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Sample records for red neuronal autorregresiva

  1. MODELADO DEL PRECIO SPOT DE LA ELECTRICIDAD EN BRASIL USANDO UNA RED NEURONAL AUTORREGRESIVA ELECTRICITY SPOT PRICE MODELLING IN BRASIL USING AN AUTOREGRESSIVE NEURAL NETWORK

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    Juan D Velásquez

    2008-12-01

    Full Text Available Una red neuronal autorregresiva es estimada para el precio mensual brasileño de corto plazo de la electricidad, la cual describe mejor la dinámica de los precios que un modelo lineal autorregresivo y que un perceptrón multicapa clásico que usan las mismas entradas y neuronas en la capa oculta. El modelo propuesto es especificado usando un procedimiento estadístico basado en el contraste del radio de verosimilitud. El modelo pasa una batería de pruebas de diagnóstico. El procedimiento de especificación propuesto permite seleccionar el número de unidades en la capa oculta y las entradas a la red neuronal, usando pruebas estadísticas que tienen en cuenta la cantidad de los datos y el ajuste del modelo a la serie de precios. La especificación del modelo final demuestra que el precio para el próximo mes es una función no lineal del precio actual, de la energía afluente actual y de la energía almacenada en el embalse equivalente en el mes actual y dos meses atrás.An autoregressive neural network model is estimated for the monthly Brazilian electricity spot price, which describes the prices dynamics better than a linear autoregressive model and a classical multilayer perceptron using the same input and neurons in the hidden layer. The proposed model is specified using a statistical procedure based on a likelihood ratio test. The model passes a battery of diagnostic tests. The proposed specification procedure allows us to select the number of units in hidden layer and the inputs to the neural network based on statistical tests, taking into account the number of data and the model fitting to the price time series. The final model specification demonstrates that the price for the next month is a nonlinear function of the current price, the current energy inflow, and the energy saved in the equivalent reservoir in the current month and two months ago.

  2. Geoestadística aplicada a series de tiempo autorregresivas: un estudio de simulación

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    Ramón Giraldo

    2017-01-01

    Full Text Available La geoestadística puede usarse como método de predicción de da- tos faltantes en series temporales. El procedimiento se bas a en el estudio de la estructura de autocorrelación temporal de la serie de tiemp o por medio de la función de variograma, que es estimada por mínimos cuadrado s (geoestadísti- ca clásica o por máxima verosimilitud (geoestadística bas ada en modelo, y en usar posteriormente Kriging para hacer predicción de los valores faltantes. En este trabajo se comparan a través de simulación las dos apr oximaciones (geoestadística clásica y basada en modelo en el contexto d e series tempora- les autorregresivas.

  3. Hearing in action; auditory properties of neurones in the red nucleus of alert primates

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    Jonathan Murray Lovell

    2014-05-01

    Full Text Available The response of neurones in the Red Nucleus pars magnocellularis (RNm to both tone bursts and electrical stimulation were observed in three cynomolgus monkeys (Macaca fascicularis, in a series of studies primarily designed to characterise the influence of the dopaminergic ventral midbrain on auditory processing. Compared to its role in motor behaviour, little is known about the sensory response properties of neurons in the red nucleus; particularly those concerning the auditory modality. Sites in the RN were recognised by observing electrically evoked body movements characteristic for this deep brain structure. In this study we applied brief monopolar electrical stimulation to 118 deep brain sites at a maximum intensity of 200 µA, thus evoking minimal body movements. Auditory sensitivity of RN neurons was analysed more thoroughly at 15 sites, with the majority exhibiting broad tuning curves and phase locking up to 1.03 kHz. Since the RN appears to receive inputs from a very early stage of the ascending auditory system, our results suggest that sounds can modify the motor control exerted by this brain nucleus. At selected locations, we also tested for the presence of functional connections between the RN and the auditory cortex by inserting additional microelectrodes into the auditory cortex and investigating how action potentials and local field potentials were affected by electrical stimulation of the RN.

  4. Chemical Characterization of an Encapsulated Red Wine Powder and Its Effects on Neuronal Cells.

    Science.gov (United States)

    Rocha-Parra, Diego; Chirife, Jorge; Zamora, Clara; de Pascual-Teresa, Sonia

    2018-04-07

    Red wine polyphenols are known for their implications for human health protection, although they suffer from high instability. For this reason, a red wine powder was prepared by freeze-drying encapsulation in maltodextrin/arabic gum matrix, and its composition was determined by means of high-performance liquid chromatography coupled quadrupole time-of-flight mass spectrometry (HPLC-MS-QTOF). More than thirty polyphenols, including anthocyanins, flavanols, flavonols, phenolic acids and stilbenoids, were identified. Some of the main quantified polyphenols were: malvidin-3- O -glucoside, malvidin 3- O -(6″-acetyl-glucose), petunidin-3- O -glucoside, quercetin-3- O -glucuronide, syringenin-3- O -glucoside, epicatechin, gallic acid and syringic acid. The biological activity of this de-alcoholized and encapsulated red wine on human neuroblastoma SH-SY5Y cells was studied. The results showed that the encapsulated red wine powder has active redox properties, as verified by performing reactive oxygen species (ROS) analysis utilizing a neuronal model. This could help explain its action against the neurotoxicity induced by 6-hydroxydopamine (6-OHDA).

  5. Chemical Characterization of an Encapsulated Red Wine Powder and Its Effects on Neuronal Cells

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    Diego Rocha-Parra

    2018-04-01

    Full Text Available Red wine polyphenols are known for their implications for human health protection, although they suffer from high instability. For this reason, a red wine powder was prepared by freeze-drying encapsulation in maltodextrin/arabic gum matrix, and its composition was determined by means of high-performance liquid chromatography coupled quadrupole time-of-flight mass spectrometry (HPLC-MS-QTOF. More than thirty polyphenols, including anthocyanins, flavanols, flavonols, phenolic acids and stilbenoids, were identified. Some of the main quantified polyphenols were: malvidin-3-O-glucoside, malvidin 3-O-(6″-acetyl-glucose, petunidin-3-O-glucoside, quercetin-3-O-glucuronide, syringenin-3-O-glucoside, epicatechin, gallic acid and syringic acid. The biological activity of this de-alcoholized and encapsulated red wine on human neuroblastoma SH-SY5Y cells was studied. The results showed that the encapsulated red wine powder has active redox properties, as verified by performing reactive oxygen species (ROS analysis utilizing a neuronal model. This could help explain its action against the neurotoxicity induced by 6-hydroxydopamine (6-OHDA.

  6. Stereological estimate of the total number of neurons in spinal segment D9 of the red-eared turtle

    DEFF Research Database (Denmark)

    Walløe, Solveig; Nissen, Ulla Vig; Berg, Rune W

    2011-01-01

    The red-eared turtle is an important animal model for investigating the neural activity in the spinal circuit that generates motor behavior. However, basic anatomical features, including the number of neurons in the spinal segments involved, are unknown. In the present study, we estimate the total...... number of neurons in segment D9 of the spinal cord in the red-eared turtle (Trachemys scripta elegans) using stereological cell counting methods. In transverse spinal cord sections stained with modified Giemsa, motoneurons (MNs), interneurons (INs), and non-neuronal cells were distinguished according...... to location and morphology. Each cell type was then counted separately using an optical disector with the cell nucleus as counting item. The number of cells in segment D9 was as follows (mean ± SE): MNs, 2049 ± 74; INs, 16,135 ± 316; non-neuronal cells, 47,504 ± 478 (n = 6). These results provide the first...

  7. Entrenamiento de una red neuronal multicapa para la tasa de cambio euro - dólar (EUR/USD

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    Jaime Alberto Villamil Torres

    2007-09-01

    Full Text Available Tanto para los inversionistas como para las autoridades económicas es necesario que se desarrolle una herramienta matemática que logre dar cuenta de la dirección de una variable como el tipo de cambio (el precio relativo entre dos monedas. Muchos de los mecanismos usados actualmente están basados en el uso de técnicas estadísticas, en particular series de tiempo lineales. Las redes neuronales artificiales (RNA son modelos matemáticos que pretenden emular el funcionamiento del cerebro humano, su aplicación en economía e ingeniería surge a finales de los años ochenta con buenos resultados. Las RNA se presentan como una alternativa para simular el comportamiento de variables financieras que, por lo general, tienden a parecerse a un paseo aleatorio. En este trabajo se muestran los resultados del entrenamiento de una red neuronal para negociación de la tasa de cambio EUR/USD y las bondades del algoritmo de entrenamiento chemotaxis, que permite entrenar redes que maximicen una función objetivo que relacione aciertos en la predicción con las ganancias de un trader.

  8. Neurons in red nucleus and primary motor cortex exhibit similar responses to mechanical perturbations applied to the upper-limb during posture

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    Troy Michael Herter

    2015-04-01

    Full Text Available Primary motor cortex (M1 and red nucleus (RN are brain regions involved in limb motor control. Both structures are highly interconnected with the cerebellum and project directly to the spinal cord, although the contribution of RN is smaller than M1. It remains uncertain whether RN and M1 serve similar or distinct roles during posture and movement. Many neurons in M1 respond rapidly to mechanical disturbances of the limb, but it remains unclear whether RN neurons also respond to such limb perturbations. We have compared discharges of single neurons in RN (n = 49 and M1 (n = 109 of one monkey during a postural perturbation task. Neural responses to whole-limb perturbations were examined by transiently applying (300 ms flexor or extensor torques to the shoulder and/or elbow while the monkeys attempted to maintain a static hand posture. Relative to baseline discharges before perturbation onset, perturbations evoked rapid (<100 ms changes of neural discharges in many RN (28 of 49, 57% and M1 (43 of 109, 39% neurons. In addition to exhibiting a greater proportion of perturbation-related neurons, RN neurons also tended to exhibit higher peak discharge frequencies in response to perturbations than M1 neurons. Importantly, neurons in both structures exhibited similar response latencies and tuning properties (preferred torque directions and tuning widths in joint-torque space. Proximal arm muscles also displayed similar tuning properties in joint-torque space. These results suggest that RN is more sensitive than M1 to mechanical perturbations applied during postural control but both structures may play a similar role in feedback control of posture.

  9. Una red neuronal binaria para la identificación de mecanismos isomorfos. // A binary Neural network for identifying isomorphic mechanisms.

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    G. Galán Marín

    2002-05-01

    Full Text Available Un problema de importancia primordial en el diseño mecánico es identificar los mecanismos isomorfos, puesto que los isomorfismos nodetectados generan soluciones duplicadas y por tanto suponen un esfuerzo innecesario en el proceso de diseño. Desde 1960, una grancantidad de métodos han sido propuestos para la detección de mecanismos isomorfos. Sin embargo, diversos trabajos han mostrado queaunque pueden existir algoritmos eficaces para casos particulares, en el caso general los métodos tradicionales para la detección deisomorfismos en cadenas cinemáticas no proporcionan usualmente soluciones eficientes para este problema, que ha sido clasificado comoNP-duro. Un eficaz método alternativo para la resolución de problemas NP-duros ha surgido recientemente con las redes neuronales. Eneste trabajo proponemos un nuevo modelo de red neuronal binaria diseñado para la resolución del problema de detección de mecanismosisomorfos. El modelo propuesto se halla basado en unas dinámicas discretas que garantizan una rápida y correcta convergencia de la redhacia soluciones aceptables. Las simulaciones numéricas muestran en los mecanismos analizados que la red neuronal propuestaproporciona excelentes resultados, mostrándose además muy superior a la red de Hopfield continua tradicional en lo que respecta al tiempode computación y en la facilidad de su implementación.Palabras claves: Mecanismos isomorfos, síntesis de mecanismos, isomorfismo de grafos, red neuronal binaria,redes de Hopfield.____________________________________________________________________________AbstractAn important step in the kinematic mechanism synthesis process is to identify graph isomorphism whilegenerating new mechanisms. Undetected isomorphisms result in duplicate solutions and unnecessary effort.Since 1960, a lot of methods have been proposed for the graph isomorphism identification. Some authors haveconcluded that, in the general case, the traditional methods of

  10. Evaluación asimétrica de una red neuronal: aplicación al caso de la inflación en Colombia

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    Maria Clara Aristizábal

    2006-12-01

    Full Text Available El objetivo de este trabajo es explorar la relación no lineal entre el dinero y la inflación en Colombia a través de una red neuronal artificial, utilizando información mensual de la variación del Índice de Precios al Consumidor y del agregado monetario M3, desde enero de 1982 hasta febrero de 2005. Las redes neuronales artificiales aparecen como una excelente alternativa para las autoridades monetarias de contar con los mejores modelos para pronosticar la inflación y guiar sus decisiones de política. El presente artículo incorpora algunas innovaciones en la modelación del dinero e inflación que permiten generar pronósticos más confiables, debido a que el modelo se aproxima con mayor exactitud a la realidad.

  11. Predicción de los precios de contratos de electricidad usando una red neuronal con arquitectura dinámica

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    Juan David Velásquez Henao

    2010-04-01

    Full Text Available Los contratos en los mercados liberalizados de electricidad constituyen una herramienta para proteger a los agentes de la volatilidad; en este contexto, los pronósticos de los precios son una entrada clave para la toma de decisiones estratégicas y operativas de los agentes. En este artículo, se pronostican los precios promedios de los contratos despachados en el mercado eléctrico colombiano, usando una red neuronal con arquitectura dinámica conocida como DAN2. El modelo desarrollado es capaz de capturar la dinámica intrínseca de la serie de precios y de pronosticar el precio para el siguiente mes con más precisión que la metodología ARIMA clásica, para horizontes de predicción de 12 y 24 meses

  12. Sistema de reconocimiento facial utilizando el análisis de componentes principales com una red neuronal Backpropagation desarrollada en C# y Matlab

    OpenAIRE

    Blanco Iturralde, David Roberto; Chávez Sánchez, Juan Daniel

    2012-01-01

    Al desarrollar el sistema basados en las técnicas y métodos anteriormente descritos se considero el lenguaje de programación C Sharp para la creación de la interfaz del sistema por las características que brinda en el manejo de imágenes a través de sus librerías que son apropiadas para este tipo de trabajo y Matlab para la red neuronal backpropagation y cálculos matemáticos complejos por ser un lenguaje nativo en la resolución de problemas matemáticos obteniendo así un sistema robusto y de al...

  13. RED NEURONAL PARA LA CLASIFICACIÓN DE FALLAS EN LÍNEAS DE TRANSMISIÓN A PARTIR DE REGISTROS DE OSCILOPERTURBOGRAFÍA

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    JHON ALBEIRO CALDERÓN

    2008-01-01

    Full Text Available El diagnóstico de fallas eléctricas en líneas de transmisión a alto voltaje es una tarea compleja no solo por la cantidad de información involucrada que puede provenir de diversas fuentes como SOE, SCADA y registradores, si no también por la variabilidad misma de las fallas. Dicha complejidad impacta en la oportunidad y certeza del diagnóstico, factores particularmente importantes para el análisis en tiempo real donde rápidamente deben tomarse pautas adecuadas para el restablecimiento del sistema eléctrico de potencia. En este artículo se propone el uso de de una red neuronal con aprendizaje por regularización bayesiana y finalización temprana para la clasificación de fallas a partir de registros de osciloperturbografía provenientes de registradores de falla y se muestra su efectividad para una amplia variedad de casos de entrenamiento y validación, los cuales son obtenidos por medio de un modelo de ATP con el cual se simularon la cantidad de fallas eléctricas requeridas.

  14. Cerebellar projections to the red nucleus and inferior olive originate from separate populations of neurons in the rat: A non-fluorescent double labeling study

    NARCIS (Netherlands)

    T.M. Teune (Thea); J. van der Burg (Johannes); T.J.H. Ruigrok (Tom)

    1995-01-01

    textabstractIn the rat, the extent of collateralization of projections from the cerebellar nuclei to the red nucleus and inferior olive was investigated using a retrograde double labeling technique. The combination of tracers selected, cholera toxin-β-subunit and WGA-BSA-gold, not only enabled the

  15. A G protein-coupled receptor (GPCR) in red: live cell imaging of the kappa opioid receptor-tdTomato fusion protein (KOPR-tdT) in neuronal cells

    Science.gov (United States)

    Huang, Peng; Chiu, Yi-Ting; Chen, Chongguang; Wang, Yujun; Liu-Chen, Lee-Yuan

    2013-01-01

    Introduction In contrast to green fluorescent protein and variants (GFPs), red fluorescent proteins (RFPs) have rarely been employed for generation of GPCR fusion proteins, likely because of formation of aggregates and cell toxicity of some RFPs. Among all the RFPs available, tdTomato (tdT), one of the non-aggregating RFP, has the highest brightness score (about 3 times that of eGFP) and unsurpassed photostability. Methods We fused tdT to the KOPR C-terminus. The KOPR-tdT cDNA construct was transfected into Neuro2A mouse neuroblastoma cell line (Neuro2A cells) and rat cortical primary neurons for characterization of pharmacological properties and imaging studies on KOPR trafficking. Results KOPR-tdT retained KOPR properties (cell surface expression, ligand binding, agonist-induced signaling and internalization) when expressed in Neuro2A cells and rat primary cortical neurons. Live cell imaging of KOPR-tdT enables visualization of time course of agonist-induced internalization of KOPR in real time for 60 min, without photobleaching and apparent cell toxicity. U50,488H-induced KOPR internalization occurred as early as 4 min and plateaued at about 30 min. A unique pattern of internalized KOPR in processes of primary neurons was induced by U50,488H. Discussion tdT is an alternative to, or even a better tool than, GFPs for fusing to GPCR for trafficking studies, because tdT has higher brightness and thus better resolution and less photobleaching problems due to reduced laser power used. It also has advantages associated with its longer-wavelength emission including spectral separation from autofluorescence and GFPs, reduced cell toxicity the laser may impose, and greater tissue penetration. These advantages of tdT over GPFs may be critical for live cell imaging studies of GPCRs in vitro and for studying GPCRs in vivo because of their low abundance. PMID:23856011

  16. COMPARACIÓN DE LA RED NEURONAL Y DEL FILTRO DE KALMAN EN LA ESTIMACIÓN DE VELOCIDAD DEL MOTOR DE INDUCCIÓN

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    Jaime González

    2015-07-01

    Full Text Available En este artículo es presentado un estudio comparativo de dos métodos muy utilizados en la estimación de velocidad. El primero es la estimación de velocidad utilizando Inteligencia Artificial por medio de redes neuronales, que se alimentan de las tensiones y corrientes del estator para producir el valor estimado de velocidad, después de haber sido realizado el entrenamiento de la red en forma off-line. El segundo método es usar un Filtro Extendido de Kalman, utilizando un modelo del motor en espacios de estado con ruidos blancos gaussianos aditivos de sistema y de medición. Para cada uno de los métodos serán presentadas sus ventajas y desventajas.

  17. Motor Neurons

    DEFF Research Database (Denmark)

    Hounsgaard, Jorn

    2017-01-01

    Motor neurons translate synaptic input from widely distributed premotor networks into patterns of action potentials that orchestrate motor unit force and motor behavior. Intercalated between the CNS and muscles, motor neurons add to and adjust the final motor command. The identity and functional...... in in vitro preparations is far from complete. Nevertheless, a foundation has been provided for pursuing functional significance of intrinsic response properties in motoneurons in vivo during motor behavior at levels from molecules to systems....

  18. Calcium signals in olfactory neurons.

    Science.gov (United States)

    Tareilus, E; Noé, J; Breer, H

    1995-11-09

    Laser scanning confocal microscopy in combination with the fluorescent calcium indicators Fluo-3 and Fura-Red was employed to estimate the intracellular concentration of free calcium ions in individual olfactory receptor neurons and to monitor temporal and spatial changes in the Ca(2+)-level upon stimulation. The chemosensory cells responded to odorants with a significant increase in the calcium concentration, preferentially in the dendritic knob. Applying various stimulation paradigma, it was found that in a population of isolated cells, subsets of receptor neurons display distinct patterns of responsiveness.

  19. Product (RED)

    DEFF Research Database (Denmark)

    Ponte, Stefano

    2011-01-01

    ) and the consumers who buy iconic brand products to help ‘distant others’. While in many other forms of causumerism, labels or certification systems ‘prove’ that a product is just, in RED, aid celebrities provide the proof. From the consumer point of view both labels and celebrities provide a similar simplification...... of complex social, economic, and environmental processes. At the same time, we argue that there are important distinctions as well—labels and certifications are ultimately about improving the conditions of production, whereas RED is about accepting existing production and trade systems and donating......(PRODUCT)RED™ (hereafter RED) is a cobranding initiative launched in 2006 by the aid celebrity Bono to raise money from product sales to support The Global Fund to Fight AIDS, Tuberculosis and Malaria. In this paper we argue that RED is shifting the boundaries of ‘causumerism’ (shopping...

  20. [Mirror neurons].

    Science.gov (United States)

    Rubia Vila, Francisco José

    2011-01-01

    Mirror neurons were recently discovered in frontal brain areas of the monkey. They are activated when the animal makes a specific movement, but also when the animal observes the same movement in another animal. Some of them also respond to the emotional expression of other animals of the same species. These mirror neurons have also been found in humans. They respond to or "reflect" actions of other individuals in the brain and are thought to represent the basis for imitation and empathy and hence the neurobiological substrate for "theory of mind", the potential origin of language and the so-called moral instinct.

  1. Red Sirius

    Energy Technology Data Exchange (ETDEWEB)

    Martynov, D Ya

    1976-01-01

    A hypothesis is proposed explaining the assumption that Sirius changed its colour from red in the second century to pale blue in the tenth century A.D. The hypothesis is based on the possibility of transformation of a Sirius satellite (Sirius B) from a red giant in the past to a white dwarf in the present. Such a transformation would have been accompanied by an explosion of Sirius B, which is clearly visible from the Earth. The fact that the increase in Sirius brightness by 4-5 units is not reflected in historical chronicles is attributed to the degradation of sciences in Europe in 4-10 centuries.

  2. Neurons other than motor neurons in motor neuron disease.

    Science.gov (United States)

    Ruffoli, Riccardo; Biagioni, Francesca; Busceti, Carla L; Gaglione, Anderson; Ryskalin, Larisa; Gambardella, Stefano; Frati, Alessandro; Fornai, Francesco

    2017-11-01

    Amyotrophic lateral sclerosis (ALS) is typically defined by a loss of motor neurons in the central nervous system. Accordingly, morphological analysis for decades considered motor neurons (in the cortex, brainstem and spinal cord) as the neuronal population selectively involved in ALS. Similarly, this was considered the pathological marker to score disease severity ex vivo both in patients and experimental models. However, the concept of non-autonomous motor neuron death was used recently to indicate the need for additional cell types to produce motor neuron death in ALS. This means that motor neuron loss occurs only when they are connected with other cell types. This concept originally emphasized the need for resident glia as well as non-resident inflammatory cells. Nowadays, the additional role of neurons other than motor neurons emerged in the scenario to induce non-autonomous motor neuron death. In fact, in ALS neurons diverse from motor neurons are involved. These cells play multiple roles in ALS: (i) they participate in the chain of events to produce motor neuron loss; (ii) they may even degenerate more than and before motor neurons. In the present manuscript evidence about multi-neuronal involvement in ALS patients and experimental models is discussed. Specific sub-classes of neurons in the whole spinal cord are reported either to degenerate or to trigger neuronal degeneration, thus portraying ALS as a whole spinal cord disorder rather than a disease affecting motor neurons solely. This is associated with a novel concept in motor neuron disease which recruits abnormal mechanisms of cell to cell communication.

  3. Numbers, Neurons and Tides, Oh My!

    Science.gov (United States)

    Ortiz, Mary Theresa

    2006-01-01

    Mathematical applications to biology are presented in Anatomy & Physiology, General and Marine Biology. Body measurements and anatomical terminology are integrated, and problems involving neuron conduction speed, red blood cells, hemoglobin and glomerular filtration presented. General Biology applications include trans-membrane potential and…

  4. Genetic algorithms used to optimize an artificial neural network design used in neutron spectrometry; Algoritmos geneticos utilizados para optimizar un diseno de red neuronal artificial usado en espectrometria de neutrones

    Energy Technology Data Exchange (ETDEWEB)

    Arteaga A, T.; Ortiz R, J. M.; Vega C, H. R., E-mail: tarcicio70@yahoo.co.uk [Universidad Autonoma de Zacatecas, Av. Lopez Velarde 117, 98600 Zacatecas, Zac. (Mexico)

    2016-10-15

    Artificial neural networks (Ann) are widely used; it which consist of an input layer, one or more hidden layers and an output layer; these layers contain neurons and each has connections called weights, where the knowledge are allowed and let to Ann solve problems proposed. These Ann is used to reconstruction of the energy spectrum of neutrons from count rates and develop Bonner sphere neutron dosimetry. Currently, we have developed Ann with high performance and generalization ability. Determine your optimal architecture is usually a difficult task, an exhaustive search of all possible combinations of parameters is rarely possible further training of the neural network with random initial weights can cause two major drawbacks: it can stuck in local minima or converge very slowly. In this project it will be used Genetic Algorithms (Ga); which are based on the principle or analogy of evolution through natural selection and has shown to be very effective in optimizing complex search functions and large spaces or to find a near optimal overall efficiency. The aim is to decrease the architecture in number of hidden neurons and therefore the total number of connections is reducing. The benefits obtained by optimizing the network are that the number of connections would be considerably smaller and thus the computational complexity, hardware integration, resources will be lower such that will allow to be even more viable implemented. To use the Ga three problems must be solve: 1) coding the problem into chromosomes. 2) Construct a fitness function. 3) Proper selection of genetic operators; crossover, selection, mutation. As a result, the scientific knowledge obtained can to be applied to similar problems having a reference parameters used and their impact on the optimization would to be generated. It concluded that the input layer and output are subject to the problem; the Ga propose the optimal number of neurons in the hidden layer without losing the quality of the

  5. Design of an artificial neural network, with the topology oriented to the reconstruction of neutron spectra; Diseno de una red neuronal artificial, con la topologia orientada a la reconstruccion del espectro de neutrones

    Energy Technology Data Exchange (ETDEWEB)

    Arteaga A, T.; Ortiz R, J.M.; Vega C, H.R.; Hernandez D, V.M.; Manzanares A, E.; Mercado S, G.A. [Unidades Academicas de Estudios Nucleares, Ingenieria Electrica y Matematicas, Universidad de Zacatecas, A.P. 336, 98000 Zacatecas (Mexico)]. e-mail: tarcicio70@yahoo.co.uk

    2006-07-01

    People that live in high places respect to the sea level, in latitudes far from the equator or that they travel by plane, they are exposed to atmospheres of high radiation generated by the cosmic rays. Another atmosphere with radiation is the medical equipment, particle accelerators and nuclear reactors. The evaluation of the biological risk for neutron radiation requires an appropriate and sure dosimetry. A commonly used system is the Bonner Sphere Spectrometer (EEB) with the purpose of reconstructing the spectrum that is important because the equivalent dose for neutrons depends strongly on its energy. The count rates obtained in each sphere are treated, in most of the cases, for iterative methods, Monte Carlo or Maximum Entropy. Each one of them has difficulties that it motivates to the development of complementary procedures. Recently it has been used Artificial Neural Networks, ANN) and not yet conclusive results have been obtained. In this work it was designed an ANN to obtain the neutron energy spectrum neutrons starting from the counting rate of count of an EEB. The ANN was trained with 129 reference spectra obtained of the IAEA (1990, 2001), 24 were built as defined energy, including isotopic sources of neutrons of reference and operational, of accelerators, reactors, mathematical functions, and of defined energy with several peaks. The spectrum was transformed from lethargy units to energy and were reaccommodated in 31 energies using the Monte Carlo code 4C. The reaccommodated spectra and the response matrix UTA4 were used to calculate the prospective count rates in the EEB. These rates were used as entrance and its respective spectrum was used as output during the net training. The net design is Retropropagation type with 5 layers of 7, 140, 140, 140 and 31 neurons, transfer function logsig, tansig, logsig, logsig, logsig respectively. Training algorithm, traingdx. After the training, the net was proven with a group of training spectra and others that

  6. Detecting and classifying faults on transmission systems using a backpropagation neural network; Deteccion y clasificacion de fallas en sistemas de transmision empleando una red neuronal con retropropagacion del error

    Energy Technology Data Exchange (ETDEWEB)

    Rosas Ortiz, German

    2000-01-01

    Fault detection and diagnosis on transmission systems is an interesting area of investigation to Artificial Intelligence (AI) based systems. Neurocomputing is one of fastest growing areas of research in the fields of AI and pattern recognition. This work explores the possible suitability of pattern recognition approach of neural networks for fault detection and classification on power systems. The conventional detection techniques in modern relays are based in digital processing of signals and it need some time (around 1 cycle) to send a tripping signal, also they are likely to make incorrect decisions if the signals are noisy. It's desirable to develop a fast, accurate and robust approach that perform accurately for changing system conditions (like load variations and fault resistance). The aim of this work is to develop a novel technique based on Artificial Neural Networks (ANN), which explores the suitability of a pattern classification approach for fault detection and diagnosis. The suggested approach is based in the fact that when a fault occurs, a change in the system impedance take place and, as a consequence changes in amplitude and phase of line voltage and current signals take place. The ANN-based fault discriminator is trained to detect this changes as indicators of the instant of fault inception. This detector uses instantaneous values of these signals to make decisions. Suitability of using neural network as pattern classifiers for transmission systems fault diagnosis is described in detail a neural network design and simulation environment for real-time is presented. Results showing the performance of this approach are presented and indicate that it is fast, secure and exact enough, and it can be used in high speed fault detection and classification schemes. [Spanish] El diagnostico y la deteccion de fallas en sistemas de transmision es una area de interes en investigacion para sistemas basados en Inteligencia Artificial (IA). El calculo neuronal

  7. Neuronal Migration Disorders

    Science.gov (United States)

    ... Understanding Sleep The Life and Death of a Neuron Genes At Work In The Brain Order Publications ... birth defects caused by the abnormal migration of neurons in the developing brain and nervous system. In ...

  8. Motor Neuron Diseases

    Science.gov (United States)

    ... and other neurodegenerative diseases to better understand the function of neurons and other support cells and identify candidate therapeutic ... and other neurodegenerative diseases to better understand the function of neurons and other support cells and identify candidate therapeutic ...

  9. Red blood cell production

    Science.gov (United States)

    ... bone marrow of bones. Stem cells in the red bone marrow called hemocytoblasts give rise to all of the formed elements in blood. If a hemocytoblast commits to becoming a cell called a proerythroblast, it will develop into a new red blood cell. The formation of a red blood ...

  10. Noninvasive optical inhibition with a red-shifted microbial rhodopsin

    DEFF Research Database (Denmark)

    Chuong, Amy S; Miri, Mitra L; Busskamp, Volker

    2014-01-01

    Optogenetic inhibition of the electrical activity of neurons enables the causal assessment of their contributions to brain functions. Red light penetrates deeper into tissue than other visible wavelengths. We present a red-shifted cruxhalorhodopsin, Jaws, derived from Haloarcula (Halobacterium......) salinarum (strain Shark) and engineered to result in red light-induced photocurrents three times those of earlier silencers. Jaws exhibits robust inhibition of sensory-evoked neural activity in the cortex and results in strong light responses when used in retinas of retinitis pigmentosa model mice. We also...... demonstrate that Jaws can noninvasively mediate transcranial optical inhibition of neurons deep in the brains of awake mice. The noninvasive optogenetic inhibition opened up by Jaws enables a variety of important neuroscience experiments and offers a powerful general-use chloride pump for basic and applied...

