Neuroscience and Neurobiology Commons^™

The Raphe-Hippocampal Tract And Its Age Differences: Diffusion Tensor Imaging And Probabilistic Tractography Study, Ashley Sekul

Honors Theses

The raphe-hippocampal tract links the raphe nuclei to the hippocampus and is responsible for the production of the neurotransmitter serotonin. The hippocampus is key in regulating emotional and stress responses. This study utilized diffusion tensor imaging which uses Functional Magnetic Resonance Imaging to provide scans of the brain for analyzing differences in the raphe-hippocampal tract as one ages. In this specific study, 491 samples were visually analyzed to gather data about the fractional anisotropy of the raphe nuclei in both male and female brains ranging from 6 to 85 years old. Through the ranking of images, some were discarded, and …

The Brain's Large-Scale Electrophysiological Signals : Fundamental Attributes And Neurosurgical Applications, Mohammad Amin N/A Nourmohammadi

Legacy Theses & Dissertations (2009 - 2024)

Brain’s electrophysiological signals are most certainly the ultimate source for studying the sophisticated neural network inside our cranium. The unparalleled complexity of these biosignalsis the quintessential manifestation of their underlying complicated neurophysiological processes. Studying brain signals on the cellular level provides valuable information regarding the brain’s electrophysiology on the small-scale. However, it is the remarkable network in the large-scale that gives rise to the brain’s extraordinary attributes and exceptional capabilities—perception, cognition, computation, and consciousness are all the emergent byproducts of the dynamic neuronal interactions on the network level. In this sense, the large-scale electrophysiological signals, recorded from the surface of …

The Dysregulation Of Circadian Rhythms And Its Relation To Hippocampal Neurodegenerative Disease, John Patrick Mccauley

Legacy Theses & Dissertations (2009 - 2024)

Circadian rhythms modulate body temperature, sleep-wake cycles and cognitive functions like learning and memory. Interestingly, patients suffering from neurodegenerative disease like Alzheimer’s disease and brain insults like traumatic brain injury experience dysregulated circadian rhythms and learning and memory deficiencies as a symptom. The core molecular machinery that establishes these rhythms relies on the activation of positive and negative transcriptional-translational feedback loops within the hypothalamic suprachiasmatic nucleus (SCN). Subordinate circadian oscillators distributed throughout the peripheral and central nervous system follow the rhythmic activity of the SCN. One of these, the hippocampus, is mostly involved in regulating memory formation and recall. Experimental …

Basigin As An Immune Mediator In The Cns, Alicia Gonzalez

UNF Graduate Theses and Dissertations

Chronic inflammation is a hallmark of many neurodegenerative disorders. Although the central nervous system (CNS) can stave peripheral pathogens from crossing the blood-brain barrier (BBB) through a network of continuous endothelia, astrocytes, and pericytes, prolonged exposure to a pathogen can comprise this barrier. Basigin, a cell adhesion molecule, is found on the surface of endothelial cells and has been demonstrated to interact with toll-like receptor 4 (TLR4). TLR4 recognizes lipopolysaccharide (LPS), found on the outer membrane of Gram-negative bacteria. The activation of TLR4 produces pro-inflammatory cytokines, like IL-6. The present study aims to address the expression pattern of Basigin gene …

Ultrafast Two-Photon Imaging Of A High-Gain Voltage Indicator In Awake Behaving Mice, Vincent Villette, Mariya Chavarha, Ivan K Dimov, Jonathan Bradley, Lagnajeet Pradhan, Benjamin Mathieu, Stephen W Evans, Simon Chamberland, Dongqing Shi, Renzhi Yang, Benjamin B Kim, Annick Ayon, Abdelali Jalil, François St-Pierre, Mark J Schnitzer, Guoqiang Bi, Katalin Toth, Jun Ding, Stéphane Dieudonné, Michael Z Lin

