Open Access. Powered by Scholars. Published by Universities.®

Medical Neurobiology Commons

Open Access. Powered by Scholars. Published by Universities.®

593 Full-Text Articles 1404 Authors 97908 Downloads 58 Institutions

All Articles in Medical Neurobiology

Faceted Search

593 full-text articles. Page 7 of 22.

Massively Parallel Nonparametric Regression, With An Application To Developmental Brain Mapping, Philip T. Reiss, Lei Huang, Yin-Hsiu Chen, Lan Huo, Thaddeus Tarpey, Maarten Mennes 2014 Johns Hopkins University

Massively Parallel Nonparametric Regression, With An Application To Developmental Brain Mapping, Philip T. Reiss, Lei Huang, Yin-Hsiu Chen, Lan Huo, Thaddeus Tarpey, Maarten Mennes

Lei Huang

We propose a penalized spline approach to performing large numbers of parallel nonparametric analyses of either of two types: restricted likelihood ratio tests of a parametric regression model versus a general smooth alternative, and nonparametric regression. Compared with naively performing each analysis in turn, our techniques reduce computation time dramatically. Viewing the large collection of scatterplot smooths produced by our methods as functional data, we develop a clustering approach to summarize and visualize these results. Our approach is applicable to ultra-high-dimensional data, particularly data acquired by neuroimaging; we illustrate it with an analysis of developmental trajectories of functional connectivity at ...


Massively Parallel Nonparametric Regression, With An Application To Developmental Brain Mapping, Philip T. Reiss, Lei Huang, Yin-Hsiu Chen, Lan Huo, Thaddeus Tarpey, Maarten Mennes 2014 Johns Hopkins University

Massively Parallel Nonparametric Regression, With An Application To Developmental Brain Mapping, Philip T. Reiss, Lei Huang, Yin-Hsiu Chen, Lan Huo, Thaddeus Tarpey, Maarten Mennes

Thaddeus Tarpey

We propose a penalized spline approach to performing large numbers of parallel nonparametric analyses of either of two types: restricted likelihood ratio tests of a parametric regression model versus a general smooth alternative, and nonparametric regression. Compared with naively performing each analysis in turn, our techniques reduce computation time dramatically. Viewing the large collection of scatterplot smooths produced by our methods as functional data, we develop a clustering approach to summarize and visualize these results. Our approach is applicable to ultra-high-dimensional data, particularly data acquired by neuroimaging; we illustrate it with an analysis of developmental trajectories of functional connectivity at ...


Substance P Differentially Modulates Firing Rate Of Solitary Complex (Sc) Neurons From Control And Chronic Hypoxia-Adapted Adult Rats, Nicole L. Nichols, Frank L. Powell, Jay B. Dean, Robert W. Putnam 2014 Wright State University

Substance P Differentially Modulates Firing Rate Of Solitary Complex (Sc) Neurons From Control And Chronic Hypoxia-Adapted Adult Rats, Nicole L. Nichols, Frank L. Powell, Jay B. Dean, Robert W. Putnam

Neuroscience, Cell Biology & Physiology Faculty Publications

NK1 receptors, which bind substance P, are present in the majority of brainstem regions that contain CO2/H+-sensitive neurons that play a role in central chemosensitivity. However, the effect of substance P on the chemosensitive response of neurons from these regions has not been studied. Hypoxia increases substance P release from peripheral afferents that terminate in the caudal nucleus tractus solitarius (NTS). Here we studied the effect of substance P on the chemosensitive responses of solitary complex (SC: NTS and dorsal motor nucleus) neurons from control and chronic hypoxia-adapted (CHx) adult rats. We simultaneously measured intracellular pH and ...


