Neurosciences Commons^™

Flanker Task Performance In Young And Older Adults: A Behavioral And Erp Study, Fatima Medrano

Dissertations, Theses, and Capstone Projects

Research suggests that as we get older, executive function abilities decline (Hasher & Zacks, 1988; Salthouse, 1996). One affected ability is that of inhibitory control, which aids in monitoring our responses to non-target stimuli or information. Current research on inhibition reveals inconsistencies across studies. Monitoring brain responses during the Flanker (used to measure inhibitory control) task may add valuable insight into the processes underlying group differences behaviorally, by studying the N200 and P300 event-related potentials which have been associated with inhibitory control processes. This study investigated whether there are differences between older and younger adults in inhibitory control and whether …

The Differential Effects Of Acoustic Discriminations On Operant Learning Performance And Neurogenesis In Male And Female Zebra Finches, Kristena L. Newman

Dissertations, Theses, and Capstone Projects

Adult neurogenesis, the creation of new neurons, occurs throughout the lifespan in most organisms. However, though neuronal proliferation occurs daily, most of these neurons do not survive to become incorporated into preexisting neural circuitry and become fully functioning neurons. In the mammalian brain, adult neurogenesis occurs within the hippocampus, a brain region known to be important in learning and memory. In rats, successful acquisition of certain learning tasks increased new neuron numbers when the learning was sufficiently challenging (Curlik and Shors, 2011). It has also been demonstrated that a spatial discrimination task requires new neurons when the discrimination is more …

Transcranial Direct Current Stimulation On Parkinson’S Disease: Systematic Review And Meta-Analysis, Paloma Cristina Alves De Oliveira, Thiago Anderson Brito De Araújo, Daniel Gomes Da Silva Machado, Abner Cardoso Rodrigues, Marom Bikson, Suellen Marinho Andrade, Alexandre Hideki Okano, Hougelle Simplicio, Rodrigo Pegado, Edgard Morya

Publications and Research

Background: Clinical impact of transcranial direct current stimulation (tDCS) alone for Parkinson’s disease (PD) is still a challenge. Thus, there is a need to synthesize available results, analyze methodologically and statistically, and provide evidence to guide tDCS in PD.

Objective: Investigate isolated tDCS effect in different brain areas and number of stimulated targets on PD motor symptoms.

Methods: A systematic review was carried out up to February 2021, in databases: Cochrane Library, EMBASE, PubMed/MEDLINE, Scopus, and Web of science. Full text articles evaluating effect of active tDCS (anodic or cathodic) vs. sham or control on motor symptoms of PD were …

Toward A Multimodal Computer-Aided Diagnostic Tool For Alzheimer’S Disease Conversion, Danilo Pena, Jessika Suescun, Mya Schiess, Timothy M. Ellmore, Luca Giancardo, Alzheimer’S Disease Neuroimaging Initiative

Publications and Research

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder. It is one of the leading sources of morbidity and mortality in the aging population AD cardinal symptoms include memory and executive function impairment that profoundly alters a patient’s ability to perform activities of daily living. People with mild cognitive impairment (MCI) exhibit many of the early clinical symptoms of patients with AD and have a high chance of converting to AD in their lifetime. Diagnostic criteria rely on clinical assessment and brain magnetic resonance imaging (MRI). Many groups are working to help automate this process to improve the clinical workflow. Current …

Apathy And Brain Atrophy During The First Year Of Moderate-Severe Traumatic Brain Injury: A Longitudinal Study, Gulnaz Kudoiarova

Dissertations, Theses, and Capstone Projects

Apathy, defined as disinterest and loss of motivation, is a common complication after moderate-severe traumatic brain injury (msTBI). The existing body of research in various neurological and neurodegenerative disorders suggests that apathetic symptoms may be associated with variation in the volume of the brain regions such as dorsal anterior cingulate cortex and ventral striatum. However, the longitudinal pattern of TBI-induced atrophy in these key regions and its relationship with apathy symptoms remain to be demonstrated. The current study aimed to describe the atrophy pattern in the anterior cingulate gyrus (ACG) and the nucleus accumbens (NAc; part of ventral striatum) after …

