Neurosciences Commons^™

The Neural Basis Of External Responsiveness In Prolonged Disorders Of Consciousness, Clara A. Stafford, Adrian M. Owen, Davinia Fernández-Espejo

Brain and Mind Institute Researchers' Publications

Objective: To investigate the structural integrity of fibre tracts underlying overt motor behaviour in PDOC. Methods: This cross-sectional study examined 15 PDOC patients and 22 healthy participants. Eight PDOC patients met the criteria for the vegetative state, 5 met the criteria for the minimally conscious state and 2 met the criteria for emerging from the minimally conscious state. We used fibre tractography to reconstruct the white matter fibres known to be involved in voluntary motor execution (i.e., those connecting thalamus with M1, M1 with cerebellum, and cerebellum with thalamus) and used fractional anisotropy (FA) as a measure of their integrity. …

Developing A Mechanistic Understanding Of Crossmodal Reorganization Following Sensory Loss, Brainscan, Western University, Blake E. Butler, Brian Allman, Ravi Menon

Project Summaries

Our long-term goal is to understand how plasticity reshapes circuits in the brain in response to atypical early experiences. This will allow us to better understand how the Deaf brain processes the world around us, and will make clear the challenges that must be overcome to optimize the function of cochlear implants and prostheses designed to restore sensory functions more broadly.

Can Self-Efficacy Training Improve Memory And Functional Activation In Older Adults With Mild Cognitive Impairment? A Proof-Of-Concept Intervention Study, Brainscan, Western University, Lindsay Nagamatsu, Derek Mitchell, Paul Minda, Amer Burhan, Becky Horst

Project Summaries

The goal of this study is to examine the changes in brain activity after a memory self-efficacy training program to better understand the mechanisms of memory self-efficacy. We will conduct a proof-of-concept six-week memory self-efficacy intervention in older adults with MCI, in order to demonstrate that self-efficacy impacts brain function. This will allow us to determine whether self-efficacy interventions may be a potential strategy for combating AD in the future.

Developing And Validating Tools To Assess Higher Level Cognition In Children And Adolescents, Brainscan, Western University, Bobby Stojanoski, Marc Joanisse, Ryan Stevenson, Cambridge Brain Sciences Inc.

Project Summaries

Collaborating with CBS, we will create a unique platform for understanding, detecting and predicting delays in cognition during the formative period from childhood to adolescence. The aim of this project is to develop and validate a battery of tests specifically for children and adolescents between the ages of 7 and 15 to measure various aspects of higher-level cognitive abilities. These include short-term and episodic memory, planning, reasoning, verbal abilities and executive functioning (those processes necessary to control behaviour, such as controlling attention and inhibition, working memory, reasoning and problem solving).

Multi-Area Organization Of Saccade-Evoked Traveling Waves, Brainscan, Western University, Julio Martinez-Trujillo, Lyle Muller, Adam Williamson

Project Summaries

In this project, we will employ new, large-scale electrophysiological recording techniques to sample widely across the visual system. It will allow us to test our hypothesis that neural traveling waves coordinated across multiple areas contribute to perceptual stability during eye movements. Using our newly developed signal processing technique to track traveling waves moment-by-moment in noisy multichannel data, we will detect and quantify them across multiple visual areas.

Detecting Fine-Grained Population Codes In Human Prefrontal Cortex, Brainscan, Western University, Marieke Mur, Julio Martinez-Trujillo, Ravi Menon, Joe Gati

Project Summaries

In this project, we will develop techniques for improving our measurement resolution so that we can gain access to prefrontal population codes. We will combine high-field fMRI with pattern analysis techniques to unlock population coding in the prefrontal cortex. This is essential for understanding how the brain supports higher-order cognition, and ultimately, for treating dysfunctions of cognitive flexibility in the clinic.

The Risk Of New-Onset Epilepsy And Refractory Epilepsy In Older Adult Stroke Survivors, Jorge G. Burneo, Tresah C. Antaya, Britney N. Allen, Andrea Belisle, Salimah Z. Shariff, Gustavo Saposnik

Neuroepidemiology Research Unit Project Summaries

Research Summary: Key Findings

• Stroke is a common cause of epilepsy in older adults, but little is known about stroke-related epilepsy or its outcomes in this population.
• 1.1% of older adult stroke survivors developed epilepsy in this study, of whom 12.9% developed refractory epilepsy, indicating that this population is particularly responsive to treatment.
• Over 85% of deaths in this population are not due to stroke or epilepsy.

Determinants Of Occupational Injuries Among Building Construction Workers In Kampala City, Uganda, Arthur Kiconco, Nathan Ruhinda, Abdullah Ali Halage, Stephen Watya, William Bazeyo, John C. Ssempebwa, Joseph Byonanebye

Biomedical Sciences Faculty Research and Publications

Background

Globally, about 1000 people die and close to 860,000 people sustain injury at work daily. Injury prevention and control require contextual evidence, although most studies in Uganda have focused on general causes. Factors associated with occupational injuries among building construction workers were assessed in this study.