Complexity Of Interferon-Γ Interactions With Hsv-1, Nancy J. Bigley 2014 Wright State University - Main Campus

Complexity Of Interferon-Γ Interactions With Hsv-1, Nancy J. Bigley

Neuroscience, Cell Biology & Physiology Faculty Publications

The intricacies involving the role of interferon-gamma (IFN-γ) in herpesvirus infection and persistence are complex. Herpes simplex virus type 1 (HSV-1) uses a variety of receptors to enter cells and is transported to and from the host cell nucleus over the microtubule railroad via retrograde and anterograde transport. IFN-γ exerts dual but conflicting effects on microtubule organization. IFN-γ stimulates production of suppressors of cytokine signaling 1 and 3 (SOCS1 and SOCS3), which are involved in microtubule stability and are negative regulators of IFN-γ signaling when overexpressed. IFN-γ also interferes with the correct assembly of microtubules causing them to undergo severe ...


Law And Neuroscience: Recommendations Submitted To The President's Bioethics Commission, Owen D. Jones, Richard J. Bonnie, B. J. Casey, Andre Davis, David L. Faigman, Morris Hoffman, Read Montague, Stephen J. Morse, Marcus E. Raichle, Jennifer A. Richeson, Elizabeth Scott, Laurence Steinberg, Kim Taylor-Thompson, Anthony Wagner, Gideon Yaffe 2014 Vanderbilt University

Law And Neuroscience: Recommendations Submitted To The President's Bioethics Commission, Owen D. Jones, Richard J. Bonnie, B. J. Casey, Andre Davis, David L. Faigman, Morris Hoffman, Read Montague, Stephen J. Morse, Marcus E. Raichle, Jennifer A. Richeson, Elizabeth Scott, Laurence Steinberg, Kim Taylor-Thompson, Anthony Wagner, Gideon Yaffe

Faculty Scholarship

President Obama charged the Presidential Commission for the Study of Bioethical Issues to identify a set of core ethical standards in the neuroscience domain, including the appropriate use of neuroscience in the criminal-justice system. The Commission, in turn, called for comments and recommendations. The MacArthur Foundation Research Network on Law and Neuroscience submitted a consensus statement, published here, containing 16 specific recommendations. These are organized within three main themes: 1) what steps should be taken to enhance the capacity of the criminal justice system to make sound decisions regarding the admissibility and weight of neuroscientific evidence?; 2) to what extent ...


Understanding Nicotine Addition: Dependency As A Result Of Maladaptive Brain Structure, Nate Thomas 2014 Virginia Commonwealth University

Understanding Nicotine Addition: Dependency As A Result Of Maladaptive Brain Structure, Nate Thomas

Auctus: The Journal of Undergraduate Research and Creative Scholarship

Nicotine addiction is the most prevalent, destructive dependency found in our culture. Despite its well-documented damaging health risks, nicotine use is still widely accepted and could be conceptualized as a social epidemic. Much of this acceptance may stem from nicotine’s lack of debilitating cognitive effects, as compared to those of other abused drugs. However, what may reign dominantly over nicotine’s legality is simple cultural precedent: tobacco has never been illegal and holds a place in human history. Therefore, attempting to alter this would prove highly unpopular and unsuccessful. This macroscopic irrationality, a blind favor for cultural precedents, parallels ...


Anticonvulsant Potencies Of The Enantiomers Of The Neurosteroids Androsterone And Etiocholanolone Exceed Those Of The Natural Forms, Dorota Zolkowska, Ashish Dhir, Kathiresan Krishnan, Douglas Covey, Michael Rogawski 2013 University of California - Davis

Anticonvulsant Potencies Of The Enantiomers Of The Neurosteroids Androsterone And Etiocholanolone Exceed Those Of The Natural Forms, Dorota Zolkowska, Ashish Dhir, Kathiresan Krishnan, Douglas Covey, Michael Rogawski

Michael A. Rogawski

RATIONALE: Androsterone [(3α,5α)-3-hydroxyandrostan-17-one; 5α,3α-A] and its 5β-epimer etiocholanolone [(3α,5β)-3-hydroxyandrostan-17-one; 5β,3α-A)], the major excreted metabolites of testosterone, are neurosteroid positive modulators of GABA-A receptors. Such neurosteroids typically show enantioselectivity in which the natural form is more potent than the corresponding unnatural enantiomer. For 5α,3α-A and 5β,3α-A, the unnatural enantiomers are more potent at GABA-A receptors than the natural forms. OBJECTIVES: The aim of this study was to compare the anticonvulsant potencies and time courses of 5α,3α-A and 5β,3α-A with their enantiomers in mouse seizure models. METHODS: Steroids were administered intraperitoneally to ...