Machine Learning Classification Of Traumatic Brain Injury Patients Versus Healthy Controls Using Arterial Spin Labeled Perfusion Mri, Vanessa I. Grass

Dissertations, Theses, and Capstone Projects

Traumatic brain injury (TBI) is one of the most common causes of death and disability worldwide, yet accurate in vivo detection of TBI neuropathology remains challenging due to complexities in the structural and functional changes observed post-injury as well as limitations in conventional neuroimaging modalities. Although advanced neuroimaging techniques such as arterial spin labeling (ASL) can noninvasively assess cerebral blood flow (CBF) changes observed post-injury, this technique is underutilized in TBI research partly due to the low signal-to-noise-ratio (SNR) inherent in ASL imaging. The aim of the current study is to examine the use of machine learning, specifically a Support …

Delayed Modulation Of Glutamate Receptors By Anti-Epileptic Drugs After Traumatic Brain Injury In Rats, Edgar Rodriguez

Dissertations, Theses, and Capstone Projects

Traumatic brain injury (TBI) is a significant health concern. Around 74 million people sustain a traumatic brain injury worldwide. The damage caused by TBI produces two types of injury; primary and secondary injuries. Primary injury is caused within milliseconds and is irreversible. Secondary brain injury is delayed and produced by molecular, cellular, and structural disruption after the initial injury. One of the most devastating dysfunction after TBI is glutamate neurotransmitter overactivation that could lead to neurotoxic levels of glutamate in the brain (i.e., excitotoxicity). Excitotoxicity has been linked with the development of epilepsy after TBI, also known as post-traumatic epilepsy …

Mitochondrial Distribution Of Glycine Receptors In Motor Neuron Cell Lines, Katsiaryna Milashevich

Student Theses and Dissertations

Although non-essential, glycine plays an important role in major metabolic reactions and is most known for its anti-inflammatory effects. An accumulation of contemporary research has shown that glycine is able to stabilize membrane potential using glycine receptors at the cellular level and to protect mitochondrial function directly, whether it is from inflammation, heavy metal poisoning, or ischemia-induced neuroinflammation. In this research, the existence of a hypothetical mitochondrial glycine receptor is examined. Immunofluorescence imaging was used to examine the presence of the glycine receptor subunits alpha 1 and alpha 2 in both non- differentiated and differentiated neuroblastoma cell lines. The preliminary …

A Systematic Review And Meta-Analysis On The Efficacy Of Repeated Transcranial Direct Current Stimulation For Migraine, Guoshuai Cai, Zhu Xia, Leigh Charvet, Feifei Xiao, Abhishek Datta, X Michelle Androulakis

Publications and Research

Purpose: Transcranial direct current stimulation (tDCS) may have therapeutic potential in the management of migraine. However, studies to date have yielded conflicting results. We reviewed studies using repeated tDCS for longer than 4 weeks in migraine treatment, and performed meta-analysis on the efficacy of tDCS in migraine.

Methods: In this meta-analysis, we included the common outcome measurements reported across randomized controlled trials (RCTs). Subgroup analysis was performed at different post-treatment endpoints, and with different stimulation intensities and polarities.

Results: Five RCTs were included in the quantitative meta-analysis with a total of 104 migraine patients. We found a significant reduction of …

Aphasia In Multilingual Patients, Mira Goral, Zahra Hejazi

Publications and Research

Purpose of Review

We summarize recent published work concerning assessment and treatment of aphasia in bilingual and multilingual people and review current related models of treatment outcomes. As well, we discuss studies that address the recently debated topic of cognitive processes in bilingual individuals with aphasia, with a focus on the effects of bilingualism on aphasia recovery and its potential protective effects.