  11. Kappe neurons, a novel population of olfactory sensory neurons

    OpenAIRE

    Ahuja, Gaurav; Nia, Shahrzad Bozorg; Zapilko, Veronika; Shiriagin, Vladimir; Kowatschew, Daniel; Oka, Yuichiro; Korsching, Sigrun I.

    2014-01-01

    Perception of olfactory stimuli is mediated by distinct populations of olfactory sensory neurons, each with a characteristic set of morphological as well as functional parameters. Beyond two large populations of ciliated and microvillous neurons, a third population, crypt neurons, has been identified in teleost and cartilaginous fishes. We report here a novel, fourth olfactory sensory neuron population in zebrafish, which we named kappe neurons for their characteristic shape. Kappe neurons ar...

  12. NEURON and Python.

    Science.gov (United States)

    Hines, Michael L; Davison, Andrew P; Muller, Eilif

    2009-01-01

    The NEURON simulation program now allows Python to be used, alone or in combination with NEURON's traditional Hoc interpreter. Adding Python to NEURON has the immediate benefit of making available a very extensive suite of analysis tools written for engineering and science. It also catalyzes NEURON software development by offering users a modern programming tool that is recognized for its flexibility and power to create and maintain complex programs. At the same time, nothing is lost because all existing models written in Hoc, including graphical user interface tools, continue to work without change and are also available within the Python context. An example of the benefits of Python availability is the use of the xml module in implementing NEURON's Import3D and CellBuild tools to read MorphML and NeuroML model specifications.

  13. Spinal cord: motor neuron diseases.

    Science.gov (United States)

    Rezania, Kourosh; Roos, Raymond P

    2013-02-01

    Spinal cord motor neuron diseases affect lower motor neurons in the ventral horn. This article focuses on the most common spinal cord motor neuron disease, amyotrophic lateral sclerosis, which also affects upper motor neurons. Also discussed are other motor neuron diseases that only affect the lower motor neurons. Despite the identification of several genes associated with familial amyotrophic lateral sclerosis, the pathogenesis of this complex disease remains elusive. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. Inquiring into Red/Red Inquiring

    Directory of Open Access Journals (Sweden)

    Ken Gale

    2013-05-01

    Full Text Available This layered account of an inquiry into ‘red’ emerged out of a collective biography workshop. In the middle of the Wiltshire countryside, an international and interdisciplinary group of scholars gathered together to write and make other things and marks on paper that asked questions of, and into, the spaces between words, people, things and their environments. We did not set out to workshop or write into or paint ‘red’ but, rather, it was red that slipped in, uninvited, and painted and wrote us. Red arose as a blush or a stain seeping amongst us that became referenced obliquely by material objects, metaphors and fairytales. The stain spread, became noticeable through our weekend together and beyond it, creating another (bright red artery vein of connection to write with.

  15. Neuronal-glial trafficking

    International Nuclear Information System (INIS)

    Bachelard, H.S.

    2001-01-01

    Full text: The name 'glia' originates from the Greek word for glue, because astro glia (or astrocytes) were thought only to provide an anatomical framework for the electrically-excitable neurones. However, awareness that astrocytes perform vital roles in protecting the neurones, which they surround, emerged from evidence that they act as neuroprotective K + -sinks, and that they remove potentially toxic extracellular glutamate from the vicinity of the neurones. The astrocytes convert the glutamate to non-toxic glutamine which is returned to the neurones and used to replenish transmitter glutamate. This 'glutamate-glutamine cycle' (established in the 1960s by Berl and his colleagues) also contributes to protecting the neurones against a build-up of toxic ammonia. Glial cells also supply the neurones with components for free-radical scavenging glutathione. Recent studies have revealed that glial cells play a more positive interactive role in furnishing the neurones with fuels. Studies using radioactive 14 C, 13 C-MRS and 15 N-GCMS have revealed that glia produce alanine, lactate and proline for consumption by neurones, with increased formation of neurotransmitter glutamate. On neuronal activation the release of NH 4 + and glutamate from the neurones stimulates glucose uptake and glycolysis in the glia to produce more alanine, which can be regarded as an 'alanine-glutamate cycle' Use of 14 C-labelled precursors provided early evidence that neurotransmitter GABA may be partly derived from glial glutamine, and this has been confirmed recently in vivo by MRS isotopomer analysis of the GABA and glutamine labelled from 13 C-acetate. Relative rates of intermediary metabolism in glia and neurones can be calculated using a combination of [1- 13 C] glucose and [1,2- 13 C] acetate. When glutamate is released by neurones there is a net neuronal loss of TCA intermediates which have to be replenished. Part of this is derived from carboxylation of pyruvate, (pyruvate carboxylase

  16. Single neuron computation

    CERN Document Server

    McKenna, Thomas M; Zornetzer, Steven F

    1992-01-01

    This book contains twenty-two original contributions that provide a comprehensive overview of computational approaches to understanding a single neuron structure. The focus on cellular-level processes is twofold. From a computational neuroscience perspective, a thorough understanding of the information processing performed by single neurons leads to an understanding of circuit- and systems-level activity. From the standpoint of artificial neural networks (ANNs), a single real neuron is as complex an operational unit as an entire ANN, and formalizing the complex computations performed by real n

  17. Mesmerising mirror neurons.

    Science.gov (United States)

    Heyes, Cecilia

    2010-06-01

    Mirror neurons have been hailed as the key to understanding social cognition. I argue that three currents of thought-relating to evolution, atomism and telepathy-have magnified the perceived importance of mirror neurons. When they are understood to be a product of associative learning, rather than an adaptation for social cognition, mirror neurons are no longer mesmerising, but they continue to raise important questions about both the psychology of science and the neural bases of social cognition. Copyright 2010 Elsevier Inc. All rights reserved.

  18. The mirror neuron system.

    Science.gov (United States)

    Cattaneo, Luigi; Rizzolatti, Giacomo

    2009-05-01

    Mirror neurons are a class of neurons, originally discovered in the premotor cortex of monkeys, that discharge both when individuals perform a given motor act and when they observe others perform that same motor act. Ample evidence demonstrates the existence of a cortical network with the properties of mirror neurons (mirror system) in humans. The human mirror system is involved in understanding others' actions and their intentions behind them, and it underlies mechanisms of observational learning. Herein, we will discuss the clinical implications of the mirror system.

  19. Simultaneous neuron- and astrocyte-specific fluorescent marking

    Energy Technology Data Exchange (ETDEWEB)

    Schulze, Wiebke [Laboratory of Molecular Neuropharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871 (Japan); Hayata-Takano, Atsuko [Molecular Research Center for Children' s Mental Development, United Graduate School of Child Development, Osaka University, Kanazawa University, Hamamatsu University School of Medicine, Chiba University and University of Fukui, 2-2 Yamadaoka, Suita, Osaka 565-0871 (Japan); Kamo, Toshihiko [Laboratory of Molecular Neuropharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871 (Japan); Nakazawa, Takanobu, E-mail: takanobunakazawa-tky@umin.ac.jp [iPS Cell-based Research Project on Brain Neuropharmacology and Toxicology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871 (Japan); Nagayasu, Kazuki [iPS Cell-based Research Project on Brain Neuropharmacology and Toxicology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871 (Japan); Kasai, Atsushi; Seiriki, Kaoru [Laboratory of Molecular Neuropharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871 (Japan); Interdisciplinary Program for Biomedical Sciences, Institute for Academic Initiatives, Osaka University, 1-1 Yamadaoka, Suita, Osaka 565-0871 (Japan); Shintani, Norihito [Laboratory of Molecular Neuropharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871 (Japan); Ago, Yukio [Laboratory of Medicinal Pharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871 (Japan); Farfan, Camille [Laboratory of Molecular Neuropharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871 (Japan); and others

    2015-03-27

    Systematic and simultaneous analysis of multiple cell types in the brain is becoming important, but such tools have not yet been adequately developed. Here, we aimed to generate a method for the specific fluorescent labeling of neurons and astrocytes, two major cell types in the brain, and we have developed lentiviral vectors to express the red fluorescent protein tdTomato in neurons and the enhanced green fluorescent protein (EGFP) in astrocytes. Importantly, both fluorescent proteins are fused to histone 2B protein (H2B) to confer nuclear localization to distinguish between single cells. We also constructed several expression constructs, including a tandem alignment of the neuron- and astrocyte-expression cassettes for simultaneous labeling. Introducing these vectors and constructs in vitro and in vivo resulted in cell type-specific and nuclear-localized fluorescence signals enabling easy detection and distinguishability of neurons and astrocytes. This tool is expected to be utilized for the simultaneous analysis of changes in neurons and astrocytes in healthy and diseased brains. - Highlights: • We develop a method for the specific fluorescent labeling of neurons and astrocytes. • Neuron-specific labeling is achieved using Scg10 and synapsin promoters. • Astrocyte-specific labeling is generated using the minimal GFAP promoter. • Nuclear localization of fluorescent proteins is achieved with histone 2B protein.

  20. Simultaneous neuron- and astrocyte-specific fluorescent marking

    International Nuclear Information System (INIS)

    Schulze, Wiebke; Hayata-Takano, Atsuko; Kamo, Toshihiko; Nakazawa, Takanobu; Nagayasu, Kazuki; Kasai, Atsushi; Seiriki, Kaoru; Shintani, Norihito; Ago, Yukio; Farfan, Camille

    2015-01-01

    Systematic and simultaneous analysis of multiple cell types in the brain is becoming important, but such tools have not yet been adequately developed. Here, we aimed to generate a method for the specific fluorescent labeling of neurons and astrocytes, two major cell types in the brain, and we have developed lentiviral vectors to express the red fluorescent protein tdTomato in neurons and the enhanced green fluorescent protein (EGFP) in astrocytes. Importantly, both fluorescent proteins are fused to histone 2B protein (H2B) to confer nuclear localization to distinguish between single cells. We also constructed several expression constructs, including a tandem alignment of the neuron- and astrocyte-expression cassettes for simultaneous labeling. Introducing these vectors and constructs in vitro and in vivo resulted in cell type-specific and nuclear-localized fluorescence signals enabling easy detection and distinguishability of neurons and astrocytes. This tool is expected to be utilized for the simultaneous analysis of changes in neurons and astrocytes in healthy and diseased brains. - Highlights: • We develop a method for the specific fluorescent labeling of neurons and astrocytes. • Neuron-specific labeling is achieved using Scg10 and synapsin promoters. • Astrocyte-specific labeling is generated using the minimal GFAP promoter. • Nuclear localization of fluorescent proteins is achieved with histone 2B protein

  1. Neuromorphic Silicon Neuron Circuits

    Science.gov (United States)

    Indiveri, Giacomo; Linares-Barranco, Bernabé; Hamilton, Tara Julia; van Schaik, André; Etienne-Cummings, Ralph; Delbruck, Tobi; Liu, Shih-Chii; Dudek, Piotr; Häfliger, Philipp; Renaud, Sylvie; Schemmel, Johannes; Cauwenberghs, Gert; Arthur, John; Hynna, Kai; Folowosele, Fopefolu; Saighi, Sylvain; Serrano-Gotarredona, Teresa; Wijekoon, Jayawan; Wang, Yingxue; Boahen, Kwabena

    2011-01-01

    Hardware implementations of spiking neurons can be extremely useful for a large variety of applications, ranging from high-speed modeling of large-scale neural systems to real-time behaving systems, to bidirectional brain–machine interfaces. The specific circuit solutions used to implement silicon neurons depend on the application requirements. In this paper we describe the most common building blocks and techniques used to implement these circuits, and present an overview of a wide range of neuromorphic silicon neurons, which implement different computational models, ranging from biophysically realistic and conductance-based Hodgkin–Huxley models to bi-dimensional generalized adaptive integrate and fire models. We compare the different design methodologies used for each silicon neuron design described, and demonstrate their features with experimental results, measured from a wide range of fabricated VLSI chips. PMID:21747754

  2. Neuromorphic silicon neuron circuits

    Directory of Open Access Journals (Sweden)

    Giacomo eIndiveri

    2011-05-01

    Full Text Available Hardware implementations of spiking neurons can be extremely useful for a large variety of applications, ranging from high-speed modeling of large-scale neural systems to real-time behaving systems, to bidirectional brain-machine interfaces. The specific circuit solutions used to implement silicon neurons depend on the application requirements. In this paper we describe the most common building blocks and techniques used to implement these circuits, and present an overview of a wide range of neuromorphic silicon neurons, which implement different computational models, ranging from biophysically realistic and conductance based Hodgkin-Huxley models to bi-dimensional generalized adaptive Integrate and Fire models. We compare the different design methodologies used for each silicon neuron design described, and demonstrate their features with experimental results, measured from a wide range of fabricated VLSI chips.

  3. NeuronBank: a tool for cataloging neuronal circuitry

    Directory of Open Access Journals (Sweden)

    Paul S Katz

    2010-04-01

    Full Text Available The basic unit of any nervous system is the neuron. Therefore, understanding the operation of nervous systems ultimately requires an inventory of their constituent neurons and synaptic connectivity, which form neural circuits. The presence of uniquely identifiable neurons or classes of neurons in many invertebrates has facilitated the construction of cellular-level connectivity diagrams that can be generalized across individuals within a species. Homologous neurons can also be recognized across species. Here we describe NeuronBank.org, a web-based tool that we are developing for cataloging, searching, and analyzing neuronal circuitry within and across species. Information from a single species is represented in an individual branch of NeuronBank. Users can search within a branch or perform queries across branches to look for similarities in neuronal circuits across species. The branches allow for an extensible ontology so that additional characteristics can be added as knowledge grows. Each entry in NeuronBank generates a unique accession ID, allowing it to be easily cited. There is also an automatic link to a Wiki page allowing an encyclopedic explanation of the entry. All of the 44 previously published neurons plus one previously unpublished neuron from the mollusc, Tritonia diomedea, have been entered into a branch of NeuronBank as have 4 previously published neurons from the mollusc, Melibe leonina. The ability to organize information about neuronal circuits will make this information more accessible, ultimately aiding research on these important models.

  4. Next generation red teaming

    CERN Document Server

    Dalziel, Henry

    2015-01-01

    Red Teaming is can be described as a type of wargaming.In private business, penetration testers audit and test organization security, often in a secretive setting. The entire point of the Red Team is to see how weak or otherwise the organization's security posture is. This course is particularly suited to CISO's and CTO's that need to learn how to build a successful Red Team, as well as budding cyber security professionals who would like to learn more about the world of information security. Teaches readers how to dentify systemic security issues based on the analysis of vulnerability and con

  5. U-shape suppressive effect of phenol red on the epileptiform burst activity via activation of estrogen receptors in primary hippocampal culture.

    Directory of Open Access Journals (Sweden)

    Xu Liu

    Full Text Available Phenol red is widely used in cell culture as a pH indicator. Recently, it also has been reported to have estrogen-like bioactivity and be capable of promoting cell proliferation in different cell lines. However, the effect of phenol red on primary neuronal culture has never been investigated. By using patch clamp technique, we demonstrated that hippocampal pyramidal neurons cultured in neurobasal medium containing no phenol red had large depolarization-associated epileptiform bursting activities, which were rarely seen in neurons cultured in phenol red-containing medium. Further experiment data indicate that the suppressive effect of the phenol red on the abnormal epileptiform burst neuronal activities was U-shape dose related, with the most effective concentration at 28 µM. In addition, this concentration related inhibitory effect of phenol red on the epileptiform neuronal discharges was mimicked by 17-β-estradiol, an estrogen receptor agonist, and inhibited by ICI-182,780, an estrogen receptor antagonist. Our results suggest that estrogen receptor activation by phenol red in the culture medium prevents formation of abnormal, epileptiform burst activity. These studies highlight the importance of phenol red as estrogen receptor stimulator and cautions of careful use of phenol red in cell culture media.

  6. Astrophysics of Red Supergiants

    Science.gov (United States)

    Levesque, Emily M.

    2017-12-01

    'Astrophysics of Red Supergiants' is the first book of its kind devoted to our current knowledge of red supergiant stars, a key evolutionary phase that is critical to our larger understanding of massive stars. It provides a comprehensive overview of the fundamental physical properties of red supergiants, their evolution, and their extragalactic and cosmological applications. It serves as a reference for researchers from a broad range of fields (including stellar astrophysics, supernovae, and high-redshift galaxies) who are interested in red supergiants as extreme stages of stellar evolution, dust producers, supernova progenitors, extragalactic metallicity indicators, members of massive binaries and mergers, or simply as compelling objects in their own right. The book is accessible to a range of experience levels, from graduate students up to senior researchers.

  7. red flour beetle

    African Journals Online (AJOL)

    STORAGESEVER

    2009-12-01

    Dec 1, 2009 ... 2Institute of Biochemistry and Biotechnology, University of the Punjab, Lahore, Pakistan. 3Department of ... most important energy source around the globe ... T. castaneum (red flour beetle) samples were collected from rice.

  8. RED-ML

    DEFF Research Database (Denmark)

    Xiong, Heng; Liu, Dongbing; Li, Qiye

    2017-01-01

    using diverse RNA-seq datasets, we have developed a software tool, RED-ML: RNA Editing Detection based on Machine learning (pronounced as "red ML"). The input to RED-ML can be as simple as a single BAM file, while it can also take advantage of matched genomic variant information when available...... accurately detect novel RNA editing sites without relying on curated RNA editing databases. We have also made this tool freely available via GitHub . We have developed a highly accurate, speedy and general-purpose tool for RNA editing detection using RNA-seq data....... With the availability of RED-ML, it is now possible to conveniently make RNA editing a routine analysis of RNA-seq. We believe this can greatly benefit the RNA editing research community and has profound impact to accelerate our understanding of this intriguing posttranscriptional modification process....

  9. Neuronal avalanches and learning

    Energy Technology Data Exchange (ETDEWEB)

    Arcangelis, Lucilla de, E-mail: dearcangelis@na.infn.it [Department of Information Engineering and CNISM, Second University of Naples, 81031 Aversa (Italy)

    2011-05-01

    Networks of living neurons represent one of the most fascinating systems of biology. If the physical and chemical mechanisms at the basis of the functioning of a single neuron are quite well understood, the collective behaviour of a system of many neurons is an extremely intriguing subject. Crucial ingredient of this complex behaviour is the plasticity property of the network, namely the capacity to adapt and evolve depending on the level of activity. This plastic ability is believed, nowadays, to be at the basis of learning and memory in real brains. Spontaneous neuronal activity has recently shown features in common to other complex systems. Experimental data have, in fact, shown that electrical information propagates in a cortex slice via an avalanche mode. These avalanches are characterized by a power law distribution for the size and duration, features found in other problems in the context of the physics of complex systems and successful models have been developed to describe their behaviour. In this contribution we discuss a statistical mechanical model for the complex activity in a neuronal network. The model implements the main physiological properties of living neurons and is able to reproduce recent experimental results. Then, we discuss the learning abilities of this neuronal network. Learning occurs via plastic adaptation of synaptic strengths by a non-uniform negative feedback mechanism. The system is able to learn all the tested rules, in particular the exclusive OR (XOR) and a random rule with three inputs. The learning dynamics exhibits universal features as function of the strength of plastic adaptation. Any rule could be learned provided that the plastic adaptation is sufficiently slow.

  10. Neuronal avalanches and learning

    International Nuclear Information System (INIS)

    Arcangelis, Lucilla de

    2011-01-01

    Networks of living neurons represent one of the most fascinating systems of biology. If the physical and chemical mechanisms at the basis of the functioning of a single neuron are quite well understood, the collective behaviour of a system of many neurons is an extremely intriguing subject. Crucial ingredient of this complex behaviour is the plasticity property of the network, namely the capacity to adapt and evolve depending on the level of activity. This plastic ability is believed, nowadays, to be at the basis of learning and memory in real brains. Spontaneous neuronal activity has recently shown features in common to other complex systems. Experimental data have, in fact, shown that electrical information propagates in a cortex slice via an avalanche mode. These avalanches are characterized by a power law distribution for the size and duration, features found in other problems in the context of the physics of complex systems and successful models have been developed to describe their behaviour. In this contribution we discuss a statistical mechanical model for the complex activity in a neuronal network. The model implements the main physiological properties of living neurons and is able to reproduce recent experimental results. Then, we discuss the learning abilities of this neuronal network. Learning occurs via plastic adaptation of synaptic strengths by a non-uniform negative feedback mechanism. The system is able to learn all the tested rules, in particular the exclusive OR (XOR) and a random rule with three inputs. The learning dynamics exhibits universal features as function of the strength of plastic adaptation. Any rule could be learned provided that the plastic adaptation is sufficiently slow.

  11. Species and Sex Differences in the Morphogenic Response of Primary Rodent Neurons to 3,3'-Dichlorobiphenyl (PCB 11).

    Science.gov (United States)

    Sethi, Sunjay; Keil, Kimberly P; Lein, Pamela J

    2017-12-23

    PCB 11 is an emerging global pollutant that we recently showed promotes axonal and dendritic growth in primary rat neuronal cell cultures. Here, we address the influence of sex and species on neuronal responses to PCB 11. Neuronal morphology was quantified in sex-specific primary hippocampal and cortical neuron-glia co-cultures derived from neonatal C57BL/6J mice and Sprague Dawley rats exposed for 48 h to vehicle (0.1% DMSO) or PCB 11 at concentrations ranging from 1 fM to 1 nM. Total axonal length was quantified in tau-1 immunoreactive neurons at day in vitro (DIV) 2; dendritic arborization was assessed by Sholl analysis at DIV 9 in neurons transfected with MAP2B-FusRed. In mouse cultures, PCB 11 enhanced dendritic arborization in female, but not male, hippocampal neurons and male, but not female, cortical neurons. In rat cultures, PCB 11 promoted dendritic arborization in male and female hippocampal and cortical neurons. PCB 11 also increased axonal growth in mouse and rat neurons of both sexes and neuronal cell types. These data demonstrate that PCB 11 exerts sex-specific effects on neuronal morphogenesis that vary depending on species, neurite type, and neuronal cell type. These findings have significant implications for risk assessment of this emerging developmental neurotoxicant.

  12. Kappe neurons, a novel population of olfactory sensory neurons.

    Science.gov (United States)

    Ahuja, Gaurav; Bozorg Nia, Shahrzad; Zapilko, Veronika; Shiriagin, Vladimir; Kowatschew, Daniel; Oka, Yuichiro; Korsching, Sigrun I

    2014-02-10

    Perception of olfactory stimuli is mediated by distinct populations of olfactory sensory neurons, each with a characteristic set of morphological as well as functional parameters. Beyond two large populations of ciliated and microvillous neurons, a third population, crypt neurons, has been identified in teleost and cartilaginous fishes. We report here a novel, fourth olfactory sensory neuron population in zebrafish, which we named kappe neurons for their characteristic shape. Kappe neurons are identified by their Go-like immunoreactivity, and show a distinct spatial distribution within the olfactory epithelium, similar to, but significantly different from that of crypt neurons. Furthermore, kappe neurons project to a single identified target glomerulus within the olfactory bulb, mdg5 of the mediodorsal cluster, whereas crypt neurons are known to project exclusively to the mdg2 glomerulus. Kappe neurons are negative for established markers of ciliated, microvillous and crypt neurons, but appear to have microvilli. Kappe neurons constitute the fourth type of olfactory sensory neurons reported in teleost fishes and their existence suggests that encoding of olfactory stimuli may require a higher complexity than hitherto assumed already in the peripheral olfactory system.

  13. Stochastic neuron models

    CERN Document Server

    Greenwood, Priscilla E

    2016-01-01

    This book describes a large number of open problems in the theory of stochastic neural systems, with the aim of enticing probabilists to work on them. This includes problems arising from stochastic models of individual neurons as well as those arising from stochastic models of the activities of small and large networks of interconnected neurons. The necessary neuroscience background to these problems is outlined within the text, so readers can grasp the context in which they arise. This book will be useful for graduate students and instructors providing material and references for applying probability to stochastic neuron modeling. Methods and results are presented, but the emphasis is on questions where additional stochastic analysis may contribute neuroscience insight. An extensive bibliography is included. Dr. Priscilla E. Greenwood is a Professor Emerita in the Department of Mathematics at the University of British Columbia. Dr. Lawrence M. Ward is a Professor in the Department of Psychology and the Brain...

  14. Short-term memory and critical clusterization in brain neurons spike series

    Science.gov (United States)

    Bershadskii, A.; Dremencov, E.; Yadid, G.

    2003-06-01

    A new phenomenon: critical clusterization, is observed in the neuron firing of a genetically defined rat model of depression. The critical clusterization is studied using a multiscaling analysis of the data obtained from the neurons belonging to the Red Nucleus area of the depressive brains. It is suggested that this critical phenomenon can be partially responsible for the observed ill behavior of the depressive brains: loss of short-term motor memory and slow motor reaction.

  15. Neuronal Migration and Neuronal Migration Disorder in Cerebral Cortex

    OpenAIRE

    SUN, Xue-Zhi; TAKAHASHI, Sentaro; GUI, Chun; ZHANG, Rui; KOGA, Kazuo; NOUYE, Minoru; MURATA, Yoshiharu

    2002-01-01

    Neuronal cell migration is one of the most significant features during cortical development. After final mitosis, neurons migrate from the ventricular zone into the cortical plate, and then establish neuronal lamina and settle onto the outermost layer, forming an "inside-out" gradient of maturation. Neuronal migration is guided by radial glial fibers and also needs proper receptors, ligands, and other unknown extracellular factors, requests local signaling (e.g. some emitted by the Cajal-Retz...

  16. Abnormal red cell structure and function in neuroacanthocytosis.

    Directory of Open Access Journals (Sweden)

    Judith C A Cluitmans

    Full Text Available Panthothenate kinase-associated neurodegeneration (PKAN belongs to a group of hereditary neurodegenerative disorders known as neuroacanthocytosis (NA. This genetically heterogeneous group of diseases is characterized by degeneration of neurons in the basal ganglia and by the presence of deformed red blood cells with thorny protrusions, acanthocytes, in the circulation.The goal of our study is to elucidate the molecular mechanisms underlying this aberrant red cell morphology and the corresponding functional consequences. This could shed light on the etiology of the neurodegeneration.We performed a qualitative and semi-quantitative morphological, immunofluorescent, biochemical and functional analysis of the red cells of several patients with PKAN and, for the first time, of the red cells of their family members.We show that the blood of patients with PKAN contains not only variable numbers of acanthocytes, but also a wide range of other misshapen red cells. Immunofluorescent and immunoblot analyses suggest an altered membrane organization, rather than quantitative changes in protein expression. Strikingly, these changes are not limited to the red blood cells of PKAN patients, but are also present in the red cells of heterozygous carriers without neurological problems. Furthermore, changes are not only present in acanthocytes, but also in other red cells, including discocytes. The patients' cells, however, are more fragile, as observed in a spleen-mimicking device.These morphological, molecular and functional characteristics of red cells in patients with PKAN and their family members offer new tools for diagnosis and present a window into the pathophysiology of neuroacanthocytosis.

  17. Neuronal nets in robotics

    International Nuclear Information System (INIS)

    Jimenez Sanchez, Raul

    1999-01-01

    The paper gives a generic idea of the solutions that the neuronal nets contribute to the robotics. The advantages and the inconveniences are exposed that have regarding the conventional techniques. It also describe the more excellent applications as the pursuit of trajectories, the positioning based on images, the force control or of the mobile robots management, among others

  18. Vasculo-Neuronal Coupling: Retrograde Vascular Communication to Brain Neurons.

    Science.gov (United States)

    Kim, Ki Jung; Ramiro Diaz, Juan; Iddings, Jennifer A; Filosa, Jessica A

    2016-12-14

    Continuous cerebral blood flow is essential for neuronal survival, but whether vascular tone influences resting neuronal function is not known. Using a multidisciplinary approach in both rat and mice brain slices, we determined whether flow/pressure-evoked increases or decreases in parenchymal arteriole vascular tone, which result in arteriole constriction and dilation, respectively, altered resting cortical pyramidal neuron activity. We present evidence for intercellular communication in the brain involving a flow of information from vessel to astrocyte to neuron, a direction opposite to that of classic neurovascular coupling and referred to here as vasculo-neuronal coupling (VNC). Flow/pressure increases within parenchymal arterioles increased vascular tone and simultaneously decreased resting pyramidal neuron firing activity. On the other hand, flow/pressure decreases evoke parenchymal arteriole dilation and increased resting pyramidal neuron firing activity. In GLAST-CreERT2; R26-lsl-GCaMP3 mice, we demonstrate that increased parenchymal arteriole tone significantly increased intracellular calcium in perivascular astrocyte processes, the onset of astrocyte calcium changes preceded the inhibition of cortical pyramidal neuronal firing activity. During increases in parenchymal arteriole tone, the pyramidal neuron response was unaffected by blockers of nitric oxide, GABA A , glutamate, or ecto-ATPase. However, VNC was abrogated by TRPV4 channel, GABA B , as well as an adenosine A 1 receptor blocker. Differently to pyramidal neuron responses, increases in flow/pressure within parenchymal arterioles increased the firing activity of a subtype of interneuron. Together, these data suggest that VNC is a complex constitutive active process that enables neurons to efficiently adjust their resting activity according to brain perfusion levels, thus safeguarding cellular homeostasis by preventing mismatches between energy supply and demand. We present evidence for vessel-to-neuron

  19. Neuronal survival in the brain: neuron type-specific mechanisms

    DEFF Research Database (Denmark)

    Pfisterer, Ulrich Gottfried; Khodosevich, Konstantin

    2017-01-01

    Neurogenic regions of mammalian brain produce many more neurons that will eventually survive and reach a mature stage. Developmental cell death affects both embryonically produced immature neurons and those immature neurons that are generated in regions of adult neurogenesis. Removal of substantial...... numbers of neurons that are not yet completely integrated into the local circuits helps to ensure that maturation and homeostatic function of neuronal networks in the brain proceed correctly. External signals from brain microenvironment together with intrinsic signaling pathways determine whether...... for survival in a certain brain region. This review focuses on how immature neurons survive during normal and impaired brain development, both in the embryonic/neonatal brain and in brain regions associated with adult neurogenesis, and emphasizes neuron type-specific mechanisms that help to survive for various...

  20. Clover, Red (Trifolium pretense)

    Science.gov (United States)

    Genetic modification of plants by the insertion of transgenes can be a powerful experimental approach to answer basic questions about gene product function. This technology can also be used to make improved crop varieties for use in the field. To apply this powerful tool to red clover, an important ...

  1. Neuronal synchrony: peculiarity and generality.

    Science.gov (United States)

    Nowotny, Thomas; Huerta, Ramon; Rabinovich, Mikhail I

    2008-09-01

    Synchronization in neuronal systems is a new and intriguing application of dynamical systems theory. Why are neuronal systems different as a subject for synchronization? (1) Neurons in themselves are multidimensional nonlinear systems that are able to exhibit a wide variety of different activity patterns. Their "dynamical repertoire" includes regular or chaotic spiking, regular or chaotic bursting, multistability, and complex transient regimes. (2) Usually, neuronal oscillations are the result of the cooperative activity of many synaptically connected neurons (a neuronal circuit). Thus, it is necessary to consider synchronization between different neuronal circuits as well. (3) The synapses that implement the coupling between neurons are also dynamical elements and their intrinsic dynamics influences the process of synchronization or entrainment significantly. In this review we will focus on four new problems: (i) the synchronization in minimal neuronal networks with plastic synapses (synchronization with activity dependent coupling), (ii) synchronization of bursts that are generated by a group of nonsymmetrically coupled inhibitory neurons (heteroclinic synchronization), (iii) the coordination of activities of two coupled neuronal networks (partial synchronization of small composite structures), and (iv) coarse grained synchronization in larger systems (synchronization on a mesoscopic scale). (c) 2008 American Institute of Physics.

