Neurosciences Commons^™

Microangiopathic Occlusion Of A Perforating Prepontine Long Circumferential Artery Presenting With Lower Motor Neuron Facial Weakness: Clinical And Radiological Correlation, Archie Defillo Md, Muhammad Shah Miran Md, Kenneth Shea Md, Michelle Peterson Np, Leah Roering Np, Jerone Kennedy Md, M. Fareed, K. Suri

Articles

Case Description: A 79-year old male patient with myelodysplastic syndrome associated with severe neutropenia, thrombocytopenia, anemia, hypertension, and hyperlipidemia was admitted for pneumonia secondary to influenza A. Two weeks later he presented with new symptoms of acute dysarthria, and left facial weakness involving his upper and lower face; the following day he developed left arm weakness. Admission computed tomography (CT) and MRI scans revealed an acute ischemic stroke (AIS) in the right posterior frontal cortex. The initial MRI was reported negative for pontine lesions. Anatomically, the cortical infarct could not explain his left lower motor neuron cranial nerve VII (LMN …

Closed-State Inactivation Involving An Internal Gate In Kv4.1 Channels Modulates Pore Blockade By Intracellular Quaternary Ammonium Ions., Jeffrey D. Fineberg, Tibor G. Szanto, Gyorgy Panyi, Manuel Covarrubias

Department of Neuroscience Faculty Papers

Voltage-gated K(+) (Kv) channel activation depends on interactions between voltage sensors and an intracellular activation gate that controls access to a central pore cavity. Here, we hypothesize that this gate is additionally responsible for closed-state inactivation (CSI) in Kv4.x channels. These Kv channels undergo CSI by a mechanism that is still poorly understood. To test the hypothesis, we deduced the state of the Kv4.1 channel intracellular gate by exploiting the trap-door paradigm of pore blockade by internally applied quaternary ammonium (QA) ions exhibiting slow blocking kinetics and high-affinity for a blocking site. We found that inactivation gating seemingly traps benzyl-tributylammonium …

Mechanical Reliability Of Implantable Polyimide-Based Magnetic Microactuators For Biofouling Removal, Christian G. Figueroa-Espada, Qi Yang, Hyowon Lee

The Summer Undergraduate Research Fellowship (SURF) Symposium

Hydrocephalus is a neurological disorder that typically requires a long-term implantation of a shunt system to manage its symptoms. These shunt systems are notorious for their extremely high failure rate. More than 40% of all implanted shunt systems fail within the first year of implantation. On average, 85% of all hydrocephalus patients with shunt systems undergo at least two shunt-revision surgeries within 10 years of implantation. A large portion of this high failure rate can be attributed to biofouling-related obstructions and infections. Previously, we developed flexible polyimide-based magnetic microactuators to remove obstructions formed on hydrocephalus shunts. To test the long-term …

A Trial-By-Trial Window Into Sensorimotor Transformations In The Human Motor Periphery., Chao Gu, Daniel K Wood, Paul L Gribble, Brian D Corneil

Brain and Mind Institute Researchers' Publications

UNLABELLED: The appearance of a novel visual stimulus generates a rapid stimulus-locked response (SLR) in the motor periphery within 100 ms of stimulus onset. Here, we recorded SLRs from an upper limb muscle while humans reached toward (pro-reach) or away (anti-reach) from a visual stimulus. The SLR on anti-reaches encoded the location of the visual stimulus rather than the movement goal. Further, SLR magnitude was attenuated when subjects reached away from rather than toward the visual stimulus. Remarkably, SLR magnitudes also correlated with reaction times on both pro-reaches and anti-reaches, but did so in opposite ways: larger SLRs preceded shorter …

Predominant Expression Of Alzheimer’S Disease-Associated Bin1 In Mature Oligodendrocytes And Localization To White Matter Tracts, Pierre De Rossi, Virginie Buggia-Prévot, Benjamin L. L. Clayton, Jared B. Vasquez, Carson Van Sanford, Robert J. Andrew, Ruben Lesnick, Alexandra Botté, Carole Deyts, Someya Salem, Eshaan Rao, Richard C. Rice, Angèle Parent, Satyabrata Kar, Brian Popko, Peter Pytel, Steven Estus, Gopal Thinakaran