Faculty, Staff and Students Publications

Optical interrogation of voltage in deep brain locations with cellular resolution would be immensely useful for understanding how neuronal circuits process information. Here, we report ASAP3, a genetically encoded voltage indicator with 51% fluorescence modulation by physiological voltages, submillisecond activation kinetics, and full responsivity under two-photon excitation. We also introduce an ultrafast local volume excitation (ULoVE) method for kilohertz-rate two-photon sampling in vivo with increased stability and sensitivity. Combining a soma-targeted ASAP3 variant and ULoVE, we show single-trial tracking of spikes and subthreshold events for minutes in deep locations, with subcellular resolution and with repeated sampling over days. In the …

Mice Exposed To Combined Chronic Low-Dose Irradiation And Modeled Microgravity Develop Long-Term Neurological Sequelae, Amber M. Paul, Eliah G. Overbey, William A. Da Silveira, Candice G.T. Tahimic, Sigrid S. Reinsch, Nathaniel Szewczyk, Seta Stanbouly, Charles Wang, Jonathan M. Galazka, Xiao Wen Mao

Publications

Spaceflight poses many challenges for humans. Ground-based analogs typically focus on single parameters of spaceflight and their associated acute effects. This study assesses the long-term transcriptional effects following single and combination spaceflight analog conditions using the mouse model: simulated microgravity via hindlimb unloading (HLU) and/or low-dose γ-ray irradiation (LDR) for 21 days, followed by 4 months of readaptation. Changes in gene expression and epigenetic modifications in brain samples during readaptation were analyzed by whole transcriptome shotgun sequencing (RNA-seq) and reduced representation bisulfite sequencing (RRBS). The results showed minimal gene expression and cytosine methylation alterations at 4 months readaptation within single …

Distinct Patterns Of Default Mode And Executive Control Network Circuitry Contribute To Present And Future Executive Function In Older Adults, Christopher A. Brown, Frederick A. Schmitt, Charles D. Smith, Brian T. Gold

Neuroscience Faculty Publications

Executive function (EF) performance in older adults has been linked with functional and structural profiles within the executive control network (ECN) and default mode network (DMN), white matter hyperintensities (WMH) burden and levels of Alzheimer's disease (AD) pathology. Here, we simultaneously explored the unique contributions of these factors to baseline and longitudinal EF performance in older adults. Thirty-two cognitively normal (CN) older adults underwent neuropsychological testing at baseline and annually for three years. Neuroimaging and AD pathology measures were collected at baseline. Separate linear regression models were used to determine which of these variables predicted composite EF scores at baseline …

The 5-Ht1a-R Knockout Mouse As A Model Of Later Life Anxiety Disorders: Implications For Sex Differences, Tatyana Budylin

Dissertations, Theses, and Capstone Projects

Anxiety affects nearly twice as many women as it affects men across all cultures and economic groups. Importantly, girls have a higher chance of inheriting anxiety disorders than boys, and many anxiety disorders appear at a very young age. However, little is known about sex differences in brain and behavioral development and how they relate to anxiety in adulthood. Serotonin 1A receptor (5-HT_1A-R) mediated signaling has been implicated in depression and anxiety, however most studies that focus on the involvement of the 5-HT_1A-R have been conducted in adults. Little is known about how the 5-HT_{1A …}

Cognition And The Brain Of Brood Parasitic Cowbirds., David F Sherry, Mélanie F Guigueno

Psychology Publications

Cowbirds are brood parasites. Females lay their eggs in the nests of other species, which then incubate the cowbird eggs and raise the young cowbirds. Finding and returning to heterospecific nests presents cowbirds with several cognitive challenges. In some species, such as brown-headed cowbirds (Molothrus ater), females but not males search for and remember the locations of potential host nests. We describe recent research on sex differences in cognition and the hippocampus associated with this sex difference in search for host nests. Female brown-headed cowbirds perform better than males on some, but not all, tests of spatial memory and females …

Cerebrovascular Smooth Muscle Cells As The Drivers Of Intramural Periarterial Drainage Of The Brain, Roxana Aldea, Roy O. Weller, Donna M. Wilcock, Roxana O Carare, Giles Richardson

