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Neuroscience and Neurobiology

2003

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Tongue Movements In Feeding And Speech, Karen M. Hiiemae, Jeffrey B. Palmer Nov 2003

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 …

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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 Oct 2003

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 …

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An Online Lab Manual For Neurophysiology, Richard F. Olivo Oct 2003

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.

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Time Course Of Loudness Recalibration: Implications For Loudness Enhancement, Yoav Arieh, Lawrence E. Marks Aug 2003

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 …

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Recalibrating The Auditory System: A Speed–Accuracy Analysis Of Intensity Perception, Yoav Arieh, Lawrence E. Marks Jun 2003

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 …

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A Research Agenda For Political Personality And Leadership Studies: An Evolutionary Proposal, Aubrey Immelman, Theodore Millon Jun 2003

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 …

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Filopodial Calcium Transients Regulate Growth Cone Motility And Guidance Through Local Activation Of Calpain, Estuardo Robles, Anna Huttenlocher, Timothy M. Gomez May 2003

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 …

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Intrinsic Role Of Polysialylated Neural Cell Adhesion Molecule In Photic Phase Resetting Of The Mammalian Circadian Clock, Rebecca Prosser Jan 2003

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 …

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Gamma Oscillations Correlate With Working Memory Load In Humans, Marc W. Howard, Daniel S. Rizzuto, Jeremy B. Caplan, Joseph R. Madsen, John Lisman Jan 2003

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 …

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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 Jan 2003

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 …

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