Erica M. Weekman, Holly M. Brothers, Kaitlyn Braun, Donna M. Wilcock

Physiology Faculty Publications

INTRODUCTION: Vascular dementia is the second most common cause of dementia after Alzheimer's disease (AD). In addition, it is estimated that almost half of all AD patients have significant cerebrovascular disease comorbid with their AD pathology. We hypothesized that cerebrovascular disease significantly impacts AD pathological progression.

METHODS: We used a dietary model of cerebrovascular disease that relies on the induction of hyperhomocysteinemia (HHcy). HHcy is a significant clinical risk factor for stroke, cardiovascular disease and type 2 diabetes. In the present study, we induced HHcy in APP/PS1 transgenic mice.

RESULTS: While total β-amyloid (Aβ) load is unchanged across groups, Congophilic …

Analgesic Tolerance Of Opioid Agonists In Mutant Mu-Opioid Receptors Expressed In Sensory Neurons Following Intrathecal Plasmid Gene Delivery, Guangwen Li, Fei Ma, Yanping Gu, Li-Yen Mae Huang

Physiology Faculty Publications

Background: Phosphorylation sites in the C-terminus of mu-opioid receptors (MORs) are known to play critical roles in the receptor functions. Our understanding of their participation in opioid analgesia is mostly based on studies of opioid effects on mutant receptors expressed in in vitro preparations, including cell lines, isolated neurons and brain slices. The behavioral consequences of the mutation have not been fully explored due to the complexity in studies of mutant receptors in vivo. To facilitate the determination of the contribution of phosphorylation sites in MOR to opioid-induced analgesic behaviors, we expressed mutant and wild-type human MORs (hMORs) in sensory …

Molecular Events In The Cell Types Of The Olfactory Epithelium During Adult Neurogenesis, Paula M. Heron, Arnold J. Stromberg, Patrick Breheny, Timothy S. Mcclintock

Physiology Faculty Publications

BACKGROUND: Adult neurogenesis, fundamental for cellular homeostasis in the mammalian olfactory epithelium, requires major shifts in gene expression to produce mature olfactory sensory neurons (OSNs) from multipotent progenitor cells. To understand these dynamic events requires identifying not only the genes involved but also the cell types that express each gene. Only then can the interrelationships of the encoded proteins reveal the sequences of molecular events that control the plasticity of the adult olfactory epithelium.

RESULTS: Of 4,057 differentially abundant mRNAs at 5 days after lesion-induced OSN replacement in adult mice, 2,334 were decreased mRNAs expressed by mature OSNs. Of the …

Tricellulin Deficiency Affects Tight Junction Architecture And Cochlear Hair Cells, Gowri Nayak, Sue I. Lee, Rizwan Yousaf, Stephanie E. Edelmann, Claire Trincot, Christina M. Van Itallie, Ghanshyam P. Sinha, Maria Rafeeq, Sherri M. Jones, Inna A. Belyantseva, James M. Anderson, Andrew Forge, Gregory I. Frolenkov, Saima Riazuddin

Physiology Faculty Publications

The two compositionally distinct extracellular cochlear fluids, endolymph and perilymph, are separated by tight junctions that outline the scala media and reticular lamina. Mutations in TRIC (also known as MARVELD2), which encodes a tricellular tight junction protein known as tricellulin, lead to nonsyndromic hearing loss (DFNB49). We generated a knockin mouse that carries a mutation orthologous to the TRIC coding mutation linked to DFNB49 hearing loss in humans. Tricellulin was absent from the tricellular junctions in the inner ear epithelia of the mutant animals, which developed rapidly progressing hearing loss accompanied by loss of mechanosensory cochlear hair cells, while …

Mouse Strain Determines Cardiac Growth Potential, Carmen Kiper, Barry Grimes, Gary Van Zant, Jonathan Satin

Physiology Faculty Publications

RATIONALE: The extent of heart disease varies from person to person, suggesting that genetic background is important in pathology. Genetic background is also important when selecting appropriate mouse models to study heart disease. This study examines heart growth as a function of strain, specifically C57BL/6 and DBA/2 mouse strains.

OBJECTIVE: In this study, we test the hypothesis that two strains of mice, C57BL/6 and DBA/2, will produce varying degrees of heart growth in both physiological and pathological settings.