Physiology Faculty Publications

Background: Genome-wide association studies have identified BIN1 within the second most significant susceptibility locus in late-onset Alzheimer’s disease (AD). BIN1 undergoes complex alternative splicing to generate multiple isoforms with diverse functions in multiple cellular processes including endocytosis and membrane remodeling. An increase in BIN1 expression in AD and an interaction between BIN1 and Tau have been reported. However, disparate descriptions of BIN1 expression and localization in the brain previously reported in the literature and the lack of clarity on brain BIN1 isoforms present formidable challenges to our understanding of how genetic variants in BIN1 increase the risk for AD.

Methods: …

Multipronged Approach To Study Glaucoma-Associated Phenotypes, Sumana Rameshbabu Chintalapudi

Theses and Dissertations (ETD)

Glaucoma refers to a group of conditions characterized by death of RGCs, increase in intraocular pressure is usually a precursor to glaucoma and irreversible optic neuropathy leads to visual impairment and blindness. Recent advances have seen a surge of new ideas and technologies to aid in the early detection, efficacious treatments and neuroprotection. Despite advances we face several challenges in understanding the pathophysiology of glaucoma. One of the many challenges scientists and ophthalmologists are facing is, to better understand IOP, its role in glaucomatous damage and design safer, more predictable IOP-lowering therapies. Another challenge is to find a practical method …

Why Numerical Symbols Count In The Development Of Mathematical Skills: Evidence From Brain And Behaviour, Rebecca Merkley, Daniel Ansari

Brain and Mind Institute Researchers' Publications

Numerical skills measured prior to school entry are predictive of mathematics achievement longitudinally. It is therefore important that young children start school with strong mathematical foundations. Here we review evidence from behavior and neuroimaging that highlights numerical symbol knowledge as a key mediator between informal and formal mathematical competencies. We argue that future research should aim to elucidate cognitive and neuronal mechanisms underpinning the acquisition of symbolic knowledge. Furthermore, multiple aspects of numerical symbol knowledge, such as identification, cardinality, and ordinality, should be emphasized in preschool childcare environments

Rapid Decrement In The Effects Of The Ponzo Display Dissociates Action And Perception., Robert L Whitwell, Gavin Buckingham, James T Enns, Philippe A Chouinard, Melvyn A Goodale

Brain and Mind Institute Researchers' Publications

It has been demonstrated that pictorial illusions have a smaller influence on grasping than they do on perceptual judgments. Yet to date this work has not considered the reduced influence of an illusion as it is measured repeatedly. Here we studied this decrement in the context of a Ponzo illusion to further characterize the dissociation between vision for perception and for action. Participants first manually estimated the lengths of single targets in a Ponzo display with their thumb and index finger, then actually grasped these targets in another series of trials, and then manually estimated the target lengths again in …

Effects Of Material Properties And Object Orientation On Precision Grip Kinematics., Vivian C Paulun, Karl R Gegenfurtner, Melvyn A Goodale, Roland W Fleming

Brain and Mind Institute Researchers' Publications

Successfully picking up and handling objects requires taking into account their physical properties (e.g., material) and position relative to the body. Such features are often inferred by sight, but it remains unclear to what extent observers vary their actions depending on the perceived properties. To investigate this, we asked participants to grasp, lift and carry cylinders to a goal location with a precision grip. The cylinders were made of four different materials (Styrofoam, wood, brass and an additional brass cylinder covered with Vaseline) and were presented at six different orientations with respect to the participant (0°, 30°, 60°, 90°, 120°, …

A Longitudinal Investigation Of Predictors Of The Association Between Age 3 And Age 6 Behavioural Inhibition., Victoria C Johnson, Thomas M Olino, Daniel N Klein, Margaret W Dyson, Sara J Bufferd, C Emily Durbin, Lea R Dougherty, Elizabeth P Hayden

Brain and Mind Institute Researchers' Publications

Children who exhibit elevated levels of the temperament trait behavioural inhibition (BI) across time may be at greatest risk for anxiety. However, little research has investigated the influence of other temperamental traits, particularly positive emotionality (PE), on the continuity of BI in childhood, nor whether parental overprotection influences associations between early and later child BI. To explore whether PE and overprotection shape associations between early and later BI, this longitudinal study of three-year-olds (