  2. From Neurons to Newtons

    DEFF Research Database (Denmark)

    Nielsen, Bjørn Gilbert

    2001-01-01

    proteins generate forces, to the macroscopic levels where overt arm movements are vol- untarily controlled within an unpredictable environment by legions of neurons¯ring in orderly fashion. An extensive computer simulation system has been developed for this thesis, which at present contains a neural...... network scripting language for specifying arbitrary neural architectures, de¯nition ¯les for detailed spinal networks, various biologically realistic models of neurons, and dynamic synapses. Also included are structurally accurate models of intrafusal and extra-fusal muscle ¯bers and a general body...... that an explicit function may be derived which expresses the force that the spindle contractile elements must produce to exactly counter spindle unloading during muscle shortening. This information was used to calculate the corresponding "optimal" °-motoneuronal activity level. For some simple arm movement tasks...

  3. Criticality in Neuronal Networks

    Science.gov (United States)

    Friedman, Nir; Ito, Shinya; Brinkman, Braden A. W.; Shimono, Masanori; Deville, R. E. Lee; Beggs, John M.; Dahmen, Karin A.; Butler, Tom C.

    2012-02-01

    In recent years, experiments detecting the electrical firing patterns in slices of in vitro brain tissue have been analyzed to suggest the presence of scale invariance and possibly criticality in the brain. Much of the work done however has been limited in two ways: 1) the data collected is from local field potentials that do not represent the firing of individual neurons; 2) the analysis has been primarily limited to histograms. In our work we examine data based on the firing of individual neurons (spike data), and greatly extend the analysis by considering shape collapse and exponents. Our results strongly suggest that the brain operates near a tuned critical point of a highly distinctive universality class.

  4. Cultured subventricular zone progenitor cells transduced with neurogenin-2 become mature glutamatergic neurons and integrate into the dentate gyrus.

    Directory of Open Access Journals (Sweden)

    Xia Chen

    Full Text Available We have previously shown that transplantation of immature DCX+/NeuN+/Prox1+ neurons (found in the neonatal DG, but not undifferentiated neuronal progenitor cells (NPCs from ventral subventricular zone (SVZ, results in neuronal maturation in vivo within the dentate niche. Here we investigated whether we could enhance the integration of SVZ NPCs by forced expression of the proneural gene Neurogenin 2 (NEUROG2. NPCs cultured from neonatal GFP-transgenic rat SVZ for 7 days in a non-differentiating medium were transduced with a retrovirus encoding NEUROG2 and DsRed or the DsRed reporter gene alone (control. By 3 days post-transduction, the NEUROG2-transduced cells maintained in culture contained mostly immature neurons (91% DCX+; 76% NeuN+, whereas the control virus-transduced cells remained largely undifferentiated (30% DCX+; <1% NeuN+. At 6 weeks following transplantation into the DG of adult male rats, there were no neurons among the transplanted cells treated with the control virus but the majority of the NEUROG2-transduced DsRed+ SVZ cells became mature neurons (92% NeuN+; DCX-negative. Although the NEUROG2-transduced SVZ cells did not express the dentate granule neuron marker Prox1, most of the NEUROG2-transduced SVZ cells (78% expressed the glutamatergic marker Tbr1, suggesting the acquisition of a glutamatergic phenotype. Moreover, some neurons extended dendrites into the molecular layer, grew axons containing Ankyrin G+ axonal initial segments, and projected into the CA3 region, thus resembling mature DG granule neurons. A proportion of NEUROG2 transduced cells also expressed c-Fos and P-CREB, two markers of neuronal activation. We conclude that NEUROG2-transduction is sufficient to promote neuronal maturation and integration of transplanted NPCs from SVZ into the DG.

  5. Skin quality in red potatoes

    Science.gov (United States)

    Attractive appearance is a highly desirable characteristic of fresh market red-skinned potatoes. The ideal red potato has a rich, uniform, deep red color. Color fading, netting, browning, and discoloration caused by skinning and disease decrease marketability and may reduce profits to growers and pa...

  6. Red alder potential in Alaska

    Science.gov (United States)

    Allen Brackley; David Nicholls; Mike Hannan

    2010-01-01

    Over the past several decades, red alder has established itself as a commercially important species in the Pacific Northwest. Once considered a weed species, red alder now commands respect within many markets, including furniture, architectural millwork, and other secondary manufactured products. Although red alder's natural range extends to southeast Alaska, an...

  7. Statistical analysis in the design of nuclear fuel cells and training of a neural network to predict safety parameters for reactors BWR; Analisis estadistico en el diseno de celdas de combustible nuclear y entrenamiento de una red neuronal para predecir parametros de seguridad para reactores BWR

    Energy Technology Data Exchange (ETDEWEB)

    Jauregui Ch, V.

    2013-07-01

    In this work the obtained results for a statistical analysis are shown, with the purpose of studying the performance of the fuel lattice, taking into account the frequency of the pins that were used. For this objective, different statistical distributions were used; one approximately to normal, another type X{sup 2} but in an inverse form and a random distribution. Also, the prediction of some parameters of the nuclear reactor in a fuel reload was made through a neuronal network, which was trained. The statistical analysis was made using the parameters of the fuel lattice, which was generated through three heuristic techniques: Ant Colony Optimization System, Neuronal Networks and a hybrid among Scatter Search and Path Re linking. The behavior of the local power peak factor was revised in the fuel lattice with the use of different frequencies of enrichment uranium pines, using the three techniques mentioned before, in the same way the infinite multiplication factor of neutrons was analyzed (k..), to determine within what range this factor in the reactor is. Taking into account all the information, which was obtained through the statistical analysis, a neuronal network was trained; that will help to predict the behavior of some parameters of the nuclear reactor, considering a fixed fuel reload with their respective control rods pattern. In the same way, the quality of the training was evaluated using different fuel lattices. The neuronal network learned to predict the next parameters: Shutdown Margin (SDM), the pin burn peaks for two different fuel batches, Thermal Limits and the Effective Neutron Multiplication Factor (k{sup eff}). The results show that the fuel lattices in which the frequency, which the inverted form of the X{sup 2} distribution, was used revealed the best values of local power peak factor. Additionally it is shown that the performance of a fuel lattice could be enhanced controlling the frequency of the uranium enrichment rods and the variety of

  8. Pseudorabies virus infection alters neuronal activity and connectivity in vitro.

    Directory of Open Access Journals (Sweden)

    Kelly M McCarthy

    2009-10-01

    Full Text Available Alpha-herpesviruses, including human herpes simplex virus 1 & 2, varicella zoster virus and the swine pseudorabies virus (PRV, infect the peripheral nervous system of their hosts. Symptoms of infection often include itching, numbness, or pain indicative of altered neurological function. To determine if there is an in vitro electrophysiological correlate to these characteristic in vivo symptoms, we infected cultured rat sympathetic neurons with well-characterized strains of PRV known to produce virulent or attenuated symptoms in animals. Whole-cell patch clamp recordings were made at various times after infection. By 8 hours of infection with virulent PRV, action potential (AP firing rates increased substantially and were accompanied by hyperpolarized resting membrane potentials and spikelet-like events. Coincident with the increase in AP firing rate, adjacent neurons exhibited coupled firing events, first with AP-spikelets and later with near identical resting membrane potentials and AP firing. Small fusion pores between adjacent cell bodies formed early after infection as demonstrated by transfer of the low molecular weight dye, Lucifer Yellow. Later, larger pores formed as demonstrated by transfer of high molecular weight Texas red-dextran conjugates between infected cells. Further evidence for viral-induced fusion pores was obtained by infecting neurons with a viral mutant defective for glycoprotein B, a component of the viral membrane fusion complex. These infected neurons were essentially identical to mock infected neurons: no increased AP firing, no spikelet-like events, and no electrical or dye transfer. Infection with PRV Bartha, an attenuated circuit-tracing strain delayed, but did not eliminate the increased neuronal activity and coupling events. We suggest that formation of fusion pores between infected neurons results in electrical coupling and elevated firing rates, and that these processes may contribute to the altered neural

  9. Parvalbumin+ Neurons and Npas1+ Neurons Are Distinct Neuron Classes in the Mouse External Globus Pallidus.

    Science.gov (United States)

    Hernández, Vivian M; Hegeman, Daniel J; Cui, Qiaoling; Kelver, Daniel A; Fiske, Michael P; Glajch, Kelly E; Pitt, Jason E; Huang, Tina Y; Justice, Nicholas J; Chan, C Savio

    2015-08-26

    Compelling evidence suggests that pathological activity of the external globus pallidus (GPe), a nucleus in the basal ganglia, contributes to the motor symptoms of a variety of movement disorders such as Parkinson's disease. Recent studies have challenged the idea that the GPe comprises a single, homogenous population of neurons that serves as a simple relay in the indirect pathway. However, we still lack a full understanding of the diversity of the neurons that make up the GPe. Specifically, a more precise classification scheme is needed to better describe the fundamental biology and function of different GPe neuron classes. To this end, we generated a novel multicistronic BAC (bacterial artificial chromosome) transgenic mouse line under the regulatory elements of the Npas1 gene. Using a combinatorial transgenic and immunohistochemical approach, we discovered that parvalbumin-expressing neurons and Npas1-expressing neurons in the GPe represent two nonoverlapping cell classes, amounting to 55% and 27% of the total GPe neuron population, respectively. These two genetically identified cell classes projected primarily to the subthalamic nucleus and to the striatum, respectively. Additionally, parvalbumin-expressing neurons and Npas1-expressing neurons were distinct in their autonomous and driven firing characteristics, their expression of intrinsic ion conductances, and their responsiveness to chronic 6-hydroxydopamine lesion. In summary, our data argue that parvalbumin-expressing neurons and Npas1-expressing neurons are two distinct functional classes of GPe neurons. This work revises our understanding of the GPe, and provides the foundation for future studies of its function and dysfunction. Until recently, the heterogeneity of the constituent neurons within the external globus pallidus (GPe) was not fully appreciated. We addressed this knowledge gap by discovering two principal GPe neuron classes, which were identified by their nonoverlapping expression of the

  10. Parvalbumin+ Neurons and Npas1+ Neurons Are Distinct Neuron Classes in the Mouse External Globus Pallidus

    Science.gov (United States)

    Hernández, Vivian M.; Hegeman, Daniel J.; Cui, Qiaoling; Kelver, Daniel A.; Fiske, Michael P.; Glajch, Kelly E.; Pitt, Jason E.; Huang, Tina Y.; Justice, Nicholas J.

    2015-01-01

    Compelling evidence suggests that pathological activity of the external globus pallidus (GPe), a nucleus in the basal ganglia, contributes to the motor symptoms of a variety of movement disorders such as Parkinson's disease. Recent studies have challenged the idea that the GPe comprises a single, homogenous population of neurons that serves as a simple relay in the indirect pathway. However, we still lack a full understanding of the diversity of the neurons that make up the GPe. Specifically, a more precise classification scheme is needed to better describe the fundamental biology and function of different GPe neuron classes. To this end, we generated a novel multicistronic BAC (bacterial artificial chromosome) transgenic mouse line under the regulatory elements of the Npas1 gene. Using a combinatorial transgenic and immunohistochemical approach, we discovered that parvalbumin-expressing neurons and Npas1-expressing neurons in the GPe represent two nonoverlapping cell classes, amounting to 55% and 27% of the total GPe neuron population, respectively. These two genetically identified cell classes projected primarily to the subthalamic nucleus and to the striatum, respectively. Additionally, parvalbumin-expressing neurons and Npas1-expressing neurons were distinct in their autonomous and driven firing characteristics, their expression of intrinsic ion conductances, and their responsiveness to chronic 6-hydroxydopamine lesion. In summary, our data argue that parvalbumin-expressing neurons and Npas1-expressing neurons are two distinct functional classes of GPe neurons. This work revises our understanding of the GPe, and provides the foundation for future studies of its function and dysfunction. SIGNIFICANCE STATEMENT Until recently, the heterogeneity of the constituent neurons within the external globus pallidus (GPe) was not fully appreciated. We addressed this knowledge gap by discovering two principal GPe neuron classes, which were identified by their nonoverlapping

  11. Metabolic reprogramming during neuronal differentiation.

    Science.gov (United States)

    Agostini, M; Romeo, F; Inoue, S; Niklison-Chirou, M V; Elia, A J; Dinsdale, D; Morone, N; Knight, R A; Mak, T W; Melino, G

    2016-09-01

    Newly generated neurons pass through a series of well-defined developmental stages, which allow them to integrate into existing neuronal circuits. After exit from the cell cycle, postmitotic neurons undergo neuronal migration, axonal elongation, axon pruning, dendrite morphogenesis and synaptic maturation and plasticity. Lack of a global metabolic analysis during early cortical neuronal development led us to explore the role of cellular metabolism and mitochondrial biology during ex vivo differentiation of primary cortical neurons. Unexpectedly, we observed a huge increase in mitochondrial biogenesis. Changes in mitochondrial mass, morphology and function were correlated with the upregulation of the master regulators of mitochondrial biogenesis, TFAM and PGC-1α. Concomitant with mitochondrial biogenesis, we observed an increase in glucose metabolism during neuronal differentiation, which was linked to an increase in glucose uptake and enhanced GLUT3 mRNA expression and platelet isoform of phosphofructokinase 1 (PFKp) protein expression. In addition, glutamate-glutamine metabolism was also increased during the differentiation of cortical neurons. We identified PI3K-Akt-mTOR signalling as a critical regulator role of energy metabolism in neurons. Selective pharmacological inhibition of these metabolic pathways indicate existence of metabolic checkpoint that need to be satisfied in order to allow neuronal differentiation.

  12. Red giants seismology

    Science.gov (United States)

    Mosser, B.; Samadi, R.; Belkacem, K.

    2013-11-01

    The space-borne missions CoRoT and Kepler are indiscreet. With their asteroseismic programs, they tell us what is hidden deep inside the stars. Waves excited just below the stellar surface travel throughout the stellar interior and unveil many secrets: how old is the star, how big, how massive, how fast (or slow) its core is dancing. This paper intends to paparazze the red giants according to the seismic pictures we have from their interiors.

  13. Multiplicar la red

    Directory of Open Access Journals (Sweden)

    John Young

    2015-01-01

    Full Text Available La tecnología comunicacional nos ha conducido precipitadamente a una existencia completamente nueva. En la carrera por crear una sociedad sustentable, una "red de redes mundiales" de computadoras personales que puedan ofrecer la primera esperanza real de acelerar ampliamente las comunicaciones. Las redes computacionales no solo sirven como un sistema de comunicación interactivo, rápido sino también como una herramienta de investigación de poderes insospechados.

  14. Organization of projection-specific interneurons in the spinal cord of the red-eared turtle

    DEFF Research Database (Denmark)

    Nissen, Ulla Vig; Moldovan, Mihai; Hounsgaard, Jørn

    2008-01-01

    Using differential retrograde axonal tracing, we identified motoneurons (MNs) and projection-specific interneuron (IN) classes in lumbar segment D9 of the adult red-eared turtle spinal cord. We characterized the distribution of these neurons in the transverse plane, and estimated their numbers...

  15. Imitation, mirror neurons and autism

    OpenAIRE

    Williams, Justin H.G.; Whiten, Andrew; Suddendorf, Thomas; Perrett, David I.

    2001-01-01

    Various deficits in the cognitive functioning of people with autism have been documented in recent years but these provide only partial explanations for the condition. We focus instead on an imitative disturbance involving difficulties both in copying actions and in inhibiting more stereotyped mimicking, such as echolalia. A candidate for the neural basis of this disturbance may be found in a recently discovered class of neurons in frontal cortex, 'mirror neurons' (MNs). These neurons show ac...

  16. The biophysics of neuronal growth

    International Nuclear Information System (INIS)

    Franze, Kristian; Guck, Jochen

    2010-01-01

    For a long time, neuroscience has focused on biochemical, molecular biological and electrophysiological aspects of neuronal physiology and pathology. However, there is a growing body of evidence indicating the importance of physical stimuli for neuronal growth and development. In this review we briefly summarize the historical background of neurobiophysics and give an overview over the current understanding of neuronal growth from a physics perspective. We show how biophysics has so far contributed to a better understanding of neuronal growth and discuss current inconsistencies. Finally, we speculate how biophysics may contribute to the successful treatment of lesions to the central nervous system, which have been considered incurable until very recently.

  17. RedNemo

    DEFF Research Database (Denmark)

    Alkan, Ferhat; Erten, Cesim

    2017-01-01

    is their erroneous nature; they contain false-positive interactions and usually many more false-negatives. Recently, several computational methods have been proposed for network reconstruction based on topology, where given an input PPI network the goal is to reconstruct the network by identifying false...... material including source code, useful scripts, experimental data and the results are available at http://webprs.khas.edu.tr/∼cesim/Red Nemo. tar.gz CONTACT: cesim@khas.edu.tr Supplementary information: Supplementary data are available at Bioinformatics online....

  18. Deep Red (Profondo Rosso)

    CERN Multimedia

    Cine Club

    2015-01-01

    Wednesday 29 April 2015 at 20:00 CERN Council Chamber    Deep Red (Profondo Rosso) Directed by Dario Argento (Italy, 1975) 126 minutes A psychic who can read minds picks up the thoughts of a murderer in the audience and soon becomes a victim. An English pianist gets involved in solving the murders, but finds many of his avenues of inquiry cut off by new murders, and he begins to wonder how the murderer can track his movements so closely. Original version Italian; English subtitles

  19. Red DirCom

    Directory of Open Access Journals (Sweden)

    Joan Costa

    2007-01-01

    Full Text Available Catorce países congregados de manera activa, a través de una plataforma de encuentro donde se comparten conocimiento y experiencias en la gestión estratégica de la comunicación en las organizaciones. La red reconoce en el DirCom una figura clave del desarrollo corporativo en el nuevo contexto de los negocios, impulsa la exigencia ética a través de la formación y consolida la proyección profesional para posicionar la gestión integral del DirCom en Iberoamérica.

  20. Rescue of axotomized rubrospinal neurons by brain-derived neurotrophic factor (BDNF) in the developing opossum, Didelphis virginiana.

    Science.gov (United States)

    Wang, X M; Terman, J R; Martin, G F

    1999-12-10

    Many rubrospinal neurons die in developing opossums when their axon is cut at thoracic levels of the spinal cord and in the present study we asked whether they can be rescued by brain-derived neurotrophic factor (BDNF). Bilateral injections of Fast Blue (FB) were made into the rostral lumbar cord to prelabel rubrospinal neurons and 5 days later the rubrospinal tract was cut unilaterally by hemisecting the thoracic cord. Immediately after hemisection, BDNF-soaked gelfoam was placed into the lesion cavity. Since pilot data indicated that one application of BDNF was not sufficient to produce a rescue effect, a second application was made 7 days later. Seven days after the second application the pups were killed by an overdose of anesthetic so that the red nucleus contralateral and ipsilateral to the lesion site could be examined for labeled neurons. The rubrospinal tract is almost entirely crossed, so the red nucleus contralateral to the lesion contained many axotomized neurons, whereas the red nucleus ipsilateral to it did not. Age-matched controls were subjected to the same procedures, but the gelfoam applied to the lesion site in the experimental animals was soaked only in the vehicle used to deliver BDNF. In all cases, labeled neurons were fewer in number in the red nucleus contralateral to the lesion than ipsilateral to it. It was of particular interest, however, that labeled neurons contralateral to the lesion were more numerous in the animals treated with BDNF than in the controls. We conclude that BDNF rescues at least some rubrospinal neurons from axotomy-induced cell death in developing opossums suggesting that loss of access to BDNF, and perhaps other neurotrophins, contributes to failure of rubrospinal neurons to survive axotomy.

  1. Red - take a closer look.

    Directory of Open Access Journals (Sweden)

    Vanessa L Buechner

    Full Text Available Color research has shown that red is associated with avoidance of threat (e.g., failure or approach of reward (e.g., mating depending on the context in which it is perceived. In the present study we explored one central cognitive process that might be involved in the context dependency of red associations. According to our theory, red is supposed to highlight the relevance (importance of a goal-related stimulus and correspondingly intensifies the perceivers' attentional reaction to it. Angry and happy human compared to non-human facial expressions were used as goal-relevant stimuli. The data indicate that the color red leads to enhanced attentional engagement to angry and happy human facial expressions (compared to neutral ones - the use of non-human facial expressions does not bias attention. The results are discussed with regard to the idea that red induced attentional biases might explain the red-context effects on motivation.

  2. Listening to Red

    Directory of Open Access Journals (Sweden)

    Sinazo Mtshemla

    Full Text Available Following a distinction John Mowitt draws between hearing (and phonics, and listening (and sonics, this article argues that the dominant notion of listening to sound was determined by the disciplinary framework of South African history and by the deployment of a cinematic documentary apparatus, both of which have served to disable the act of listening. The conditions of this hearing, and a deafness to a reduced or bracketed listening (Chion via Schaeffer that would enable us to think the post in post-apartheid differently, is thus at the centre of our concerns here. We stage a series of screenings of expected possible soundtracks for Simon Gush's film and installation Red, simultaneously tracking the ways that sound - and particularly music and dialogue - can be shown to hold a certain way of thinking both the political history of South Africa and the politics of South African history. We conclude by listening more closely to hiss and murmur in the soundtrack to Red and suggest this has major implications for considering ways of thinking and knowing.

  3. The Neuronal Ceroid-Lipofuscinoses

    Science.gov (United States)

    Bennett, Michael J.; Rakheja, Dinesh

    2013-01-01

    The neuronal ceroid-lipofuscinoses (NCL's, Batten disease) represent a group of severe neurodegenerative diseases, which mostly present in childhood. The phenotypes are similar and include visual loss, seizures, loss of motor and cognitive function, and early death. At autopsy, there is massive neuronal loss with characteristic storage in…

  4. The straintronic spin-neuron

    International Nuclear Information System (INIS)

    Biswas, Ayan K; Bandyopadhyay, Supriyo; Atulasimha, Jayasimha

    2015-01-01

    In artificial neural networks, neurons are usually implemented with highly dissipative CMOS-based operational amplifiers. A more energy-efficient implementation is a ‘spin-neuron’ realized with a magneto-tunneling junction (MTJ) that is switched with a spin-polarized current (representing weighted sum of input currents) that either delivers a spin transfer torque or induces domain wall motion in the soft layer of the MTJ to mimic neuron firing. Here, we propose and analyze a different type of spin-neuron in which the soft layer of the MTJ is switched with mechanical strain generated by a voltage (representing weighted sum of input voltages) and term it straintronic spin-neuron. It dissipates orders of magnitude less energy in threshold operations than the traditional current-driven spin neuron at 0 K temperature and may even be faster. We have also studied the room-temperature firing behaviors of both types of spin neurons and find that thermal noise degrades the performance of both types, but the current-driven type is degraded much more than the straintronic type if both are optimized for maximum energy-efficiency. On the other hand, if both are designed to have the same level of thermal degradation, then the current-driven version will dissipate orders of magnitude more energy than the straintronic version. Thus, the straintronic spin-neuron is superior to current-driven spin neurons. (paper)

  5. Signalling properties of identified deep cerebellar nuclear neurons related to eye and head movements in the alert cat.

    Science.gov (United States)

    Gruart, A; Delgado-García, J M

    1994-07-01

    1. The spike activity of deep cerebellar nuclear neurons was recorded in the alert cat during spontaneous and during vestibularly and visually induced eye movements. 2. Neurons were classified according to their location in the nuclei, their antidromic activation from projection sites, their sensitivity to eye position and velocity during spontaneous eye movements, and their responses to vestibular and optokinetic stimuli. 3. Type I EPV (eye position and velocity) neurons were located mainly in the posterior part of the fastigial nucleus and activated antidromically almost exclusively from the medial longitudinal fasciculus close to the oculomotor complex. These neurons, reported here for the first time, increased their firing rate during saccades and eye fixations towards the contralateral hemifield. Their position sensitivity to eye fixations in the horizontal plane was 5.3 +/- 2.6 spikes s-1 deg-1 (mean +/- S.D.). Eye velocity sensitivity during horizontal saccades was 0.71 +/- 0.52 spikes s-1 deg-1 s-1. Variability of their firing rate during a given eye fixation was higher than that shown by abducens motoneurons. 4. Type I EPV neurons increased their firing rate during ipsilateral head rotations at 0.5 Hz with a mean phase lead over eye position of 95.3 +/- 9.5 deg. They were also activated by contralateral optokinetic stimulation at 30 deg s-1. Their sensitivity to eye position and velocity in the horizontal plane during vestibular and optokinetic stimuli yielded values similar to those obtained for spontaneous eye movements. 5. Type II neurons were located in both fastigial and dentate nuclei and were activated antidromically from the restiform body, the medial longitudinal fasciculus close to the oculomotor complex, the red nucleus and the pontine nuclei. Type II neurons were not related to spontaneous eye movements. These neurons increased their firing rate in response to contralateral head rotation and during ipsilateral optokinetic stimulation, and

  6. Optimizing NTS-polyplex as a tool for gene transfer to cultured dopamine neurons.

    Directory of Open Access Journals (Sweden)

    Daniel Hernandez-Baltazar

    Full Text Available The study of signal transduction in dopamine (DA-containing neurons as well as the development of new therapeutic approaches for Parkinson's disease requires the selective expression of transgenes in such neurons. Here we describe optimization of the use of the NTS-polyplex, a gene carrier system taking advantage of neurotensin receptor internalization, to transfect mouse DA neurons in primary culture. The plasmids DsRed2 (4.7 kbp and VGLUT2-Venus (11 kbp were used to compare the ability of this carrier system to transfect plasmids of different sizes. We examined the impact of age of the neurons (1, 3, 5 and 8 days after seeding, of culture media used during the transfection (Neurobasal with B27 vs. conditioned medium and of three molar ratios of plasmid DNA to carrier. While the NTS-polyplex successfully transfected both plasmids in a control N1E-115 cell line, only the pDsRed2 plasmid could be transfected in primary cultured DA neurons. We achieved 20% transfection efficiency of pDsRed2 in DA neurons, with 80% cell viability. The transfection was demonstrated pharmacologically to be dependent on activation of neurotensin receptors and to be selective for DA neurons. The presence of conditioned medium for transfection was found to be required to insure cell viability. Highest transfection efficiency was achieved in the most mature neurons. In contrast, transfection with the VGLUT2-Venus plasmid produced cell damage, most likely due to the high molar ratios required, as evidenced by a 15% cell viability of DA neurons at the three molar ratios tested (1:36, 1:39 and 1:42. We conclude that, when used at molar ratios lower than 1:33, the NTS-polyplex can selectively transfect mature cultured DA neurons with only low levels of toxicity. Our results provide evidence that the NTS-polyplex has good potential for targeted gene delivery in cultured DA neurons, an in vitro system of great use for the screening of new therapeutic approaches for Parkinson

  7. Anatomical distribution of estrogen target neurons in turtle brain

    International Nuclear Information System (INIS)

    Kim, Y.S.; Stumpf, W.E.; Sar, M.

    1981-01-01

    Autoradiographic studies with [ 3 H]estradiol-17β in red-eared turtle (Pseudemys scripta elegans) show concentration and retention of radioactivity in nuclei of neurons in certain regions. Accumulations of estrogen target neurons exist in the periventricular brain with relationships to ventral extensions of the forebrain ventricles, including parolfactory, amygdaloid, septal, preoptic, hypothalamic and thalamic areas, as well as the dorsal ventricular ridge, the piriform cortex, and midbrain-pontine periaqueductal structures. The general anatomical pattern of distribution of estrogen target neurons corresponds to those observed not only in another reptile (Anolis carolinensis), but also in birds and mammals, as well as in teleosts and cyclostomes. In Pseudemys, which appears to display an intermediate degree of phylogenetic differentiation, the amygdaloid-septal-preoptic groups of estrogen target neurons constitute a continuum. In phylogenetic ascendency, e.g. in mammals, these cell populations are increasingly separated and distinct, while in phylogenetic descendency, e.g. in teleosts and cyclostomes, an amygdaloid group appears to be absent or contained within the septal-preoptic target cell population. (Auth.)

  8. Anatomical distribution of estrogen target neurons in turtle brain

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Y.S.; Stumpf, W.E.; Sar, M. (North Carolina Univ., Chapel Hill (USA))

    1981-12-28

    Autoradiographic studies with (/sup 3/H)estradiol-17..beta.. in red-eared turtle (Pseudemys scripta elegans) show concentration and retention of radioactivity in nuclei of neurons in certain regions. Accumulations of estrogen target neurons exist in the periventricular brain with relationships to ventral extensions of the forebrain ventricles, including parolfactory, amygdaloid, septal, preoptic, hypothalamic and thalamic areas, as well as the dorsal ventricular ridge, the piriform cortex, and midbrain-pontine periaqueductal structures. The general anatomical pattern of distribution of estrogen target neurons corresponds to those observed not only in another reptile (Anolis carolinensis), but also in birds and mammals, as well as in teleosts and cyclostomes. In Pseudemys, which appears to display an intermediate degree of phylogenetic differentiation, the amygdaloid-septal-preoptic groups of estrogen target neurons constitute a continuum. In phylogenetic ascendency, e.g. in mammals, these cell populations are increasingly separated and distinct, while in phylogenetic descendency, e.g. in teleosts and cyclostomes, an amygdaloid group appears to be absent or contained within the septal-preoptic target cell population.

  9. Modulatory Mechanism of Nociceptive Neuronal Activity by Dietary Constituent Resveratrol

    Directory of Open Access Journals (Sweden)

    Mamoru Takeda

    2016-10-01

    Full Text Available Changes to somatic sensory pathways caused by peripheral tissue, inflammation or injury can result in behavioral hypersensitivity and pathological pain, such as hyperalgesia. Resveratrol, a plant polyphenol found in red wine and various food products, is known to have several beneficial biological actions. Recent reports indicate that resveratrol can modulate neuronal excitability, including nociceptive sensory transmission. As such, it is possible that this dietary constituent could be a complementary alternative medicine (CAM candidate, specifically a therapeutic agent. The focus of this review is on the mechanisms underlying the modulatory effects of resveratrol on nociceptive neuronal activity associated with pain relief. In addition, we discuss the contribution of resveratrol to the relief of nociceptive and/or pathological pain and its potential role as a functional food and a CAM.

  10. Red Teaming: Past and Present

    National Research Council Canada - National Science Library

    Longbine, David F

    2008-01-01

    .... Key aspects of the Army red teaming definition are its emphasis on independent thinking, challenging organizational thinking, incorporating alternative perspectives, and incorporating alternative analysis...

