Neuroscience and Neurobiology Commons^™

Epilepsy-Associated Dysfunction In The Voltage-Gated Neuronal Sodium Channel Scn1a, Christoph Lossin, T. Rhodes, R. Desai, C. Vanoye, S. Caniciu, O. Devinsky, A. George

Christoph Lossin, Ph.D.

Mutations in SCN1A, the gene encoding the brain voltage-gated sodium channel subunit (Nav1.1) are associated with at least two forms of epilepsy, generalized epilepsy with febrile seizures plus (GEFS+) and severe myoclonic epilepsy of infancy (SMEI). We examined the functional properties of four GEFS+ alleles and one SMEI allele using whole-cell patch-clamp analysis of heterologously expressed recombinant human SCN1A. One previously reported GEFS+ mutation (I1656M) and an additional novel allele (R1657C), both affecting residues in a voltage-sensing S4 segment, exhibited a similar depolarizing shift in the voltage dependence of activation. Additionally, R1657C showed a 50% reduction in current density and …

Tongue Movements In Feeding And Speech, Karen M. Hiiemae, Jeffrey B. Palmer

Biomedical and Chemical Engineering - All Scholarship

The position of the tongue relative to the upper and lower jaws is regulated in part by the position of the hyoid bone, which, with the anterior and posterior suprahyoid muscles, controls the angulation and length of the floor of the mouth on which the tongue body 'rides'. The instantaneous shape of the tongue is controlled by the 'extrinsic muscles ' acting in concert with the 'intrinsic ' muscles. Recent anatomical research in non-human mammals has shown that the intrinsic muscles can best be regarded as a 'laminated segmental system ' with tightly packed layers of the 'transverse', 'longitudinal', and …

Il-23 Produced By Cns-Resident Cells Controls T Cell Encephalitogenicity During The Effector Phase Of Experimental Autoimmune Encephalomyelitis, Burkhard Becher, Brigit G. Durell, Randolph J. Noelle

Dartmouth Scholarship

CNS-resident cells, in particular microglia and macrophages, are a source of inflammatory cytokines during inflammation within the CNS. Expression of IL-23, a recently discovered cytokine, has been shown to be critical for the development of experimental autoimmune encephalomyelitis (EAE) in mice. Expression of the p40 subunit of IL-12 and IL-23 by microglia has been shown in situ and in vitro, but direct evidence for a functional significance of p40 expression by CNS cells during an immune response in vivo is still lacking. Here we report that p40 plays a critical role in maintaining encephalitogenicity during the disease course. By using …

An Online Lab Manual For Neurophysiology, Richard F. Olivo

Neuroscience: Faculty Publications

A combination of student interest, a grant for computers, and a suggestion from a colleague led me to convert the printed lab manual for my neurophysiology course into an online version. The web-based version incorporates videos of procedures, color photos, diagrams, links to articles, and other supplementary materials. This paper discusses designing for the web, retaining compatibility with print, layering information, making videos in digital format, and sharing self-published resources. The labs themselves (appendix) are traditional “wet” experiments with crayfish that have been used in many neurobiology courses.

Radiation Effects On Dopamine-Mediated Prepulse Inhibition In The C57bl/6 Mouse, Cara Nicole Zuccarelli Miller

Loma Linda University Electronic Theses, Dissertations & Projects

This study examined the effects of proton and gamma radiation on a dopamine-dependent sensory gating mechanism: prepulse inhibition of the startle reflex. The purpose of this research was to describe potential hazards of proton radiation to the central nervous system in long-term space fight and for proton therapy patients. Results from previous research indicate that startle behavior is modified by proton and iron radiation. Forty-eight 10-½ week old, male C57BL/6 mice were used to characterize the optimal parameters for the model (prepulse duration, probe duration, and stimulus-onset-asynchrony). Three hundred and fifty two mice were used to characterize the time course …