Reduced Motor Neuron Excitability Is An Important Contributor To Weakness In A Rat Model Of Sepsis, Paul Nardelli, Jacob A. Vincent, Randall K. Powers, Timothy C. Cope, Mark M. Rich

Neuroscience, Cell Biology & Physiology Faculty Publications

The mechanisms by which sepsis triggers intensive care unit acquired weakness (ICUAW) remain unclear. We previously identified difficulty with motor unit recruitment in patients as a novel contributor to ICUAW. To study the mechanism underlying poor recruitment of motor units we used the rat cecal ligation and puncture model of sepsis. We identified striking dysfunction of alpha motor neurons during repetitive firing. Firing was more erratic, and often intermittent. Our data raised the possibility that reduced excitability of motor neurons was a significant contributor to weakness induced by sepsis. In this study we quantified the contribution of reduced motor neuron …

Repeated Zolpidem Treatment Effects On Sedative Tolerance, Withdrawal, Mrna Levels, And Protein Expression, Brittany T. Wright

Theses and Dissertations (ETD)

Zolpidem and benzodiazepines (BZs) potentiate the inhibitory action of gamma-Aminobutyric acid (GABA) by allosterically binding to GABAA receptors (GABAAR). Prolonged use of GABAAR positive allosteric modulators (PAM) can lead to behavioral tolerance, the diminished response to the same drug dose with repeated use, and withdrawal, a group of symptoms that occur due to abrupt end of drug treatment. Zolpidem is a short-acting, non-BZ GABAAR PAM whose potential for tolerance and withdrawal is unclear. Zolpidem demonstrates sedative efficacy similar to BZs and has become a main treatment of insomnia in lieu of BZs. Zolpidem replaced BZs due to lower incidences of …

Pituitary Adenylate-Cyclase Activating Polypeptide Regulates Hunger- And Palatability-Induced Binge Eating, Matthew M. Hurley, Brian Maunze, Megan E. Block, Michael J. Reilly, Eugene Kim, Yao Chen, Yan Li, David A. Baker, Qing-Song Liu, Sujean Choi

Biomedical Sciences Faculty Research and Publications

While pituitary adenylate cyclase activating polypeptide (PACAP) signaling in the hypothalamic ventromedial nuclei (VMN) has been shown to regulate feeding, a challenge in unmasking a role for this peptide in obesity is that excess feeding can involve numerous mechanisms including homeostatic (hunger) and hedonic-related (palatability) drives. In these studies, we first isolated distinct feeding drives by developing a novel model of binge behavior in which homeostatic-driven feeding was temporally separated from feeding driven by food palatability. We found that stimulation of the VMN, achieved by local microinjections of AMPA, decreased standard chow consumption in food-restricted rats (e.g., homeostatic feeding); surprisingly, …

Neuroanatomical Maps And Taste Reactivity To Sweet, Umami, And Bitter Taste In The Pbn Of C57bl/6j Mice, Jennifer Marie Saputra

Theses and Dissertations (ETD)

Humans can distinguish at least five different taste qualities, sour, salty, bitter, sweet, and umami (the savory taste of certain amino acids). In neuroscience research, behavioral testing is used to measure the ability of rodents (including inbred mice) to discriminate between the different taste qualities. Taste reactivity and two-bottle preference are behavioral tests that are utilized to investigate different aspects of taste. These tests involve either voluntary or forced consumption of taste stimuli, respectively. Either test can be used to infer the preference and palatability of the stimulus consumed by an animal.

In order to understand the basis of taste …

Evaluating The Therapeutic Effect Of An Hsp90 Inhibitor In Mouse Models Of Alzheimer’S Disease, Bin Wang

Theses and Dissertations (ETD)

The excessive accumulation of amyloid peptides (Aβ) represents one major pathological hallmark of Alzheimer’s disease (AD), which is most notably characterized by synaptic dysfunction. Strategies targeting heat shock protein 90 (Hsp90) inhibition have been widely investigated in the treatment of cancer for over two decades. Its application in the treatment of neurodegenerative diseases however, has emerged more recently in the last decade. The role of the Hsp90 chaperone in clearing misfolded protein aggregates has been well established (in vitro only), but its function in synaptic activity remains elusive.