  11. Neuronal discrimination capacity

    International Nuclear Information System (INIS)

    Deng Yingchun; Williams, Peter; Feng Jianfeng; Liu Feng

    2003-01-01

    We explore neuronal mechanisms of discriminating between masked signals. It is found that when the correlation between input signals is zero, the output signals are separable if and only if input signals are separable. With positively (negatively) correlated signals, the output signals are separable (mixed) even when input signals are mixed (separable). Exact values of discrimination capacity are obtained for two most interesting cases: the exactly balanced inhibitory and excitatory input case and the uncorrelated input case. Interestingly, the discrimination capacity obtained in these cases is independent of model parameters, input distribution and is universal. Our results also suggest a functional role of inhibitory inputs and correlated inputs or, more generally, the large variability of efferent spike trains observed in in vivo experiments: the larger the variability of efferent spike trains, the easier it is to discriminate between masked input signals

  12. Neuronal discrimination capacity

    Energy Technology Data Exchange (ETDEWEB)

    Deng Yingchun [Department of Mathematics, Hunan Normal University 410081, Changsha (China); COGS, University of Sussex at Brighton, BN1 9QH (United Kingdom); Williams, Peter; Feng Jianfeng [COGS, University of Sussex at Brighton, BN1 9QH (United Kingdom); Liu Feng [COGS, University of Sussex at Brighton, BN1 9QH (United Kingdom); Physics Department, Nanjing University (China)

    2003-12-19

    We explore neuronal mechanisms of discriminating between masked signals. It is found that when the correlation between input signals is zero, the output signals are separable if and only if input signals are separable. With positively (negatively) correlated signals, the output signals are separable (mixed) even when input signals are mixed (separable). Exact values of discrimination capacity are obtained for two most interesting cases: the exactly balanced inhibitory and excitatory input case and the uncorrelated input case. Interestingly, the discrimination capacity obtained in these cases is independent of model parameters, input distribution and is universal. Our results also suggest a functional role of inhibitory inputs and correlated inputs or, more generally, the large variability of efferent spike trains observed in in vivo experiments: the larger the variability of efferent spike trains, the easier it is to discriminate between masked input signals.

  13. Orexin neurons receive glycinergic innervations.

    Directory of Open Access Journals (Sweden)

    Mari Hondo

    Full Text Available Glycine, a nonessential amino-acid that acts as an inhibitory neurotransmitter in the central nervous system, is currently used as a dietary supplement to improve the quality of sleep, but its mechanism of action is poorly understood. We confirmed the effects of glycine on sleep/wakefulness behavior in mice when administered peripherally. Glycine administration increased non-rapid eye movement (NREM sleep time and decreased the amount and mean episode duration of wakefulness when administered in the dark period. Since peripheral administration of glycine induced fragmentation of sleep/wakefulness states, which is a characteristic of orexin deficiency, we examined the effects of glycine on orexin neurons. The number of Fos-positive orexin neurons markedly decreased after intraperitoneal administration of glycine to mice. To examine whether glycine acts directly on orexin neurons, we examined the effects of glycine on orexin neurons by patch-clamp electrophysiology. Glycine directly induced hyperpolarization and cessation of firing of orexin neurons. These responses were inhibited by a specific glycine receptor antagonist, strychnine. Triple-labeling immunofluorescent analysis showed close apposition of glycine transporter 2 (GlyT2-immunoreactive glycinergic fibers onto orexin-immunoreactive neurons. Immunoelectron microscopic analysis revealed that GlyT2-immunoreactive terminals made symmetrical synaptic contacts with somata and dendrites of orexin neurons. Double-labeling immunoelectron microscopy demonstrated that glycine receptor alpha subunits were localized in the postsynaptic membrane of symmetrical inhibitory synapses on orexin neurons. Considering the importance of glycinergic regulation during REM sleep, our observations suggest that glycine injection might affect the activity of orexin neurons, and that glycinergic inhibition of orexin neurons might play a role in physiological sleep regulation.

  14. International red meat trade.

    Science.gov (United States)

    Brester, Gary W; Marsh, John M; Plain, Ronald L

    2003-07-01

    The maturation of the US beef and pork markets and increasing consumer demands for convenience, safety, and nutrition suggests that the beef and pork industries must focus on product development and promotion. New marketing arrangements are developing that help coordinate production with consumer demands. The relative high levels of incomes in the United States are likely to increase the demands for branded products rather than increase total per capita consumption. Foreign markets represent the greatest opportunity for increased demand for commodity beef and pork products. Increasing incomes in developing countries will likely allow consumers to increase consumption of animal-source proteins. Real prices of beef and pork have declined substantially because of sagging domestic demand and increasing farm-level production technologies. Increasing US beef and pork exports have obviated some of the price declines. Pork attained a net export position from a quantity perspective in 1995. The United States continues to be a net importer of beef on a quantity basis but is close to becoming a net exporter in terms of value. By-products continue to play a critical role in determining the red meat trade balance and producer prices. The United States, however, must continue to become cost, price, and quality competitive with other suppliers and must secure additional market access if it is to sustain recent trade trends. Several trade tensions remain in the red meat industry. For example, mandated COOL will undoubtedly have domestic and international effects on the beef and pork sectors. Domestically, uncertainty regarding consumer demand responses or quality perceptions regarding product origin, as well as added processor-retailer costs will be nontrivial. How these factors balance out in terms of benefits versus costs to the industry is uncertain. From an international perspective, some beef and pork export suppliers to the United States could view required labeling as a

  15. Pulsating red variables

    International Nuclear Information System (INIS)

    Whitelock, P.A.

    1990-01-01

    The observational characteristics of pulsating red variables are reviewed with particular emphasis on the Miras. These variables represent the last stage in the evolution of stars on the Asymptotic Giant Branch (AGB). A large fraction of the IRAS sources in the Bulge are Mira variables and a subset of these are also OH/IR sources. Their periods range up to 720 days, though most are between 360 and 560 days. At a given period those stars with the highest pulsation amplitudes have the highest mass-loss rates; this is interpreted as evidence for a causal connection between mass-loss and pulsation. It is suggested that once an AGB star has become a Mira it will evolve with increasing pulsation amplitude and mass-loss, but with very little change of luminosity or logarithmic period. 26 refs

  16. Pathogenesis of motor neuron disease

    Institute of Scientific and Technical Information of China (English)

    Xuefei Wang

    2006-01-01

    OBJECTIVE: To summarize and analyze the factors and theories related to the attack of motor neuron disease, and comprehensively investigate the pathogenesis of motor neuron disease.DATA SOURCES: A search of Pubmed database was undertaken to identify articles about motor neuron disease published in English from January 1994 to June 2006 by using the keywords of "neurodegenerative diseases". Other literatures were collected by retrieving specific journals and articles.STUDY SELECTION: The data were checked primarily, articles related to the pathogenesis of motor neuron disease were involved, and those obviously irrelated to the articles were excluded.DATA EXTRACTION: Totally 54 articles were collected, 30 of them were involved, and the other 24 were excluded.DATA SYNTHESIS: The pathogenesis of motor neuron disease has multiple factors, and the present related theories included free radical oxidation, excitotoxicity, genetic and immune factors, lack of neurotrophic factor,injury of neurofilament, etc. The studies mainly come from transgenic animal models, cell culture in vitro and patients with familial motor neuron disease, but there are still many restrictions and disadvantages.CONCLUSION: It is necessary to try to find whether there is internal association among different mechanisms,comprehensively investigate the pathogenesis of motor neuron diseases, in order to provide reliable evidence for the clinical treatment.

  17. Volume tables for red alder.

    Science.gov (United States)

    Floyd A. Johnson; R. M. Kallander; Paul G. Lauterbach

    1949-01-01

    The increasing importance of red alder as a commercial species in the Pacific Northwest has prompted the three agencies listed above to pool their tree measurement data for the construction of standard regional red alder volume tables. The tables included here were based on trees from a variety of sites and form classes. Approximately one quarter of the total number of...

  18. Skeleton decay in red cedar

    Science.gov (United States)

    Kevin T. Smith; Jessie A. Glaeser

    2013-01-01

    Eastern red cedar (Juniperus virginiana) is a common tree species throughout the eastern United States and the Great Plains. Although “cedar” is in the common name, the scientifc name shows a botanical kinship to the juniper species of the American southwest. Red cedar can survive and thrive within a broad range of soil conditions, seasonal...

  19. Simulating synchronization in neuronal networks

    Science.gov (United States)

    Fink, Christian G.

    2016-06-01

    We discuss several techniques used in simulating neuronal networks by exploring how a network's connectivity structure affects its propensity for synchronous spiking. Network connectivity is generated using the Watts-Strogatz small-world algorithm, and two key measures of network structure are described. These measures quantify structural characteristics that influence collective neuronal spiking, which is simulated using the leaky integrate-and-fire model. Simulations show that adding a small number of random connections to an otherwise lattice-like connectivity structure leads to a dramatic increase in neuronal synchronization.

  20. Glial tumors with neuronal differentiation.

    Science.gov (United States)

    Park, Chul-Kee; Phi, Ji Hoon; Park, Sung-Hye

    2015-01-01

    Immunohistochemical studies for neuronal differentiation in glial tumors revealed subsets of tumors having both characteristics of glial and neuronal lineages. Glial tumors with neuronal differentiation can be observed with diverse phenotypes and histologic grades. The rosette-forming glioneuronal tumor of the fourth ventricle and papillary glioneuronal tumor have been newly classified as distinct disease entities. There are other candidates for classification, such as the glioneuronal tumor without pseudopapillary architecture, glioneuronal tumor with neuropil-like islands, and the malignant glioneuronal tumor. The clinical significance of these previously unclassified tumors should be confirmed. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Mechanosensing in hypothalamic osmosensory neurons.

    Science.gov (United States)

    Prager-Khoutorsky, Masha

    2017-11-01

    Osmosensory neurons are specialized cells activated by increases in blood osmolality to trigger thirst, secretion of the antidiuretic hormone vasopressin, and elevated sympathetic tone during dehydration. In addition to multiple extrinsic factors modulating their activity, osmosensory neurons are intrinsically osmosensitive, as they are activated by increased osmolality in the absence of neighboring cells or synaptic contacts. This intrinsic osmosensitivity is a mechanical process associated with osmolality-induced changes in cell volume. This review summarises recent findings revealing molecular mechanisms underlying the mechanical activation of osmosensory neurons and highlighting important roles of microtubules, actin, and mechanosensitive ion channels in this process. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. From Neurons to Brain: Adaptive Self-Wiring of Neurons

    OpenAIRE

    Segev, Ronen; Ben-Jacob, Eshel

    1998-01-01

    During embryonic morpho-genesis, a collection of individual neurons turns into a functioning network with unique capabilities. Only recently has this most staggering example of emergent process in the natural world, began to be studied. Here we propose a navigational strategy for neurites growth cones, based on sophisticated chemical signaling. We further propose that the embryonic environment (the neurons and the glia cells) acts as an excitable media in which concentric and spiral chemical ...

  3. The neuroprotective role and mechanisms of TERT in neurons with oxygen-glucose deprivation.

    Science.gov (United States)

    Li, J; Qu, Y; Chen, D; Zhang, L; Zhao, F; Luo, L; Pan, L; Hua, J; Mu, D

    2013-11-12

    Telomerase reverse transcriptase (TERT) is reported to protect neurons from apoptosis induced by various stresses including hypoxia-ischemia (HI). However, the mechanisms by which TERT exerts its anti-apoptotic role in neurons with HI injury remain unclear. In this study, we examined the protective role and explored the possible mechanisms of TERT in neurons with HI injury in vitro. Primary cultured neurons were exposed to oxygen and glucose deprivation (OGD) for 3h followed by reperfusion to mimic HI injury in vivo. Plasmids containing TERT antisense, sense nucleotides, or mock were transduced into neurons at 48h before OGD. Expression and distribution of TERT were measured by immunofluorescence labeling and western blot. The expression of cleaved caspase 3 (CC3), Bcl-2 and Bax were detected by western blot. Neuronal apoptosis was measured with terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL). The mitochondrial reactive oxygen species (ROS) were measured by MitoSOX Red staining. Fluorescent probe JC-1 was used to measure the mitochondrial membrane potential (ΔΨm). We found that TERT expression increased at 8h and peaked at 24h in neurons after OGD. CC3 expression and neuronal apoptosis were induced and peaked at 24h after OGD. TERT inhibition significantly increased CC3 expression and neuronal apoptosis after OGD treatment. Additionally, TERT inhibition decreased the expression ratio of Bcl-2/Bax, and enhanced ROS production and ΔΨm dissipation after OGD. These data suggest that TERT plays a neuroprotective role via anti-apoptosis in neurons after OGD. The underlying mechanisms may be associated with regulating Bcl-2/Bax expression ratio, attenuating ROS generation, and increasing mitochondrial membrane potential. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

  4. Imaging of intracranial neuronal and mixed neuronal-glial tumours

    International Nuclear Information System (INIS)

    Cui Shimin; Qin Jinxi; Zhang Leili; Liu Meili; Jin Song; Yan Shixin; Liu Li; Dai Weiying; Li Tao; Gao Man

    2001-01-01

    Objective: To investigate the characteristic clinical, imaging , and pathologic findings of intracranial neuronal and mixed neuronal-glial tumours. Methods: The imaging findings of surgery and pathobiology proved intracranial neuronal and mixed neuronal-glial tumours in 14 cases (7 male and 7 female, ranging in age from 6-56 years; mean age 33.8 years) were retrospectively analyzed. Results: Eight gangliogliomas were located in the frontal lobe (4 cases), temporal lobe (1 case), front- temporal lobe (2 cases), and pons (1 case). They appeared as iso-or low density on CT, iso-or low signal intensity on T 1 WI, and high signal intensity on T 2 WI on MR imaging. Two central neurocytomas were located in the supratentorial ventricles. Four desmoplastic gangliogliomas were seen as cystic masses, appearing as low signal intensity on T 1 WI and high signal intensity on T 2 WI. Conclusion: Intracranial neuronal and mixed neuronal-glial tumours had imaging characteristics. Combined with clinical history, it was possible to make a tendency preoperative diagnosis using CT or MR

  5. Tinbergen on mirror neurons

    Science.gov (United States)

    Heyes, Cecilia

    2014-01-01

    Fifty years ago, Niko Tinbergen defined the scope of behavioural biology with his four problems: causation, ontogeny, survival value and evolution. About 20 years ago, there was another highly significant development in behavioural biology—the discovery of mirror neurons (MNs). Here, I use Tinbergen's original four problems (rather than the list that appears in textbooks) to highlight the differences between two prominent accounts of MNs, the genetic and associative accounts; to suggest that the latter provides the defeasible ‘best explanation’ for current data on the causation and ontogeny of MNs; and to argue that functional analysis, of the kind that Tinbergen identified somewhat misleadingly with studies of ‘survival value’, should be a high priority for future research. In this kind of functional analysis, system-level theories would assign MNs a small, but potentially important, role in the achievement of action understanding—or another social cognitive function—by a production line of interacting component processes. These theories would be tested by experimental intervention in human and non-human animal samples with carefully documented and controlled developmental histories. PMID:24778376

  6. Neurons on the couch.

    Science.gov (United States)

    Marić, Nadja P; Jašović-Gašić, Miroslava

    2010-12-01

    A hundred years after psychoanalysis was introduced, neuroscience has taken a giant step forward. It seems nowadays that effects of psychotherapy could be monitored and measured by state-of-the art brain imaging techniques. Today, the psychotherapy is considered as a strategic and purposeful environmental influence intended to enhance learning. Since gene expression is regulated by environmental influences throughout life and these processes create brain architecture and influence the strength of synaptic connections, psychotherapy (as a kind of learning) should be explored in the context of aforementioned paradigm. In other words, when placing a client on the couch, therapist actually placed client's neuronal network; while listening and talking, expressing and analyzing, experiencing transference and counter transference, therapist tends to stabilize synaptic connections and influence dendritic growth by regulating gene-transcriptional activity. Therefore, we strongly believe that, in the near future, an increasing knowledge on cellular and molecular interactions and mechanisms of action of different psycho- and pharmaco-therapeutic procedures will enable us to tailor a sophisticated therapeutic approach toward a person, by combining major therapeutic strategies in psychiatry on the basis of rational goals and evidence-based therapeutic expectations.

  7. Tinbergen on mirror neurons.

    Science.gov (United States)

    Heyes, Cecilia

    2014-01-01

    Fifty years ago, Niko Tinbergen defined the scope of behavioural biology with his four problems: causation, ontogeny, survival value and evolution. About 20 years ago, there was another highly significant development in behavioural biology-the discovery of mirror neurons (MNs). Here, I use Tinbergen's original four problems (rather than the list that appears in textbooks) to highlight the differences between two prominent accounts of MNs, the genetic and associative accounts; to suggest that the latter provides the defeasible 'best explanation' for current data on the causation and ontogeny of MNs; and to argue that functional analysis, of the kind that Tinbergen identified somewhat misleadingly with studies of 'survival value', should be a high priority for future research. In this kind of functional analysis, system-level theories would assign MNs a small, but potentially important, role in the achievement of action understanding-or another social cognitive function-by a production line of interacting component processes. These theories would be tested by experimental intervention in human and non-human animal samples with carefully documented and controlled developmental histories.

  8. Understanding Neuronal Mechanisms of Epilepsy ...

    Indian Academy of Sciences (India)

    Admin

    α subunit of Rat Brain type IIA Voltage Gated Sodium Channel and geneticin selection ..... scaling the mother wavelet. Scale = 1/ .... through dynamic clamp. Dynamic Clamp ... It has been shown that like in vivo neurons, cortical networks in.

  9. Imitation, mirror neurons and autism.

    Science.gov (United States)

    Williams, J H; Whiten, A; Suddendorf, T; Perrett, D I

    2001-06-01

    Various deficits in the cognitive functioning of people with autism have been documented in recent years but these provide only partial explanations for the condition. We focus instead on an imitative disturbance involving difficulties both in copying actions and in inhibiting more stereotyped mimicking, such as echolalia. A candidate for the neural basis of this disturbance may be found in a recently discovered class of neurons in frontal cortex, 'mirror neurons' (MNs). These neurons show activity in relation both to specific actions performed by self and matching actions performed by others, providing a potential bridge between minds. MN systems exist in primates without imitative and 'theory of mind' abilities and we suggest that in order for them to have become utilized to perform social cognitive functions, sophisticated cortical neuronal systems have evolved in which MNs function as key elements. Early developmental failures of MN systems are likely to result in a consequent cascade of developmental impairments characterised by the clinical syndrome of autism.

  10. Information processing by neuronal populations

    National Research Council Canada - National Science Library

    Hölscher, Christian; Munk, Matthias

    2009-01-01

    ... simultaneously recorded spike trains 120 Mark Laubach, Nandakumar S. Narayanan, and Eyal Y. Kimchi Part III Neuronal population information coding and plasticity in specific brain areas 149 7 F...

  11. Chimera states in bursting neurons

    OpenAIRE

    Bera, Bidesh K.; Ghosh, Dibakar; Lakshmanan, M.

    2015-01-01

    We study the existence of chimera states in pulse-coupled networks of bursting Hindmarsh-Rose neurons with nonlocal, global and local (nearest neighbor) couplings. Through a linear stability analysis, we discuss the behavior of stability function in the incoherent (i.e. disorder), coherent, chimera and multi-chimera states. Surprisingly, we find that chimera and multi-chimera states occur even using local nearest neighbor interaction in a network of identical bursting neurons alone. This is i...

  12. Romantic red: red enhances men's attraction to women.

    Science.gov (United States)

    Elliot, Andrew J; Niesta, Daniela

    2008-11-01

    In many nonhuman primates, the color red enhances males' attraction to females. In 5 experiments, the authors demonstrate a parallel effect in humans: Red, relative to other achromatic and chromatic colors, leads men to view women as more attractive and more sexually desirable. Men seem unaware of this red effect, and red does not influence women's perceptions of the attractiveness of other women, nor men's perceptions of women's overall likeability, kindness, or intelligence. The findings have clear practical implications for men and women in the mating game and, perhaps, for fashion consultants, product designers, and marketers. Furthermore, the findings document the value of extending research on signal coloration to humans and of considering color as something of a common language, both within and across species. (c) 2008 APA, all rights reserved.

  13. Communication among neurons.

    Science.gov (United States)

    Marner, Lisbeth

    2012-04-01

    The communication among neurons is the prerequisite for the working brain. To understand the cellular, neurochemical, and structural basis of this communication, and the impacts of aging and disease on brain function, quantitative measures are necessary. This thesis evaluates several quantitative neurobiological methods with respect to possible bias and methodological issues. Stereological methods are suited for the unbiased estimation of number, length, and volumes of components of the nervous system. Stereological estimates of the total length of myelinated nerve fibers were made in white matter of post mortem brains, and the impact of aging and diseases as Schizophrenia and Alzheimer's disease were evaluated. Although stereological methods are in principle unbiased, shrinkage artifacts are difficult to account for. Positron emission tomography (PET) recordings, in conjunction with kinetic modeling, permit the quantitation of radioligand binding in brain. The novel serotonin 5-HT4 antagonist [11C]SB207145 was used as an example of the validation process for quantitative PET receptor imaging. Methods based on reference tissue as well as methods based on an arterial plasma input function were evaluated with respect to precision and accuracy. It was shown that [11C]SB207145 binding had high sensitivity to occupancy by unlabeled ligand, necessitating high specific activity in the radiosynthesis to avoid bias. The established serotonin 5-HT2A ligand [18F]altanersin was evaluated in a two-year follow-up study in elderly subjects. Application of partial volume correction of the PET data diminished the reliability of the measures, but allowed for the correct distinction between changes due to brain atrophy and receptor availability. Furthermore, a PET study of patients with Alzheimer's disease with the serotonin transporter ligand [11C]DASB showed relatively preserved serotonergic projections, despite a marked decrease in 5-HT2A receptor binding. Possible confounders are

  14. Red Yeast Rice: An Introduction

    Science.gov (United States)

    ... rice are used in food products in Chinese cuisine, including Peking duck. Others have been sold as ... Medicine . 2010;170(19):1722–1727. Halbert SC, French B, Gordon RY, et al. Tolerability of red ...

  15. Learning of time series through neuron-to-neuron instruction

    Energy Technology Data Exchange (ETDEWEB)

    Miyazaki, Y [Department of Physics, Kyoto University, Kyoto 606-8502, (Japan); Kinzel, W [Institut fuer Theoretische Physik, Universitaet Wurzburg, 97074 Wurzburg (Germany); Shinomoto, S [Department of Physics, Kyoto University, Kyoto (Japan)

    2003-02-07

    A model neuron with delayline feedback connections can learn a time series generated by another model neuron. It has been known that some student neurons that have completed such learning under the instruction of a teacher's quasi-periodic sequence mimic the teacher's time series over a long interval, even after instruction has ceased. We found that in addition to such faithful students, there are unfaithful students whose time series eventually diverge exponentially from that of the teacher. In order to understand the circumstances that allow for such a variety of students, the orbit dimension was estimated numerically. The quasi-periodic orbits in question were found to be confined in spaces with dimensions significantly smaller than that of the full phase space.

  16. Learning of time series through neuron-to-neuron instruction

    International Nuclear Information System (INIS)

    Miyazaki, Y; Kinzel, W; Shinomoto, S

    2003-01-01

    A model neuron with delayline feedback connections can learn a time series generated by another model neuron. It has been known that some student neurons that have completed such learning under the instruction of a teacher's quasi-periodic sequence mimic the teacher's time series over a long interval, even after instruction has ceased. We found that in addition to such faithful students, there are unfaithful students whose time series eventually diverge exponentially from that of the teacher. In order to understand the circumstances that allow for such a variety of students, the orbit dimension was estimated numerically. The quasi-periodic orbits in question were found to be confined in spaces with dimensions significantly smaller than that of the full phase space

  17. "Congo" red: out of Africa?

    Science.gov (United States)

    Steensma, D P

    2001-02-01

    Congo red is the essential histologic stain for demonstrating the presence of amyloidosis in fixed tissues. To the best of my knowledge, nothing has been written about why the stain is named "Congo." To understand the etymology and history of the Congo red histologic stain. Primary sources were consulted extensively, including 19th-century corporate documents, newspapers, legal briefs, patents, memoirs, and scientific papers. Sources were obtained from multiple university libraries and German corporate archives. To Europeans in 1885, the word Congo evoked exotic images of far-off central Africa known as The Dark Continent. The African Congo was also a political flashpoint during the Age of Colonialism. "Congo" red was introduced in Berlin in 1885 as the first of the economically lucrative direct textile dyes. A patent on Congo red was filed by the AGFA Corporation of Berlin 3 weeks after the conclusion of the well-publicized Berlin West Africa Conference. During these important diplomatic talks, German Chancellor Otto von Bismarck presided over a discussion of free trade issues in the Congo River basin. A challenge to AGFA's Congo red patent led to a precedent-setting decision in intellectual property law. The Congo red stain was named "Congo" for marketing purposes by a German textile dyestuff company in 1885, reflecting geopolitical current events of that time.

  18. Trained neurons-based motion detection in optical camera communications

    Science.gov (United States)

    Teli, Shivani; Cahyadi, Willy Anugrah; Chung, Yeon Ho

    2018-04-01

    A concept of trained neurons-based motion detection (TNMD) in optical camera communications (OCC) is proposed. The proposed TNMD is based on neurons present in a neural network that perform repetitive analysis in order to provide efficient and reliable motion detection in OCC. This efficient motion detection can be considered another functionality of OCC in addition to two traditional functionalities of illumination and communication. To verify the proposed TNMD, the experiments were conducted in an indoor static downlink OCC, where a mobile phone front camera is employed as the receiver and an 8 × 8 red, green, and blue (RGB) light-emitting diode array as the transmitter. The motion is detected by observing the user's finger movement in the form of centroid through the OCC link via a camera. Unlike conventional trained neurons approaches, the proposed TNMD is trained not with motion itself but with centroid data samples, thus providing more accurate detection and far less complex detection algorithm. The experiment results demonstrate that the TNMD can detect all considered motions accurately with acceptable bit error rate (BER) performances at a transmission distance of up to 175 cm. In addition, while the TNMD is performed, a maximum data rate of 3.759 kbps over the OCC link is obtained. The OCC with the proposed TNMD combined can be considered an efficient indoor OCC system that provides illumination, communication, and motion detection in a convenient smart home environment.

  19. The mirror-neuron system.

    Science.gov (United States)

    Rizzolatti, Giacomo; Craighero, Laila

    2004-01-01

    A category of stimuli of great importance for primates, humans in particular, is that formed by actions done by other individuals. If we want to survive, we must understand the actions of others. Furthermore, without action understanding, social organization is impossible. In the case of humans, there is another faculty that depends on the observation of others' actions: imitation learning. Unlike most species, we are able to learn by imitation, and this faculty is at the basis of human culture. In this review we present data on a neurophysiological mechanism--the mirror-neuron mechanism--that appears to play a fundamental role in both action understanding and imitation. We describe first the functional properties of mirror neurons in monkeys. We review next the characteristics of the mirror-neuron system in humans. We stress, in particular, those properties specific to the human mirror-neuron system that might explain the human capacity to learn by imitation. We conclude by discussing the relationship between the mirror-neuron system and language.

  20. Neuronal factors determining high intelligence.

    Science.gov (United States)

    Dicke, Ursula; Roth, Gerhard

    2016-01-05

    Many attempts have been made to correlate degrees of both animal and human intelligence with brain properties. With respect to mammals, a much-discussed trait concerns absolute and relative brain size, either uncorrected or corrected for body size. However, the correlation of both with degrees of intelligence yields large inconsistencies, because although they are regarded as the most intelligent mammals, monkeys and apes, including humans, have neither the absolutely nor the relatively largest brains. The best fit between brain traits and degrees of intelligence among mammals is reached by a combination of the number of cortical neurons, neuron packing density, interneuronal distance and axonal conduction velocity--factors that determine general information processing capacity (IPC), as reflected by general intelligence. The highest IPC is found in humans, followed by the great apes, Old World and New World monkeys. The IPC of cetaceans and elephants is much lower because of a thin cortex, low neuron packing density and low axonal conduction velocity. By contrast, corvid and psittacid birds have very small and densely packed pallial neurons and relatively many neurons, which, despite very small brain volumes, might explain their high intelligence. The evolution of a syntactical and grammatical language in humans most probably has served as an additional intelligence amplifier, which may have happened in songbirds and psittacids in a convergent manner. © 2015 The Author(s).

  1. Energy Model of Neuron Activation.

    Science.gov (United States)

    Romanyshyn, Yuriy; Smerdov, Andriy; Petrytska, Svitlana

    2017-02-01

    On the basis of the neurophysiological strength-duration (amplitude-duration) curve of neuron activation (which relates the threshold amplitude of a rectangular current pulse of neuron activation to the pulse duration), as well as with the use of activation energy constraint (the threshold curve corresponds to the energy threshold of neuron activation by a rectangular current pulse), an energy model of neuron activation by a single current pulse has been constructed. The constructed model of activation, which determines its spectral properties, is a bandpass filter. Under the condition of minimum-phase feature of the neuron activation model, on the basis of Hilbert transform, the possibilities of phase-frequency response calculation from its amplitude-frequency response have been considered. Approximation to the amplitude-frequency response by the response of the Butterworth filter of the first order, as well as obtaining the pulse response corresponding to this approximation, give us the possibility of analyzing the efficiency of activating current pulses of various shapes, including analysis in accordance with the energy constraint.

  2. Habitability of planets around red dwarf stars.

    Science.gov (United States)

    Heath, M J; Doyle, L R; Joshi, M M; Haberle, R M

    1999-08-01

    Recent models indicate that relatively moderate climates could exist on Earth-sized planets in synchronous rotation around red dwarf stars. Investigation of the global water cycle, availability of photosynthetically active radiation in red dwarf sunlight, and the biological implications of stellar flares, which can be frequent for red dwarfs, suggests that higher plant habitability of red dwarf planets may be possible.

  3. Silvical characteristics of red maple (Acer rubrum)

    Science.gov (United States)

    Russell J. Hutnik; Harry W. Yawney

    1961-01-01

    Red maple (Acer rubrum L.) is also known as Carolina red maple, scarlet maple, soft maple, swamp maple, water maple, and white maple. Taxonomists recognize several varieties of red maple. The most common is Drummond red maple (Acer rubrum var. drummondii (Hook, & Arn.) Sarg.).

  4. Resveratrol Produces Neurotrophic Effects on Cultured Dopaminergic Neurons through Prompting Astroglial BDNF and GDNF Release

    Directory of Open Access Journals (Sweden)

    Feng Zhang

    2012-01-01

    Full Text Available Increasing evidence indicated astroglia-derived neurotrophic factors generation might hold a promising therapy for Parkinson’s disease (PD. Resveratrol, naturally present in red wine and grapes with potential benefit for health, is well known to possess a number of pharmacological activities. Besides the antineuroinflammatory properties, we hypothesized the neuroprotective potency of resveratrol is partially due to its additional neurotrophic effects. Here, primary rat midbrain neuron-glia cultures were applied to investigate the neurotrophic effects mediated by resveratrol on dopamine (DA neurons and further explore the role of neurotrophic factors in its actions. Results showed resveratrol produced neurotrophic effects on cultured DA neurons. Additionally, astroglia-derived neurotrophic factors release was responsible for resveratrol-mediated neurotrophic properties as evidenced by the following observations: (1 resveratrol failed to exert neurotrophic effects on DA neurons in the cultures without astroglia; (2 the astroglia-conditioned medium prepared from astroglia-enriched cultures treated with resveratrol produced neurotrophic effects in neuron-enriched cultures; (3 resveratrol increased neurotrophic factors release in the concentration- and time-dependent manners; (4 resveratrol-mediated neurotrophic effects were suppressed by blocking the action of the neurotrophic factors. Together, resveratrol could produce neurotrophic effects on DA neurons through prompting neurotrophic factors release, and these effects might open new alternative avenues for neurotrophic factor-based therapy targeting PD.

  5. Piezo Is Essential for Amiloride-Sensitive Stretch-Activated Mechanotransduction in Larval Drosophila Dorsal Bipolar Dendritic Sensory Neurons.