Physiology Faculty Publications

The human brain is the organ with the highest metabolic activity but it lacks a traditional lymphatic system responsible for clearing waste products. We have demonstrated that the basement membranes of cerebral capillaries and arteries represent the lymphatic pathways of the brain along which intramural periarterial drainage (IPAD) of soluble metabolites occurs. Failure of IPAD could explain the vascular deposition of the amyloid-beta protein as cerebral amyloid angiopathy (CAA), which is a key pathological feature of Alzheimer's disease. The underlying mechanisms of IPAD, including its motive force, have not been clarified, delaying successful therapies for CAA. Although arterial pulsations from …

Regional Specialization Of The Adult Meninges Supports Different Brain Areas And Alters With Age, Christina Ann Calabrese

Legacy Theses & Dissertations (2009 - 2024)

The meninges comprise three heterogeneous connective tissue coverings, referred to as the dura, arachnoid, and pia mater, which completely envelop the brain and spinal cord. Given the meninges’ vast coverage over the entire CNS and its unique development, I hypothesized that regional leptomeninges (arachnoid and pia mater layers combined) provide specialized support to different brain areas. During development, anterior meninges, overlying the frontal cortex, derive from neural crest cells that are ectodermal in origin. Posterior meninges, overlying the midbrain to the spinal cord, derive from a mesodermal lineage. This difference in lineage and location suggests potential functional differences between the …

Chemosensory Communication And Neural Substrates Of Social Behavior In The African Cichlid Fish, Astatotilapia Burtoni, Karen Elizabeth Field

LSU Doctoral Dissertations

Social animals must constantly assess their environment to make appropriate decisions. In several fish species, chemosensory signaling is crucial for social communication, conveying information on sex, reproductive state, and social status. Despite its importance in fishes, relatively little is known about how they employ chemical signaling, with only a few of the over 30,000 extant species investigated thus far. Further, there is a scarcity of information about where and how socially-relevant chemosensory signals are processed in the brain of fishes, or how chemosensory signals are integrated with other senses to elicit appropriate behaviors. For my doctoral research, I examined the …

Effect Sizes In Task-Based Functional Magnetic Resonance Imaging, Tyler Kellett

Celebration of Learning

Task-based functional magnetic resonance imaging (t-fMRI) techniques have changed the way scientists probe the neurological mechanisms underlying behavior. However, there are many problems surrounding t-fMRI especially underpowered studies leading to misleading effect sizes. This study is using a recent large data collection study, the Human Connectome Project, to investigate effect sizes in specific regions of the brain involving working memory. Previous studies have come up with relatively small effect sizes due to small sample sizes and large regions of interest (ROI). This study is concentrated on using more precise ROI called parcels to find larger effect sizes.

Bilateral Carotid Artery Stenosis Causes Unexpected Early Changes In Brain Extracellular Matrix And Blood-Brain Barrier Integrity In Mice, Jill M. Roberts, Michael E. Maniskas, Gregory J. Bix

Neuroscience Faculty Publications

Bilateral carotid artery stenosis (BCAS) is one experimental model of vascular dementia thought to preferentially impact brain white matter. Indeed, few studies report hippocampal and cortical pathology prior to 30 days post-stenosis; though it is unclear whether those studies examined regions outside the white matter. Since changes in the blood-brain barrier (BBB) permeability precede more overt brain pathology in various diseases, we hypothesized that changes within the BBB and/or BBB-associated extracellular matrix (ECM) could occur earlier after BCAS in the hippocampus, cortex and striatum and be a precursor of longer term pathology. Here, C57Bl/6 mice underwent BCAS or sham surgeries …

Minocycline Protects Developing Brain Against Ethanol-Induced Damage, Xin Wang, Kai Zhang, Fanmuyi Yang, Zhenhua Ren, Mei Xu, Jacqueline A. Frank, Zun-Ji Ke, Jia Luo

Pharmacology and Nutritional Sciences Faculty Publications

Fetal alcohol spectrum disorders (FASD) are caused by ethanol exposure during the pregnancy and is the leading cause of mental retardation. Ethanol exposure during the development results in the loss of neurons in the developing brain, which may underlie many neurobehavioral deficits associated with FASD. It is important to understand the mechanisms underlying ethanol-induced neuronal loss and develop appropriate therapeutic strategies. One of the potential mechanisms involves neuroimmune activation. Using a third trimester equivalent mouse model of ethanol exposure, we demonstrated that ethanol induced a wide-spread neuroapoptosis, microglial activation, and neuroinflammation in C57BL/6 mice. Minocycline is an antibiotic that inhibits …