Time Course Of Loudness Recalibration: Implications For Loudness Enhancement, Yoav Arieh, Lawrence E. Marks

Department of Psychology Faculty Scholarship and Creative Works

Loudness recalibration, the effect of a relatively loud 2500-Hz recalibrating tone on the loudness of a relatively soft 2500-Hz target tone, was measured as a function of the interstimulus interval (ISI) between them. The loudness of the target tone, assessed by a 500-Hz comparison tone, declined when the ISI equaled or exceeded about 200 ms and leveled off at an ISI of about 700 ms. Notably, the target tone’s loudness did not change significantly at very short ISIs (<150 ms). The latter result is incompatible with the literature reporting loudness enhancement in this time window but is compatible with the suggestion made by Scharf, Buus, and Nieder [J. Acoust. Soc. Am. 112, 807–810 (2002)] that early measurements of enhancement were contaminated by the influence of the recalibrating tone on the comparison …

Recalibrating The Auditory System: A Speed–Accuracy Analysis Of Intensity Perception, Yoav Arieh, Lawrence E. Marks

Department of Psychology Faculty Scholarship and Creative Works

Recalibration in loudness perception refers to an adaptation-like change in relative responsiveness to auditory signals of different sound frequencies. Listening to relatively weak tones at one frequency and stronger tones at another make the latter appear softer. The authors showed recalibration not only in magnitude estimates of loudness but also in simple response times (RTs) and choice RTs. RTs depend on the sound intensity and may serve as surrogates for loudness. Most important, the speeded classification paradigm also provided measures of errors. RTs and errors can serve jointly to distinguish changes in sensitivity from changes in response criterion. The changes …

A Research Agenda For Political Personality And Leadership Studies: An Evolutionary Proposal, Aubrey Immelman, Theodore Millon

Psychology Faculty Publications

Despite major neuroscientific advances in the past two decades and parallel conceptual refinement in evolutionary theory, personality-in-politics inquiry remains adrift, divorced from these broader spheres of scientific knowledge. This paper reviews the neurobiological substrates of three major domains of evolutionary biology and behavioral ecology relevant to political personality assessment and the psychological examination of political leaders; furnishes a context and set of guiding ideas to revitalize the study of the person as biopsychosocial entity in politics; advances a generative theory of personality and political leadership performance; and proposes an agenda for advancing personality-in-politics and leadership inquiry, informed by insights derived …

Filopodial Calcium Transients Regulate Growth Cone Motility And Guidance Through Local Activation Of Calpain, Estuardo Robles, Anna Huttenlocher, Timothy M. Gomez

Neuroscience: Faculty Publications

Spontaneous intracellular calcium ([Ca2+]i) transients in growth cone filopodia reduce filopodial motility, slow neurite outgrowth, and promote turning when generated asymmetrically; however, the downstream effectors of these Ca2+-dependent behaviors are unknown. We report that Ca2+ transients in filopodia activate the intracellular protease calpain, which slows neurite outgrowth and promotes repulsive growth cone turning upon local activation. Active calpain alters the balance between tyrosine kinase and phosphatase activities in filopodia, resulting in a net decrease in tyrosine phosphorylation, which mediates both filopodial stabilization and reduced lamellipodial protrusion. Our findings indicate that locally generated Ca2+ signals repel axon outgrowth through calpain-dependent regulation …

Intrinsic Role Of Polysialylated Neural Cell Adhesion Molecule In Photic Phase Resetting Of The Mammalian Circadian Clock, Rebecca Prosser

Faculty Publications and Other Works -- Biochemistry, Cellular and Molecular Biology

The suprachiasmatic nuclei (SCN), the location of the mammalian circadian clock, are one of the few adult brain regions that express the highly polysialylated form of neural cell adhesion molecule (PSA-NCAM). A role for the polysialic acid (PSA) component of PSA-NCAM, which is known to promote tissue plasticity, has been reported for photic entrainment of circadian rhythmicity in vivo. The in vivo results, however, do not discriminate between PSA acting upstream or downstream of the glutamatergic synapses that convey photic information to the SCN. To address this key issue, we exploited an in vitro rat brain slice preparation that retains …