Methods

A cross-sectional study among building construction workers was conducted in Kampala, Uganda. A standardized semi-structured questionnaire was used to collect data. Three hundred nineteen (319) participants were randomly and proportionately selected from 57 construction sites. Descriptive statistics were used to describe the variables while generalized linear modeling was used to estimate the …

Stress-Dependent Regulation Of A Major Node Of The Insulin-Like Peptide Network That Modulates Survival, Rashmi Chandra

Wayne State University Dissertations

Chronic stress disrupts insulin signaling, predisposing human populations to diabetes, cardiovascular disease, Alzheimer’s Disease, and other metabolic and neurological disorders, including post-traumatic disorders (PTSD). Thus, efficient recovery from stress optimizes survival. However, stress recovery in humans is difficult to study, but is much easier to dissect in model organisms. The worm genetic model Caenorhabditis elegans can switch between stressed and non-stressed states, and this switch is largely regulated by insulin signaling. Previously, the Alcedo lab proposed that insulin-like peptides (ILPs), which exist as multiple members of a protein family in both C. elegans and humans, implements a combinatorial coding strategy …

Characterizing The Development Of Episodic Memory And Assessing The Reliability Of Fmri Measures, Lingfei Tang

Wayne State University Dissertations

The ability to remember past events is critical for everyday life and showed robust improvement over development from childhood to adulthood. With advances in noninvasive neuroimaging methods such as functional MRI in recent years, research efforts have been focused on identifying neural correlates underpinning developmental gains in memory performance. In my dissertation work, using a widely-validated subsequent memory paradigm, I aim to characterize functional MRI correlates of memory development. Specifically, I focused my investigation on identifying age differences in the functional patterns of two brain regions critical for memory, the prefrontal cortex and the hippocampus. Focusing on the prefrontal cortex …

A Synthetic Agonist To Vasoactive Intestinal Peptide Receptor-2 Induces Regulatory T Cell Neuroprotective Activities In Models Of Parkinson's Disease, R. Lee Mosley, Yaman Lu, Katherine E. Olson, Jatin Machhi, Wenhui Yan, Krista L. Namminga, Jenell R. Smith, Scott J. Shandler, Howard Gendelman

Journal Articles: Pharmacology & Experimental Neuroscience

A paradigm shift has emerged in Parkinson's disease (PD) highlighting the prominent role of CD4⁺ Tregs in pathogenesis and treatment. Bench to bedside research, conducted by others and our own laboratories, advanced a neuroprotective role for Tregs making pharmacologic transformation of immediate need. Herein, a vasoactive intestinal peptide receptor-2 (VIPR2) peptide agonist, LBT-3627, was developed as a neuroprotectant for PD-associated dopaminergic neurodegeneration. Employing both 6-hydroxydopamine (6-OHDA) and α-synuclein (α-Syn) overexpression models in rats, the sequential administration of LBT-3627 increased Treg activity without altering cell numbers both in naïve animals and during progressive nigrostriatal degeneration. LBT-3627 administration was linked to …

Ca2+ Sensor Synaptotagmin-1 Mediates Exocytosis In Mammalian Photoreceptors, Justin J. Grassmeyer, Asia L. Cahill, Cassandra L. Hays, Cody Barta, Rolen M. Quadros, Channabasavaiah B. Gurumurthy, Wallace B. Thoreson

Journal Articles: Pharmacology & Experimental Neuroscience

To encode light-dependent changes in membrane potential, rod and cone photoreceptors utilize synaptic ribbons to sustain continuous exocytosis while making rapid, fine adjustments to release rate. Release kinetics are shaped by vesicle delivery down ribbons and by properties of exocytotic Ca²⁺ sensors. We tested the role for synaptotagmin-1 (Syt1) in photoreceptor exocytosis by using novel mouse lines in which Syt1 was conditionally removed from rods or cones. Photoreceptors lacking Syt1 exhibited marked reductions in exocytosis as measured by electroretinography and single-cell recordings. Syt1 mediated all evoked release in cones, whereas rods appeared capable of some slow Syt1-independent release. Spontaneous …

Mice, Acorns, And Lyme Disease: A Case Study To Teach The Ecology Of Emerging Infectious Diseases, Laurieann Klockow

Biomedical Sciences Faculty Research and Publications

Ebola, Zika, the recall of contaminated lettuce - these are just a few recent outbreaks making headlines. Students should be able to connect what they learn in their biology courses to explain these events happening around them. Unfortunately, students do not necessarily make those connections. Therefore, it is important, as instructors, to provide opportunities where students engage with societal issues and problems related to course content and case studies, using headlines from the news are one way to do this.