Effects Of Environmental Conditions On C-Fos Expression In Rat Nucleus Accumbens After Remifentanil, Usman Z. Hamid, Rebecca S. Hofford, Michael T. Bardo

Oswald Research and Creativity Competition

Previous studies have shown that adolescents raised in impoverished conditions are more likely to develop drug abuse in adulthood. In addition, both stress-inducing living conditions (impoverishment/isolation) and drugs of abuse may lead to an increase in the c-fos transcription factor in the reward circuit of the brain, particularly in the nucleus accumbens. The aim of the current study was to quantify the number of c-fos positive cells in the nucleus accumbens of enriched and isolated rats exposed to the opioid remifentanil. Thirty-two male Sprague-Dawley rats were raised in either enriched or isolated conditions for one month, after which they received …

If It Looks Like A Duck: Fish Fit The Criteria For Pain Perception, Julia E. Meyers-Manor

Animal Sentience

Whereas we have denied the experience of pain to animals, including human babies, the evidence is becoming clearer that animals across a variety of species have the capacity to feel pain (Bellieni, 2012). As converging findings are collected from pain studies and the study of cognition, it is becoming harder to deny that fish are among the species that do feel pain.

Comparative Phylogeography, Taxonomy, And Neuroanatomy Of Montane Chameleons In The Albertine Rift, Central Africa, Daniel Hughes

Open Access Theses & Dissertations

How do traits vary across the tree of life? Our ability to address this question is diminished if: A taxonomic group has a poorly sampled phylogeny, a species goes extinct before their systematic position is resolved, or a trait is inadequately characterized for detailed studies. In the current era of mass extinction, it is imperative to not only accelerate species discovery through traditional studies in taxonomy and expeditionary research, but also to increase rescue efforts for all types of data before poorly understood species and potentially undescribed traits are lost. Here, an integrative taxonomic approach was used and novel methods …

Pain In Fish: Evidence From Peripheral Nociceptors To Pallial Processing, Michael L. Woodruff

Animal Sentience

The target article by Sneddon et al. (2018) presents convincing behavioral and pharmacological evidence that ray-finned fish consciously perceive noxious stimuli as painful. One objection to this interpretation of the evidence is that the fish nervous system is not complex enough to support the conscious experience of pain. Data that contradict this objection are presented in this commentary. The neuroanatomy and neurophysiology of the fish nervous system from the peripheral nerves to the pallium is able to support the sentient appreciation of pain.

Brain Energy Homeostasis And The Regulation Of N-Acetyl-Aspartate Metabolism In Development And Disease, Samantha Zaroff

Graduate School of Biomedical Sciences Theses and Dissertations

N-acetylaspartate (NAA) is a non-invasive clinical marker of neuronal metabolic integrity because of its strong proton magnetic resonance spectroscopy (H-MRS) peak and direct correlation with energetic integrity. Specifically, NAA is used to track the progression of neurodegenerative diseases due to the characteristic reduction of whole brain levels of NAA which occur simultaneously with reduced glucose utilization and mitochondrial dysfunction, but prior to the onset of disease specific pathology. However, NAA will also significantly increase simultaneously with energetic integrity during periods of recovery or remission in applicable disorders, such as traumatic brain injuries. Unfortunately, it remains enigmatic exactly why NAA is …

A Customized Quantitative Pcr Microrna Panel Provides A Technically Robust Context For Studying Neurodegenerative Disease Biomarkers And Indicates A High Correlation Between Cerebrospinal Fluid And Choroid Plexus Microrna Expression, Wang-Xia Wang, David W. Fardo, Gregory A. Jicha, Peter T. Nelson