The Potential Of Antiseizure Drugs And Agents That Act On Novel Molecular Targets As Antiepileptogenic Treatments, Rafal Kaminski, Michael Rogawski, Henrik Klitgaard 2013 University of California - Davis

The Potential Of Antiseizure Drugs And Agents That Act On Novel Molecular Targets As Antiepileptogenic Treatments, Rafal Kaminski, Michael Rogawski, Henrik Klitgaard

Michael A. Rogawski

A major goal of contemporary epilepsy research is the identification of therapies to prevent the development of recurrent seizures in individuals at risk, including those with brain injuries, infections, or neoplasms; status epilepticus; cortical dysplasias; or genetic epilepsy susceptibility. In this review we consider the evidence largely from preclinical models for the antiepileptogenic activity of a diverse range of potential therapies, including some marketed antiseizure drugs, as well as agents that act by immune and inflammatory mechanisms; reduction of oxidative stress; activation of the mammalian target of rapamycin or peroxisome proliferator-activated receptors γ pathways; effects on factors related to thrombolysis ...


Perinatal Or Adult Nf1 Inactivation Using Tamoxifen-Inducible Plpcre Each Cause Neurofibroma Formation, Debra A. Mayes, Tilat A. Rizvi, Jose A. Cancelas, Nathan T. Kolasinski, Georgianne M. Ciraolo, Anat O. Stemmer-Rachamimov, Nancy Ratner 2013 Wright State University - Main Campus

Perinatal Or Adult Nf1 Inactivation Using Tamoxifen-Inducible Plpcre Each Cause Neurofibroma Formation, Debra A. Mayes, Tilat A. Rizvi, Jose A. Cancelas, Nathan T. Kolasinski, Georgianne M. Ciraolo, Anat O. Stemmer-Rachamimov, Nancy Ratner

Debra A. Mayes

OBJECTIVES

Neurofibromas are tumors initiated by biallelic mutation of the NF1 tumor suppressor gene in the Schwann cell lineage. One idea within the field suggests that Nf1loss must occur within progenitor cells present within a critical window during Schwann cell development in order for neurofibromas to form. To test this hypothesis and to examine whethermyelinating Schwann cells can serve as aneurofibroma cell of origin, Nf1 loss was induced at perinatal or adult timepoints using a tamoxifen-inducible Plp-CreERT driver.

RESULTS

Perinatal loss of Nf1 resulted in small neurofibromas late in life, while adult loss caused large neurofibromas and morbidity beginning ...


Gamma Motor Neurons Express Distinct Genetic Markers At Birth And Require Muscle Spindle-Derived Gdnf For Postnatal Survival, Neil Shneider, Meghan Brown, Courtney Smith, James Pickel, Francisco Alvarez 2013 Wright State University - Main Campus

Gamma Motor Neurons Express Distinct Genetic Markers At Birth And Require Muscle Spindle-Derived Gdnf For Postnatal Survival, Neil Shneider, Meghan Brown, Courtney Smith, James Pickel, Francisco Alvarez

Francisco J. Alvarez

Background: Gamma motor neurons (γ-MNs) selectively innervate muscle spindle intrafusal fibers and regulate their sensitivity to stretch. They constitute a distinct subpopulation that differs in morphology, physiology and connectivity from α-MNs, which innervate extrafusal muscle fibers and exert force. The mechanisms that control the differentiation of functionally distinct fusimotor neurons are unknown. Progress on this question has been limited by the absence of molecular markers to specifically distinguish and manipulate γ-MNs. Recently, it was reported that early embryonic γ-MN precursors are dependent on GDNF. Using this knowledge we characterized genetic strategies to label developing γ-MNs based on GDNF receptor expression ...


