Neuroscience and Neurobiology Commons^™

Strong Neuron-To-Body Coupling Implies Weak Neuron-To-Neuron Coupling In Motor Cortex, Patrick A. Kells, Shree Hari Gautam, Leila Fakhraei, Jingwen Li, Woodrow L. Shew

Physics Faculty Publications and Presentations

Cortical neurons can be strongly or weakly coupled to the network in which they are embedded, firing in sync with the majority or firing independently. Both these scenarios have potential computational advantages in motor cortex. Commands to the body might be more robustly conveyed by a strongly coupled population, whereas a motor code with greater information capacity could be implemented by neurons that fire more independently. Which of these scenarios prevails? Here we measure neuron-to-body coupling and neuron-to-population coupling for neurons in motor cortex of freely moving rats. We find that neurons with high and low population coupling coexist, and …

Scale-Change Symmetry In The Rules Governing Neural Systems, Vidit Agrawal, Srimoy Chakraborty, Thomas Knöpfel, Woodrow L. Shew

Physics Faculty Publications and Presentations

Similar universal phenomena can emerge in different complex systems when those systems share a common symmetry in their governing laws. In physical systems operating near a critical phase transition, the governing physical laws obey a fractal symmetry; they are the same whether considered at fine or coarse scales. This scale-change symmetry is responsible for universal critical phenomena found across diverse systems. Experiments suggest that the cerebral cortex can also operate near a critical phase transition. Thus we hypothesize that the laws governing cortical dynamics may obey scale-change symmetry. Here we develop a practical approach to test this hypothesis. We confirm, …

Crispr Knockouts Reveal An Endogenous Role For Ancient Neuropeptides In Regulating Developmental Timing In A Sea Anemone, Nagayasu Nakanishi, Mark Q. Martindale

Biological Sciences Faculty Publications and Presentations

Neuropeptides are evolutionarily ancient peptide hormones of the nervous and neuroendocrine systems, and are thought to have regulated metamorphosis in early animal ancestors. In particular, the deeply conserved Wamide family of neuropeptides—shared across Bilateria (e.g. insects and worms) and its sister group Cnidaria (e.g. jellyfishes and corals)—has been implicated in mediating life-cycle transitions, yet their endogenous roles remain poorly understood. By using CRISPR-Cas9-mediated reverse genetics, we show that cnidarian Wamide—referred to as GLWamide—regulates the timing of life cycle transition in the sea anemone cnidarian Nematostella vectensis. We find that mutant planula larvae lacking GLWamides transform into morphologically normal polyps …

Examining The Appropriate Recovery Interval Following Maximal Exertion For Baseline Computerized Neurocognitive Testing (Cnt), Samantha Mohler

Graduate Theses and Dissertations

Background: Computerized neurocognitive testing is part of the recommended multi-faceted approach to SRC assessment. Prior research has suggested that maximal exertion negatively effects CNT test scores. Purpose: To identify the appropriate timing of the administration of CNT following maximal exertion in healthy college-aged students. Study Design: Random cross-over, repeated measures design. Methods: Participants will be administered CNT on four different visits, with at least one week between administrations. A VO2 max treadmill test will be performed before CNT administration during three of the four trials. Following the VO2 max test, participants will rest for <2 minutes (immediate), 10-minutes, or 20-minutes before taking CNT. The fourth trial, without maximal exertion preceding CNT administration, will serve as the control. All trials will be randomly-counterbalanced to negate practice effects. RESULTS: There was a significant within-subjects effect for prescribed post-exertion recovery intervals on total symptom scores (Wilks λ = .62, F [3, 23] = 4.64, p = .01, η2= .38). Total symptom scores were significantly higher at the immediate (p < .002), 10-minutes (p = .018), and 20-minutes (p = .011) post-exertion recovery intervals compared to baseline. Additionally, a significantly positive within-subjects effect for prescribed post exertion recovery was observed for processing speed (p=.009, Wilks λ = .60, F [3, 27] = 5.9, η2 = .396). No significant effect was observed for visual memory (p = .07), verbal memory (p = .06), or reaction time (p = .40). CONCLUSION: Baseline symptom scores were negatively influenced processing speed was enhanced by maximal exertion. These changes continue to be elevated 20 minutes post-exertion. Moreover, cognitive performance was not significantly impaired following maximal exercise. To obtain more accurate baseline symptom scores, and allow processing speed composites to return to normal, sports medicine professionals should wait at least 20 minutes following maximal exertion before administering CNT.