Sanders-Brown Center on Aging Faculty Publications

MicroRNA (miRNA) expression varies in association with different tissue types and in diseases. Having been found in body fluids including blood and cerebrospinal fluid (CSF), miRNAs constitute potential biomarkers. CSF miRNAs have been proposed as biomarkers for neurodegenerative diseases; however, there is a lack of consensus about the best candidate miRNA biomarkers and there has been variability in results from different research centers, perhaps due to technical factors. Here, we sought to optimize technical parameters for CSF miRNA studies. We examined different RNA isolation methods and performed miRNA expression profiling with TaqMan® miRNA Arrays. More specifically, we developed a customized …

Low Arousal Positive Emotional Stimuli Attenuate Aberrant Working Memory Processing In Persons With Mild Cognitive Impairment, Lucas S. Broster, Shonna L. Jenkins, Sarah D. Holmes, Gregory A. Jicha, Yang Jiang

Behavioral Science Faculty Publications

Emotional enhancement effects on memory have been reported to mitigate the pathophysiology of Alzheimer’s disease (AD). However, relative to their manifestation in persons without pathologic aging, these effects may be reduced in magnitude or even deleterious, especially in tasks that more closely model ecologic memory performance. Based upon a synthesis of such reports, we hypothesized that in persons with AD low arousal positive stimuli would evoke relatively intact emotional enhancement effects, but that high arousal negative stimuli would evoke disordered emotional enhancement effects. To assess this, participants with and without mild cognitive impairment (MCI) presumed to be due to AD …

Chronic Traumatic Encephalopathy-Integration Of Canonical Traumatic Brain Injury Secondary Injury Mechanisms With Tau Pathology, Jacqueline R. Kulbe, Edward D. Hall

Spinal Cord and Brain Injury Research Center Faculty Publications

In recent years, a new neurodegenerative tauopathy labeled Chronic Traumatic Encephalopathy (CTE), has been identified that is believed to be primarily a sequela of repeated mild traumatic brain injury (TBI), often referred to as concussion, that occurs in athletes participating in contact sports (e.g. boxing, football, football, rugby, soccer, ice hockey) or in military combatants, especially after blast-induced injuries. Since the identification of CTE, and its neuropathological finding of deposits of hyperphosphorylated tau protein, mechanistic attention has been on lumping the disorder together with various other non-traumatic neurodegenerative tauopathies. Indeed, brains from suspected CTE cases that have come to autopsy …

Confabulation In Individuals With Disorders Of The Corpus Callosum: Educational Implications, Cheryl Lynn Wright

Dissertations

Individuals with disorders of the corpus callosum (DCC) may have subtle cognitive differences. Historically, confabulation has been associated with DCC. Therapies to mitigate confabulation is a newly emerging field. This study explores the possible educational implications that those with DCC may experience with confabulation.

The community of people with DCC and the community of people who interact with individuals with DCC were surveyed to ascertain the prevalence of confabulation within the population of those with DCC. A subset of questions probed whether age and/or gender impact the rates of reported confabulation. The research paradigm included a section that covered the …

Clinically Silent Alzheimer's And Vascular Pathologies Influence Brain Networks Supporting Executive Function In Healthy Older Adults, Brian T. Gold, Christopher A. Brown, Jonathan G. Hakun, Leslie M. Shaw, John Q. Trojanowski, Charles D. Smith

Neuroscience Faculty Publications

Aging is associated with declines in executive function. We examined how executive functional brain systems are influenced by clinically silent Alzheimer’s disease (AD) pathology and cerebral white matter hyperintensities (WMHs). Twenty-nine younger adults and thirty-four cognitively normal older adults completed a working memory paradigm while functional magnetic resonance imaging (fMRI) was performed. Older adults further underwent lumbar cerebrospinal fluid (CSF) draw for assessment of AD pathology and FLAIR imaging for assessment of WMHs. Accurate working memory performance in both age groups was associated with high fronto-visual functional connectivity (fC). However, in older adults, higher expression of fronto-visual fC was linked …