Adjuvant Ccnu (Lomustine) And Prednisone Chemotherapy For Dogs With Incompletely Excised Grade 2 Mast Cell Tumors, Kenji Hosoya, William Kisseberth, Francisco Alvarez, Ana Lara-Garcia, Gillian Beamer, Paul Stromberg, C. Couto 2013 Wright State University - Main Campus

Adjuvant Ccnu (Lomustine) And Prednisone Chemotherapy For Dogs With Incompletely Excised Grade 2 Mast Cell Tumors, Kenji Hosoya, William Kisseberth, Francisco Alvarez, Ana Lara-Garcia, Gillian Beamer, Paul Stromberg, C. Couto

Francisco J. Alvarez

The use of adjuvant 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU; lomustine) to treat incompletely excised canine mast cell tumors (MCTs) has not been evaluated. Medical records of 12 dogs with grade 2 MCT treated with incomplete surgical excision and adjuvant CCNU and prednisone chemotherapy were reviewed. Local recurrence rate, metastasis rate, and survival time were evaluated. None of the dogs developed local recurrence or regional/ distant metastases. Two dogs developed fatal liver failure. The 1- and 2-year progression-free rates of surviving dogs were 100% and 77%, respectively. Postoperative adjuvant CCNU appears to be a useful alternative to radiation therapy for incompletely excised ...


Spinal Epidural Abscess Caused By Brucella: Case Report, J. Paz, Francisco Alvarez, J. Roda, R. Frutos, A. Isla 2013 Wright State University - Main Campus

Spinal Epidural Abscess Caused By Brucella: Case Report, J. Paz, Francisco Alvarez, J. Roda, R. Frutos, A. Isla

Francisco J. Alvarez

We report a case of a patient with symptoms and signs of sciatica, due to spinal epidural abscess caused by Brucella, which was diagnosed by Magnetic Resonance Image. The literature is reviewed and the radiological features, particularly magnetic resonance image findings, are analyzed.


Immunolocalization Of The Na+–K+–2cl- Cotransporter In Peripheral Nervous Tissue Of Vertebrates, Francisco Alvarez-Leefmans, M. León-Olea, J. Mendoza-Sotelo, Francisco Alvarez, B. Antón, R. Garduño 2013 Wright State University - Main Campus

Immunolocalization Of The Na+–K+–2cl- Cotransporter In Peripheral Nervous Tissue Of Vertebrates, Francisco Alvarez-Leefmans, M. León-Olea, J. Mendoza-Sotelo, Francisco Alvarez, B. Antón, R. Garduño

Francisco J. Alvarez

Efflux of Cl− through GABAA-gated anion channels depolarizes the cell bodies and intraspinal terminals of sensory neurons, and contributes to the generation of presynaptic inhibition in the spinal cord. Active accumulation of Cl− inside sensory neurons occurs through an Na+–K+–2Cl− cotransport system that generates and maintains the electrochemical gradient for this outward Cl− current. We studied the immunolocalization of the Na+–K+–2Cl− cotransporter protein using a monoclonal antibody (T4) against a conserved epitope in the C-terminus of the molecule. Western blots of frog, rat and cat dorsal root ganglion membranes revealed a single band of cotransporter immunoreactivity ...