    Science.gov (United States)

    Suslak, Thomas J; Watson, Sonia; Thompson, Karen J; Shenton, Fiona C; Bewick, Guy S; Armstrong, J Douglas; Jarman, Andrew P

    2015-01-01

    Stretch-activated afferent neurons, such as those of mammalian muscle spindles, are essential for proprioception and motor co-ordination, but the underlying mechanisms of mechanotransduction are poorly understood. The dorsal bipolar dendritic (dbd) sensory neurons are putative stretch receptors in the Drosophila larval body wall. We have developed an in vivo protocol to obtain receptor potential recordings from intact dbd neurons in response to stretch. Receptor potential changes in dbd neurons in response to stretch showed a complex, dynamic profile with similar characteristics to those previously observed for mammalian muscle spindles. These profiles were reproduced by a general in silico model of stretch-activated neurons. This in silico model predicts an essential role for a mechanosensory cation channel (MSC) in all aspects of receptor potential generation. Using pharmacological and genetic techniques, we identified the mechanosensory channel, DmPiezo, in this functional role in dbd neurons, with TRPA1 playing a subsidiary role. We also show that rat muscle spindles exhibit a ruthenium red-sensitive current, but found no expression evidence to suggest that this corresponds to Piezo activity. In summary, we show that the dbd neuron is a stretch receptor and demonstrate that this neuron is a tractable model for investigating mechanisms of mechanotransduction.

  6. Turning skin into dopamine neurons

    Institute of Scientific and Technical Information of China (English)

    Malin Parmar; Johan Jakobsson

    2011-01-01

    The possibility to generate neurons from fibroblasts became a reality with the development of iPS technology a few years ago.By reprogramming somatic cells using transcription factor (TF) overexpression,it is possible to generate pluripotent stem cells that then can be differentiated into any somatic cell type including various subtypes of neurons.This raises the possibility of using donor-matched or even patientspecific cells for cell therapy of neurological disorders such as Parkinson's disease (PD),Huntington's disease and stroke.Supporting this idea,dopamine neurons,which are the cells dying in PD,derived from human iPS cells have been demonstrated to survive transplantation and reverse motor symptoms in animal models of PD [1].

  7. Neuronal involvement in cisplatin neuropathy

    DEFF Research Database (Denmark)

    Krarup-Hansen, A; Helweg-Larsen, Susanne Elisabeth; Schmalbruch, H

    2007-01-01

    of large dorsal root ganglion cells. Motor conduction studies, autonomic function and warm and cold temperature sensation remained unchanged at all doses of cisplatin treatment. The results of these studies are consistent with degeneration of large sensory neurons whereas there was no evidence of distal......Although it is well known that cisplatin causes a sensory neuropathy, the primary site of involvement is not established. The clinical symptoms localized in a stocking-glove distribution may be explained by a length dependent neuronopathy or by a distal axonopathy. To study whether the whole neuron...

  8. Acetaminophen inhibits neuronal inflammation and protects neurons from oxidative stress

    Directory of Open Access Journals (Sweden)

    Grammas Paula

    2009-03-01

    Full Text Available Abstract Background Recent studies have demonstrated a link between the inflammatory response, increased cytokine formation, and neurodegeneration in the brain. The beneficial effects of anti-inflammatory drugs in neurodegenerative diseases, such as Alzheimer's disease (AD, have been documented. Increasing evidence suggests that acetaminophen has unappreciated anti-oxidant and anti-inflammatory properties. The objectives of this study are to determine the effects of acetaminophen on cultured brain neuronal survival and inflammatory factor expression when exposed to oxidative stress. Methods Cerebral cortical cultured neurons are pretreated with acetaminophen and then exposed to the superoxide-generating compound menadione (5 μM. Cell survival is assessed by MTT assay and inflammatory protein (tumor necrosis factor alpha, interleukin-1, macrophage inflammatory protein alpha, and RANTES release quantitated by ELISA. Expression of pro- and anti-apoptotic proteins is assessed by western blots. Results Acetaminophen has pro-survival effects on neurons in culture. Menadione, a superoxide releasing oxidant stressor, causes a significant (p Conclusion These data show that acetaminophen has anti-oxidant and anti-inflammatory effects on neurons and suggest a heretofore unappreciated therapeutic potential for this drug in neurodegenerative diseases such as AD that are characterized by oxidant and inflammatory stress.

  9. Neuronal coherence and its functional role in communication between neurons

    NARCIS (Netherlands)

    Zeitler-Geurds, M.

    2010-01-01

    Neuronal oscillations are observed in many brain areas in various frequency bands. Each of the frequency bands is associated with a particular functional role. Gamma oscillations (30-80 Hz) are thought to be related to cognitive tasks like memory and attention and possibly also involved in the

  10. DAVs: Red Edge and Outbursts

    Science.gov (United States)

    Luan, Jing

    2018-04-01

    As established by ground based surveys, white dwarfs with hydrogen atmospheres pulsate as they cool across the temperature range, 12500Kred edge is a two-decade old puzzle. Recently, Kepler discovered a number of cool DAVs exhibiting sporadic outbursts separated by days, each lasting several hours, and releasing \\sim 10^{33}-10^{34} {erg}. We provide quantitative explanations for both the red edge and the outbursts. The minimal frequency for overstable modes rises abruptly near the red edge. Although high frequency overstable modes exist below the red edge, their photometric amplitudes are generally too small to be detected by ground based observations. Nevertheless, these overstable parent modes can manifest themselves through nonlinear mode couplings to damped daughter modes which generate limit cycles giving rise to photometric outbursts.

  11. Unbalanced Neuronal Circuits in Addiction

    OpenAIRE

    Volkow, Nora D.; Wang, Gen-Jack; Tomasi, Dardo; Baler, Ruben D.

    2013-01-01

    Through sequential waves of drug-induced neurochemical stimulation, addiction co-opts the brain's neuronal circuits that mediate reward, motivation, , to behavioral inflexibility and a severe disruption of self-control and compulsive drug intake. Brain imaging technologies have allowed neuroscientists to map out the neural landscape of addiction in the human brain and to understand how drugs modify it.

  12. Computing with Spiking Neuron Networks

    NARCIS (Netherlands)

    H. Paugam-Moisy; S.M. Bohte (Sander); G. Rozenberg; T.H.W. Baeck (Thomas); J.N. Kok (Joost)

    2012-01-01

    htmlabstractAbstract Spiking Neuron Networks (SNNs) are often referred to as the 3rd gener- ation of neural networks. Highly inspired from natural computing in the brain and recent advances in neurosciences, they derive their strength and interest from an ac- curate modeling of synaptic interactions

  13. What do mirror neurons mirror?

    NARCIS (Netherlands)

    Uithol, S.; Rooij, I.J.E.I. van; Bekkering, H.; Haselager, W.F.G.

    2011-01-01

    Single cell recordings in monkeys provide strong evidence for an important role of the motor system in action understanding. This evidence is backed up by data from studies of the (human) mirror neuron system using neuroimaging or TMS techniques, and behavioral experiments. Although the data

  14. Optimal compensation for neuron loss

    Science.gov (United States)

    Barrett, David GT; Denève, Sophie; Machens, Christian K

    2016-01-01

    The brain has an impressive ability to withstand neural damage. Diseases that kill neurons can go unnoticed for years, and incomplete brain lesions or silencing of neurons often fail to produce any behavioral effect. How does the brain compensate for such damage, and what are the limits of this compensation? We propose that neural circuits instantly compensate for neuron loss, thereby preserving their function as much as possible. We show that this compensation can explain changes in tuning curves induced by neuron silencing across a variety of systems, including the primary visual cortex. We find that compensatory mechanisms can be implemented through the dynamics of networks with a tight balance of excitation and inhibition, without requiring synaptic plasticity. The limits of this compensatory mechanism are reached when excitation and inhibition become unbalanced, thereby demarcating a recovery boundary, where signal representation fails and where diseases may become symptomatic. DOI: http://dx.doi.org/10.7554/eLife.12454.001 PMID:27935480

  15. Hypothalamic neurones governing glucose homeostasis.

    Science.gov (United States)

    Coppari, R

    2015-06-01

    The notion that the brain directly controls the level of glucose in the blood (glycaemia) independent of its known action on food intake and body weight has been known ever since 1849. That year, the French physiologist Dr Claude Bernard reported that physical puncture of the floor of the fourth cerebral ventricle rapidly leads to an increased level of sugar in the blood (and urine) in rabbits. Despite this important discovery, it took approximately 150 years before significant efforts aimed at understanding the underlying mechanism of brain-mediated control of glucose metabolism were made. Technological developments allowing for genetically-mediated manipulation of selected molecular pathways in a neurone-type-specific fashion unravelled the importance of specific molecules in specific neuronal populations. These neuronal pathways govern glucose metabolism in the presence and even in the absence of insulin. Also, a peculiarity of these pathways is that certain biochemically-defined neurones govern glucose metabolism in a tissue-specific fashion. © 2015 British Society for Neuroendocrinology.

  16. Red nucleus and rubrospinal tract disorganization in the absence of Pou4f1

    Science.gov (United States)

    Martinez-Lopez, Jesus E.; Moreno-Bravo, Juan A.; Madrigal, M. Pilar; Martinez, Salvador; Puelles, Eduardo

    2015-01-01

    The red nucleus (RN) is a neuronal population that plays an important role in forelimb motor control and locomotion. Histologically it is subdivided into two subpopulations, the parvocellular RN (pRN) located in the diencephalon and the magnocellular RN (mRN) in the mesencephalon. The RN integrates signals from motor cortex and cerebellum and projects to spinal cord interneurons and motor neurons through the rubrospinal tract (RST). Pou4f1 is a transcription factor highly expressed in this nucleus that has been related to its specification. Here we profoundly analyzed consequences of Pou4f1 loss-of-function in development, maturation and axonal projection of the RN. Surprisingly, RN neurons are specified and maintained in the mutant, no cell death was detected. Nevertheless, the nucleus appeared disorganized with a strong delay in radial migration and with a wider neuronal distribution; the neurons did not form a compacted population as they do in controls, Robo1 and Slit2 were miss-expressed. Cplx1 and Npas1, expressed in the RN, are transcription factors involved in neurotransmitter release, neuronal maturation and motor function processes among others. In our mutant mice, both transcription factors are lost, suggesting an abnormal maturation of the RN. The resulting altered nucleus occupied a wider territory. Finally, we examined RST development and found that the RN neurons were able to project to the spinal cord but their axons appeared defasciculated. These data suggest that Pou4f1 is necessary for the maturation of RN neurons but not for their specification and maintenance. PMID:25698939

  17. Red Plague Control Plan (RPCP)

    Science.gov (United States)

    Cooke, Robert W.

    2010-01-01

    SCOPE: Prescribes the minimum requirements for the control of cuprous / cupric oxide corrosion (a.k.a. Red Plague) of silver-coated copper wire, cable, and harness assemblies. PURPOSE: Targeted for applications where exposure to assembly processes, environmental conditions, and contamination may promote the development of cuprous / cupric oxide corrosion (a.k.a. Red Plague) in silver-coated copper wire, cable, and harness assemblies. Does not exclude any alternate or contractor-proprietary documents or processes that meet or exceed the baseline of requirements established by this document. Use of alternate or contractor-proprietary documents or processes shall require review and prior approval of the procuring NASA activity.

  18. Red de senderos universitarios inteligentes

    OpenAIRE

    Ibarra-Berrocal, I.J.; Romero, J.; Pérez, J.

    2017-01-01

    Introducción: El Proyecto de red de senderos universitarios inteligentes UR se inspira en tres realidades, la red de senderos europeos ya existentes y su importancia en el fomento de la actividad deportiva y los hábitos saludables, la creciente importancia de la implantación, intercambio y difusión de políticas y planes de acción en materia de sostenibilidad ambiental en el ámbito universitario europeo, y por último, el uso y desarrollo de infraestructuras y aplicaciones, cada vez más impresc...

  19. Seguridad en una red universitaria

    OpenAIRE

    Bernal España, Juan Antonio

    2014-01-01

    Las redes de comunicaciones son muy importantes para las empresas. Se solicita una red de altas prestaciones que pueda llevar muchos sistemas sobre ella (cámaras de seguridad, video, voz, datos, SCADA, wifi). Ahora también necesitamos que la red sea segura. Cuando hablamos de seguridad no solo nos referimos a evitar ataques o virus, también hablamos de cómo puede afectarnos el incendio de un centro de proceso de datos. Basándonos en la ISO 27001:2013 daremos las principales pau...

  20. BlastNeuron for Automated Comparison, Retrieval and Clustering of 3D Neuron Morphologies.

    Science.gov (United States)

    Wan, Yinan; Long, Fuhui; Qu, Lei; Xiao, Hang; Hawrylycz, Michael; Myers, Eugene W; Peng, Hanchuan

    2015-10-01

    Characterizing the identity and types of neurons in the brain, as well as their associated function, requires a means of quantifying and comparing 3D neuron morphology. Presently, neuron comparison methods are based on statistics from neuronal morphology such as size and number of branches, which are not fully suitable for detecting local similarities and differences in the detailed structure. We developed BlastNeuron to compare neurons in terms of their global appearance, detailed arborization patterns, and topological similarity. BlastNeuron first compares and clusters 3D neuron reconstructions based on global morphology features and moment invariants, independent of their orientations, sizes, level of reconstruction and other variations. Subsequently, BlastNeuron performs local alignment between any pair of retrieved neurons via a tree-topology driven dynamic programming method. A 3D correspondence map can thus be generated at the resolution of single reconstruction nodes. We applied BlastNeuron to three datasets: (1) 10,000+ neuron reconstructions from a public morphology database, (2) 681 newly and manually reconstructed neurons, and (3) neurons reconstructions produced using several independent reconstruction methods. Our approach was able to accurately and efficiently retrieve morphologically and functionally similar neuron structures from large morphology database, identify the local common structures, and find clusters of neurons that share similarities in both morphology and molecular profiles.

  1. Nonlinear analysis of RED - a comparative study

    International Nuclear Information System (INIS)

    Jiang Kai; Wang Xiaofan; Xi Yugeng

    2004-01-01

    Random Early Detection (RED) is an active queue management (AQM) mechanism for routers on the Internet. In this paper, performance of RED and Adaptive RED are compared from the viewpoint of nonlinear dynamics. In particular, we reveal the relationship between the performance of the network and its nonlinear dynamical behavior. We measure the maximal Lyapunov exponent and Hurst parameter of the average queue length of RED and Adaptive RED, as well as the throughput and packet loss rate of the aggregate traffic on the bottleneck link. Our simulation scenarios include FTP flows and Web flows, one-way and two-way traffic. In most situations, Adaptive RED has smaller maximal Lyapunov exponents, lower Hurst parameters, higher throughput and lower packet loss rate than that of RED. This confirms that Adaptive RED has better performance than RED

  2. Nonlinear analysis of RED - a comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Jiang Kai; Wang Xiaofan E-mail: xfwang@sjtu.edu.cn; Xi Yugeng

    2004-09-01

    Random Early Detection (RED) is an active queue management (AQM) mechanism for routers on the Internet. In this paper, performance of RED and Adaptive RED are compared from the viewpoint of nonlinear dynamics. In particular, we reveal the relationship between the performance of the network and its nonlinear dynamical behavior. We measure the maximal Lyapunov exponent and Hurst parameter of the average queue length of RED and Adaptive RED, as well as the throughput and packet loss rate of the aggregate traffic on the bottleneck link. Our simulation scenarios include FTP flows and Web flows, one-way and two-way traffic. In most situations, Adaptive RED has smaller maximal Lyapunov exponents, lower Hurst parameters, higher throughput and lower packet loss rate than that of RED. This confirms that Adaptive RED has better performance than RED.

  3. Oscillating from Neurosecretion to Multitasking Dopamine Neurons

    Directory of Open Access Journals (Sweden)

    David R. Grattan

    2016-04-01

    Full Text Available In this issue of Cell Reports, Stagkourakis et al. (2016 report that oscillating hypothalamic TIDA neurons, previously thought to be simple neurosecretory neurons controlling pituitary prolactin secretion, control dopamine output via autoregulatory mechanisms and thus could potentially regulate other physiologically important hypothalamic neuronal circuits.

  4. Redes neuronales artificiales para el análisis de componentes principales. La red de OJA

    Directory of Open Access Journals (Sweden)

    Piedad Tolmos Rodríguez-Piñero

    2000-01-01

    Full Text Available El análisis de componentes principales es una herramienta estadísticomatemática de gran utilidad en multitud de campos, especialmente en el de la compresión de datos. En este artículo se estudia el proceso de la extracción de componentes principales, y se detalla una Red Neuronal Artificial, la red de Oja, diseñada específicamente para el cálculo de la primera componente principal de la matriz de momentos de segundo orden asociada al vector de datos. Se concluye exponiendo algunas redes que generalizan la red de Oja, y permiten extraer el número deseado de componentes principales. Finalmente se explican algunas aplicaciones, fundamentalmente la del procesamiento de imágenes, y la compresión de datos.

  5. Control Neuronal Combinado para Generar Espectros de Oleajes

    Directory of Open Access Journals (Sweden)

    Luis P. Sánchez Fernández

    2013-10-01

    Full Text Available Resumen: Se presenta un método novedoso para controlar la obtención de espectros de energía de oleajes, de gran utilidad en los laboratorios de investigación y desarrollo de Hidráulica Marítima. El elemento final de control o manipulador es un motor eléctrico lineal conectado a un servo-control el cual es supervisado mediante una computadora. El algoritmo de control automático se realiza con un esquema neuronal combinado, compuesto por una red neuronal artificial “feed-forward” y un controlador proporcional integral. El sistema computacional implementado incluye características de autoaprendizaje, materializado en el re-entrenamiento en línea de la red neuronal lo cual hace posible adaptarse a cambios en los parámetros del “proceso controlado” y a perturbaciones, altamente influyentes en el espectro de energía que impacta una obra hidráulica objeto de estudio. Abstract: A novel method is presented to control the generation of wave energy spectrum, useful in research and development laboratories of Maritime Hydraulic. The final control element is a linear electric motor connected to a servo-control which is monitored by a computer. The automatic control algorithm is performed with a combined neural scheme. It consists of an artificial neural network “feed-forward” and a proportional integral controller. The computer system includes self-learning based on an online training of the neural network. It makes possible to adapt to changes in the parameters of the “controlled process” and disturbances that impact the studied hydraulic work. Palabras clave: Control, neuronal, oleaje, espectros, hidráulica, Keywords: Control, neural, wave, spectrums, hydraulic

  6. Coherence resonance in globally coupled neuronal networks with different neuron numbers

    International Nuclear Information System (INIS)

    Ning Wei-Lian; Zhang Zheng-Zhen; Zeng Shang-You; Luo Xiao-Shu; Hu Jin-Lin; Zeng Shao-Wen; Qiu Yi; Wu Hui-Si

    2012-01-01

    Because a brain consists of tremendous neuronal networks with different neuron numbers ranging from tens to tens of thousands, we study the coherence resonance due to ion channel noises in globally coupled neuronal networks with different neuron numbers. We confirm that for all neuronal networks with different neuron numbers there exist the array enhanced coherence resonance and the optimal synaptic conductance to cause the maximal spiking coherence. Furthermoremore, the enhancement effects of coupling on spiking coherence and on optimal synaptic conductance are almost the same, regardless of the neuron numbers in the neuronal networks. Therefore for all the neuronal networks with different neuron numbers in the brain, relative weak synaptic conductance (0.1 mS/cm 2 ) is sufficient to induce the maximal spiking coherence and the best sub-threshold signal encoding. (interdisciplinary physics and related areas of science and technology)

  7. Responses of single neurons and neuronal ensembles in frog first- and second-order olfactory neurons

    Czech Academy of Sciences Publication Activity Database

    Rospars, J. P.; Šanda, Pavel; Lánský, Petr; Duchamp-Viret, P.

    2013-01-01

    Roč. 1536, NOV 6 (2013), s. 144-158 ISSN 0006-8993 R&D Projects: GA ČR(CZ) GBP304/12/G069; GA ČR(CZ) GAP103/11/0282 Institutional support: RVO:67985823 Keywords : olfaction * spiking activity * neuronal model Subject RIV: JD - Computer Applications, Robotics Impact factor: 2.828, year: 2013

  8. Germination of red alder seed.

    Science.gov (United States)

    M.A. Radwan; D.S. DeBell

    1981-01-01

    Red alder seeds were collected from six locations throughout the natural range of the species. Each seed lot was obtained from a single tree, and the seeds were used to determine germination with and without stratification treatment. Irrespective of treatment, germination varied significantly (P

  9. Red light running camera assessment.

    Science.gov (United States)

    2011-04-01

    In the 2004-2007 period, the Mission Street SE and 25th Street SE intersection in Salem, Oregon showed relatively few crashes attributable to red light running (RLR) but, since a high number of RLR violations were observed, the intersection was ident...

  10. Red Teaming: Past and Present

    Science.gov (United States)

    2008-05-22

    cultural and ethnocentric bias, and a focus on fully exploring alternatives. The purpose of this monograph is to examine historical and...Planning and Orders Production, introduces red team principles into the army problem solving method.14 Additionally, TRADOC staffed and funded the...organization, incorporating alternative perspectives in an attempt to eliminate cultural and ethnocentric bias, and a focus on fully exploring

  11. The red-blue conundrum

    DEFF Research Database (Denmark)

    Nørtoft, Mikkel Johansen

    2017-01-01

    Plants from the Rubiaceae family (Rubia, Galium, and Asperula) are often grouped together as madder because they have been used for dyeing red since at least the Bronze Age. The English plant name madder can be traced through the Germanic language all the way back to Proto-Indo-European (PIE), as...

  12. Divergent projections of catecholaminergic neurons in the nucleus of the solitary tract to limbic forebrain and medullary autonomic brain regions.

    Science.gov (United States)

    Reyes, Beverly A S; Van Bockstaele, Elisabeth J

    2006-10-30

    The nucleus of the solitary tract (NTS) is a critical structure involved in coordinating autonomic and visceral activities. Previous independent studies have demonstrated efferent projections from the NTS to the nucleus paragigantocellularis (PGi) and the central nucleus of the amygdala (CNA) in rat brain. To further characterize the neural circuitry originating from the NTS with postsynaptic targets in the amygdala and medullary autonomic targets, distinct green or red fluorescent latex microspheres were injected into the PGi and the CNA, respectively, of the same rat. Thirty-micron thick tissue sections through the lower brainstem and forebrain were collected. Every fourth section through the NTS region was processed for immunocytochemical detection of tyrosine hydroxylase (TH), a marker of catecholaminergic neurons. Retrogradely labeled neurons from the PGi or CNA were distributed throughout the rostro-caudal segments of the NTS. However, the majority of neurons containing both retrograde tracers were distributed within the caudal third of the NTS. Cell counts revealed that approximately 27% of neurons projecting to the CNA in the NTS sent collateralized projections to the PGi while approximately 16% of neurons projecting to the PGi sent collateralized projections to the CNA. Interestingly, more than half of the PGi and CNA-projecting neurons in the NTS expressed TH immunoreactivity. These data indicate that catecholaminergic neurons in the NTS are poised to simultaneously coordinate activities in limbic and medullary autonomic brain regions.

  13. How to make spinal motor neurons.

    Science.gov (United States)

    Davis-Dusenbery, Brandi N; Williams, Luis A; Klim, Joseph R; Eggan, Kevin

    2014-02-01

    All muscle movements, including breathing, walking, and fine motor skills rely on the function of the spinal motor neuron to transmit signals from the brain to individual muscle groups. Loss of spinal motor neuron function underlies several neurological disorders for which treatment has been hampered by the inability to obtain sufficient quantities of primary motor neurons to perform mechanistic studies or drug screens. Progress towards overcoming this challenge has been achieved through the synthesis of developmental biology paradigms and advances in stem cell and reprogramming technology, which allow the production of motor neurons in vitro. In this Primer, we discuss how the logic of spinal motor neuron development has been applied to allow generation of motor neurons either from pluripotent stem cells by directed differentiation and transcriptional programming, or from somatic cells by direct lineage conversion. Finally, we discuss methods to evaluate the molecular and functional properties of motor neurons generated through each of these techniques.

  14. Firing dynamics of an autaptic neuron

    International Nuclear Information System (INIS)

    Wang Heng-Tong; Chen Yong

    2015-01-01

    Autapses are synapses that connect a neuron to itself in the nervous system. Previously, both experimental and theoretical studies have demonstrated that autaptic connections in the nervous system have a significant physiological function. Autapses in nature provide self-delayed feedback, thus introducing an additional timescale to neuronal activities and causing many dynamic behaviors in neurons. Recently, theoretical studies have revealed that an autapse provides a control option for adjusting the response of a neuron: e.g., an autaptic connection can cause the electrical activities of the Hindmarsh–Rose neuron to switch between quiescent, periodic, and chaotic firing patterns; an autapse can enhance or suppress the mode-locking status of a neuron injected with sinusoidal current; and the firing frequency and interspike interval distributions of the response spike train can also be modified by the autapse. In this paper, we review recent studies that showed how an autapse affects the response of a single neuron. (topical review)

  15. Neurons from the adult human dentate nucleus: neural networks in the neuron classification.

    Science.gov (United States)

    Grbatinić, Ivan; Marić, Dušica L; Milošević, Nebojša T

    2015-04-07

    Topological (central vs. border neuron type) and morphological classification of adult human dentate nucleus neurons according to their quantified histomorphological properties using neural networks on real and virtual neuron samples. In the real sample 53.1% and 14.1% of central and border neurons, respectively, are classified correctly with total of 32.8% of misclassified neurons. The most important result present 62.2% of misclassified neurons in border neurons group which is even greater than number of correctly classified neurons (37.8%) in that group, showing obvious failure of network to classify neurons correctly based on computational parameters used in our study. On the virtual sample 97.3% of misclassified neurons in border neurons group which is much greater than number of correctly classified neurons (2.7%) in that group, again confirms obvious failure of network to classify neurons correctly. Statistical analysis shows that there is no statistically significant difference in between central and border neurons for each measured parameter (p>0.05). Total of 96.74% neurons are morphologically classified correctly by neural networks and each one belongs to one of the four histomorphological types: (a) neurons with small soma and short dendrites, (b) neurons with small soma and long dendrites, (c) neuron with large soma and short dendrites, (d) neurons with large soma and long dendrites. Statistical analysis supports these results (pneurons can be classified in four neuron types according to their quantitative histomorphological properties. These neuron types consist of two neuron sets, small and large ones with respect to their perykarions with subtypes differing in dendrite length i.e. neurons with short vs. long dendrites. Besides confirmation of neuron classification on small and large ones, already shown in literature, we found two new subtypes i.e. neurons with small soma and long dendrites and with large soma and short dendrites. These neurons are

  16. Mirror neurons and motor intentionality.

    Science.gov (United States)

    Rizzolatti, Giacomo; Sinigaglia, Corrado

    2007-01-01

    Our social life rests to a large extent on our ability to understand the intentions of others. What are the bases of this ability? A very influential view is that we understand the intentions of others because we are able to represent them as having mental states. Without this meta-representational (mind-reading) ability their behavior would be meaningless to us. Over the past few years this view has been challenged by neurophysiological findings and, in particular, by the discovery of mirror neurons. The functional properties of these neurons indicate that intentional understanding is based primarily on a mechanism that directly matches the sensory representation of the observed actions with one's own motor representation of those same actions. These findings reveal how deeply motor and intentional components of action are intertwined, suggesting that both can be fully comprehended only starting from a motor approach to intentionality.

  17. Oscillatory integration windows in neurons

    Science.gov (United States)

    Gupta, Nitin; Singh, Swikriti Saran; Stopfer, Mark

    2016-01-01

    Oscillatory synchrony among neurons occurs in many species and brain areas, and has been proposed to help neural circuits process information. One hypothesis states that oscillatory input creates cyclic integration windows: specific times in each oscillatory cycle when postsynaptic neurons become especially responsive to inputs. With paired local field potential (LFP) and intracellular recordings and controlled stimulus manipulations we directly test this idea in the locust olfactory system. We find that inputs arriving in Kenyon cells (KCs) sum most effectively in a preferred window of the oscillation cycle. With a computational model, we show that the non-uniform structure of noise in the membrane potential helps mediate this process. Further experiments performed in vivo demonstrate that integration windows can form in the absence of inhibition and at a broad range of oscillation frequencies. Our results reveal how a fundamental coincidence-detection mechanism in a neural circuit functions to decode temporally organized spiking. PMID:27976720

  18. Comparative metagenomics of the Red Sea

    KAUST Repository

    Mineta, Katsuhiko

    2016-01-01

    started monthly samplings of the metagenomes in the Red Sea under KAUST-CCF project. In collaboration with Kitasato University, we also collected the metagenome data from the ocean in Japan, which shows contrasting features to the Red Sea. Therefore

  19. Nutrient Limitation in Central Red Sea Mangroves

    KAUST Repository

    Almahasheer, Hanan; Duarte, Carlos M.; Irigoien, Xabier

    2016-01-01

    Red Sea have characteristic heights of ~2 m, suggesting nutrient limitation. We assessed the nutrient status of mangrove stands in the Central Red Sea and conducted a fertilization experiment (N, P and Fe and various combinations thereof) on 4-week

  20. Unbalanced neuronal circuits in addiction.

    Science.gov (United States)

    Volkow, Nora D; Wang, Gen-Jack; Tomasi, Dardo; Baler, Ruben D

    2013-08-01

    Through sequential waves of drug-induced neurochemical stimulation, addiction co-opts the brain's neuronal circuits that mediate reward, motivation to behavioral inflexibility and a severe disruption of self-control and compulsive drug intake. Brain imaging technologies have allowed neuroscientists to map out the neural landscape of addiction in the human brain and to understand how drugs modify it. Published by Elsevier Ltd.

  1. Neurochemical phenotypes of cardiorespiratory neurons.

    Science.gov (United States)

    Pilowsky, Paul M

    2008-12-10

    Interactions between the cardiovascular and respiratory systems have been known for many years but the functional significance of the interactions is still widely debated. Here I discuss the possible role of metabotropic receptors in regulating cardiorespiratory neurons in the brainstem and spinal cord. It is clear that, although much has been discovered, cardiorespiratory regulation is certainly one area that still has a long way to go before its secrets are fully divulged and their function in controlling circulatory and respiratory function is revealed.

  2. Mirror Neurons from Associative Learning

    OpenAIRE

    Catmur, Caroline; Press, Clare; Heyes, Cecilia

    2016-01-01

    Mirror neurons fire both when executing actions and observing others perform similar actions. Their sensorimotor matching properties have generally been considered a genetic adaptation for social cognition; however, in the present chapter we argue that the evidence in favor of this account is not compelling. Instead we present evidence supporting an alternative account: that mirror neurons’ matching properties arise from associative learning during individual development. Notably, this proces...

  3. Trafficking of neuronal calcium channels

    Czech Academy of Sciences Publication Activity Database

    Weiss, Norbert; Zamponi, G. W.