In our study, we utilized a widely used Hsp90 inhibitor, 17-AAG …

Mir-27a And Mir-27b Regulate Autophagic Clearance Of Damaged Mitochondria By Targeting Pten-Induced Putative Kinase 1 (Pink1), Jaekwang Kim, Fabienne C. Fiesel, Krystal C. Belmonte, Roman Hudec, Wang-Xia Wang, Chaeyoung Kim, Peter T. Nelson, Wolfdieter Springer, Jungsu Kim

Pathology and Laboratory Medicine Faculty Publications

Background: Loss-of-function mutations in PINK1 and PARKIN are the most common causes of autosomal recessive Parkinson’s disease (PD). PINK1 is a mitochondrial serine/threonine kinase that plays a critical role in mitophagy, a selective autophagic clearance of damaged mitochondria. Accumulating evidence suggests mitochondrial dysfunction is one of central mechanisms underlying PD pathogenesis. Therefore, identifying regulatory mechanisms of PINK1 expression may provide novel therapeutic opportunities for PD. Although post-translational stabilization of PINK1 upon mitochondrial damage has been extensively studied, little is known about the regulation mechanism of PINK1 at the transcriptional or translational levels.

Results: Here, we demonstrated that microRNA-27a (miR-27a) and …

Disentangling Representations Of Object And Grasp Properties In The Human Brain, Sara Fabbri, Kevin M. Stubbs, Rhodri Cusack, Jody C. Culham

Brain and Mind Institute Researchers' Publications

No abstract provided.

Cerebral Functional Connectivity Periodically (De)Synchronizes With Anatomical Constraints., Raphaël Liégeois, Erik Ziegler, Christophe Phillips, Pierre Geurts, Francisco Gómez, Mohamed Ali Bahri, B T Thomas Yeo, Andrea Soddu, Audrey Vanhaudenhuyse, Steven Laureys, Rodolphe Sepulchre

Brain and Mind Institute Researchers' Publications

This paper studies the link between resting-state functional connectivity (FC), measured by the correlations of fMRI BOLD time courses, and structural connectivity (SC), estimated through fiber tractography. Instead of a static analysis based on the correlation between SC and FC averaged over the entire fMRI time series, we propose a dynamic analysis, based on the time evolution of the correlation between SC and a suitably windowed FC. Assessing the statistical significance of the time series against random phase permutations, our data show a pronounced peak of significance for time window widths around 20-30 TR (40-60 s). Using the appropriate window …

Collective Timekeeping Among Cells Of The Master Circadian Clock, Jennifer A. Evans

Biomedical Sciences Faculty Research and Publications

The suprachiasmatic nucleus (SCN) of the anterior hypothalamus is the master circadian clock that coordinates daily rhythms in behavior and physiology in mammals. Like other hypothalamic nuclei, the SCN displays an impressive array of distinct cell types characterized by differences in neurotransmitter and neuropeptide expression. Individual SCN neurons and glia are able to display self-sustained circadian rhythms in cellular function that are regulated at the molecular level by a 24h transcriptional–translational feedback loop. Remarkably, SCN cells are able to harmonize with one another to sustain coherent rhythms at the tissue level. Mechanisms of cellular communication in the SCN network are …

The Concerted Regulation Of Intracellular Signaling By Amyloid Precursor Protein And Aβ Peptide, Lisa Kirouac

USF Tampa Graduate Theses and Dissertations

It is widely accepted that A-beta (Aβ) generated from amyloid precursor protein (APP) oligomerizes and fibrillizes to form neuritic plaques in the Alzheimer’s disease (AD) brain, yet little is known about the contribution of APP preceding AD pathogenesis. Our data presented here suggest that APP has a functional role in cell cycle regulation and proliferation. First, we demonstrat that APP is pathologically phosphorylated at Thr₆₆₈ and that P-APP localizes to the centrosomes. Furthermore, P-APP is proteolytically processed in a cell cycle -dependent manner to generate its pathogenic metabolites. Using Stable Isotope Labeling by Amino Acids in Culture (SILAC) and …