Gpr37l1 Modulates Seizure Susceptibility: Evidence From Mouse Studies And Analyses Of A Human Gpr37l1 Variant, Michelle M. Giddens, Jennifer C. Wong, Jason P. Schroeder, Emily G. Farrow, Brilee M. Smith, Sharon Owino, Sarah E. Soden, Rebecca C. Meyer, Carol Saunders, J. B. Lepichon, David Weinshenker, Andrew Escayg, Randy A. Hall

Neuroscience: Faculty Publications

Progressive myoclonus epilepsies (PMEs) are disorders characterized by myoclonic and generalized seizures with progressive neurological deterioration. While several genetic causes for PMEs have been identified, the underlying causes remain unknown for a substantial portion of cases. Here we describe several affected individuals from a large, consanguineous family presenting with a novel PME in which symptoms begin in adolescence and result in death by early adulthood. Whole exome analyses revealed that affected individuals have a homozygous variant in GPR37L1 (c.1047G > T [Lys349Asn]), an orphan G protein-coupled receptor (GPCR) expressed predominantly in the brain. In vitro studies demonstrated that the K349N substitution …

Targeting Mitochondrial Dysfunction In Cns Injury Using Methylene Blue; Still A Magic Bullet?, Hemendra J. Vekaria, Lora Talley Watts, Ai-Ling Lin, Patrick G. Sullivan

Spinal Cord and Brain Injury Research Center Faculty Publications

Complex, multi-factorial secondary injury cascades are initiated following traumatic brain injury, which makes this a difficult disease to treat. The secondary injury cascades following the primary mechanical tissue damage, are likely where effective therapeutic interventions may be targeted. One promising therapeutic target following brain injury are mitochondria. Mitochondria are complex organelles found within the cell, which act as powerhouses within all cells by supplying ATP. These organelles are also necessary for calcium cycling, redox signaling and play a major role in the initiation of cell death pathways. When mitochondria become dysfunctional, there is a tendency for the cell to loose …

Impulsive Personality Dimensions Are Associated With Altered Behavioral Performance And Neural Responses In The Monetary Incentive Delay Task, Ruolei Gu, Yang Jiang, Seth Kiser, Chelsea L. Black, Lucas S. Broster, Yue-Jia Luo, Thomas H. Kelly

Behavioral Science Faculty Publications

Individual differences in dimensions of impulsivity personality including disinhibition and sensation seeking modulate approach responses to reinforcing stimuli, such as drugs and money. The current study examined the effects of monetary incentive on both behavioral performance and electrophysiological activity among individuals varying in disinhibition and sensation seeking. The monetary incentive delay (MID) task was completed under electroencephalogram (EEG) recording. Behavioral data showed that higher disinhibition and sensation-seeking were associated with lower performance accuracy. Event-related potential (ERP) data showed that high reinforcement cues elicited a larger late positive component (LPC) than other conditions among high disinhibition participants, indicating its strong emotional …

Peripheral Administration Of The Soluble Tnf Inhibitor Xpro1595 Modifies Brain Immune Cell Profiles, Decreases Beta-Amyloid Plaque Load, And Rescues Impaired Long-Term Potentiation In 5xfad Mice, Kathryn P. Macpherson, Pradoldej Sompol, George T. Kannarkat, Jianjun Chang, Lindsey Sniffen, Mary E. Wildner, Christopher M. Norris, Malú G. Tansey

Sanders-Brown Center on Aging Faculty Publications

Clinical and animal model studies have implicated inflammation and peripheral immune cell responses in the pathophysiology of Alzheimer’s disease (AD). Peripheral immune cells including T cells circulate in the cerebrospinal fluid (CSF) of healthy adults and are found in the brains of AD patients and AD rodent models. Blocking entry of peripheral macrophages into the CNS was reported to increase amyloid burden in an AD mouse model. To assess inflammation in the 5xFAD (Tg) mouse model, we first quantified central and immune cell profiles in the deep cervical lymph nodes and spleen. In the brains of Tg mice, activated (MHCII …

Transcranial Direct Current Stimulation And Sports Performance, Dylan J. Edwards, Mar Cortes, Susan Wortman-Jutt, David Putrino, Marom Bikson, Gary Thickbroom, Alvaro Pascual-Leone

Publications and Research

No abstract provided.