Intrinsic Role Of Polysialylated Neural Cell Adhesion Molecule In Photic Phase Resetting Of The Mammalian Circadian Clock, Rebecca Prosser

Rebecca Prosser

The suprachiasmatic nuclei (SCN), the location of the mammalian circadian clock, are one of the few adult brain regions that express the highly polysialylated form of neural cell adhesion molecule (PSA-NCAM). A role for the polysialic acid (PSA) component of PSA-NCAM, which is known to promote tissue plasticity, has been reported for photic entrainment of circadian rhythmicity in vivo. The in vivo results, however, do not discriminate between PSA acting upstream or downstream of the glutamatergic synapses that convey photic information to the SCN. To address this key issue, we exploited an in vitro rat brain slice preparation that retains …

Sensorimotor Coordination And The Structure Of Space, Gin Mccollum

Gin McCollum

Embedded in neural and behavioral organization is a structure of sensorimotor space. Both this embedded spatial structure and the structure of physical space inform sensorimotor control. This paper reviews studies in which the gravitational vertical and horizontal are crucial. The mathematical expressions of spatial geometry in these studies indicate methods for investigating sensorimotor control in freefall.

In freefall, the spatial structure introduced by gravitation – the distinction between vertical and horizontal – does not exist. However, an astronaut arriving in space carries the physiologically-embedded distinction between horizontal and vertical learned on earth. The physiological organization based on this distinction collapses …

Gamma Oscillations Correlate With Working Memory Load In Humans, Marc W. Howard, Daniel S. Rizzuto, Jeremy B. Caplan, Joseph R. Madsen, John Lisman

Psychology - All Scholarship

Functional imaging of human cortex implicates a diverse network of brain regions supporting working memory—the capacity to hold and manipulate information for short periods of time. Although we are beginning to map out the brain networks supporting working memory, little is known about its physiological basis. We analyzed intracranial recordings from two epileptic patients as they performed a working memory task. Spectral analyses revealed that, in both patients, gamma (30-60 Hz) oscillations increased approximately linearly with memory load, tracking closely with memory load over the course of the trial. This constitutes the first evidence that gamma oscillations, widely implicated in …

Exposure Of Nervous System Cells To Polychlorinated Biphenyls (Pcbs) Results In Significant Alterations In Levels Of Expression Of Neurotrophic Factors, Charles F. Ide, Jay C. Means, Trisha M. Basford, John Spitsbergen

Biological Sciences Faculty and Graduate Student Research

Toxic insult by PCBs results in learning and memory deficits in humans. Alterations in expression of neurotrophic factors and/or their receptors have been linked to changes in cognition. How PCBs affect cognition is not known. We propose that PCBs affect cognition by altering neurotrophic factor expression or effects. We exposed cultured C6 glial cells in medium containing PCB (Aroclor 1254 (10ppm)). Control cells were treated with DMSO or regular medium. Cells were incubated at 37o C for up to 72 hours. Medium samples were taken at 6hr, 24hr, 48hr, and 72hr intervals. Enzyme-linked immunosorbent assays (ELISA) were used to determine …

Acutely-Administered Ethanol Participates In Testosterone Synthesis And Increases Testosterone In The Rat Brain., Laura O'Dell

Laura Elena O'Dell

No abstract provided.