Combining Microdialysis And Electrophysiology In Cerebral Cortex To Delineate Functional Implications Of Acetylcholine Gradients, Tazima Nur

Graduate Theses and Dissertations

The neuronal network in cerebral cortex is a dynamic system that can undergo changes in collective neural activity as the organism changes its behavior. For example, during sleep and quiet restful awake state, many neurons tend to fire together in synchrony. In contrast, during alert awake states, firing patterns of neurons tend to be more asynchronous, firing more independently. These changes in population-level synchrony are defined as changes in cortical state. Response to sensory input is state-dependent, i.e., change in cortical state can impact the sensory information processing in cortex and introduce trial-to-trial variability in response to the same repeated …

Examining The Relationship Between State Anxiety And Vestibular And Ocular Motor Impairments And Symptoms In High School Athletes With Concussion, Mallory Kathleen Mcelroy

Graduate Theses and Dissertations

Anxiety has been associated with vestibular and ocular motor impairment in the general population. However, there is limited research regarding the connection between the vestibular and ocular motor systems and anxiety following sport-related concussion (SRC). OBJECTIVE: The purpose of this study is to compare state anxiety between concussed adolescent male and female athletes with and without vestibular and ocular motor impairments and symptoms. DESIGN: Prospective, repeated measures SUBJECTS: Thirty adolescent athletes between the ages of 15-18 years, diagnosed with a SRC completed the STAI-State at initial and medical clearance clinical visit. These adolescent athletes were categorized into vestibular and ocular …

Deep Learning-Based Framework For Autism Functional Mri Image Classification, Xin Yang, Saman Sarraf, Ning Zhang

Journal of the Arkansas Academy of Science

The purpose of this paper is to introduce deep learning-based framework LeNet-5 architecture and implement the experiments for functional MRI image classification of Autism spectrum disorder. We implement our experiments under the NVIDIA deep learning GPU Training Systems (DIGITS). By using the Convolutional Neural Network (CNN) LeNet-5 architecture, we successfully classified functional MRI image of Autism spectrum disorder from normal controls. The results show that we obtained satisfactory results for both sensitivity and specificity.

Exercise, Cognition, And The Aging Process Among Active, Competitive, And Sedentary Middle-Aged And Older Adults, Katherine Adams

Health, Human Performance and Recreation Undergraduate Honors Theses

Purpose This study aimed to compare the cognitive measures of reaction time and dual-task performance among recreationally active, master athletes, and sedentary older adults aged 50 years or older. Methods 59 late middle-aged and older adults between the ages of 50 to 88 years old participated in reaction time and dual-task tests of which consisted of multiple trials on the same day. Subjects were placed either into the recreationally active, masters athlete, or sedentary activity level group based on the Rapid Assessment of Physical Activity (RAPA) form. For the gait speed with associated dual-task component, subjects walked 10-meters at two …

Detecting Cognitive Load During Working Memory Tasks Utilizing A Digitizer Tablet, Cassandra K. Ward, Pradyumn Srivastava

Rehabilitation, Human Resources and Communication Disorders Undergraduate Honors Theses

The purpose of this line of research is to determine whether the ‘Digitizer’ is a reliable and valid way to measure cognitive load during dual working memory-drawing tasks. A quasi-experimental study was conducted at the University of Arkansas in a research laboratory, and participants included seven right-handed healthy adults with normal or corrected vision and no reading difficulty. The participants were selected on a volunteer basis. The study required participants to draw circles while continuously performing in three conditions – one baseline and two working memory experimental tasks, administered in counterbalanced order. The baseline task was to read an 8 …

Role Of Trpv4 In Astrocyte Extracellular Matrix Production, Abby Terlouw

Biomedical Engineering Undergraduate Honors Theses

Traumatic Brain Injury (TBI) is an alteration of brain pathology following damage of the central nervous system (CNS) by an external force. In the CNS, glial scar formation often occurs following TBI, and astrocytes are widely believed to contribute to this scar formation. While the role of astrocytes in extracellular matrix (ECM) production is known, the exact mechanism(s) for this event remain unclear. One possible method is the activation of transient receptor potential vanilloid 4 (TRPV4). TRPV4 is a channel protein found in the astrocyte membrane which has been shown to generate intracellular calcium ions following mechanical stimulation. Previous research …

The Relationship Between Habitual Dietary Protein Intake And Dual Task Performance In Sedentary, Recreationally Active, And Masters Athlete Older Adults, Whitney L. Freeman