Recent Findings

Providing assessment and treatment tools that best serve multilingual individuals with aphasia and unpacking the variables and mechanisms that underlie response to treatment have emerged as goals of several recent studies. Additionally, while findings are still …

Update On The Use Of Transcranial Electrical Brain Stimulation To Manage Acute And Chronic Covid-19 Symptoms, Giuseppina Pilloni, Marom Bikson, Bashar W. Badran, Mark S. George, Steven A. Kautz, Alexandre Hideki Okano, Abrahão Fontes Baptista, Leigh E. Charvet

Publications and Research

The coronavirus disease 19 (COVID-19) pandemic has resulted in the urgent need to develop and deploy treatment approaches that can minimize mortality and morbidity. As infection, resulting illness, and the often prolonged recovery period continue to be characterized, therapeutic roles for transcranial electrical stimulation (tES) have emerged as promising non-pharmacological interventions. tES techniques have established therapeutic potential for managing a range of conditions relevant to COVID-19 illness and recovery, and may further be relevant for the general management of increased mental health problems during this time. Furthermore, these tES techniques can be inexpensive, portable, and allow for trained self-administration. Here, …

Visual Corticocortical Inputs To Ferret Area 18, Reem Khalil, Moody Roberne Jensy Saint Louis, Shaima Alsuwaidi, Jonathan B. Levitt

Publications and Research

Visual cortical areas in the adult mammalian brain are linked by a network of interareal feedforward and feedback circuits. We investigated the topography of feedback projections to ferret (Mustela putorius furo) area 18 from extrastriate areas 19, 21, and Ssy. Our objective was to characterize the anatomical organization of the extrastriate feedback pool to area 18. We also wished to determine if feedback projections to area 18 share similar features as feedback projections to area 17. We injected the tracer cholera toxin B subunit (CTb) into area 18 of adult ferrets to visualize the distribution and pattern of retrogradely labeled …

Olfaction Modulates Inter-Subject Correlation Of Neural Responses, Paul Deguzman, Anshul Jain, Matthias H. Tabert, Lucas C. Parra

Publications and Research

Odors can be powerful stimulants. It is well-established that odors provide strong cues for recall of locations, people and events. The effects of specific scents on other cognitive functions are less well-established. We hypothesized that scents with different odor qualities will have a different effect on attention. To assess attention, we used Inter-Subject Correlation of the EEG because this metric is strongly modulated by attentional engagement with natural audiovisual stimuli.We predicted that scents known to be “energizing” would increase Inter-Subject Correlation during watching of videos as compared to “calming” scents. In a first experiment, we confirmed this for eucalyptol and …

Two Nights Of Recovery Sleep Restores Hippocampal Connectivity But Not Episodic Memory After Total Sleep Deprivation, Ya Chai, Zhuo Fang, Fan Nils Yang, Sihua Xu, Yao Deng, Andrew Raine, Jieqiong Wang, Meichen Yu, Mathias Basner, Namni Goel, Junghoon J. Kim, David A. Wolk, John A. Detre, David F. Dinges, Hengyi Rao

Publications and Research

Sleep deprivation significantly impairs a range of cognitive and brain function, particularly episodic memory and the underlying hippocampal function. However, it remains controversial whether one or two nights of recovery sleep following sleep deprivation fully restores brain and cognitive function. In this study, we used functional magnetic resonance imaging (fMRI) and examined the effects of two consecutive nights (20-hour time-in-bed) of recovery sleep on resting-state hippocampal connectivity and episodic memory deficits following one night of total sleep deprivation (TSD) in 39 healthy adults in a controlled in-laboratory protocol. TSD significantly reduced memory performance in a scene recognition task, impaired hippocampal …

Transcutaneous Auricular Vagus Nerve Stimulation-Paired Rehabilitation For Oromotor Feeding Problems In Newborns: An Open-Label Pilot Study, Bashar W. Badran, Dorothea D. Jenkins, Daniel Cook, Sean Thompson, Morgan Darcy, William H. Devries, Georgia Mappin, Philipp Summers, Marom Bikson, Mark S. George