    2017-01-01

    Roč. 1, č. 1 (2017), č. článku NS20160003. ISSN 2059-6553 R&D Projects: GA ČR GA15-13556S; GA MŠk 7AMB15FR015 Institutional support: RVO:61388963 Keywords : calcium channel * neuron * trafficing Subject RIV: ED - Physiology OBOR OECD: Physiology (including cytology) http://www.neuronalsignaling.org/content/1/1/NS20160003

  4. Selective serotonergic excitation of callosal projection neurons

    Directory of Open Access Journals (Sweden)

    Daniel eAvesar

    2012-03-01

    Full Text Available Serotonin (5-HT acting as a neurotransmitter in the cerebral cortex is critical for cognitive function, yet how 5-HT regulates information processing in cortical circuits is not well understood. We tested the serotonergic responsiveness of layer 5 pyramidal neurons (L5PNs of the mouse medial prefrontal cortex (mPFC, and found 3 distinct response types: long-lasting 5-HT1A (1A receptor-dependent inhibitory responses (84% of L5PNs, 5-HT2A (2A receptor-dependent excitatory responses (9%, and biphasic responses in which 2A-dependent excitation followed brief inhibition (5%. Relative to 5-HT-inhibited neurons, those excited by 5-HT had physiological properties characteristic of callosal/commissural (COM neurons that project to the contralateral cortex. We tested whether serotonergic responses in cortical pyramidal neurons are correlated with their axonal projection pattern using retrograde fluorescent labeling of COM and corticopontine-projecting (CPn neurons. 5-HT generated excitatory or biphasic responses in all 5-HT-responsive layer 5 COM neurons. Conversely, CPn neurons were universally inhibited by 5-HT. Serotonergic excitation of COM neurons was blocked by the 2A antagonist MDL 11939, while serotonergic inhibition of CPn neurons was blocked by the 1A antagonist WAY 100635, confirming a role for these two receptor subtypes in regulating pyramidal neuron activity. Selective serotonergic excitation of COM neurons was not layer-specific, as COM neurons in layer 2/3 were also selectively excited by 5-HT relative to their non-labeled pyramidal neuron neighbors. Because neocortical 2A receptors are implicated in the etiology and pathophysiology of schizophrenia, we propose that COM neurons may represent a novel cellular target for intervention in psychiatric disease.

  5. Zebrafish embryos exposed to alcohol undergo abnormal development of motor neurons and muscle fibers.

    Science.gov (United States)

    Sylvain, Nicole J; Brewster, Daniel L; Ali, Declan W

    2010-01-01

    Children exposed to alcohol in utero have significantly delayed gross and fine motor skills, as well as deficiencies in reflex development. The reasons that underlie the motor deficits caused by ethanol (EtOH) exposure remain to be fully elucidated. The present study was undertaken to investigate the effects of embryonic alcohol exposure (1.5%, 2% and 2.5% EtOH) on motor neuron and muscle fiber morphology in 3 days post fertilization (dpf) larval zebrafish. EtOH treated fish exhibited morphological deformities and fewer bouts of swimming in response to touch, compared with untreated fish. Immunolabelling with anti-acetylated tubulin indicated that fish exposed to 2.5% EtOH had significantly higher rates of motor neuron axon defects. Immunolabelling of primary and secondary motor neurons, using znp-1 and zn-8, revealed that fish exposed to 2% and 2.5% EtOH exhibited significantly higher rates of primary and secondary motor neuron axon defects compared to controls. Examination of red and white muscle fibers revealed that fish exposed to EtOH had significantly smaller fibers compared with controls. These findings indicate that motor neuron and muscle fiber morphology is affected by early alcohol exposure in zebrafish embryos, and that this may be related to deficits in locomotion. Copyright 2010 Elsevier Inc. All rights reserved.

  6. A Knockin Reporter Allows Purification and Characterization of mDA Neurons from Heterogeneous Populations

    Directory of Open Access Journals (Sweden)

    Ninuo Xia

    2017-03-01

    Full Text Available Generation of midbrain dopaminergic (mDA neurons from human pluripotent stem cells provides a platform for inquiry into basic and translational studies of Parkinson’s disease (PD. However, heterogeneity in differentiation in vitro makes it difficult to identify mDA neurons in culture or in vivo following transplantation. Here, we report the generation of a human embryonic stem cell (hESC line with a tyrosine hydroxylase (TH-RFP (red fluorescent protein reporter. We validated that RFP faithfully mimicked TH expression during differentiation. Use of this TH-RFP reporter cell line enabled purification of mDA-like neurons from heterogeneous cultures with subsequent characterization of neuron transcriptional and epigenetic programs (global binding profiles of H3K27ac, H3K4me1, and 5-hydroxymethylcytosine [5hmC] at four different stages of development. We anticipate that the tools and data described here will contribute to the development of mDA neurons for applications in disease modeling and/or drug screening and cell replacement therapies for PD.

  7. Effects of procaine on a central neuron of the snail, Achatina fulica Ferussac.

    Science.gov (United States)

    Lin, Chia-Hsien; Tsai, Ming-Cheng

    2005-02-18

    Effects of procaine on a central neuron (RP1) of the giant African snail (Achatina fulica Ferussac) were studied pharmacologically. The RP1 neuron showed spontaneous firing of action potential. Extra-cellular application of procaine (10 mM) reversibly elicited bursts of potential. The bursts of potential elicited by procaine were not blocked after administration of (1) prazosin, propranolol, atropine, d-tubocurarine, (2) calcium-free solution, (3) ryanodine (4) pretreatment with KT-5720 or chelerythrine. The bursts of potential elicited by procaine were blocked by adding U73122 (10 microM) and the bursts of potential were decreased if physiological sodium ion was replaced with lithium ion or incubated with either neomycin (3.5 mM) or high magnesium solution (30 mM). Preatment with U73122 (10 microM) blocked the initiation of bursts of potential. Ruthenium red (100 microM) or caffeine (10 mM) facilitated the procaine-elicited bursts of potential. It is concluded that procaine reversibly elicits bursts of potential in the central snail neuron. This effect was not directly related to (1) the extra-cellular calcium ion fluxes, (2) the ryanodine sensitive calcium channels in the neuron, or (3) the PKC or PKA related messenger systems. The procaine-elicited bursts of potential were associated with the phospholipase activity and the calcium mobilization in the neuron.

  8. A Knockin Reporter Allows Purification and Characterization of mDA Neurons from Heterogeneous Populations.

    Science.gov (United States)

    Xia, Ninuo; Fang, Fang; Zhang, Pengbo; Cui, Jun; Tep-Cullison, Chhavy; Hamerley, Tim; Lee, Hyun Joo; Palmer, Theo; Bothner, Brian; Lee, Jin Hyung; Pera, Renee Reijo

    2017-03-07

    Generation of midbrain dopaminergic (mDA) neurons from human pluripotent stem cells provides a platform for inquiry into basic and translational studies of Parkinson's disease (PD). However, heterogeneity in differentiation in vitro makes it difficult to identify mDA neurons in culture or in vivo following transplantation. Here, we report the generation of a human embryonic stem cell (hESC) line with a tyrosine hydroxylase (TH)-RFP (red fluorescent protein) reporter. We validated that RFP faithfully mimicked TH expression during differentiation. Use of this TH-RFP reporter cell line enabled purification of mDA-like neurons from heterogeneous cultures with subsequent characterization of neuron transcriptional and epigenetic programs (global binding profiles of H3K27ac, H3K4me1, and 5-hydroxymethylcytosine [5hmC]) at four different stages of development. We anticipate that the tools and data described here will contribute to the development of mDA neurons for applications in disease modeling and/or drug screening and cell replacement therapies for PD. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  9. Red Assembly: the work remains

    Directory of Open Access Journals (Sweden)

    Leslie Witz

    Full Text Available This issue of Kronos is dedicated to Terry Flynn, assistant curator at the Ann Bryant Art Gallery, who was instrumental in the successful installing of 'Red Assembly' there in 2015. Friend, colleague, artist and inspiration. Hamba Kahle. The work that emerged from the encounter with Red, an art installation by Simon Gush and his collaborators, in the workshop 'Red Assembly', held in East London in August 2015, is assembled here in Kronos, the journal of southern African histories based at the University of the Western Cape, and previously in parallax, the cultural studies journal based at the University of Leeds published in May 2016. What is presented there and here is not simply more work, work that follows, or even additional works. Rather, it is the work that arises as a response to a question that structured our entire project: does Red, now also installed in these two journals, have the potential to call the discourse of history into question? This article responds to this question through several pairings: theft - gift; copy - rights; time - history; kronos - chronos. Here we identify a reversal in this installation of the gift into the commodity, and another with regard to conventional historical narratives which privilege the search for sources and origins. A difference between (the historian's search for origination and (the artist's originality becomes visible in a conversation between and over the historic and the artistic that does not simply try to rescue History by means of the work of art. It is in this sense that we invite the displacements, detours, and paths made possible through Simon Gush's Red, the 'Red Assembly' workshop and the work/gift of installation and parallaxing. To gesture beyond 'histories' is the provocation to which art is neither cause nor effect. Thinking with the work of art, that is, grasping thought in the working of art, has extended the sense of history's limit and the way the limit of history is

  10. Results on a Binding Neuron Model and Their Implications for Modified Hourglass Model for Neuronal Network

    Directory of Open Access Journals (Sweden)

    Viswanathan Arunachalam

    2013-01-01

    Full Text Available The classical models of single neuron like Hodgkin-Huxley point neuron or leaky integrate and fire neuron assume the influence of postsynaptic potentials to last till the neuron fires. Vidybida (2008 in a refreshing departure has proposed models for binding neurons in which the trace of an input is remembered only for a finite fixed period of time after which it is forgotten. The binding neurons conform to the behaviour of real neurons and are applicable in constructing fast recurrent networks for computer modeling. This paper develops explicitly several useful results for a binding neuron like the firing time distribution and other statistical characteristics. We also discuss the applicability of the developed results in constructing a modified hourglass network model in which there are interconnected neurons with excitatory as well as inhibitory inputs. Limited simulation results of the hourglass network are presented.

  11. Single-cell axotomy of cultured hippocampal neurons integrated in neuronal circuits.

    Science.gov (United States)

    Gomis-Rüth, Susana; Stiess, Michael; Wierenga, Corette J; Meyn, Liane; Bradke, Frank

    2014-05-01

    An understanding of the molecular mechanisms of axon regeneration after injury is key for the development of potential therapies. Single-cell axotomy of dissociated neurons enables the study of the intrinsic regenerative capacities of injured axons. This protocol describes how to perform single-cell axotomy on dissociated hippocampal neurons containing synapses. Furthermore, to axotomize hippocampal neurons integrated in neuronal circuits, we describe how to set up coculture with a few fluorescently labeled neurons. This approach allows axotomy of single cells in a complex neuronal network and the observation of morphological and molecular changes during axon regeneration. Thus, single-cell axotomy of mature neurons is a valuable tool for gaining insights into cell intrinsic axon regeneration and the plasticity of neuronal polarity of mature neurons. Dissociation of the hippocampus and plating of hippocampal neurons takes ∼2 h. Neurons are then left to grow for 2 weeks, during which time they integrate into neuronal circuits. Subsequent axotomy takes 10 min per neuron and further imaging takes 10 min per neuron.

  12. Glutamate neurons are intermixed with midbrain dopamine neurons in nonhuman primates and humans

    Science.gov (United States)

    Root, David H.; Wang, Hui-Ling; Liu, Bing; Barker, David J.; Mód, László; Szocsics, Péter; Silva, Afonso C.; Maglóczky, Zsófia; Morales, Marisela

    2016-01-01

    The rodent ventral tegmental area (VTA) and substantia nigra pars compacta (SNC) contain dopamine neurons intermixed with glutamate neurons (expressing vesicular glutamate transporter 2; VGluT2), which play roles in reward and aversion. However, identifying the neuronal compositions of the VTA and SNC in higher mammals has remained challenging. Here, we revealed VGluT2 neurons within the VTA and SNC of nonhuman primates and humans by simultaneous detection of VGluT2 mRNA and tyrosine hydroxylase (TH; for identification of dopamine neurons). We found that several VTA subdivisions share similar cellular compositions in nonhuman primates and humans; their rostral linear nuclei have a high prevalence of VGluT2 neurons lacking TH; their paranigral and parabrachial pigmented nuclei have mostly TH neurons, and their parabrachial pigmented nuclei have dual VGluT2-TH neurons. Within nonhuman primates and humans SNC, the vast majority of neurons are TH neurons but VGluT2 neurons were detected in the pars lateralis subdivision. The demonstration that midbrain dopamine neurons are intermixed with glutamate or glutamate-dopamine neurons from rodents to humans offers new opportunities for translational studies towards analyzing the roles that each of these neurons play in human behavior and in midbrain-associated illnesses such as addiction, depression, schizophrenia, and Parkinson’s disease. PMID:27477243

  13. Red alder: a state of knowledge.

    Science.gov (United States)

    Robert L. Deal; Constance A. Harrington

    2006-01-01

    In March 23-25, 2005, an international symposium on red alder was held at the University of Washington Center for Urban Horticulture in Seattle, WA. The symposium was entitled "Red alder: A State of Knowledge" and brought together regional experts to critically examine the economic, ecological and social values of red alder. The primary goal of the symposium...

  14. Red and green fluorescence from oral biofilms

    NARCIS (Netherlands)

    Volgenant, C.M.C.; Hoogenkamp, M.A.; Krom, B.P.; Janus, M.M.; ten Cate, J.M.; de Soet, J.J.; Crielaard, W.; van der Veen, M.H.

    2016-01-01

    Red and green autofluorescence have been observed from dental plaque after excitation by blue light. It has been suggested that this red fluorescence is related to caries and the cariogenic potential of dental plaque. Recently, it was suggested that red fluorescence may be related to gingivitis.

  15. Peroxiredoxin distribution in the mouse brain with emphasis on neuronal populations affected in neurodegenerative disorders.

    Science.gov (United States)

    Goemaere, Julie; Knoops, Bernard

    2012-02-01

    Redox changes are observed in neurodegenerative diseases, ranging from increased levels of reactive oxygen/nitrogen species and disturbance of antioxidant systems, to nitro-oxidative damage. By reducing hydrogen peroxide, peroxynitrite, and organic hydroperoxides, peroxiredoxins (Prdxs) represent a major potential protective barrier against nitro-oxidative insults in the brain. While recent works have investigated the putative role of Prdxs in neurodegenerative disorders, less is known about their expression in the healthy brain. Here we used immunohistochemistry to map basal expression of Prdxs throughout C57BL/6 mouse brain. We first confirmed the neuronal localization of Prdx2-5 and the glial expression of Prdx1, Prdx4, and Prdx6. Then we performed an in-depth analysis of neuronal Prdx distribution in the brain. Our results show that Prdx2-5 are widely detected in the different neuronal populations, and especially well expressed in the olfactory bulb, in the cerebral cortex, in pons nuclei, in the red nucleus, in all cranial nerve nuclei, in the cerebellum, and in motor neurons of the spinal cord. In contrast, Prdx expression is very low in the dopaminergic neurons of substantia nigra pars compacta and in the CA1/2 pyramidal cells of hippocampus. This low basal expression may contribute to the vulnerability of these neurons to nitro-oxidative attacks occurring in Parkinson's disease and Alzheimer's disease. In addition, we found that Prdx expression levels are unevenly distributed among neurons of a determined region and that distinct regional patterns of expression are observed between isoforms, reinforcing the hypothesis of the nonredundant function of Prdxs. Copyright © 2011 Wiley-Liss, Inc.

  16. Allergic reactions in red tattoos

    DEFF Research Database (Denmark)

    Hutton Carlsen, K; Køcks, M; Sepehri, M

    2016-01-01

    to be feasible for chemical analysis of red pigments in allergic reactions. Raman spectroscopy has a major potential for fingerprint screening of problematic tattoo pigments in situ in skin, ex vivo in skin biopsies and in tattoo ink stock products, thus, to eliminate unsafe ink products from markets.......AIM: The aim of this study was to assess the feasibility of Raman spectroscopy as a screening technique for chemical characterisation of tattoo pigments in pathologic reacting tattoos and tattoo ink stock products to depict unsafe pigments and metabolites of pigments. MATERIALS/METHODS: Twelve...... dermatome shave biopsies from allergic reactions in red tattoos were analysed with Raman spectroscopy (A 785-nm 300 mW diode laser). These were referenced to samples of 10 different standard tattoo ink stock products, three of these identified as the culprit inks used by the tattooist and thus by history...

  17. Neuronal Differentiation Modulated by Polymeric Membrane Properties.

    Science.gov (United States)

    Morelli, Sabrina; Piscioneri, Antonella; Drioli, Enrico; De Bartolo, Loredana

    2017-01-01

    In this study, different collagen-blend membranes were successfully constructed by blending collagen with chitosan (CHT) or poly(lactic-co-glycolic acid) (PLGA) to enhance their properties and thus create new biofunctional materials with great potential use for neuronal tissue engineering and regeneration. Collagen blending strongly affected membrane properties in the following ways: (i) it improved the surface hydrophilicity of both pure CHT and PLGA membranes, (ii) it reduced the stiffness of CHT membranes, but (iii) it did not modify the good mechanical properties of PLGA membranes. Then, we investigated the effect of the different collagen concentrations on the neuronal behavior of the membranes developed. Morphological observations, immunocytochemistry, and morphometric measures demonstrated that the membranes developed, especially CHT/Col30, PLGA, and PLGA/Col1, provided suitable microenvironments for neuronal growth owing to their enhanced properties. The most consistent neuronal differentiation was obtained in neurons cultured on PLGA-based membranes, where a well-developed neuronal network was achieved due to their improved mechanical properties. Our findings suggest that tensile strength and elongation at break are key material parameters that have potential influence on both axonal elongation and neuronal structure and organization, which are of fundamental importance for the maintenance of efficient neuronal growth. Hence, our study has provided new insights regarding the effects of membrane mechanical properties on neuronal behavior, and thus it may help to design and improve novel instructive biomaterials for neuronal tissue engineering. © 2017 S. Karger AG, Basel.

  18. Synaptic Circuit Organization of Motor Corticothalamic Neurons

    Science.gov (United States)

    Yamawaki, Naoki

    2015-01-01

    Corticothalamic (CT) neurons in layer 6 constitute a large but enigmatic class of cortical projection neurons. How they are integrated into intracortical and thalamo-cortico-thalamic circuits is incompletely understood, especially outside of sensory cortex. Here, we investigated CT circuits in mouse forelimb motor cortex (M1) using multiple circuit-analysis methods. Stimulating and recording from CT, intratelencephalic (IT), and pyramidal tract (PT) projection neurons, we found strong CT↔ CT and CT↔ IT connections; however, CT→IT connections were limited to IT neurons in layer 6, not 5B. There was strikingly little CT↔ PT excitatory connectivity. Disynaptic inhibition systematically accompanied excitation in these pathways, scaling with the amplitude of excitation according to both presynaptic (class-specific) and postsynaptic (cell-by-cell) factors. In particular, CT neurons evoked proportionally more inhibition relative to excitation (I/E ratio) than IT neurons. Furthermore, the amplitude of inhibition was tuned to match the amount of excitation at the level of individual neurons; in the extreme, neurons receiving no excitation received no inhibition either. Extending these studies to dissect the connectivity between cortex and thalamus, we found that M1-CT neurons and thalamocortical neurons in the ventrolateral (VL) nucleus were remarkably unconnected in either direction. Instead, VL axons in the cortex excited both IT and PT neurons, and CT axons in the thalamus excited other thalamic neurons, including those in the posterior nucleus, which additionally received PT excitation. These findings, which contrast in several ways with previous observations in sensory areas, illuminate the basic circuit organization of CT neurons within M1 and between M1 and thalamus. PMID:25653383

  19. Red fox sightings in Rome

    Directory of Open Access Journals (Sweden)

    Bruno Cignini

    1997-12-01

    Full Text Available Abstract In this study preliminary data on the presence of Red fox in Rome (an area of 360 km² within the Rome ringroad. G.R.A. since 1980 are presented. The data were mapped on a UTM 1 sq. km. grid. Data were analysed and correlated, for each City district, with the prevalent environment (green, built-up, river-side areas and with the density of inhabitants.

  20. Resveratrol: Chemoprevention with red wine

    OpenAIRE

    Arısan, Elif Damla; Palavan-Ünsal, Narçin

    2007-01-01

    According to epidemiological studies, western diet has disadvantages because of cancer prevalence more than Mediterranean or Asia people who consume more vegetables and fruits. Resveratrol (trans-3,4,5-trihydroxystilbene) which is highly found in grapes, berries has received attention for its potential chemopreventive and antitumor effects in experimental systems. Because of high resveratrol content, researchers noted that red wine has multidimensional benefits for ...

  1. Hindbrain Catecholamine Neurons Activate Orexin Neurons During Systemic Glucoprivation in Male Rats.

    Science.gov (United States)

    Li, Ai-Jun; Wang, Qing; Elsarelli, Megan M; Brown, R Lane; Ritter, Sue

    2015-08-01

    Hindbrain catecholamine neurons are required for elicitation of feeding responses to glucose deficit, but the forebrain circuitry required for these responses is incompletely understood. Here we examined interactions of catecholamine and orexin neurons in eliciting glucoprivic feeding. Orexin neurons, located in the perifornical lateral hypothalamus (PeFLH), are heavily innervated by hindbrain catecholamine neurons, stimulate food intake, and increase arousal and behavioral activation. Orexin neurons may therefore contribute importantly to appetitive responses, such as food seeking, during glucoprivation. Retrograde tracing results showed that nearly all innervation of the PeFLH from the hindbrain originated from catecholamine neurons and some raphe nuclei. Results also suggested that many catecholamine neurons project collaterally to the PeFLH and paraventricular hypothalamic nucleus. Systemic administration of the antiglycolytic agent, 2-deoxy-D-glucose, increased food intake and c-Fos expression in orexin neurons. Both responses were eliminated by a lesion of catecholamine neurons innervating orexin neurons using the retrogradely transported immunotoxin, anti-dopamine-β-hydroxylase saporin, which is specifically internalized by dopamine-β-hydroxylase-expressing catecholamine neurons. Using designer receptors exclusively activated by designer drugs in transgenic rats expressing Cre recombinase under the control of tyrosine hydroxylase promoter, catecholamine neurons in cell groups A1 and C1 of the ventrolateral medulla were activated selectively by peripheral injection of clozapine-N-oxide. Clozapine-N-oxide injection increased food intake and c-Fos expression in PeFLH orexin neurons as well as in paraventricular hypothalamic nucleus neurons. In summary, catecholamine neurons are required for the activation of orexin neurons during glucoprivation. Activation of orexin neurons may contribute to appetitive responses required for glucoprivic feeding.

  2. A chimeric path to neuronal synchronization

    Science.gov (United States)

    Essaki Arumugam, Easwara Moorthy; Spano, Mark L.

    2015-01-01

    Synchronization of neuronal activity is associated with neurological disorders such as epilepsy. This process of neuronal synchronization is not fully understood. To further our understanding, we have experimentally studied the progression of this synchronization from normal neuronal firing to full synchronization. We implemented nine FitzHugh-Nagumo neurons (a simplified Hodgkin-Huxley model) via discrete electronics. For different coupling parameters (synaptic strengths), the neurons in the ring were either unsynchronized or completely synchronized when locally coupled in a ring. When a single long-range connection (nonlocal coupling) was introduced, an intermediate state known as a chimera appeared. The results indicate that (1) epilepsy is likely not only a dynamical disease but also a topological disease, strongly tied to the connectivity of the underlying network of neurons, and (2) the synchronization process in epilepsy may not be an "all or none" phenomenon, but can pass through an intermediate stage (chimera).

  3. A chimeric path to neuronal synchronization

    Energy Technology Data Exchange (ETDEWEB)

    Essaki Arumugam, Easwara Moorthy; Spano, Mark L. [School of Biological and Health Systems Engineering, Arizona State University, Tempe, Arizona 85287-9709 (United States)

    2015-01-15

    Synchronization of neuronal activity is associated with neurological disorders such as epilepsy. This process of neuronal synchronization is not fully understood. To further our understanding, we have experimentally studied the progression of this synchronization from normal neuronal firing to full synchronization. We implemented nine FitzHugh-Nagumo neurons (a simplified Hodgkin-Huxley model) via discrete electronics. For different coupling parameters (synaptic strengths), the neurons in the ring were either unsynchronized or completely synchronized when locally coupled in a ring. When a single long-range connection (nonlocal coupling) was introduced, an intermediate state known as a chimera appeared. The results indicate that (1) epilepsy is likely not only a dynamical disease but also a topological disease, strongly tied to the connectivity of the underlying network of neurons, and (2) the synchronization process in epilepsy may not be an “all or none” phenomenon, but can pass through an intermediate stage (chimera)

  4. Mini Review: Biomaterials for Enhancing Neuronal Repair

    Science.gov (United States)

    Cangellaris, Olivia V.; Gillette, Martha U.

    2018-04-01

    As they differentiate from neuroblasts, nascent neurons become highly polarized and elongate. Neurons extend and elaborate fine and fragile cellular extensions that form circuits enabling long-distance communication and signal integration within the body. While other organ systems are developing, projections of differentiating neurons find paths to distant targets. Subsequent post-developmental neuronal damage is catastrophic because the cues for reinnervation are no longer active. Advances in biomaterials are enabling fabrication of micro-environments that encourage neuronal regrowth and restoration of function by recreating these developmental cues. This mini-review considers new materials that employ topographical, chemical, electrical, and/or mechanical cues for use in neuronal repair. Manipulating and integrating these elements in different combinations will generate new technologies to enhance neural repair.

  5. Npas4: Linking Neuronal Activity to Memory.

    Science.gov (United States)

    Sun, Xiaochen; Lin, Yingxi

    2016-04-01

    Immediate-early genes (IEGs) are rapidly activated after sensory and behavioral experience and are believed to be crucial for converting experience into long-term memory. Neuronal PAS domain protein 4 (Npas4), a recently discovered IEG, has several characteristics that make it likely to be a particularly important molecular link between neuronal activity and memory: it is among the most rapidly induced IEGs, is expressed only in neurons, and is selectively induced by neuronal activity. By orchestrating distinct activity-dependent gene programs in different neuronal populations, Npas4 affects synaptic connections in excitatory and inhibitory neurons, neural circuit plasticity, and memory formation. It may also be involved in circuit homeostasis through negative feedback and psychiatric disorders. We summarize these findings and discuss their implications. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. A chimeric path to neuronal synchronization

    International Nuclear Information System (INIS)

    Essaki Arumugam, Easwara Moorthy; Spano, Mark L.

    2015-01-01

    Synchronization of neuronal activity is associated with neurological disorders such as epilepsy. This process of neuronal synchronization is not fully understood. To further our understanding, we have experimentally studied the progression of this synchronization from normal neuronal firing to full synchronization. We implemented nine FitzHugh-Nagumo neurons (a simplified Hodgkin-Huxley model) via discrete electronics. For different coupling parameters (synaptic strengths), the neurons in the ring were either unsynchronized or completely synchronized when locally coupled in a ring. When a single long-range connection (nonlocal coupling) was introduced, an intermediate state known as a chimera appeared. The results indicate that (1) epilepsy is likely not only a dynamical disease but also a topological disease, strongly tied to the connectivity of the underlying network of neurons, and (2) the synchronization process in epilepsy may not be an “all or none” phenomenon, but can pass through an intermediate stage (chimera)

  7. ESTIMACIÓN DE LA CARGA DE TRANSFORMADORES DE POTENCIA UTILIZANDO UNA RED NEURONAL ARTIFICIAL

    OpenAIRE

    Agudelo, Laura; Velilla, Esteban; López, Jesús M

    2014-01-01

    En este artículo se presenta una metodología para estimar la curva de carga de transformadores de potencia utilizando redes neuronales artificiales. Para implementar la metodología propuesta se utilizaron datos reales de dos transformadores ubicados en diferentes zonas geográficas y con diferentes condiciones de operación. La técnica de estimación de carga fue implementada con datos históricos de la empresa Interconexión Eléctrica S.A (ISA). Para realizar la predicción de las curvas de carga ...

  8. Neuronal Networks on Nanocellulose Scaffolds.

    Science.gov (United States)

    Jonsson, Malin; Brackmann, Christian; Puchades, Maja; Brattås, Karoline; Ewing, Andrew; Gatenholm, Paul; Enejder, Annika

    2015-11-01

    Proliferation, integration, and neurite extension of PC12 cells, a widely used culture model for cholinergic neurons, were studied in nanocellulose scaffolds biosynthesized by Gluconacetobacter xylinus to allow a three-dimensional (3D) extension of neurites better mimicking neuronal networks in tissue. The interaction with control scaffolds was compared with cationized nanocellulose (trimethyl ammonium betahydroxy propyl [TMAHP] cellulose) to investigate the impact of surface charges on the cell interaction mechanisms. Furthermore, coatings with extracellular matrix proteins (collagen, fibronectin, and laminin) were investigated to determine the importance of integrin-mediated cell attachment. Cell proliferation was evaluated by a cellular proliferation assay, while cell integration and neurite propagation were studied by simultaneous label-free Coherent anti-Stokes Raman Scattering and second harmonic generation microscopy, providing 3D images of PC12 cells and arrangement of nanocellulose fibrils, respectively. Cell attachment and proliferation were enhanced by TMAHP modification, but not by protein coating. Protein coating instead promoted active interaction between the cells and the scaffold, hence lateral cell migration and integration. Irrespective of surface modification, deepest cell integration measured was one to two cell layers, whereas neurites have a capacity to integrate deeper than the cell bodies in the scaffold due to their fine dimensions and amoeba-like migration pattern. Neurites with lengths of >50 μm were observed, successfully connecting individual cells and cell clusters. In conclusion, TMAHP-modified nanocellulose scaffolds promote initial cellular scaffold adhesion, which combined with additional cell-scaffold treatments enables further formation of 3D neuronal networks.

  9. C. elegans model of neuronal aging

    OpenAIRE

    Peng, Chiu-Ying; Chen, Chun-Hao; Hsu, Jiun-Min; Pan, Chun-Liang

    2011-01-01

    Aging of the nervous system underlies the behavioral and cognitive decline associated with senescence. Understanding the molecular and cellular basis of neuronal aging will therefore contribute to the development of effective treatments for aging and age-associated neurodegenerative disorders. Despite this pressing need, there are surprisingly few animal models that aim at recapitulating neuronal aging in a physiological context. We recently developed a C. elegans model of neuronal aging, and...

  10. Spike timing precision of neuronal circuits.

    Science.gov (United States)

    Kilinc, Deniz; Demir, Alper

    2018-04-17

    Spike timing is believed to be a key factor in sensory information encoding and computations performed by the neurons and neuronal circuits. However, the considerable noise and variability, arising from the inherently stochastic mechanisms that exist in the neurons and the synapses, degrade spike timing precision. Computational modeling can help decipher the mechanisms utilized by the neuronal circuits in order to regulate timing precision. In this paper, we utilize semi-analytical techniques, which were adapted from previously developed methods for electronic circuits, for the stochastic characterization of neuronal circuits. These techniques, which are orders of magnitude faster than traditional Monte Carlo type simulations, can be used to directly compute the spike timing jitter variance, power spectral densities, correlation functions, and other stochastic characterizations of neuronal circuit operation. We consider three distinct neuronal circuit motifs: Feedback inhibition, synaptic integration, and synaptic coupling. First, we show that both the spike timing precision and the energy efficiency of a spiking neuron are improved with feedback inhibition. We unveil the underlying mechanism through which this is achieved. Then, we demonstrate that a neuron can improve on the timing precision of its synaptic inputs, coming from multiple sources, via synaptic integration: The phase of the output spikes of the integrator neuron has the same variance as that of the sample average of the phases of its inputs. Finally, we reveal that weak synaptic coupling among neurons, in a fully connected network, enables them to behave like a single neuron with a larger membrane area, resulting in an improvement in the timing precision through cooperation.