Health, Human Performance and Recreation Undergraduate Honors Theses

As the body ages, physical and cognitive declines can result in balance and mobility deficits, but research has shown that proper nutrition and exercise can help maintain physical and mental capacity. The purpose of this study was to analyze the relationship between habitual dietary protein intake and dual task performance in sedentary (SED), recreationally active (RA), and masters athletes (MA). To measure physical activity levels, the Rapid Physical Activity Questionnaire (RAPA) was completed by all participants. The participants were placed into a high or low protein group using the ASA-24 hour dietary recall. If the participant consumed less than 0.8 …

Comparing Before-And After-School Neurocognitive Performance In High School Athletes- Implications For Concussion Management, Morgan Anderson

Graduate Theses and Dissertations

There are several factors that influence computerized neurocognitive testing performance however, one factor that has not been examined is the potential deleterious effects of cognitive fatigue from an academic school day combined with time of computerized neurocognitive testing (CNT) administration. The primary purpose of this study was to compare before-and after-school CNT performance and total symptoms in non-concussed high school student athletes. The secondary purpose of this study was to compare before-school and after-school CNT performance and total symptoms and chronotypes in non-concussed student athletes. A crossover design was used to compare before-and after-school CNT performance and total symptoms of …

Central Role Of Vasotocin In The Neuroendocrine Regulation Of Stress Responses And Food Intake In Chickens, Gallus Gallus, Gurueswar Nagarajan

Graduate Theses and Dissertations

It is well known that arginine vasotocin (AVT) in birds is involved in physiological homeostasis such as cardiovascular, osmotic regulation as well as reproductive functions. Pertinent to these physiological functions, AVT immunoreactive (-ir) neurons in the hypothalamus have been found associated with hemorrhage, dehydration, oviposition and other physiological regulation. Evidence, however, suggests that AVT also plays significant roles in modulating behavior, memory, stress, and food intake. This dissertation research addresses the latter two neuroendocrine functions of AVT in detail within the chicken brain. First, the functional role of AVT-ir neurons in conjunction with corticotropin releasing hormone (CRH)-ir neurons in the …

Examining Fear Of Re-Injury In High School Athletes With Sport-Related Concussion, Melissa Nicole Anderson

Graduate Theses and Dissertations

Recent consensus statements have advocated for research on the emotional sequelae that is associated with sport-related concussion (McCrory et al., 2012). However, changes in fear of re-injury throughout SRC recovery are understudied. The purpose of this study was two-fold: 1) to describe fear of re-injury in high school athletes with SRC, and 2) to document changes in fear of re-injury throughout SRC recovery. This study addressed several exploratory questions regarding fear of re-injury in high school athletes with SRC that pertain to identifying predictors of fear of re-injury as well as examining the relationship between fear of re-injury and locus …

Exploring The Production Of Extracellular Matrix By Astrocytes In Response To Mimetic Traumatic Brain Injury, Addison Walker

Graduate Theses and Dissertations

Following injury to the central nervous system, extracellular modulations are apparent at

the site of injury, often resulting in a glial scar. Astrocytes are mechanosensitive cells, which can create a neuroinhibitory extracellular environment in response to injury. The aim for this research was to gain a fundamental understanding of the affects a diffuse traumatic brain injury has on the astrocyte extracellular environment after injury. To accomplish this, a bioreactor culturing astrocytes in 3D constructs delivered 150G decelerations with 20% biaxial strain to mimic a traumatic brain injury. Experiments were designed to compare the potential effects of media type, number of …

An Investigation Of Short-Term Plasticity In Human Motor Cortex, Matthew Alan Gannon

Graduate Theses and Dissertations

Transcranial magnetic stimulation (TMS) produces a transient magnetic field that activates underlying cortical tissue by eliciting an electrical discharge of the neurons in the targeted area. Repetitive TMS (rTMS) uses patterns of repetitive TMS pulses and has been reliably shown to produce changes in the state of cortical excitability outlasting the time of stimulation. One such protocol that has demonstrated states of increased excitability is intermittent theta burst stimulation (iTBS). This method applies high-frequency bursts (50Hz) of pulses every 200 ms in trains of ten bursts. The effects of and differences between rTMS protocols have been investigated since gaining popularity …

Recognition Training For Faces Across Age Gaps, William Blake Erickson

Graduate Theses and Dissertations

Face recognition is a problem that has theoretical and applied value. However, the fact of facial aging is rarely addressed in research and unmentioned in the major theories of face recognition. Facial aging also has ramifications for missing persons and fugitive cases, confounding attempts by law enforcement to recover these people whose last known images are years or decades out of date. This dissertation reports three studies aimed at measuring baseline age-gap recognition ability and testing various training regimens designed to increase accuracy rates for this unique kind of recognition task.