Publications and Research

Neonates born premature or who suffer brain injury at birth often have oral feeding dysfunction and do not meet oral intake requirements needed for discharge. Low oral intake volumes result in extended stays in the hospital (>2 months) and can lead to surgical implant and explant of a gastrostomy tube (G-tube). Prior work suggests pairing vagus nerve stimulation (VNS) with motor activity accelerates functional improvements after stroke, and transcutaneous auricular VNS (taVNS) has emerged as promising noninvasive form of VNS. Pairing taVNS with bottle-feeding rehabilitation may improve oromotor coordination and lead to improved oral intake volumes, ultimately avoiding the …

Activation Of The Sonic Hedgehog Effector Smoothened Counteracts L-Dopa Induced Dyskinesia By Restoring Cholinergic Interneuron Function, Lauren Malave

Dissertations, Theses, and Capstone Projects

Many types of neurons act as multimodal signaling centers. Yet, we have only limited insight into the regulation and functional consequences of neuronal co-transmission. For example, dopamine (DA) neurons, whose degeneration causes motor deficits characteristic of Parkinson’s Diseases (PD), communicate with all their targets by DA but only a selective subset of their targets using GABA, Glutamate, and the secreted cell signaling protein Sonic Hedgehog (Shh). It is unknown whether Levo-dopamine (L-Dopa) induced dyskinesia (LIDs), a severely debilitating side effect of DA supplementation in PD, might appear because DA neuron targets are exposed to high DA- but low Shh- signaling …

Brain Development: Why The Young Sleep Longer, Budhaditya Chowdhury, Orie T. Shafer

Advanced Science Research Center

From absorbing new languages to mastering musical instruments, young children are wired to learn in ways that adults are not (Johnson and Newport, 1989). This ability coincides with periods of intense brain plasticity during which neurons can easily remodel their connections (Hubel and Wiesel, 1970). Many children are also scandalously good sleepers, typically getting several more hours of sleep per night than their parents (Jenni and Carskadon, 2007). As sleep deprivation has negative effects on learning and memory, learning like a child likely requires sleeping like one (Diekelmann and Born, 2010). Yet, how the ability to sleep for longer is …

Mechanisms Of Value-Biased Prioritization In Fast Sensorimotor Decision Making, Kivilcim Afacan-Seref

Dissertations and Theses

In dynamic environments, split-second sensorimotor decisions must be prioritized according to potential payoffs to maximize overall rewards. The impact of relative value on deliberative perceptual judgments has been examined extensively, but relatively little is known about value-biasing mechanisms in the common situation where physical evidence is strong but the time to act is severely limited. This research examines the behavioral and electrophysiological indices of how value biases split-second perceptual decisions and the possible mechanisms underlying the process. In prominent decision models, a noisy but statistically stationary representation of sensory evidence is integrated over time to an action-triggering bound, and value-biases …

Inference Of Language Functional Network In Healthy, Cancerous And Bilingual Brains By Fmri And Network Modeling, Qiongge Li

Dissertations, Theses, and Capstone Projects

We study the underlying mechanism by which language processing occurs in the human brain using inference methods on functional magnetic resonance imaging data. The data analyzed stems from several cohorts of subjects; a monolingual group, a bilingual group, a healthy control group and one diseased case. We applied a complex statistical inference pipeline to determine the network structure of brain components involved with language. This healthy network reveals a fully connected triangular relationship between the pre-Supplementary Motor Area (pre-SMA), the Broca's Area (BA), and the ventral Pre-Motor Area (PreMA) in the left hemisphere. This "triangle'' shows consistently in all the …

Electroencephalographic Asymmetry, Emotion Regulation, And Their Relationships With Depression Risk, Aliza Jacob

Dissertations, Theses, and Capstone Projects

Background: Research investigating patterns of electroencephalographic (EEG) brain asymmetry aids our understanding of neural systems involved in the processing of emotion, motivation, and psychopathology. Withdrawal-motivated negative emotions characteristic of depression are associated with relative right prefrontal cortex (PFC) activity, whereas approach- motivated positive emotions are associated with relative left PFC activity. Styles of emotion regulation (ER), or modulation of the intensity and duration of emotional responses, are also associated with presence (e.g., suppression, or maladaptive ER) versus absence (e.g., cognitive reappraisal, or adaptive ER) of depression vulnerability. Most PFC asymmetry studies of emotion, depression, and/or ER rely upon EEG recorded …