METHODS AND RESULTS: Differences in heart dimensions are detectable by echocardiography at 8 weeks of age. Percentages of cardiac progenitor cells (c-kit+ …

Dexamethasone Rapidly Increases Gaba Release In The Dorsal Motor Nucleus Of The Vagus Via Retrograde Messenger-Mediated Enhancement Of Trpv1 Activity, Andrei V. Derbenev, Bret N. Smith

Physiology Faculty Publications

Glucocorticoids influence vagal parasympathetic output to the viscera via mechanisms that include modulation of neural circuitry in the dorsal vagal complex, a principal autonomic regulatory center. Glucocorticoids can modulate synaptic neurotransmitter release elsewhere in the brain by inducing release of retrograde signalling molecules. We tested the hypothesis that the glucocorticoid agonist dexamethasone (DEX) modulates GABA release in the rat dorsal motor nucleus of the vagus (DMV). Whole-cell patch-clamp recordings revealed that DEX (1-10 µM) rapidly (i.e. within three minutes) increased the frequency of tetrodotoxin-resistant, miniature IPSCs (mIPSCs) in 67% of DMV neurons recorded in acutely prepared slices. Glutamate-mediated mEPSCs were …

Down's Syndrome, Neroinflammation, And Alzheimer Neuropathogenesis, Donna M. Wilcock, W. Sue T. Griffin

Physiology Faculty Publications

Down syndrome (DS) is the result of triplication of chromosome 21 (trisomy 21) and is the prevailing cause of mental retardation. In addition to the mental deficiencies and physical anomalies noted at birth, triplication of chromosome 21 gene products results in the neuropathological and cognitive changes of Alzheimer's disease (AD). Mapping of the gene that encodes the precursor protein (APP) of the β-amyloid (Aβ) present in the Aβ plaques in both AD and DS to chromosome 21 was strong evidence that this chromosome 21 gene product was a principal neuropathogenic culprit in AD as well as DS. The discovery of …

Voluntary Exercise Protects Against Methamphetamine-Induced Oxidative Stress In Brain Microvasculature And Disruption Of The Blood--Brain Barrier, Michal Toborek, Melissa J. Seelbach, Cetewayo S. Rashid, Ibolya E. András, Lei Chen, Minseon Park, Karyn A. Esser

Physiology Faculty Publications

BACKGROUND: There is no effective therapeutic intervention developed targeting cerebrovascular toxicity of drugs of abuse, including methamphetamine (METH). We hypothesize that exercise protects against METH-induced disruption of the blood--brain barrier (BBB) by enhancing the antioxidant capacity of cerebral microvessels and modulating caveolae-associated signaling. Mice were subjected to voluntary wheel running for 5 weeks resembling the voluntary pattern of human exercise, followed by injection with METH (10 mg/kg). The frequency, duration, and intensity of each running session were monitored for each mouse via a direct data link to a computer and the running data are analyzed by Clock labTM Analysis software. …

Neural Circuit Mechanisms Of Post-Traumatic Epilepsy, Robert F. Hunt, Jeffery A. Boychuk, Bret N. Smith

Physiology Faculty Publications

Traumatic brain injury (TBI) greatly increases the risk for a number of mental health problems and is one of the most common causes of medically intractable epilepsy in humans. Several models of TBI have been developed to investigate the relationship between trauma, seizures, and epilepsy-related changes in neural circuit function. These studies have shown that the brain initiates immediate neuronal and glial responses following an injury, usually leading to significant cell loss in areas of the injured brain. Over time, long-term changes in the organization of neural circuits, particularly in neocortex and hippocampus, lead to an imbalance between excitatory and …

Molecular Remodeling Of Tip Links Underlies Mechanosensory Regeneration In Auditory Hair Cells, Artur A. Indzhykulian, Ruben Stepanyan, Anastasiia Nelina, Kateri J. Spinelli, Zubair M. Ahmed, Inna A. Belyantseva, Thomas B. Friedman, Peter G. Barr-Gillespie, Gregory I. Frolenkov

Physiology Faculty Publications

Sound detection by inner ear hair cells requires tip links that interconnect mechanosensory stereocilia and convey force to yet unidentified transduction channels. Current models postulate a static composition of the tip link, with protocadherin 15 (PCDH15) at the lower and cadherin 23 (CDH23) at the upper end of the link. In terminally differentiated mammalian auditory hair cells, tip links are subjected to sound-induced forces throughout an organism's life. Although hair cells can regenerate disrupted tip links and restore hearing, the molecular details of this process are unknown. We developed a novel implementation of backscatter electron scanning microscopy to visualize simultaneously …

Does Naloxone Reinstate Secondary Hyperalgesia In Humans After Resolution Of A Burn Injury? A Placebo-Controlled, Double-Blind, Randomized, Cross-Over Study, Manuel P. Pereira, Mads U. Werner, Thomas K. Ringsted, Michael C. Rowbotham, Bradley K. Taylor, Joergen B. Dahl

Physiology Faculty Publications

INTRODUCTION: Development of secondary hyperalgesia following a cutaneous injury is a centrally mediated, robust phenomenon. The pathophysiological role of endogenous opioid signalling to the development of hyperalgesia is unclear. Recent animal studies, carried out after the resolution of inflammatory pain, have demonstrated reinstatement of tactile hypersensitivity following administration of μ-opioid-receptor-antagonists. In the present study in humans, we analyzed the effect of naloxone when given after the resolution of secondary hyperalgesia following a first-degree burn injury.