Building Object Representations: Mechanisms Of Perceptual Learning In Human Visual Cortex, Stephanie M. Long

Psychological Science Undergraduate Honors Theses

Extensive literature in the cognitive neurosciences has been dedicated to understanding the neural processes involved in object category learning. However, much remains to be learned regarding the mechanisms by which high-level visual patterns are extracted from a crowded visual scene, segregated into discrete object categories, and represented in the cortical visual hierarchy. Here, we used event-related potentials (ERPs) to investigate the neural underpinnings of visual object category extraction in a cluttered visual environment. Electroencephalography (EEG) was continuously recorded while subjects were given a hybrid of an object category learning and visual search task. In this hybrid task, a peripheral array …

Experimental And Computational Studies Of Cortical Neural Network Properties Through Signal Processing, Wesley Patrick Clawson

Graduate Theses and Dissertations

Previous studies, both theoretical and experimental, of network level dynamics in the cerebral cortex show evidence for a statistical phenomenon called criticality; a phenomenon originally studied in the context of phase transitions in physical systems and that is associated with favorable information processing in the context of the brain. The focus of this thesis is to expand upon past results with new experimentation and modeling to show a relationship between criticality and the ability to detect and discriminate sensory input. A line of theoretical work predicts maximal sensory discrimination as a functional benefit of criticality, which can then be characterized …

Disentangling Embodied Cognition: An Examination Of The State, Problems, And Possibilities Of Embodied Cognition, Cody Cash

Graduate Theses and Dissertations

Embodied cognition has received a fair amount of attention in philosophical, neuroscientific, and robotic research during the past several decades, yet the precise nature of its goals, methods, and claims are unclear. This dissertation will ascertain and examine the primary themes in the field of embodied cognition as well as why, and if, they offer significant challenges to traditional cognitive science models. Though many theories believe they are providing accounts that should replace traditional models, to do so they will have to overcome the very difficult challenge of arguing that mental content and capabilities derived from sensorimotor activity can continue …

Spatiotemporal Fluctuations Of Olfactory Stimuli And Its Detection By An Optical Method, Mitu Chandra Acharjee

Graduate Theses and Dissertations

Olfactory processing in the mammalian brain is a highly dynamic process, yet most of the olfaction experiments have been studied primarily with static stimuli. Odors in the natural environment are transported by turbulent flow of air or water. Natural odorants have fluctuations in concentration and it changes rapidly with time. These rapid fluctuations may pose some challenges to identifying an odor; on the other hand, the variation itself may provide important clues about the odor source. The goal of this thesis project was to create a similar odorant environment like the rapid odor fluctuations encountered in nature – to meet …

Examining The Relationship Between Neurocognitive Performance And Functional Fitness Levels Among Older Adults, Kristen J. Holmes

Health, Human Performance and Recreation Undergraduate Honors Theses

The goal of this thesis was to examine the relationship between neurocognitive performance and functional fitness levels among older adults. This is important because the geriatric population is the fastest growing demographic in the United States (USDHHS, CDC & Prevention, 2012). By 2030, the older adult population is expected to double. With the cumulative health effects associated with aging and pathological disease, adults typically experience a normal decline in cognitive function termed age-associated memory impairment (AAMI) (Kramer, Colcombe, McAuley, Scalf, & Erickson, 2005; O’Brien, 1999). It is believed to be a non-progressive disorder. Mild cognitive impairment (MCI), on the other …

A Descriptive Study Of The Use Of Neurofeedback In Counseling, Khwlah Jamil Al-Ansari

Graduate Theses and Dissertations

This study examines neuro-counseling in the mental health field and the concept of neurofeedback training (NFB) as an intervention in the counseling profession. Numbers of studies have indicated that NFB may be effective in the field of counseling. The purpose of this survey study is to explore the use of neurofeedback in the field of counseling.

Additionally, the study used a quantitative descriptive survey research method and descriptive statistics. The survey was sent to members of the American Counseling Association (ACA), and 93 professionals participated. The majority of the sample was licensed professional counselors, professionals with a degree in counseling, …

Functional Characterization Of The Arginine Vasotocin 4 Receptor (Vt4r) In Sensory Circumventricular Organs Of The Chicken Gallus Gallus, Nguiessan Alphonse Aman

Graduate Theses and Dissertations

Past studies have shown that the avian vasotocin 4 receptor (VT4R), homologous to the mammalian arginine vasopressin receptor 1a (V1aR/AVPR1A) is involved in immobilization stress. It was not known, however, whether the receptor is also associated with osmotic stress, and if so, what brain regions may be involved. Four treatment groups of chicks were used for the study. One group was subjected to 1h immobilization stress and two groups were administered intraperitoneal injection of 3 M NaCl or 0.15 M NaCl. One additional group served as controls. After 1 h, blood samples were taken for the determination of plasma levels …