Distribution Of Small-Diameter Primary Afferents Containing Oligosaccharide Residues Recognized By Monoclonal Antibody La4 In The Dorsal Horn Of The Cat, Francisco Alvarez, José Rodrigo, John Priestley 2013 Wright State University - Main Campus

Distribution Of Small-Diameter Primary Afferents Containing Oligosaccharide Residues Recognized By Monoclonal Antibody La4 In The Dorsal Horn Of The Cat, Francisco Alvarez, José Rodrigo, John Priestley

Francisco J. Alvarez

Small-diameter primary afferents expressing oligosaccharide residues recognized by the monoclonal antibody LA4 constitute a newly described primary afferent population in the cat. LA4-immunoreactive primary afferents are found mainly in lamina II (LII) at all levels of the cat spinal cord. However, within LII immunoreactive fibers are most concentrated in outer LII and practically absent from the inner third of the lamina. In addition at sacral levels, a lateral bundle of immunoreactive fibers enters laminae V–VII. The distribution pattern and the type of oligosaccharide expressed by LA4-immunoreactive fibers suggest that they may be homologous to primary afferents shown in the ...


Análisis Automático Del Patrón Interferencial: Principios Y Aplicaciones, J. Fernández, J. Saborido, Francisco Alvarez 2013 Wright State University - Main Campus

Análisis Automático Del Patrón Interferencial: Principios Y Aplicaciones, J. Fernández, J. Saborido, Francisco Alvarez

Francisco J. Alvarez

Introduction: The signals obtained during conventional needle examination are usually assessed subjectively by the neurophysiologist. Buchthal's approach allows quantification of several motor unit parameters during mild effort.

Development: The automatic methods of analysis of the EMG interference pattern (IP), in particular Turns/Amplitude, give us information concerning the number, firing rate, and morphology of the motor units, as well as the recruitment pattern at different degrees of effort. In pathological conditions, the changes in the IP allow distinction between myopathies and neuropathies.

Conclusion: These methods, which complement other methods of motor unit analysis, have also proved to be excellent ...


Quantal Size Is Correlated With Receptor Cluster Area At Glycinergic Synapses In The Rat Brainstem, Rebecca Lim, Francisco Alvarez, Bruce Walmsley 2013 Wright State University - Main Campus

Quantal Size Is Correlated With Receptor Cluster Area At Glycinergic Synapses In The Rat Brainstem, Rebecca Lim, Francisco Alvarez, Bruce Walmsley

Francisco J. Alvarez

1. Whole-cell patch electrode recordings of glycinergic miniature inhibitory postsynaptic currents (mIPSCs) were obtained in neurons of the rat anteroventral cochlear nucleus (AVCN). Mean mIPSC peak amplitude was found to vary considerably between AVCN neurons (range, -19·1 to -317·9 pA; mean ± s.d., -159·1 ± 100·7 pA; 14 cells).

2. Immunolabelling of glycinergic receptor clusters in AVCN neurons was performed using antibodies against the glycine receptor clustering protein gephyrin. Measurements of the area of gephyrin immunoreactive clusters were obtained using confocal fluorescence microscopy. These measurements showed a large variability in cluster area, not only in the same ...


Distribution Of 5-Hydroxytryptamine-Immunoreactive Boutons On Alpha-Motoneurons In The Lumbar Spinal Cord Of Adult Cats, Francisco Alvarez, John Pearson, Deborah Harrington, Dianne Dewey, L. Torbeck, Robert Fyffe 2013 Wright State University - Main Campus

Distribution Of 5-Hydroxytryptamine-Immunoreactive Boutons On Alpha-Motoneurons In The Lumbar Spinal Cord Of Adult Cats, Francisco Alvarez, John Pearson, Deborah Harrington, Dianne Dewey, L. Torbeck, Robert Fyffe

Francisco J. Alvarez

Recent studies have shown that at least some of the functional effects of serotonin (5-HT) on motoneuron excitability are direct and are mediated via postsynaptic 5-HT receptors on motoneurons. To determine the spatial distribution of direct inputs from the serotonin system on the proximal and distal dendrites of individual motoneurons, we examined identified motoneurons in vivo with a combination of immunohistochemical localization of 5-HT-immunoreactive boutons and intracellular staining with horseradish peroxidase. Seventeen intracellularly stained motoneurons from 12 adult cats were analyzed with light microscopy. Quantitative analysis of 5-HT boutons apposed to dendrites of five representative motoneurons that were entirely reconstructed ...