  11. Do enteric neurons make hypocretin? ☆

    OpenAIRE

    Baumann, Christian R.; Clark, Erika L.; Pedersen, Nigel P.; Hecht, Jonathan L.; Scammell, Thomas E.

    2007-01-01

    Hypocretins (orexins) are wake-promoting neuropeptides produced by hypothalamic neurons. These hypocretin-producing cells are lost in people with narcolepsy, possibly due to an autoimmune attack. Prior studies described hypocretin neurons in the enteric nervous system, and these cells could be an additional target of an autoimmune process. We sought to determine whether enteric hypocretin neurons are lost in narcoleptic subjects. Even though we tried several methods (including whole mounts, s...

  12. High-Degree Neurons Feed Cortical Computations.

    Directory of Open Access Journals (Sweden)

    Nicholas M Timme

    2016-05-01

    Full Text Available Recent work has shown that functional connectivity among cortical neurons is highly varied, with a small percentage of neurons having many more connections than others. Also, recent theoretical developments now make it possible to quantify how neurons modify information from the connections they receive. Therefore, it is now possible to investigate how information modification, or computation, depends on the number of connections a neuron receives (in-degree or sends out (out-degree. To do this, we recorded the simultaneous spiking activity of hundreds of neurons in cortico-hippocampal slice cultures using a high-density 512-electrode array. This preparation and recording method combination produced large numbers of neurons recorded at temporal and spatial resolutions that are not currently available in any in vivo recording system. We utilized transfer entropy (a well-established method for detecting linear and nonlinear interactions in time series and the partial information decomposition (a powerful, recently developed tool for dissecting multivariate information processing into distinct parts to quantify computation between neurons where information flows converged. We found that computations did not occur equally in all neurons throughout the networks. Surprisingly, neurons that computed large amounts of information tended to receive connections from high out-degree neurons. However, the in-degree of a neuron was not related to the amount of information it computed. To gain insight into these findings, we developed a simple feedforward network model. We found that a degree-modified Hebbian wiring rule best reproduced the pattern of computation and degree correlation results seen in the real data. Interestingly, this rule also maximized signal propagation in the presence of network-wide correlations, suggesting a mechanism by which cortex could deal with common random background input. These are the first results to show that the extent to

  13. Design of memristive interface between electronic neurons

    Science.gov (United States)

    Gerasimova, S. A.; Mikhaylov, A. N.; Belov, A. I.; Korolev, D. S.; Guseinov, D. V.; Lebedeva, A. V.; Gorshkov, O. N.; Kazantsev, V. B.

    2018-05-01

    Nonlinear dynamics of two electronic oscillators coupled via a memristive device has been investigated. Such model mimics the interaction between synaptically coupled brain neurons with the memristive device imitating neuron axon. The synaptic connection is provided by the adaptive behavior of memristive device that changes its resistance under the action of spike-like activity. Mathematical model of such a memristive interface has been developed to describe and predict the experimentally observed regularities of forced synchronization of neuron-like oscillators.

  14. Mirror neurons: From origin to function

    OpenAIRE

    Cook, R; Bird, G; Catmur, C; Press, C; Heyes, C

    2014-01-01

    This article argues that mirror neurons originate in sensorimotor associative learning and therefore a new approach is needed to investigate their functions. Mirror neurons were discovered about 20 years ago in the monkey brain, and there is now evidence that they are also present in the human brain. The intriguing feature of many mirror neurons is that they fire not only when the animal is performing an action, such as grasping an object using a power grip, but also when the animal passively...

  15. Geometrical Determinants of Neuronal Actin Waves

    OpenAIRE

    Tomba, Caterina; Bra?ni, C?line; Bugnicourt, Ghislain; Cohen, Floriane; Friedrich, Benjamin M.; Gov, Nir S.; Villard, Catherine

    2017-01-01

    Hippocampal neurons produce in their early stages of growth propagative, actin-rich dynamical structures called actin waves. The directional motion of actin waves from the soma to the tip of neuronal extensions has been associated with net forward growth, and ultimately with the specification of neurites into axon and dendrites. Here, geometrical cues are used to control actin wave dynamics by constraining neurons on adhesive stripes of various widths. A key observable, the average time betwe...

  16. The Relevance of AgRP Neuron-Derived GABA Inputs to POMC Neurons Differs for Spontaneous and Evoked Release

    OpenAIRE

    Rau, Andrew R.; Hentges, Shane T.

    2017-01-01

    Hypothalamic agouti-related peptide (AgRP) neurons potently stimulate food intake, whereas proopiomelanocortin (POMC) neurons inhibit feeding. Whether AgRP neurons exert their orexigenic actions, at least in part, by inhibiting anorexigenic POMC neurons remains unclear. Here, the connectivity between GABA-releasing AgRP neurons and POMC neurons was examined in brain slices from male and female mice. GABA-mediated spontaneous IPSCs (sIPSCs) in POMC neurons were unaffected by disturbing GABA re...

  17. Performance limitations of relay neurons.

    Directory of Open Access Journals (Sweden)

    Rahul Agarwal

    Full Text Available Relay cells are prevalent throughout sensory systems and receive two types of inputs: driving and modulating. The driving input contains receptive field properties that must be transmitted while the modulating input alters the specifics of transmission. For example, the visual thalamus contains relay neurons that receive driving inputs from the retina that encode a visual image, and modulating inputs from reticular activating system and layer 6 of visual cortex that control what aspects of the image will be relayed back to visual cortex for perception. What gets relayed depends on several factors such as attentional demands and a subject's goals. In this paper, we analyze a biophysical based model of a relay cell and use systems theoretic tools to construct analytic bounds on how well the cell transmits a driving input as a function of the neuron's electrophysiological properties, the modulating input, and the driving signal parameters. We assume that the modulating input belongs to a class of sinusoidal signals and that the driving input is an irregular train of pulses with inter-pulse intervals obeying an exponential distribution. Our analysis applies to any [Formula: see text] order model as long as the neuron does not spike without a driving input pulse and exhibits a refractory period. Our bounds on relay reliability contain performance obtained through simulation of a second and third order model, and suggest, for instance, that if the frequency of the modulating input increases or the DC offset decreases, then relay increases. Our analysis also shows, for the first time, how the biophysical properties of the neuron (e.g. ion channel dynamics define the oscillatory patterns needed in the modulating input for appropriately timed relay of sensory information. In our discussion, we describe how our bounds predict experimentally observed neural activity in the basal ganglia in (i health, (ii in Parkinson's disease (PD, and (iii in PD during

  18. Neurosemantics, neurons and system theory.

    Science.gov (United States)

    Breidbach, Olaf

    2007-08-01

    Following the concept of internal representations, signal processing in a neuronal system has to be evaluated exclusively based on internal system characteristics. Thus, this approach omits the external observer as a control function for sensory integration. Instead, the configuration of the system and its computational performance are the effects of endogenous factors. Such self-referential operation is due to a strictly local computation in a network and, thereby, computations follow a set of rules that constitute the emergent behaviour of the system. These rules can be shown to correspond to a "logic" that is intrinsic to the system, an idea which provides the basis for neurosemantics.

  19. Neuronal involvement in cisplatin neuropathy

    DEFF Research Database (Denmark)

    Krarup-Hansen, A; Helweg-Larsen, Susanne Elisabeth; Schmalbruch, H

    2007-01-01

    Although it is well known that cisplatin causes a sensory neuropathy, the primary site of involvement is not established. The clinical symptoms localized in a stocking-glove distribution may be explained by a length dependent neuronopathy or by a distal axonopathy. To study whether the whole neuron...... of the foot evoked by a tactile probe showed similar changes to those observed in SNAPs evoked by electrical stimulation. At these doses, somatosensory evoked potentials (SEPs) from the tibial nerve had increased latencies of peripheral, spinal and central responses suggesting loss of central processes...

  20. A New Population of Parvocellular Oxytocin Neurons Controlling Magnocellular Neuron Activity and Inflammatory Pain Processing.

    Science.gov (United States)

    Eliava, Marina; Melchior, Meggane; Knobloch-Bollmann, H Sophie; Wahis, Jérôme; da Silva Gouveia, Miriam; Tang, Yan; Ciobanu, Alexandru Cristian; Triana Del Rio, Rodrigo; Roth, Lena C; Althammer, Ferdinand; Chavant, Virginie; Goumon, Yannick; Gruber, Tim; Petit-Demoulière, Nathalie; Busnelli, Marta; Chini, Bice; Tan, Linette L; Mitre, Mariela; Froemke, Robert C; Chao, Moses V; Giese, Günter; Sprengel, Rolf; Kuner, Rohini; Poisbeau, Pierrick; Seeburg, Peter H; Stoop, Ron; Charlet, Alexandre; Grinevich, Valery

    2016-03-16

    Oxytocin (OT) is a neuropeptide elaborated by the hypothalamic paraventricular (PVN) and supraoptic (SON) nuclei. Magnocellular OT neurons of these nuclei innervate numerous forebrain regions and release OT into the blood from the posterior pituitary. The PVN also harbors parvocellular OT cells that project to the brainstem and spinal cord, but their function has not been directly assessed. Here, we identified a subset of approximately 30 parvocellular OT neurons, with collateral projections onto magnocellular OT neurons and neurons of deep layers of the spinal cord. Evoked OT release from these OT neurons suppresses nociception and promotes analgesia in an animal model of inflammatory pain. Our findings identify a new population of OT neurons that modulates nociception in a two tier process: (1) directly by release of OT from axons onto sensory spinal cord neurons and inhibiting their activity and (2) indirectly by stimulating OT release from SON neurons into the periphery. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Mechanisms of Neuronal Apoptosis In Vivo

    National Research Council Canada - National Science Library

    Martin, Lee J

    2004-01-01

    .... Neuronal cell death in the form of apoptosis or necrosis occurs after exposure to neurotoxins, chemical warfare agents, radiation, viruses, and after seizures, trauma, limb amputation, and hypoxic...

  2. Autosomal dominant adult neuronal ceroid lipofuscinosis

    NARCIS (Netherlands)

    Nijssen, Peter C.G.

    2011-01-01

    this thesis investigates a family with autosomal dominant neuronal ceroid lipofuscinosis, with chapters on clinical neurology, neuropathology, neurogenetics, neurophysiology, auditory and visual aspects.

  3. Neurochemistry of olivocochlear neurons in the hamster.

    Science.gov (United States)

    Reuss, Stefan; Disque-Kaiser, Ursula; Antoniou-Lipfert, Patricia; Gholi, Maryam Najaf; Riemann, Elke; Riemann, Randolf

    2009-04-01

    The present study was conducted to characterize the superior olivary complex (SOC) of the lower brain stem in the pigmented Djungarian hamster Phodopus sungorus. Using Nissl-stained serial cryostat sections from fresh-frozen brains, we determined the borders of the SOC nuclei. We also identified olivocochlear (OC) neurons by retrograde neuronal tracing upon injection of Fluoro-Gold into the scala tympani. To evaluate the SOC as a putative source of neuronal nitric oxide synthase (nNOS), arginine-vasopressin (AVP), oxytocin (OT), vasoactive intestinal polypeptide (VIP), or pituitary adenylate cyclase-activating polypeptide (PACAP) that were all found in the cochlea, we conducted immunohistochemistry on sections exhibiting retrogradely labeled neurons. We did not observe AVP-, OT-, or VIP-immunoreactivity, neither in OC neurons nor in the SOC at all, revealing that cochlear AVP, OT, and VIP are of nonolivary origin. However, we found nNOS, the enzyme responsible for nitric oxide synthesis in neurons, and PACAP in neuronal perikarya of the SOC. Retrogradely labeled neurons of the lateral olivocochlear (LOC) system in the lateral superior olive did not contain PACAP and were only infrequently nNOS-immunoreactive. In contrast, some shell neurons and some of the medial OC (MOC) system exhibited immunofluorescence for either substance. Our data obtained from the dwarf hamster Phodopus sungorus confirm previous observations that a part of the LOC system is nitrergic. They further demonstrate that the medial olivocochlear system is partly nitrergic and use PACAP as neurotransmitter or modulator.

  4. Mirror neurons and language in schizophrenia

    OpenAIRE

    Bendová, Marie

    2016-01-01

    Mirror neurons are a specific kind of visuomotor neurons that are involved in action execution and also in action perception. The mirror mechanism is linked to a variety of complex psychological functions such as social-cognitive functions and language. People with schizophrenia have often difficulties both in mirror neuron system and in language skills. In the first part of our research we studied the connectivity of mirror neuron areas (such as IFG, STG, PMC, SMC and so on) by fMRI in resti...

  5. Beyond Critical Exponents in Neuronal Avalanches

    Science.gov (United States)

    Friedman, Nir; Butler, Tom; Deville, Robert; Beggs, John; Dahmen, Karin

    2011-03-01

    Neurons form a complex network in the brain, where they interact with one another by firing electrical signals. Neurons firing can trigger other neurons to fire, potentially causing avalanches of activity in the network. In many cases these avalanches have been found to be scale independent, similar to critical phenomena in diverse systems such as magnets and earthquakes. We discuss models for neuronal activity that allow for the extraction of testable, statistical predictions. We compare these models to experimental results, and go beyond critical exponents.

  6. Glutamate mediated astrocytic filtering of neuronal activity.

    Directory of Open Access Journals (Sweden)

    Gilad Wallach

    2014-12-01

    Full Text Available Neuron-astrocyte communication is an important regulatory mechanism in various brain functions but its complexity and role are yet to be fully understood. In particular, the temporal pattern of astrocyte response to neuronal firing has not been fully characterized. Here, we used neuron-astrocyte cultures on multi-electrode arrays coupled to Ca2+ imaging and explored the range of neuronal stimulation frequencies while keeping constant the amount of stimulation. Our results reveal that astrocytes specifically respond to the frequency of neuronal stimulation by intracellular Ca2+ transients, with a clear onset of astrocytic activation at neuron firing rates around 3-5 Hz. The cell-to-cell heterogeneity of the astrocyte Ca2+ response was however large and increasing with stimulation frequency. Astrocytic activation by neurons was abolished with antagonists of type I metabotropic glutamate receptor, validating the glutamate-dependence of this neuron-to-astrocyte pathway. Using a realistic biophysical model of glutamate-based intracellular calcium signaling in astrocytes, we suggest that the stepwise response is due to the supralinear dynamics of intracellular IP3 and that the heterogeneity of the responses may be due to the heterogeneity of the astrocyte-to-astrocyte couplings via gap junction channels. Therefore our results present astrocyte intracellular Ca2+ activity as a nonlinear integrator of glutamate-dependent neuronal activity.

  7. Glutamate Mediated Astrocytic Filtering of Neuronal Activity

    Science.gov (United States)

    Herzog, Nitzan; De Pittà, Maurizio; Jacob, Eshel Ben; Berry, Hugues; Hanein, Yael

    2014-01-01

    Neuron-astrocyte communication is an important regulatory mechanism in various brain functions but its complexity and role are yet to be fully understood. In particular, the temporal pattern of astrocyte response to neuronal firing has not been fully characterized. Here, we used neuron-astrocyte cultures on multi-electrode arrays coupled to Ca2+ imaging and explored the range of neuronal stimulation frequencies while keeping constant the amount of stimulation. Our results reveal that astrocytes specifically respond to the frequency of neuronal stimulation by intracellular Ca2+ transients, with a clear onset of astrocytic activation at neuron firing rates around 3-5 Hz. The cell-to-cell heterogeneity of the astrocyte Ca2+ response was however large and increasing with stimulation frequency. Astrocytic activation by neurons was abolished with antagonists of type I metabotropic glutamate receptor, validating the glutamate-dependence of this neuron-to-astrocyte pathway. Using a realistic biophysical model of glutamate-based intracellular calcium signaling in astrocytes, we suggest that the stepwise response is due to the supralinear dynamics of intracellular IP3 and that the heterogeneity of the responses may be due to the heterogeneity of the astrocyte-to-astrocyte couplings via gap junction channels. Therefore our results present astrocyte intracellular Ca2+ activity as a nonlinear integrator of glutamate-dependent neuronal activity. PMID:25521344

  8. Spiking Neurons for Analysis of Patterns

    Science.gov (United States)

    Huntsberger, Terrance

    2008-01-01

    Artificial neural networks comprising spiking neurons of a novel type have been conceived as improved pattern-analysis and pattern-recognition computational systems. These neurons are represented by a mathematical model denoted the state-variable model (SVM), which among other things, exploits a computational parallelism inherent in spiking-neuron geometry. Networks of SVM neurons offer advantages of speed and computational efficiency, relative to traditional artificial neural networks. The SVM also overcomes some of the limitations of prior spiking-neuron models. There are numerous potential pattern-recognition, tracking, and data-reduction (data preprocessing) applications for these SVM neural networks on Earth and in exploration of remote planets. Spiking neurons imitate biological neurons more closely than do the neurons of traditional artificial neural networks. A spiking neuron includes a central cell body (soma) surrounded by a tree-like interconnection network (dendrites). Spiking neurons are so named because they generate trains of output pulses (spikes) in response to inputs received from sensors or from other neurons. They gain their speed advantage over traditional neural networks by using the timing of individual spikes for computation, whereas traditional artificial neurons use averages of activity levels over time. Moreover, spiking neurons use the delays inherent in dendritic processing in order to efficiently encode the information content of incoming signals. Because traditional artificial neurons fail to capture this encoding, they have less processing capability, and so it is necessary to use more gates when implementing traditional artificial neurons in electronic circuitry. Such higher-order functions as dynamic tasking are effected by use of pools (collections) of spiking neurons interconnected by spike-transmitting fibers. The SVM includes adaptive thresholds and submodels of transport of ions (in imitation of such transport in biological

  9. Life-long stability of neurons: a century of research on neurogenesis, neuronal death and neuron quantification in adult CNS.

    Science.gov (United States)

    Turlejski, Kris; Djavadian, Ruzanna

    2002-01-01

    In this chapter we provide an extensive review of 100 years of research on the stability of neurons in the mammalian brain, with special emphasis on humans. Although Cajal formulated the Neuronal Doctrine, he was wrong in his beliefs that adult neurogenesis did not occur and adult neurons are dying throughout life. These two beliefs became accepted "common knowledge" and have shaped much of neuroscience research and provided much of the basis for clinical treatment of age-related brain diseases. In this review, we consider adult neurogenesis from a historical and evolutionary perspective. It is concluded, that while adult neurogenesis is a factor in the dynamics of the dentate gyrus and olfactory bulb, it is probably not a major factor during the life-span in most brain areas. Likewise, the acceptance of neuronal death as an explanation for normal age-related senility is challenged with evidence collected over the last fifty years. Much of the problem in changing this common belief of dying neurons was the inadequacies of neuronal counting methods. In this review we discuss in detail implications of recent improvements in neuronal quantification. We conclude: First, age-related neuronal atrophy is the major factor in functional deterioration of existing neurons and could be slowed down, or even reversed by various pharmacological interventions. Second, in most cases neuronal degeneration during aging is a pathology that in principle may be avoided. Third, loss of myelin and of the white matter is more frequent and important than the limited neuronal death in normal aging.

  10. Endorphinic neurons are contacting the tuberoinfundibular dopaminergic neurons in the rat brain

    International Nuclear Information System (INIS)

    Morel, G.; Pelletier, G.

    1986-01-01

    The anatomical relationships between endorphinic neurons and dopaminergic neurons were evaluated in the rat hypothalamus using a combination of immunocytochemistry and autoradiography. In the arcuate nucleus, endorphinic endings were seen making contacts with dopaminergic cell bodies and dendrites. No synapsis could be observed at the sites of contacts. These results strongly suggest that the endorphinic neurons are directly acting on dopaminergic neurons to modify the release of dopamine into the pituitary portal system

  11. Discrimination of communication vocalizations by single neurons and groups of neurons in the auditory midbrain.

    Science.gov (United States)

    Schneider, David M; Woolley, Sarah M N

    2010-06-01

    Many social animals including songbirds use communication vocalizations for individual recognition. The perception of vocalizations depends on the encoding of complex sounds by neurons in the ascending auditory system, each of which is tuned to a particular subset of acoustic features. Here, we examined how well the responses of single auditory neurons could be used to discriminate among bird songs and we compared discriminability to spectrotemporal tuning. We then used biologically realistic models of pooled neural responses to test whether the responses of groups of neurons discriminated among songs better than the responses of single neurons and whether discrimination by groups of neurons was related to spectrotemporal tuning and trial-to-trial response variability. The responses of single auditory midbrain neurons could be used to discriminate among vocalizations with a wide range of abilities, ranging from chance to 100%. The ability to discriminate among songs using single neuron responses was not correlated with spectrotemporal tuning. Pooling the responses of pairs of neurons generally led to better discrimination than the average of the two inputs and the most discriminating input. Pooling the responses of three to five single neurons continued to improve neural discrimination. The increase in discriminability was largest for groups of neurons with similar spectrotemporal tuning. Further, we found that groups of neurons with correlated spike trains achieved the largest gains in discriminability. We simulated neurons with varying levels of temporal precision and measured the discriminability of responses from single simulated neurons and groups of simulated neurons. Simulated neurons with biologically observed levels of temporal precision benefited more from pooling correlated inputs than did neurons with highly precise or imprecise spike trains. These findings suggest that pooling correlated neural responses with the levels of precision observed in the

  12. BigNeuron: Large-scale 3D Neuron Reconstruction from Optical Microscopy Images

    OpenAIRE

    Peng, Hanchuan; Hawrylycz, Michael; Roskams, Jane; Hill, Sean; Spruston, Nelson; Meijering, Erik; Ascoli, Giorgio A.

    2015-01-01

    textabstractUnderstanding the structure of single neurons is critical for understanding how they function within neural circuits. BigNeuron is a new community effort that combines modern bioimaging informatics, recent leaps in labeling and microscopy, and the widely recognized need for openness and standardization to provide a community resource for automated reconstruction of dendritic and axonal morphology of single neurons. Understanding the structure of single neurons is critical for unde...

  13. Leptin Action on GABAergic Neurons Prevents Obesity and Reduces Inhibitory Tone to POMC Neurons

    OpenAIRE

    Vong, Linh; Ye, Chianping; Yang, Zongfang; Choi, Brian; Chua, Streamson; Lowell, Bradford B.

    2011-01-01

    Leptin acts in the brain to prevent obesity. The underlying neurocircuitry responsible for this is poorly understood, in part due to incomplete knowledge regarding first order, leptin-responsive neurons. To address this, we and others have been removing leptin receptors from candidate first order neurons. While functionally relevant neurons have been identified, the observed effects have been small suggesting that most first order neurons remain unidentified. Here we take an alternative appro...

  14. La red sobre trabajo infantil peligroso (Red Tip

    Directory of Open Access Journals (Sweden)

    Walter Varillas

    2003-01-01

    Full Text Available En el mundo, aproximadamente 351.7 millones de niños entre 5 y 17 años realizaban algún tipo de actividad económica, de ellos 170.5 millones (48.5% realizaban algún tipo de trabajo considerado peligroso. Un alto porcentaje se encuentra en la agricultura, otros en minas, manufacturas, ladrilleras, predominantemente en la economía informal. El Convenio 138 (cobre la edad mínima de admisión en el empleo de la OIT y el Convenio 182 (sobre las peores formas de trabajo infantil, definen como trabajo infantil peligroso el que puede afectar la salud, seguridad y moralidad de los menores. Estudios específicos sobre los menores muestran su susceptibilidad particular frente a los riesgos laborales, aumentando la peligrosidad para su normal desarrollo y crecimiento: "los niños no son adultos pequeños". Los profesionales de la seguridad y salud en el trabajo pueden colaborar con los profesionales y las organizaciones especializadas en el trabajo infantil, en la definición y caracterización de lo que significa el trabajo infantil peligroso. Para ello se ha conformado la Red sobre Trabajo Infantil Peligroso (Red TIP, con la finalidad de articular estos dos espacios, orientados a eliminar el trabajo infantil peligroso y rescatar al menor y devolverle la oportunidad de sonreír ahora y en el futuro.

  15. Red giants: then and now

    Science.gov (United States)

    Faulkner, John

    Fred Hoyle's work on the structure and evolution of red giants, particularly his pathbreaking contribution with Martin Schwarzschild (Hoyle and Schwarzschild 1955), is both lauded and critically assessed. In his later lectures and work with students in the early 1960s, Hoyle presented more physical ways of understanding some of the approximations used, and results obtained, in that seminal paper. Although later ideas by other investigators will be touched upon, Hoyle's viewpoint - that low-mass red giants are essentially white dwarfs with a serious mass-storage problem - is still extremely fruitful. Over the years, I have further developed his method of attack. Relatively recently, I have been able to deepen and broaden the approach, finally extending the theory to provide a unifying treatment of the structure of low-mass stars from the main sequence though both the red-giant and horizontal-branch phases of evolution. Many aspects of these stars that had remained puzzling, even mysterious, for decades have now fallen into place, and some questions have been answered that were not even posed before. With low-mass red giants as the simplest example, this recent work emphasizes that stars, in general, may have at least two distinct but very important centres: (I) a geometrical centre, and (II) a separate nuclear centre, residing in a shell outside a zero-luminosity dense core for example. This two-centre perspective leads to an explicit, analytical, asymptotic theory of low-mass red-giant structure. It enables one to appreciate that the problem of understanding why such stars become red giants is one of anticipating a remarkable yet natural structural bifurcation that occurs in them. This bifurcation occurs because of a combination of known and understandable facts just summarized namely that, following central hydrogen exhaustion, a thin nuclear-burning shell does develop outside a more-or-less dense core. In the resulting theory, both ρsh/ρolinec and

  16. Essential roles of mitochondrial depolarization in neuron loss through microglial activation and attraction toward neurons.

    Science.gov (United States)

    Nam, Min-Kyung; Shin, Hyun-Ah; Han, Ji-Hye; Park, Dae-Wook; Rhim, Hyangshuk

    2013-04-10

    As life spans increased, neurodegenerative disorders that affect aging populations have also increased. Progressive neuronal loss in specific brain regions is the most common cause of neurodegenerative disease; however, key determinants mediating neuron loss are not fully understood. Using a model of mitochondrial membrane potential (ΔΨm) loss, we found only 25% cell loss in SH-SY5Y (SH) neuronal mono-cultures, but interestingly, 85% neuronal loss occurred when neurons were co-cultured with BV2 microglia. SH neurons overexpressing uncoupling protein 2 exhibited an increase in neuron-microglia interactions, which represent an early step in microglial phagocytosis of neurons. This result indicates that ΔΨm loss in SH neurons is an important contributor to recruitment of BV2 microglia. Notably, we show that ΔΨm loss in BV2 microglia plays a crucial role in microglial activation and phagocytosis of damaged SH neurons. Thus, our study demonstrates that ΔΨm loss in both neurons and microglia is a critical determinant of neuron loss. These findings also offer new insights into neuroimmunological and bioenergetical aspects of neurodegenerative disease. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Cerebellar Nuclear Neurons Use Time and Rate Coding to Transmit Purkinje Neuron Pauses.

    Science.gov (United States)

    Sudhakar, Shyam Kumar; Torben-Nielsen, Benjamin; De Schutter, Erik

    2015-12-01

    Neurons of the cerebellar nuclei convey the final output of the cerebellum to their targets in various parts of the brain. Within the cerebellum their direct upstream connections originate from inhibitory Purkinje neurons. Purkinje neurons have a complex firing pattern of regular spikes interrupted by intermittent pauses of variable length. How can the cerebellar nucleus process this complex input pattern? In this modeling study, we investigate different forms of Purkinje neuron simple spike pause synchrony and its influence on candidate coding strategies in the cerebellar nuclei. That is, we investigate how different alignments of synchronous pauses in synthetic Purkinje neuron spike trains affect either time-locking or rate-changes in the downstream nuclei. We find that Purkinje neuron synchrony is mainly represented by changes in the firing rate of cerebellar nuclei neurons. Pause beginning synchronization produced a unique effect on nuclei neuron firing, while the effect of pause ending and pause overlapping synchronization could not be distinguished from each other. Pause beginning synchronization produced better time-locking of nuclear neurons for short length pauses. We also characterize the effect of pause length and spike jitter on the nuclear neuron firing. Additionally, we find that the rate of rebound responses in nuclear neurons after a synchronous pause is controlled by the firing rate of Purkinje neurons preceding it.

  18. Cerebellar Nuclear Neurons Use Time and Rate Coding to Transmit Purkinje Neuron Pauses

    Science.gov (United States)

    Sudhakar, Shyam Kumar; Torben-Nielsen, Benjamin; De Schutter, Erik

    2015-01-01

    Neurons of the cerebellar nuclei convey the final output of the cerebellum to their targets in various parts of the brain. Within the cerebellum their direct upstream connections originate from inhibitory Purkinje neurons. Purkinje neurons have a complex firing pattern of regular spikes interrupted by intermittent pauses of variable length. How can the cerebellar nucleus process this complex input pattern? In this modeling study, we investigate different forms of Purkinje neuron simple spike pause synchrony and its influence on candidate coding strategies in the cerebellar nuclei. That is, we investigate how different alignments of synchronous pauses in synthetic Purkinje neuron spike trains affect either time-locking or rate-changes in the downstream nuclei. We find that Purkinje neuron synchrony is mainly represented by changes in the firing rate of cerebellar nuclei neurons. Pause beginning synchronization produced a unique effect on nuclei neuron firing, while the effect of pause ending and pause overlapping synchronization could not be distinguished from each other. Pause beginning synchronization produced better time-locking of nuclear neurons for short length pauses. We also characterize the effect of pause length and spike jitter on the nuclear neuron firing. Additionally, we find that the rate of rebound responses in nuclear neurons after a synchronous pause is controlled by the firing rate of Purkinje neurons preceding it. PMID:26630202

  19. Stages of neuronal network formation

    International Nuclear Information System (INIS)

    Woiterski, Lydia; Käs, Josef A; Claudepierre, Thomas; Luxenhofer, Robert; Jordan, Rainer

    2013-01-01

    Graph theoretical approaches have become a powerful tool for investigating the architecture and dynamics of complex networks. The topology of network graphs revealed small-world properties for very different real systems among these neuronal networks. In this study, we observed the early development of mouse retinal ganglion cell (RGC) networks in vitro using time-lapse video microscopy. By means of a time-resolved graph theoretical analysis of the connectivity, shortest path length and the edge length, we were able to discover the different stages during the network formation. Starting from single cells, at the first stage neurons connected to each other ending up in a network with maximum complexity. In the further course, we observed a simplification of the network which manifested in a change of relevant network parameters such as the minimization of the path length. Moreover, we found that RGC networks self-organized as small-world networks at both stages; however, the optimization occurred only in the second stage. (paper)

  20. [Infantile autism and mirror neurons].

    Science.gov (United States)

    Cornelio-Nieto, J O

    2009-02-27

    Infantile autism is a disorder that is characterised by alterations affecting reciprocal social interactions, abnormal verbal and non-verbal communication, poor imaginative activity and a restricted repertoire of activities and interests. The causes of autism remain unknown, but there are a number of different approaches that attempt to explain the neurobiological causes of the syndrome. A recent theory that has been considered is that of a dysfunction in the mirror neuron system (MNS). The MNS is a neuronal complex, originally described in monkeys and also found in humans, that is related with our movements and which offers specific responses to the movements and intended movements of other subjects. This system is believed to underlie processes of imitation and our capacity to learn by imitation. It is also thought to play a role in language acquisition, in expressing the emotions, in understanding what is happening to others and in empathy. Because these functions are altered in children with autism, it has been suggested that there is some dysfunction present in the MNS of those with autism. Dysfunction of the MNS could account for the symptoms that are observed in children with autism.