The Development Of A Traumatic Brain Injury Bioreactor, Zachery Heller

Graduate Theses and Dissertations

Approximately 1.7 million Americans experience a traumatic brain injury (TBI) each year. Concussive injuries are a subset of TBI in which blows to the head cause the brain to collide against the interior of the skull. Damage to the neurons, supporting cells, and surrounding extra cellular matrix resulting from these collisions can lead to permanent physical, cognitive, and psychological impairment. We believe the prevalence and clinical significance of concussive injures warrants research investment. To study brain injury following TBI, in vivo models have been the gold standard for TBI experiments. Although a valuable research alternative, animals are expensive, raise ethical …

Effects Of Head Position And Head-Supported Mass On Nerve Function Of The Flexor Carpi Radialis Muscle In Healthy Individuals, Bethany Lauren Shivers

Graduate Theses and Dissertations

Long-term exposure to head-supported mass (HSM) has been linked with spinal degeneration including foraminal stenosis and disc deterioration. Anecdotally, HSM has also been linked to neck and arm pain and muscle atrophy, but nerve function has not been tested specifically. The combined effect of various head positions and HSM may be sufficient to compress the nerve root in aviators and Soldiers during job performance, potentially leading to short- and long-term neuromuscular effects. The Hoffmann (H) reflex, a well-established measure of nerve function, has shown to be sensitive to changes in nerve root space which occurs with different head positions. This …

Characterization Of Neuronal Groups Regulating Sexual And Agonistic Behavior In Male Chicken (Gallus Gallus), Jingjing Xie

Graduate Theses and Dissertations

The study aimed to understand the neuronal regulation of male sexual and agonistic behavior in broiler breeders. First, brain structures associated with sexual and agonistic behavior were identified by mapping Fos expression. The ventromedial subnucleus of medial portion of bed nucleus of the stria teriminalis (BSTM2) was specifically activated by male courtship behavior. The medial preoptic nucleus (POM) and lateral septum (SL) were associated with both sexual and agonistic behaviors. The bed nucleus of the pallial commissure (NCPa) and the paraventricular nucleus (PVN) were closely related to stress. Second, Fos-ir neurons were phenotyped by double labeling Fos with aromatase (ARO) …

Psycho-Social Effects Of A Brain-Training Program Among Healthy Older Adults, Desma Hurley, M. Jean Turner, William C. Bailey

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Grounded in cognitive neuroscience and social exchange theory, this research evaluated the relationship between changes in cognitive functioning and two psycho-social dimensions of life among healthy adults over the age of 70 (N=12). Specific psycho-social dimensions examined were social interaction and depression. Six females and six males participated in the study. All were white, college-educated individuals residing in a life-care residential retirement community. The participants used the Posit Science® Brain Fitness Program™, an auditory-based computer training program that improves memory and speed of processing, for forty hours over an eight-week period. Pre- and post-tests related to social interaction and depressive …

Method To Correct The Voxel Size In Press Localized Nmr Stereoscopy, Diana M. Lindquist, Roger M. Hawk, Richard A. Komoroski

Journal of the Arkansas Academy of Science

Two techniques commonly used on human magnetic resonance spectroscopy systems to obtain spectra from localized volumes in the brain are point resolved spectroscopy (PRESS) and stimulated echo acquisition mode (STEAM) spectroscopy. PRESS gives a signal twice as large as that obtained with STEAM, but suffers from longer minimum echo times. While STEAM must be used to detect species with short spin-spin relaxation times, PRESS can be used for species with longer relaxation times to give a spectrum with a better signal to noise ratio. Only STEAM was provided for the GE Omega 4.7 T small animal imager used in this …

Multisite Microprobes For Electrochemical Recordings In Biological Dynamics, G. Sreenivas, S. S. Ang, R. M. Ranade, A. S. Salian, W. D. Brown

Journal of the Arkansas Academy of Science

For over 30 years, techniques have been developed that allow for the microscale (10-30 /mum) measurement of chemical signals with high temporal resolution (1-200 Hz). Such measurements, called in vivo electrochemical recordings, allow for the direct determination of neurotransmitter molecules and related compounds in biological systems. Multiple recordings, simultaneously performed at different, closely spaced, well defined locations throughout a three-dimensional tissue volume in the brain, are of interest in neuroscience. Developments in microelectronic techniques enable the fabrication of multi-electrode microprobes for recording extracellular action potentials generated by individual neurons simultaneously. A high-yield microfabrication process has been successfully developed for the …