METHODS: Twenty-two healthy volunteers were included in this placebo-controlled, randomized, double-blind, cross-over study. Following baseline assessment of thermal and mechanical thresholds, a first-degree burn injury …

Summary Of Papers Presented At The 2012 Seventh International Cough Symposium, Peter V. Dicpinigaitis, Giovanni A. Fontana, Lu-Yuan Lee, Milos Tatar

Physiology Faculty Publications

Twenty six papers were presented as posters in the Seventh International Symposium on Cough; 12 papers were presented in the Basic Science of Cough session, and 14 papers presented in the Clinical Science of Cough session. These papers explored a wide spectrum of cough-related areas including pathophysiological mechanisms, treatment and detection of cough, and symptom assessment and perception, and were grouped into several general themes for facilitate the discussion. Studies presented in these posters have provided new information that should improve our knowledge on the basic physiology and pharmacology of cough, and the peripheral and central neural mechanisms involved in …

Derivation Of Multivariate Syndromic Outcome Metrics For Consistent Testing Across Multiple Models Of Cervical Spinal Cord Injury In Rats, Adam R. Ferguson, Karen-Amanda Irvine, John C. Gensel, Jessica L. Nielson, Amity Lin, Johnathan Ly, Mark R. Segal, Rajiv R. Ratan, Jacqueline C. Bresnahan, Michael S. Beattie

Physiology Faculty Publications

Spinal cord injury (SCI) and other neurological disorders involve complex biological and functional changes. Well-characterized preclinical models provide a powerful tool for understanding mechanisms of disease; however managing information produced by experimental models represents a significant challenge for translating findings across research projects and presents a substantial hurdle for translation of novel therapies to humans. In the present work we demonstrate a novel 'syndromic' information-processing approach for capitalizing on heterogeneous data from diverse preclinical models of SCI to discover translational outcomes for therapeutic testing. We first built a large, detailed repository of preclinical outcome data from 10 years of basic …

Excitatory Amino Acids Display Compartmental Disparity Between Plasma And Synovial Fluid In Clinical Arthropathies, Terry A. Mcnearney, Karin N. Westlund

Physiology Faculty Publications

BACKGROUND: Previous studies have demonstrated elevated levels of excitatory amino acids (EAA) glutamate (Glu) and aspartate (Asp) in the synovial fluid (SF) of patients with active arthritis. The source of SF EAA concentrations are thought in large part to be secondary to passive diffusion from the plasma across synovial membranes and less so, reflective of local synovial pathology.

OBJECTIVE: This descriptive report assesses the hypothesis that the SF EAA levels reflect inflammatory processes of the joint and are not dependent on plasma levels.

METHODS: Simultaneously drawn plasma and SF samples were obtained from 14 recently deceased cadavers and 10 patients …

The Feasibility Of A Fiber Optic Laser Approach To Relieving Lymphedematous Syndrome: A Case Report, Beniamino Palmieri, Alessandro Di Cerbo, Valentina Rottigni, Gregorio Fistetto, Tommaso Iannitti

Physiology Faculty Publications

Here we report a case of successful fiber optic laser treatment of lymphedema in a swollen arm post mastectomy. At the moment, this procedure has only anecdotal evidence to justify its use, but in our experience is a feasible, minimally invasive day-stay procedure which has been demonstrated to be safe and effective. Further nonhomogeneous case pooling and follow-up would enable guidelines and definite surgical protocols for its use to be implemented.