Behavioral Aspects Of Apolipoprotein E Knockout Mice, Melissa T. Litherland

Masters Theses

Apolipoprotein E (apoE) is a lipid transporting protein that has been shown to play a vital role in nerve repair and remodeling. Previous studies have shown that apoE is highly expressed in human and mouse olfactory bulbs. ApoE deficiency in apolipoprotein E knockout (apoE-KO) mice leads to considerable delay in olfactory nerve repair and deficits in olfactory functioning. Olfactory function is necessary for a number of social behaviors in mice. Loss of olfaction can greatly reduce social behaviors. Since apoE-KO mice display olfactory dysfunction, this deficit may result in alterations in social behavior. Olfactory function was assessed in apoE-KO mice …

Cell Biology Of Apoe In Cortical Cultured Neurons: Possible Roles In Alzheimer's Disease, Anna G. Barsukova

Masters Theses

The apolipoprotein E4 (apoE4) genotype is a major risk factor for Alzheimer's disease (AD). Previous studies have shown that apoE4 is less effective than apoE3 in supporting neurite outgrowth in adult mice cortical cultures. However the mechanism underlying this phenomenon is not known. To understand this mechanism and the broader role of apoE isoforms on neuronal biology I examined the rate of apoE isoforms internalization in neurons, effects of apoE isoforms on lipid uptake by neurons, effects of apoE isoforms on neuronal environment - microglia and on neuroregeneration, or neurogenesis.

I examined the binding and internalization of recombinant human apoE3 …

Assessing Brain Activity Using Spatial Bayesian Variable Selection, Michael Smith, B Putz, D Auer, Ludwig Fahrmeir

Michael Stanley Smith

Statistical parametric mapping (SPM), relying on the general linear model and classical hypothesis testing, is a benchmark tool for assessing human brain activity using data from fMRI experiments. Friston et al. (Neuroimage 16 (2002a), 484) discuss some limitations of this frequentist approach and point out promising Bayesian perspectives. In particular, a Bayesian formulation allows explicit modeling and estimation of activation probabilities. In this study, we directly address this issue and develop a new regression based approach using spatial Bayesian variable selection. Our method has several advantages. First, spatial correlation is directly modeled for activation probabilities and indirectly for activation amplitudes. …

Classifying Instantaneous Cognitive States From Fmri Data, Tom Mitchell, Rebecca Hutchinson, Marcel Just, Radu Niculescu, Francisco Pereira, Xuerui Wang

Marcel Adam Just

No abstract provided.

Neuroindices Of Cognitive Workload: Neuroimaging, Pupillometric, And Event-Related Potential Studies Of Brain Work, Marcel Adam Just, Patricia A. Carpenter, Akira Miyake

Marcel Adam Just

No abstract provided.

Ambiguity In The Brain: What Brain Imaging Reveals About The Processing Of Syntactically Ambiguous Sentences, Robert A. Mason, Marcel Adam Just, Timothy A. Keller, Patricia A. Carpenter

Marcel Adam Just

No abstract provided.

Brain Imaging Of Tongue-Twister Sentence Comprehension: Twisting The Tongue And The Brain, Timothy A. Keller, Patricia A. Carpenter, Marcel Adam Just

Marcel Adam Just

No abstract provided.

Tools And Approaches For The Construction Of Knowledge Models From The Neuroscientific Literature, Gully Apc Burns, Arshad M. Khan, Shahram Ghandeharizadeh, Mark O'Neill, Yi-Shin Chen

Arshad M. Khan, Ph.D.

Within this paper, we describe a neuroinformatics project (called "NeuroScholar," http://www.neuroscholar.org/) that enables researchers to examine, manage, manipulate, and use the information contained within the published neuroscientific literature. The project is built within a multi-level, multi-component framework constructed with the use of software engineering methods that themselves provide code-building functionality for neuroinformaticians. We describe the different software layers of the system. First, we present a hypothetical usage scenario illustrating how NeuroScholar permits users to address large-scale questions in a way that would otherwise be impossible. We do this by applying NeuroScholar to a "real-world" neuroscience question: How is stress-related information …

Differential Effects Of Syntactic And Semantic Processing On The Subregions Of Broca's Area, Sharlene D. Newman, Marcel Adam Just, Timothy A. Keller, Jennifer Roth, Patricia A. Carpenter

Marcel Adam Just

No abstract provided.