Noncholinergic Excitatory Actions Of Motoneurons In The Neonatal Mammalian Spinal Cord, George Mentis, Francisco Alvarez, Agnes Bonnot, Dannette Richards, David Gonzalez-Forero, Ricardo Zerda, Michael O'Donovan 2013 Wright State University - Main Campus

Noncholinergic Excitatory Actions Of Motoneurons In The Neonatal Mammalian Spinal Cord, George Mentis, Francisco Alvarez, Agnes Bonnot, Dannette Richards, David Gonzalez-Forero, Ricardo Zerda, Michael O'Donovan

Francisco J. Alvarez

Mammalian spinal motoneurons are considered to be output elements of the spinal cord that generate exclusively cholinergic actions on Renshaw cells, their intraspinal synaptic targets. Here, we show that antidromic stimulation of motor axons evokes depolarizing monosynaptic potentials in Renshaw cells that are depressed, but not abolished, by cholinergic antagonists. This residual potential was abolished by 2-amino-5-phosphonovaleric acid and 6-cyano-7-nitroquinoxaline-2,3-dione. In the presence of cholinergic antagonists, motor axon stimulation triggered locomotor-like activity that was blocked by 2-amino-5-phosphonovaleric acid. Some cholinergic motoneuronal terminals on both Renshaw cells and motoneurons were enriched in glutamate, but none expressed vesicular glutamate transporters. Our ...


Modulation Of Motoneuron Activity: Distribution Of Glycine Receptors, Robert Fyffe, Francisco Alvarez, John Pearson, Deborah Harrington, Dianne Dewey 2013 Wright State University - Main Campus

Modulation Of Motoneuron Activity: Distribution Of Glycine Receptors, Robert Fyffe, Francisco Alvarez, John Pearson, Deborah Harrington, Dianne Dewey

Francisco J. Alvarez

Physiologically identified alpha- and gamma-motoneurons (MNs) were labeled by intracellular injection of neurobiotin (NB) or horseradish peroxidase (HRP). NB-labeled cells were revealed using 7-amine-4-methylcoumarin- 3-acetic acid and glycine receptors (Gly-Rs) on these cells were detected by immunofluorescence with an antibody against the 93 kDa Gly-R-associated protein, and fluorescein-labeled secondary antibodies. a-MN display Gly-Rs throughout their dendritic tree including dendrites in the white matter and in some dendritic spines. On soma and proximal dendrites, Gly-R labeling appeared in small clusters, whereas on distal dendrites the clusters were larger. In contrast, y-MNs had few Gly-R clusters, and they were usually found only ...


C-Pon Containing Neurons In The Rat Striatum Are Also Positive For Nadph-Diaphorase Activity A Light Microscopic Study, Rosa Villalba, Ricardo Martínez-Murillo, Isabel Blasco, Francisco Alvarez, José Rodrigo 2013 Wright State University - Main Campus

C-Pon Containing Neurons In The Rat Striatum Are Also Positive For Nadph-Diaphorase Activity A Light Microscopic Study, Rosa Villalba, Ricardo Martínez-Murillo, Isabel Blasco, Francisco Alvarez, José Rodrigo

Francisco J. Alvarez

The indirect immunofluorescence technique to detect endogenous C-flanking peptide of neuropeptide Y (NPY), C-PON, in combination with NADPH-diaphorase (NADPH-d) histochemistry, were applied to the same sections to establish whether C-PON containing cell bodies in the rat striatum can be labelled by their content of NADPH-diaphorase activity. NADPH-diaphorase activity proved to be a reliable marker for these positive C-PON neurons. Our results suggest that, in the rat striatum, C-PON, SOM and NPY co-exist in the same cells.


Digital Commons powered by bepress