The Role Of Macrophages In Exercise And Insulin Resistance In Human Skeletal Muscle, Jason S. Groshong

Theses and Dissertations--Physiology

Muscle biopsies were taken at baseline, post eccentric exercise, post aerobic training, and after training followed by eccentric exercise from adults with different health status. In Cell Western analysis of pAkt/Akt ratio suggests that muscle cells isolated from baseline biopsies respond to insulin in a dose dependent manner that tracks with sensitivity to insulin of the host; however, this is uncoupled from glucose disposal in vitro. Nitrotyrosine (NY), a marker of free radical damage, was employed to assess the efficacy of the exercise paradigm. NY immunohistochemistry on muscle cross-sections revealed that eccentric exercise significantly increased damage in older ( …

The Effects Of Hydrostatic Pressure On Early Endothelial Tubulogenic Processes, Ryan M. Underwood

Theses and Dissertations--Biomedical Engineering

The effects of mechanical forces on endothelial cell function and behavior are well documented, but have not been fully characterized. Specifically, fluid pressure has been shown to elicit physical and chemical responses known to be involved in the initiation and progression of endothelial cell-mediated vascularization. Central to the process of vascularization is the formation of tube-like structures. This process—tubulogenesis—is essential to both the physiological and pathological growth of tissues. Given the known effects of pressure on endothelial cells and its ubiquitous presence in the vasculature, we investigated pressure as a magnitude-dependent parameter for the regulation of endothelial tubulogenic activity. To …

Noninvasive Near-Infrared Diffuse Optical Monitoring Of Cerebral Hemodynamics And Autoregulation, Ran Cheng

Theses and Dissertations--Biomedical Engineering

Many cerebral diseases are associated with abnormal cerebral hemodynamics and impaired cerebral autoregulation (CA). CA is a mechanism to maintain cerebral blood flow (CBF) stable when mean arterial pressure (MAP) fluctuates. Evaluating these abnormalities requires direct measurements of cerebral hemodynamics and MAP. Several near-infrared diffuse optical instruments have been developed in our laboratory for hemodynamic measurements including near-infrared spectroscopy (NIRS), diffuse correlation spectroscopy (DCS), hybrid NIRS/DCS, and dual-wavelength DCS flow-oximeter. We utilized these noninvasive technologies to quantify CBF and cerebral oxygenation in different populations under different physiological conditions/manipulations. A commercial finger plethysmograph was used to continuously monitor MAP. For investigating …

Nmda Receptors In The Dorsal Vagal Complex Of Normal And Diabetic Mice, Eva C. Bach

Theses and Dissertations--Physiology

The dorsal vagal complex (DVC), containing the nucleus of the solitary tract (NTS) and the dorsal motor nucleus of the vagus nerve (DMV), plays a pivotal role in autonomic regulation. Afferent fibers from peripheral organs and higher brain centers synapse in the NTS, which integrates these synaptic connections as well as information from systemically circulating hormones and metabolites. The integrated information is relayed to the dorsal motor nucleus of the vagus nerve (DMV), which in turn, projects motor fibers to elicit parasympathetic control of digestive and other viscera. Physiological functions mediated by the DVC are disrupted in diabetic patients and …

Diet-Induced Obesity: Dopaminergic And Behavioral Mechanisms As Outcomes And Predictors, Vidya Narayanaswami

Theses and Dissertations--Pharmacy

Obesity and drug abuse share common neural circuitries including the mesocoticolimbic and striatal dopamine reward system. In the current study, a rat model of diet-induced obesity (DIO) was used to determine striatal dopamine function, impulsivity and motivation as neurobehavioral outcomes and predictors of obesity. For the outcome study, rats were randomly assigned a high-fat (HF) or a low-fat (LF) diet for 8 wk. Following the 8-wk HF-diet exposure, rats were segregated into obesity-prone and obesity-resistant groups based on maximum and minimum body weight gain, respectively, and neurobehavioral outcomes were evaluated. For the predictor study, neurobehavioral antecedents were evaluated prior to …

Rapid Glucocorticoid-Induced Activation Of Trp And Cb1 Receptors Causes Biphasic Modulation Of Glutamate Release In Gastric-Related Hypothalamic Preautonomic Neurons, Carie R. Boychuk, Andrea Zsombok, Jeffrey G. Tasker, Bret N. Smith

Physiology Faculty Publications

Glucocorticoids rapidly regulate synaptic input to neuroendocrine cells in the hypothalamic paraventricular nucleus (PVN) by inducing the retrograde release of endogenous messengers. Here we investigated the rapid effects of dexamethasone (DEX) on excitatory synaptic input to feeding-related, preautonomic PVN neurons using whole-cell patch-clamp recordings. In ∼50% of identified gastric-related preautonomic PVN neurons, DEX elicited a biphasic synaptic response characterized by an initial rapid and transient increase in the frequency of miniature excitatory postsynaptic currents (mEPSCs), followed by a decrease in mEPSC frequency within 9 min; remaining cells displayed only a decrease in mEPSC frequency. The late-phase decrease in mEPSC frequency …