Competitive Frontoparietal Interactions Mediate Implicit Inferences, Martijn E. Wokke, Tony Ro

Publications and Research

Frequent experience with regularities in our environment allows us to use predictive information to guide our decision process. However, contingencies in our environment are not always explicitly present and sometimes need to be inferred. Heretofore, it remained unknown how predictive information guides decision-making when explicit knowledge is absent and how the brain shapes such implicit inferences. In the present experiment, 17 human participants (9 females) performed a discrimination task in which a target stimulus was preceded by a predictive cue. Critically, participants had no explicit knowledge that some of the cues signaled an upcoming target, allowing us to investigate how …

Effects Of The Kcnq Channel Opener Ezogabine On Functional Connectivity Of The Ventral Striatum And Clinical Symptoms In Patients With Major Depressive Disorder, Aaron Tan, Sara Costi, Laurel S. Morris, Nicholas T. Van Dam, Marin Kautz, Alexis E. Whitton, Allyson K. Friedman, Katherine A. Collins, Gabriella Ahle, Nisha Chadha, Brian Do, Diego A. Pizzagalli, Dan V. Iosifescu, Eric J. Nestler, Ming-Hu Han, James W. Murrough

Publications and Research

Major depressive disorder (MDD) is a leading cause of disability worldwide, yet current treatment strategies remain limited in their mechanistic diversity. Recent evidence has highlighted a promising novel pharmaceutical target—the KCNQ-type potassium channel—for the treatment of depressive disorders, which may exert a therapeutic effect via functional changes within the brain reward system, including the ventral striatum. The current study assessed the effects of the KCNQ channel opener ezogabine (also known as retigabine) on reward circuitry and clinical symptoms in patients with MDD. Eighteen medication-free individuals with MDD currently in a major depressive episode were enrolled in an open-label study and …

Transspinal Stimulation Increases Motoneuron Output Of Multiple Segments In Human Spinal Cord Injury, Lynda M. Murray, Maria Knikou

Publications and Research

Targeted neuromodulation strategies that strengthen neuronal activity are in great need for restoring sensorimotor function after chronic spinal cord injury (SCI). In this study, we established changes in the motoneuron output of individuals with and without SCI after repeated noninvasive transspinal stimulation at rest over the thoracolumbar enlargement, the spinal location of leg motor circuits. Cases of motor incomplete and complete SCI were included to delineate potential differences when corticospinal motor drive is minimal. All 10 SCI and 10 healthy control subjects received daily monophasic transspinal stimuli of 1-ms duration at 0.2 Hz at right soleus transspinal evoked potential (TEP) …

Using Fundamental Properties Of Light To Investigate Photonic Effects In Condensed Matter And Biological Tissues, Laura A. Sordillo

Dissertations and Theses

Light possesses characteristics such as polarization, wavelength and coherence. The interaction of light and matter, whether in a semiconductor or in a biological sample, can reveal important information about the internal properties of a system. My thesis focuses on two areas: photocarriers in gallium arsenide and biomedical optics. Varying the excitation wavelength can be used to study both biological tissue and condensed matter. I altered the excitation wavelengths to be in the longer near-infrared (NIR) optical windows, in the shortwave infrared (SWIR) range, a wavelength region previously thought to be unusable for medical imaging. With this method, I acquired high …

Translational Modeling Of Non-Invasive Electrical Stimulation, Dennis Quangvinh Truong

Dissertations and Theses

Seminal work in the early 2000’s demonstrated the effect of low amplitude non-invasive electrical stimulation in people using neurophysiological measures (motor evoked potentials, MEPs). Clinical applications of transcranial Direct Current Stimulation (tDCS) have since proliferated, though the mechanisms are not fully understood. Efforts to refine the technique to improve results are on-going as are mechanistic studies both in vivo and in vitro. Volume conduction models are being applied to these areas of research, especially in the design and analysis of clinical montages. However, additional research on the parameterization of models remains.