Here I describe a case study about Lyme disease that engages students in learning about the ecology of infectious disease. …

When Brain Stimulation Backfires, Sarah Beth Bell

Theses and Dissertations--Psychology

tDCS brain stimulation does not always work in the intended direction. It has been found to sometimes worsen behavior rather than improve it. A preliminary study shows that people high on sensation-seeking and lack of premeditation were prone to reverse effects of tDCS on performance on a Stop Signal Task. Both of these constructs are related to dopamine levels. Study 2 seeks to intentionally cause a reverse effect of tDCS by increasing participants’ dopamine levels via caffeine. There was not a significant interaction between tDCS and caffeine on errors on the Stop Signal Task in this study. However, other factors …

Prefrontal-Accumbens Opioid Plasticity: Implications For Relapse And Dependence, Matthew C. Hearing

Biomedical Sciences Faculty Research and Publications

In addiction, an individual’s ability to inhibit drug seeking and drug taking is thought to reflect a pathological strengthening of drug-seeking behaviors or impairments in the capacity to control maladaptive behavior. These processes are not mutually exclusive and reflect drug-induced modifications within prefrontal cortical and nucleus accumbens circuits, however unlike psychostimulants such as cocaine, far less is known about the temporal, anatomical, and cellular dynamics of these changes. We discuss what is known regarding opioid-induced adaptations in intrinsic membrane physiology and pre-/postsynaptic neurotransmission in principle pyramidal and medium spiny neurons in the medial prefrontal cortex and nucleus accumbens from electrophysiological …

Neuroprotective Strategies Following Experimental Traumatic Brain Injury: Lipid Peroxidation-Derived Aldehyde Scavenging And Inhibition Of Mitochondrial Permeability Transition, Jacqueline Renee Kulbe

Theses and Dissertations--Neuroscience

Traumatic brain injury (TBI) represents a significant health crisis. To date there are no FDA-approved pharmacotherapies available to prevent the neurologic deficits caused by TBI. Following TBI, dysfunctional mitochondria generate reactive oxygen and nitrogen species, initiating lipid peroxidation (LP) and the formation of LP-derived neurotoxic aldehydes, which bind mitochondrial proteins, exacerbating dysfunction and opening of the mitochondrial permeability pore (mPTP), resulting in extrusion of mitochondrial sequestered calcium into the cytosol, and initiating a downstream cascade of calpain activation, spectrin degradation, neurodegeneration and neurologic impairment.

As central mediators of the TBI secondary injury cascade, mitochondria and LP-derived neurotoxic aldehydes make promising …

Investigating The Effects Of Methylphenidate On Cue Salience And Behavioral Flexibility: Role Of D2 Receptors, Mercedes Mcwaters

Graduate Research Theses & Dissertations

Healthy individuals worldwide are using cognitive enhancing drugs in an attempt to remain competitive in society for education, careers, and athletics. Commonly, these individuals are using prescription stimulants, such as methylphenidate (MPH), due to their known acute neuroenhancing effects. While these neuroenhancing effects have been established using a variety of learning, memory, and attention tasks in humans and rodents, little research has investigated the effects of MPH use on specific components of these tasks, such as cue salience. One process that is important for learning the relationship between a cue and a reward is salience, or the heightened perception and …

Translational Tests Involving Non-Reward: Methodological Considerations, Benjamin U. Phillips, Laura Lopez-Cruz, Lisa M. Saksida, Timothy J. Bussey

Brain and Mind Institute Researchers' Publications

© 2018, The Author(s). This review is concerned with methods for assessing the processing of unrewarded responses in experimental animals and the mechanisms underlying performance of these tasks. A number of clinical populations, including Parkinson’s disease, depression, compulsive disorders, and schizophrenia demonstrate either abnormal processing or learning from non-rewarded responses in laboratory-based reinforcement learning tasks. These effects are hypothesized to result from disturbances in modulatory neurotransmitter systems, including dopamine and serotonin. Parallel work in experimental animals has revealed consistent behavioral patterns associated with non-reward and, consistent with the human literature, modulatory roles for specific neurotransmitters. Classical tests involving an important …

Girls' Internalizing Symptoms And White Matter Tracts In Cortico-Limbic Circuitry, Ola Mohamed Ali, Matthew R.J. Vandermeer, Haroon I. Sheikh, Marc F. Joanisse, Elizabeth P. Hayden

Brain and Mind Institute Researchers' Publications

© 2019 The Authors Dysfunction in cortico-limbic circuitry is implicated in internalizing disorders (i.e., depressive and anxious disorders), but less is known about whether structural variations precede frank disorder and thus potentially mark risk. We therefore examined associations between white matter (WM) tract microstructure in cortico-limbic circuitry at age 7 and concurrent and longitudinal patterns of internalizing symptoms in 42 typically developing girls using Diffusion Tensor Imaging (DTI). Girls' internalizing symptoms were concurrently associated with reduced fractional anisotropy (FA) in segments of the cingulum bundle (CB) and the uncinate fasciculus (UF), bilaterally. Moreover, latent profile analysis showed that girls with …

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 …