The Regulation And Packaging Of Synaptic Vesicles Related To Recruitment Within Crayfish And Fruit Fly Neuromuscular Junctions: Variations In Low- And High-Output Terminals, Wenhui Wu

Theses and Dissertations--Biology

Glutamate is the main excitatory neurotransmitter in the CNS and at the neuromuscular junctions (NMJs) of invertebrate. The characteristic similarities to CNS glutamatergic synapses in vertebrate and the anatomical simplicity of invertebrate NMJs favor the investigation of glutamatergic synaptic functions in this system. This dissertation mainly aimed to physiologically separate two functional vesicle groups, the reserve pool (RP) and readily releasable pool (RRP) within presynaptic nerve terminals of Procambarus Clarkii and Drosophila melanogaster. This was addressed in part by blocking the vesicular glutamate transporter (VGlut) with bafilomycin A1. Various frequencies of motor nerve stimulation, exposure time, and concentration of …

Expression Of Borderline Personality Disorder Symptoms Across The Ovulatory Cycle: A Multilevel Investigation, Tory A. Eisenlohr-Moul

Theses and Dissertations--Psychology

Borderline Personality Disorder (BPD) is a disabling condition characterized by chronic emotion dysregulation and behavioral impulsivity. Prospective studies that test proposed mechanisms of within-person change in BPD hold the key to improving symptom predictability and control in this disorder. A small body of evidence suggests that fluctuations in estradiol such as those occurring naturally at ovulation during the monthly female reproductive cycle may increase symptoms in women with BPD (DeSoto et al., 2003). Furthermore, there is preliminary evidence that both self-esteem and feelings of social rejection are highest at ovulation, when estradiol peaks (Durante and Hill, 2009; Eisenlohr-Moul et al., …

Effect Of Muscle Length On Cross-Bridge Kinetics In Intact Cardiac Trabeculae At Body Temperature, Nima Milani-Nejad, Ying Xu, Jonathan P. Davis, Kenneth S. Campbell, Paul M. L. Janssen

Physiology Faculty Publications

Dynamic force generation in cardiac muscle, which determines cardiac pumping activity, depends on both the number of sarcomeric cross-bridges and on their cycling kinetics. The Frank–Starling mechanism dictates that cardiac force development increases with increasing cardiac muscle length (corresponding to increased ventricular volume). It is, however, unclear to what extent this increase in cardiac muscle length affects the rate of cross-bridge cycling. Previous studies using permeabilized cardiac preparations, sub-physiological temperatures, or both have obtained conflicting results. Here, we developed a protocol that allowed us to reliably and reproducibly measure the rate of tension redevelopment (k_tr; which depends …

Orofacial Neuropathic Pain Mouse Model Induced By Trigeminal Inflammatory Compression (Tic) Of The Infraorbital Nerve, Fei Ma, Liping Zhang, Danielle Lyons, Karin N. Westlund

Physiology Faculty Publications

BACKGROUND: Trigeminal neuropathic pain attacks can be excruciating for patients, even after being lightly touched. Although there are rodent trigeminal nerve research models to study orofacial pain, few models have been applied to studies in mice. A mouse trigeminal inflammatory compression (TIC) model is introduced here which successfully and reliably promotes vibrissal whisker pad hypersensitivity.

RESULTS: The chronic orofacial neuropathic pain model is induced after surgical placement of chromic gut suture in the infraorbital nerve fissure in the maxillary bone. Slight compression and chemical effects of the chromic gut suture on the portion of the infraorbital nerve contacted cause mild …

Characterization Of Secretory Sphingomyelinase Activity, Lipoprotein Sphingolipid Content And Ldl Aggregation In Ldlr-/- Mice Fed On A High-Fat Diet, Gergana M. Deevska, Manjula Sunkara, Andrew J. Morris, Mariana N. Nikolova‑Karakashian

Physiology Faculty Publications

The propensity of LDLs (low-density lipoproteins) for aggregation and/or oxidation has been linked to their sphingolipid content, specifically the levels of SM (sphingomyelin) and ceramide. To investigate this association in vivo, ldlr (LDL receptor)-null mice (ldlr-/-) were fed on a modified (atherogenic) diet containing saturated fats and cholesterol. The diet led to significantly elevated SM content in all serum lipoproteins. In contrast, ceramide increased only in the LDL particles. MS-based analyses of the lipid acyl chain composition revealed a marked elevation in C16:0 fatty acid in SM and ceramide, consistent with the prevalence of palmitic acid in the modified diet. …