In this dissertation, Finite Element Method (FEM) models of …

Resting-State Functional Connectivity In Youth With Gender Dysphoria, Felix L. Garcia

Dissertations, Theses, and Capstone Projects

Current developmental models of gender identity and gender dysphoria (GD) lack sex-specific profiles of brain function that differentiate between typically-developing and cross-gender identified youth, as postulated by models like the unified theory of the origins of sex differences (Arnold, 2009) and the neurobiological theory of the origins of transsexuality (Swaab & Garcia-Falgueras, 2009). Previously, investigators have used brain imaging modalities such as Resting-State functional Magnetic Resonance Imaging (R-fMRI) to demonstrate differences in resting-state functional connectivity (RSFC) between typically-developing male and female youth, and between typically-developing and GID-diagnosed youth. In the present pilot study, I used R-fMRI to investigate differences in …

Spinal Control Of Locomotion: Individual Neurons, Their Circuits And Functions, Marie-Pascale Côté, Lynda M. Murray, Maria Knikou

Publications and Research

Systematic research on the physiological and anatomical characteristics of spinal cord interneurons along with their functional output has evolved for more than one century. Despite significant progress in our understanding of these networks and their role in generating and modulating movement, it has remained a challenge to elucidate the properties of the locomotor rhythm across species. Neurophysiological experimental evidence indicates similarities in the function of interneurons mediating afferent information regarding muscle stretch and loading, being affected by motor axon collaterals and those mediating presynaptic inhibition in animals and humans when their function is assessed at rest. However, significantly different muscle …

Multiple Sclerosis Identification Based On Fractional Fourier Entropy And A Modified Jaya Algorithm, Shui-Hua Wang, Hong Cheng, Preetha Phillips, Yu-Dong Zhang

Publications and Research

Aim: Currently, identifying multiple sclerosis (MS) by human experts may come across the problem of “normal-appearing white matter”, which causes a low sensitivity. Methods: In this study, we presented a computer vision based approached to identify MS in an automatic way. This proposed method first extracted the fractional Fourier entropy map from a specified brain image. Afterwards, it sent the features to a multilayer perceptron trained by a proposed improved parameter-free Jaya algorithm. We used cost-sensitivity learning to handle the imbalanced data problem. Results: The 10 × 10-fold cross validation showed our method yielded a sensitivity of 97.40 ± 0.60%, …

Transspinal Direct Current Stimulation Produces Persistent Plasticity In Human Motor Pathways, Lynda M. Murray, Behdad Tahayori, Maria Knikou

Publications and Research

The spinal cord is an integration center for descending, ascending, and segmental neural signals. Noninvasive transspinal stimulation may thus constitute an effective method for concomitant modulation of local and distal neural circuits. In this study, we established changes in cortical excitability and input/output function of corticospinal and spinal neural circuits before, at 0–15 and at 30–45 minutes after cathodal, anodal, and sham transspinal direct current stimulation (tsDCS) to the thoracic region in healthy individuals. We found that intracortical inhibition was different among stimulation polarities, however remained unchanged over time. Intracortical facilitation increased after cathodal and anodal tsDCS delivered with subjects …

Spinal Excitability Changes After Transspinal And Transcortical Paired Associative Stimulation In Humans, Maria Knikou

Publications and Research

Paired associative stimulation (PAS) produces enduring neuroplasticity based on Hebbian associative plasticity. This study established the changes in spinal motoneuronal excitability by pairing transcortical and transspinal stimulation. Transcortical stimulation was delivered after (transspinal-transcortical PAS) or before (transcortical-transspinal PAS) transspinal stimulation. Before and after 40 minutes of each PAS protocol, spinal neural excitability was assessed based on the amplitude of the transspinal-evoked potentials (TEPs) recorded from ankle muscles of both legs at different stimulation intensities (recruitment input-output curve). Changes in TEPs amplitude in response to low-frequency stimulation and paired transspinal stimuli were also established before and after each PAS protocol. TEP …