  1. Activation of SF1 Neurons in the Ventromedial Hypothalamus by DREADD Technology Increases Insulin Sensitivity in Peripheral Tissues.

    Science.gov (United States)

    Coutinho, Eulalia A; Okamoto, Shiki; Ishikawa, Ayako Wendy; Yokota, Shigefumi; Wada, Nobuhiro; Hirabayashi, Takahiro; Saito, Kumiko; Sato, Tatsuya; Takagi, Kazuyo; Wang, Chen-Chi; Kobayashi, Kenta; Ogawa, Yoshihiro; Shioda, Seiji; Yoshimura, Yumiko; Minokoshi, Yasuhiko

    2017-09-01

    The ventromedial hypothalamus (VMH) regulates glucose and energy metabolism in mammals. Optogenetic stimulation of VMH neurons that express steroidogenic factor 1 (SF1) induces hyperglycemia. However, leptin acting via the VMH stimulates whole-body glucose utilization and insulin sensitivity in some peripheral tissues, and this effect of leptin appears to be mediated by SF1 neurons. We examined the effects of activation of SF1 neurons with DREADD (designer receptors exclusively activated by designer drugs) technology. Activation of SF1 neurons by an intraperitoneal injection of clozapine- N -oxide (CNO), a specific hM3Dq ligand, reduced food intake and increased energy expenditure in mice expressing hM3Dq in SF1 neurons. It also increased whole-body glucose utilization and glucose uptake in red-type skeletal muscle, heart, and interscapular brown adipose tissue, as well as glucose production and glycogen phosphorylase a activity in the liver, thereby maintaining blood glucose levels. During hyperinsulinemic-euglycemic clamp, such activation of SF1 neurons increased insulin-induced glucose uptake in the same peripheral tissues and tended to enhance insulin-induced suppression of glucose production by suppressing gluconeogenic gene expression and glycogen phosphorylase a activity in the liver. DREADD technology is thus an important tool for studies of the role of the brain in the regulation of insulin sensitivity in peripheral tissues. © 2017 by the American Diabetes Association.

  2. Inhibitory neurons modulate spontaneous signaling in cultured cortical neurons: density-dependent regulation of excitatory neuronal signaling

    International Nuclear Information System (INIS)

    Serra, Michael; Guaraldi, Mary; Shea, Thomas B

    2010-01-01

    Cortical neuronal activity depends on a balance between excitatory and inhibitory influences. Culturing of neurons on multi-electrode arrays (MEAs) has provided insight into the development and maintenance of neuronal networks. Herein, we seeded MEAs with murine embryonic cortical/hippocampal neurons at different densities ( 1000 cells mm −2 ) and monitored resultant spontaneous signaling. Sparsely seeded cultures displayed a large number of bipolar, rapid, high-amplitude individual signals with no apparent temporal regularity. By contrast, densely seeded cultures instead displayed clusters of signals at regular intervals. These patterns were observed even within thinner and thicker areas of the same culture. GABAergic neurons (25% of total neurons in our cultures) mediated the differential signal patterns observed above, since addition of the inhibitory antagonist bicuculline to dense cultures and hippocampal slice cultures induced the signal pattern characteristic of sparse cultures. Sparsely seeded cultures likely lacked sufficient inhibitory neurons to modulate excitatory activity. Differential seeding of MEAs can provide a unique model for analyses of pertubation in the interaction between excitatory and inhibitory function during aging and neuropathological conditions where dysregulation of GABAergic neurons is a significant component

  3. Iridotomy with red krypton laser.

    Science.gov (United States)

    Yassur, Y; David, R; Rosenblatt, I; Marmour, U

    1986-01-01

    Iridotomy with red krypton laser instead of blue-green argon laser was performed on 68 eyes with various types of angle-closure glaucoma. Patent iridotomy was obtained in all the eyes, mostly in one working session. In eight eyes secondary closure by pigment needed reopening with a few applications at the iridotomy site. There were no immediate or late complications of importance, the main advantage of the technique being the avoidance of the corneal epithelial and endothelial burns which commonly occur during argon laser iridotomy, particularly when the anterior chamber is shallow. PMID:3964628

  4. Interactive Exploration for Continuously Expanding Neuron Databases.

    Science.gov (United States)

    Li, Zhongyu; Metaxas, Dimitris N; Lu, Aidong; Zhang, Shaoting

    2017-02-15

    This paper proposes a novel framework to help biologists explore and analyze neurons based on retrieval of data from neuron morphological databases. In recent years, the continuously expanding neuron databases provide a rich source of information to associate neuronal morphologies with their functional properties. We design a coarse-to-fine framework for efficient and effective data retrieval from large-scale neuron databases. In the coarse-level, for efficiency in large-scale, we employ a binary coding method to compress morphological features into binary codes of tens of bits. Short binary codes allow for real-time similarity searching in Hamming space. Because the neuron databases are continuously expanding, it is inefficient to re-train the binary coding model from scratch when adding new neurons. To solve this problem, we extend binary coding with online updating schemes, which only considers the newly added neurons and update the model on-the-fly, without accessing the whole neuron databases. In the fine-grained level, we introduce domain experts/users in the framework, which can give relevance feedback for the binary coding based retrieval results. This interactive strategy can improve the retrieval performance through re-ranking the above coarse results, where we design a new similarity measure and take the feedback into account. Our framework is validated on more than 17,000 neuron cells, showing promising retrieval accuracy and efficiency. Moreover, we demonstrate its use case in assisting biologists to identify and explore unknown neurons. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Neuron Morphology Influences Axon Initial Segment Plasticity.

    Science.gov (United States)

    Gulledge, Allan T; Bravo, Jaime J

    2016-01-01

    In most vertebrate neurons, action potentials are initiated in the axon initial segment (AIS), a specialized region of the axon containing a high density of voltage-gated sodium and potassium channels. It has recently been proposed that neurons use plasticity of AIS length and/or location to regulate their intrinsic excitability. Here we quantify the impact of neuron morphology on AIS plasticity using computational models of simplified and realistic somatodendritic morphologies. In small neurons (e.g., dentate granule neurons), excitability was highest when the AIS was of intermediate length and located adjacent to the soma. Conversely, neurons having larger dendritic trees (e.g., pyramidal neurons) were most excitable when the AIS was longer and/or located away from the soma. For any given somatodendritic morphology, increasing dendritic membrane capacitance and/or conductance favored a longer and more distally located AIS. Overall, changes to AIS length, with corresponding changes in total sodium conductance, were far more effective in regulating neuron excitability than were changes in AIS location, while dendritic capacitance had a larger impact on AIS performance than did dendritic conductance. The somatodendritic influence on AIS performance reflects modest soma-to-AIS voltage attenuation combined with neuron size-dependent changes in AIS input resistance, effective membrane time constant, and isolation from somatodendritic capacitance. We conclude that the impact of AIS plasticity on neuron excitability will depend largely on somatodendritic morphology, and that, in some neurons, a shorter or more distally located AIS may promote, rather than limit, action potential generation.

  6. Neuromodulation and mitochondrial transport: live imaging in hippocampal neurons over long durations.

    Science.gov (United States)

    Edelman, David B; Owens, Geoffrey C; Chen, Sigeng

    2011-06-17

    with a lentivirus encoding a red fluorescent protein that is targeted to the mitochondrion. This assures a strong and persistent signal, which, in conjunction with the use of a stable xenon light source, allows us to limit exposure times during image acquisition and all but precludes photobleaching and phototoxicity. Two injection ports on the top of the stage-top incubator allow the acute administration of neurotransmitters and other reagents intended to modulate mitochondrial movement. In sum, lentivirus-mediated expression of an organelle-targeted red fluorescent protein and the combination of our stage-top incubator, a conventional inverted fluorescence microscope, CCD camera, and xenon light source allow us to acquire time-lapse images of mitochondrial transport in living neurons over longer durations than those possible in studies deploying conventional vital dyes and off-the-shelf life support systems.

  7. Red is Romantic, but Only for Feminine Females: Sexual Dimorphism Moderates Red Effect on Sexual Attraction

    Directory of Open Access Journals (Sweden)

    Fangfang Wen

    2014-10-01

    Full Text Available Previous researchers have documented that the color red enhances one's sexual attraction to the opposite sex. The current study further examined the moderating role of sexual dimorphism in red effects. The results indicated that red enhanced men's sexual attraction to women with more feminine facial characteristics but had no effect on ratings of perceived general attractiveness. Red clothing also had a marginally significant effect on men's sexual attractiveness. In addition, regardless of sexual dimorphism cues, male participants rated women with red as warmer and more competent. The underlying mechanisms of the red effect, the limitations of the current study, and suggestions for future directions are discussed.

  8. Adsorption of procion red and congo red dyes using microalgae Spirulina sp

    Directory of Open Access Journals (Sweden)

    Risfidian Mohadi

    2017-10-01

    Full Text Available Adsorption of procion red and congo red dyes using microalgae Spirulina sp was conducted. Spirulina sp was obtained by cultivation and production in laboratory scale. Spirulina sp was used as adsorbent for adsorption of dyes. Adsorption process was studied by kinetic and thermodynamic in order to know the adsorption phenomena. The results showed that kinetically congo red is reactive than procion red on Spirulina sp. On the other hand, thermodynamically procion red was stable than congo red on Spirulina sp which was indicated by adsorption capacity, enthalpy, and entropy.

  9. Intratelencephalic corticostriatal neurons equally excite striatonigral and striatopallidal neurons and their discharge activity is selectively reduced in experimental parkinsonism

    OpenAIRE

    Ballion, B. (B.); Mallet, N. (Nicolas); Bezard, E. (E.); Lanciego, J.L. (José Luis); Gonon, F. (Francois)

    2008-01-01

    Striatonigral and striatopallidal neurons form distinct populations of striatal projection neurons. Their discharge activity is imbalanced after dopaminergic degeneration in Parkinson's disease. Striatal projection neurons receive massive cortical excitatory inputs from bilateral intratelencephalic (IT) neurons projecting to both the ipsilateral and contralateral striatum and from collateral axons of ipsilateral neurons that send their main axon through the pyramidal tract (PT). Previous anat...

  10. Heavy metals in locus ceruleus and motor neurons in motor neuron disease.

    Science.gov (United States)

    Pamphlett, Roger; Kum Jew, Stephen

    2013-12-12

    The causes of sporadic amyotrophic lateral sclerosis (SALS) and other types of motor neuron disease (MND) remain largely unknown. Heavy metals have long been implicated in MND, and it has recently been shown that inorganic mercury selectively enters human locus ceruleus (LC) and motor neurons. We therefore used silver nitrate autometallography (AMG) to look for AMG-stainable heavy metals (inorganic mercury and bismuth) in LC and motor neurons of 24 patients with MND (18 with SALS and 6 with familial MND) and in the LC of 24 controls. Heavy metals in neurons were found in significantly more MND patients than in controls when comparing: (1) the presence of any versus no heavy metal-containing LC neurons (MND 88%, controls 42%), (2) the median percentage of heavy metal-containing LC neurons (MND 9.5%, control 0.0%), and (3) numbers of individuals with heavy metal-containing LC neurons in the upper half of the percentage range (MND 75%, controls 25%). In MND patients, 67% of remaining spinal motor neurons contained heavy metals; smaller percentages were found in hypoglossal, nucleus ambiguus and oculomotor neurons, but none in cortical motor neurons. The majority of MND patients had heavy metals in both LC and spinal motor neurons. No glia or other neurons, including neuromelanin-containing neurons of the substantia nigra, contained stainable heavy metals. Uptake of heavy metals by LC and lower motor neurons appears to be fairly common in humans, though heavy metal staining in the LC, most likely due to inorganic mercury, was seen significantly more often in MND patients than in controls. The LC innervates many cell types that are affected in MND, and it is possible that MND is triggered by toxicant-induced interactions between LC and motor neurons.

  11. Heavy metals in locus ceruleus and motor neurons in motor neuron disease

    Science.gov (United States)

    2013-01-01

    Background The causes of sporadic amyotrophic lateral sclerosis (SALS) and other types of motor neuron disease (MND) remain largely unknown. Heavy metals have long been implicated in MND, and it has recently been shown that inorganic mercury selectively enters human locus ceruleus (LC) and motor neurons. We therefore used silver nitrate autometallography (AMG) to look for AMG-stainable heavy metals (inorganic mercury and bismuth) in LC and motor neurons of 24 patients with MND (18 with SALS and 6 with familial MND) and in the LC of 24 controls. Results Heavy metals in neurons were found in significantly more MND patients than in controls when comparing: (1) the presence of any versus no heavy metal-containing LC neurons (MND 88%, controls 42%), (2) the median percentage of heavy metal-containing LC neurons (MND 9.5%, control 0.0%), and (3) numbers of individuals with heavy metal-containing LC neurons in the upper half of the percentage range (MND 75%, controls 25%). In MND patients, 67% of remaining spinal motor neurons contained heavy metals; smaller percentages were found in hypoglossal, nucleus ambiguus and oculomotor neurons, but none in cortical motor neurons. The majority of MND patients had heavy metals in both LC and spinal motor neurons. No glia or other neurons, including neuromelanin-containing neurons of the substantia nigra, contained stainable heavy metals. Conclusions Uptake of heavy metals by LC and lower motor neurons appears to be fairly common in humans, though heavy metal staining in the LC, most likely due to inorganic mercury, was seen significantly more often in MND patients than in controls. The LC innervates many cell types that are affected in MND, and it is possible that MND is triggered by toxicant-induced interactions between LC and motor neurons. PMID:24330485

  12. Pulsed infrared radiation excites cultured neonatal spiral and vestibular ganglion neurons by modulating mitochondrial calcium cycling.

    Science.gov (United States)

    Lumbreras, Vicente; Bas, Esperanza; Gupta, Chhavi; Rajguru, Suhrud M

    2014-09-15

    Cochlear implants are currently the most effective solution for profound sensorineural hearing loss, and vestibular prostheses are under development to treat bilateral vestibulopathies. Electrical current spread in these neuroprostheses limits channel independence and, in some cases, may impair their performance. In comparison, optical stimuli that are spatially confined may result in a significant functional improvement. Pulsed infrared radiation (IR) has previously been shown to elicit responses in neurons. This study analyzes the response of neonatal rat spiral and vestibular ganglion neurons in vitro to IR (wavelength = 1,863 nm) using Ca(2+) imaging. Both types of neurons responded consistently with robust intracellular Ca(2+) ([Ca(2+)]i) transients that matched the low-frequency IR pulses applied (4 ms, 0.25-1 pps). Radiant exposures of ∼637 mJ/cm(2) resulted in continual neuronal activation. Temperature or [Ca(2+)] variations in the media did not alter the IR-evoked transients, ruling out extracellular Ca(2+) involvement or primary mediation by thermal effects on the plasma membrane. While blockage of Na(+), K(+), and Ca(2+) plasma membrane channels did not alter the IR-evoked response, blocking of mitochondrial Ca(2+) cycling with CGP-37157 or ruthenium red reversibly inhibited the IR-evoked [Ca(2+)]i transients. Additionally, the magnitude of the IR-evoked transients was dependent on ryanodine and cyclopiazonic acid-dependent Ca(2+) release. These results suggest that IR modulation of intracellular calcium cycling contributes to stimulation of spiral and vestibular ganglion neurons. As a whole, the results suggest selective excitation of neurons in the IR beam path and the potential of IR stimulation in future auditory and vestibular prostheses. Copyright © 2014 the American Physiological Society.

  13. Transfection in Primary Cultured Neuronal Cells.

    Science.gov (United States)

    Marwick, Katie F M; Hardingham, Giles E

    2017-01-01

    Transfection allows the introduction of foreign nucleic acid into eukaryotic cells. It is an important tool in understanding the roles of NMDARs in neurons. Here, we describe using lipofection-mediated transfection to introduce cDNA encoding NMDAR subunits into postmitotic rodent primary cortical neurons maintained in culture.

  14. IGF-1: elixir for motor neuron diseases.

    Science.gov (United States)

    Papanikolaou, Theodora; Ellerby, Lisa M

    2009-08-13

    Modulation of testosterone levels is a therapeutic approach for spinal and bulbar muscular atrophy (SBMA), a polyglutamine disorder that affects the motor neurons. The article by Palazzolo et al. in this issue of Neuron provides compelling evidence that the expression of insulin growth hormone is a potential therapeutic for SBMA.

  15. Neuromodulation of vertebrate motor neuron membrane properties

    DEFF Research Database (Denmark)

    Hultborn, Hans; Kiehn, Ole

    1992-01-01

    The short-term function of motor neurons is to integrate synaptic inputs converging onto the somato-dendritic membrane and to transform the net synaptic drive into spike trains. A set of voltage-gated ion channels determines the electro-responsiveness and thereby the motor neuron's input-output f...

  16. Neuronal hyperplasia in the anal canal

    DEFF Research Database (Denmark)

    Fenger, C; Schrøder, H D

    1990-01-01

    In a consecutive series of minor surgical specimens from the anal canal, neuronal hyperplasia was found in nine of 56 haemorrhoidectomy specimens and in four of 23 fibrous polyps. In an additional series of 14 resections of the anal canal, neuronal hyperplasia was present in six cases, of which f...

  17. Life and Death of a Neuron

    Science.gov (United States)

    ... order to clear debris. Hope Through Research Scientists hope that by understanding more about the life and death of neurons they can develop new ... NIH is appreciated. Patient & Caregiver Education ... Your Brain Preventing Stroke Understanding Sleep The Life and Death of a Neuron Genes At Work ...

  18. The Mirror Neuron System and Action Recognition

    Science.gov (United States)

    Buccino, Giovanni; Binkofski, Ferdinand; Riggio, Lucia

    2004-01-01

    Mirror neurons, first described in the rostral part of monkey ventral premotor cortex (area F5), discharge both when the animal performs a goal-directed hand action and when it observes another individual performing the same or a similar action. More recently, in the same area mirror neurons responding to the observation of mouth actions have been…

  19. Mirror neurons: functions, mechanisms and models.

    Science.gov (United States)

    Oztop, Erhan; Kawato, Mitsuo; Arbib, Michael A

    2013-04-12

    Mirror neurons for manipulation fire both when the animal manipulates an object in a specific way and when it sees another animal (or the experimenter) perform an action that is more or less similar. Such neurons were originally found in macaque monkeys, in the ventral premotor cortex, area F5 and later also in the inferior parietal lobule. Recent neuroimaging data indicate that the adult human brain is endowed with a "mirror neuron system," putatively containing mirror neurons and other neurons, for matching the observation and execution of actions. Mirror neurons may serve action recognition in monkeys as well as humans, whereas their putative role in imitation and language may be realized in human but not in monkey. This article shows the important role of computational models in providing sufficient and causal explanations for the observed phenomena involving mirror systems and the learning processes which form them, and underlines the need for additional circuitry to lift up the monkey mirror neuron circuit to sustain the posited cognitive functions attributed to the human mirror neuron system. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  20. Where do mirror neurons come from?

    Science.gov (United States)

    Heyes, Cecilia

    2010-03-01

    Debates about the evolution of the 'mirror neuron system' imply that it is an adaptation for action understanding. Alternatively, mirror neurons may be a byproduct of associative learning. Here I argue that the adaptation and associative hypotheses both offer plausible accounts of the origin of mirror neurons, but the associative hypothesis has three advantages. First, it provides a straightforward, testable explanation for the differences between monkeys and humans that have led some researchers to question the existence of a mirror neuron system. Second, it is consistent with emerging evidence that mirror neurons contribute to a range of social cognitive functions, but do not play a dominant, specialised role in action understanding. Finally, the associative hypothesis is supported by recent data showing that, even in adulthood, the mirror neuron system can be transformed by sensorimotor learning. The associative account implies that mirror neurons come from sensorimotor experience, and that much of this experience is obtained through interaction with others. Therefore, if the associative account is correct, the mirror neuron system is a product, as well as a process, of social interaction. (c) 2009 Elsevier Ltd. All rights reserved.

  1. Antibacterial Compounds from Red Seaweeds (Rhodophyta)

    OpenAIRE

    Noer Kasanah; Triyanto Triyanto; Drajad Sarwo Seto; Windi Amelia; Alim Isnansetyo

    2015-01-01

    Seaweeds produce great variety of metabolites benefit for human. Red seaweeds (Rhodophyta) are well known as producer of phycocolloids such agar, agarose, carragenan and great variety of secondary metabolites. This review discusses the red algal secondary metabolites with antibacterial activity. The chemical constituents of red algae are steroid, terpenoid, acetogenin and dominated by halogenated compounds mainly brominated compounds. Novel compounds with intriguing skeleton are also reported...

  2. Radiosensitivity of red flour beetle tribolium castaneum

    International Nuclear Information System (INIS)

    Sattar, A.; Khattak, S.; Hamed, M.

    1992-07-01

    In this report radiosensitivity of red beetle has been discussed. Red flour beetle is the most injurious pest causing great losses to stored grain. Radiation is one of the best tools of insect control. Different radiation doses (50 to 200 krads) were employed for different age groups from 1 to 60 days. It is concluded from these results that 200 krad radiation dose caused 100% mortality in red beetle in all age group. (A.B.)

  3. Nicotinic activation of laterodorsal tegmental neurons

    DEFF Research Database (Denmark)

    Ishibashi, Masaru; Leonard, Christopher S; Kohlmeier, Kristi A

    2009-01-01

    Identifying the neurological mechanisms underlying nicotine reinforcement is a healthcare imperative, if society is to effectively combat tobacco addiction. The majority of studies of the neurobiology of addiction have focused on dopamine (DA)-containing neurons of the ventral tegmental area (VTA......). However, recent data suggest that neurons of the laterodorsal tegmental (LDT) nucleus, which sends cholinergic, GABAergic, and glutamatergic-containing projections to DA-containing neurons of the VTA, are critical to gating normal functioning of this nucleus. The actions of nicotine on LDT neurons...... are unknown. We addressed this issue by examining the effects of nicotine on identified cholinergic and non-cholinergic LDT neurons using whole-cell patch clamp and Ca(2+)-imaging methods in brain slices from mice (P12-P45). Nicotine applied by puffer pipette or bath superfusion elicited membrane...

  4. Timing control by redundant inhibitory neuronal circuits

    Energy Technology Data Exchange (ETDEWEB)

    Tristan, I., E-mail: itristan@ucsd.edu; Rulkov, N. F.; Huerta, R.; Rabinovich, M. [BioCircuits Institute, University of California, San Diego, La Jolla, California 92093-0402 (United States)

    2014-03-15

    Rhythms and timing control of sequential activity in the brain is fundamental to cognition and behavior. Although experimental and theoretical studies support the understanding that neuronal circuits are intrinsically capable of generating different time intervals, the dynamical origin of the phenomenon of functionally dependent timing control is still unclear. Here, we consider a new mechanism that is related to the multi-neuronal cooperative dynamics in inhibitory brain motifs consisting of a few clusters. It is shown that redundancy and diversity of neurons within each cluster enhances the sensitivity of the timing control with the level of neuronal excitation of the whole network. The generality of the mechanism is shown to work on two different neuronal models: a conductance-based model and a map-based model.

  5. Neuronal migration, apoptosis and bipolar disorder.

    Science.gov (United States)

    Uribe, Ezequiel; Wix, Richard

    2012-01-01

    Bipolar disorder, like the majority of psychiatric disorders, is considered a neurodevelopment disease of neurodevelopment. There is an increased rate of neuronal birth and death during this development period. In the particular case of the processes that determine neuronal death, it is known that those neurons that establish connections have to be removed from the central nervous system. There is a deficit of GABAergic interneurons in the cerebral cortex in bipolar disorder, accompanied by overexpression of proapoptic genes. There is also an alteration in the expression of molecules that mediate in the migration of these neurons and their inclusion in functional synapsis during the foetal stage. The role of these molecules in the neuronal death pathways by apoptosis will be reviewed here in an attempt to establish biological hypotheses of the genesis of bipolar disorder. Copyright © 2011 SEP y SEPB. Published by Elsevier Espana. All rights reserved.

  6. Chromatin Regulation of Neuronal Maturation and Plasticity.

    Science.gov (United States)

    Gallegos, David A; Chan, Urann; Chen, Liang-Fu; West, Anne E

    2018-05-01

    Neurons are dynamic cells that respond and adapt to stimuli throughout their long postmitotic lives. The structural and functional plasticity of neurons requires the regulated transcription of new gene products, and dysregulation of transcription in either the developing or adult brain impairs cognition. We discuss how mechanisms of chromatin regulation help to orchestrate the transcriptional programs that underlie the maturation of developing neurons and the plasticity of adult neurons. We review how chromatin regulation acts locally to modulate the expression of specific genes and more broadly to coordinate gene expression programs during transitions between cellular states. These data highlight the importance of epigenetic transcriptional mechanisms in postmitotic neurons. We suggest areas where emerging methods may advance understanding in the future. Copyright © 2018 Elsevier Ltd. All rights reserved.

  7. A COMPUTATIONAL MODEL OF MOTOR NEURON DEGENERATION

    Science.gov (United States)

    Le Masson, Gwendal; Przedborski, Serge; Abbott, L.F.

    2014-01-01

    SUMMARY To explore the link between bioenergetics and motor neuron degeneration, we used a computational model in which detailed morphology and ion conductance are paired with intracellular ATP production and consumption. We found that reduced ATP availability increases the metabolic cost of a single action potential and disrupts K+/Na+ homeostasis, resulting in a chronic depolarization. The magnitude of the ATP shortage at which this ionic instability occurs depends on the morphology and intrinsic conductance characteristic of the neuron. If ATP shortage is confined to the distal part of the axon, the ensuing local ionic instability eventually spreads to the whole neuron and involves fasciculation-like spiking events. A shortage of ATP also causes a rise in intracellular calcium. Our modeling work supports the notion that mitochondrial dysfunction can account for salient features of the paralytic disorder amyotrophic lateral sclerosis, including motor neuron hyperexcitability, fasciculation, and differential vulnerability of motor neuron subpopulations. PMID:25088365

  8. A computational model of motor neuron degeneration.

    Science.gov (United States)

    Le Masson, Gwendal; Przedborski, Serge; Abbott, L F

    2014-08-20

    To explore the link between bioenergetics and motor neuron degeneration, we used a computational model in which detailed morphology and ion conductance are paired with intracellular ATP production and consumption. We found that reduced ATP availability increases the metabolic cost of a single action potential and disrupts K+/Na+ homeostasis, resulting in a chronic depolarization. The magnitude of the ATP shortage at which this ionic instability occurs depends on the morphology and intrinsic conductance characteristic of the neuron. If ATP shortage is confined to the distal part of the axon, the ensuing local ionic instability eventually spreads to the whole neuron and involves fasciculation-like spiking events. A shortage of ATP also causes a rise in intracellular calcium. Our modeling work supports the notion that mitochondrial dysfunction can account for salient features of the paralytic disorder amyotrophic lateral sclerosis, including motor neuron hyperexcitability, fasciculation, and differential vulnerability of motor neuron subpopulations. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Interaction function of coupled bursting neurons

    International Nuclear Information System (INIS)

    Shi Xia; Zhang Jiadong

    2016-01-01

    The interaction functions of electrically coupled Hindmarsh–Rose (HR) neurons for different firing patterns are investigated in this paper. By applying the phase reduction technique, the phase response curve (PRC) of the spiking neuron and burst phase response curve (BPRC) of the bursting neuron are derived. Then the interaction function of two coupled neurons can be calculated numerically according to the PRC (or BPRC) and the voltage time course of the neurons. Results show that the BPRC is more and more complicated with the increase of the spike number within a burst, and the curve of the interaction function oscillates more and more frequently with it. However, two certain things are unchanged: ϕ = 0, which corresponds to the in-phase synchronization state, is always the stable equilibrium, while the anti-phase synchronization state with ϕ = 0.5 is an unstable equilibrium. (paper)

  10. Timing control by redundant inhibitory neuronal circuits

    International Nuclear Information System (INIS)

    Tristan, I.; Rulkov, N. F.; Huerta, R.; Rabinovich, M.

    2014-01-01

    Rhythms and timing control of sequential activity in the brain is fundamental to cognition and behavior. Although experimental and theoretical studies support the understanding that neuronal circuits are intrinsically capable of generating different time intervals, the dynamical origin of the phenomenon of functionally dependent timing control is still unclear. Here, we consider a new mechanism that is related to the multi-neuronal cooperative dynamics in inhibitory brain motifs consisting of a few clusters. It is shown that redundancy and diversity of neurons within each cluster enhances the sensitivity of the timing control with the level of neuronal excitation of the whole network. The generality of the mechanism is shown to work on two different neuronal models: a conductance-based model and a map-based model

  11. Reflections on mirror neurons and speech perception

    Science.gov (United States)

    Lotto, Andrew J.; Hickok, Gregory S.; Holt, Lori L.

    2010-01-01

    The discovery of mirror neurons, a class of neurons that respond when a monkey performs an action and also when the monkey observes others producing the same action, has promoted a renaissance for the Motor Theory (MT) of speech perception. This is because mirror neurons seem to accomplish the same kind of one to one mapping between perception and action that MT theorizes to be the basis of human speech communication. However, this seeming correspondence is superficial, and there are theoretical and empirical reasons to temper enthusiasm about the explanatory role mirror neurons might have for speech perception. In fact, rather than providing support for MT, mirror neurons are actually inconsistent with the central tenets of MT. PMID:19223222

  12. Attractor dynamics in local neuronal networks

    Directory of Open Access Journals (Sweden)

    Jean-Philippe eThivierge

    2014-03-01

    Full Text Available Patterns of synaptic connectivity in various regions of the brain are characterized by the presence of synaptic motifs, defined as unidirectional and bidirectional synaptic contacts that follow a particular configuration and link together small groups of neurons. Recent computational work proposes that a relay network (two populations communicating via a third, relay population of neurons can generate precise patterns of neural synchronization. Here, we employ two distinct models of neuronal dynamics and show that simulated neural circuits designed in this way are caught in a global attractor of activity that prevents neurons from modulating their response on the basis of incoming stimuli. To circumvent the emergence of a fixed global attractor, we propose a mechanism of selective gain inhibition that promotes flexible responses to external stimuli. We suggest that local neuronal circuits may employ this mechanism to generate precise patterns of neural synchronization whose transient nature delimits the occurrence of a brief stimulus.

  13. Central auditory neurons have composite receptive fields.

    Science.gov (United States)

    Kozlov, Andrei S; Gentner, Timothy Q

    2016-02-02

    High-level neurons processing complex, behaviorally relevant signals are sensitive to conjunctions of features. Characterizing the receptive fields of such neurons is difficult with standard statistical tools, however, and the principles governing their organization remain poorly understood. Here, we demonstrate multiple distinct receptive-field features in individual high-level auditory neurons in a songbird, European starling, in response to natural vocal signals (songs). We then show that receptive fields with similar characteristics can be reproduced by an unsupervised neural network trained to represent starling songs with a single learning rule that enforces sparseness and divisive normalization. We conclude that central auditory neurons have composite receptive fields that can arise through a combination of sparseness and normalization in neural circuits. Our results, along with descriptions of random, discontinuous receptive fields in the central olfactory neurons in mammals and insects, suggest general principles of neural computation across sensory systems and animal classes.

  14. A single-neuron tracing study of arkypallidal and prototypic neurons in healthy rats.

    Science.gov (United States)

    Fujiyama, Fumino; Nakano, Takashi; Matsuda, Wakoto; Furuta, Takahiro; Udagawa, Jun; Kaneko, Takeshi

    2016-12-01

    The external globus pallidus (GP) is known as a relay nucleus of the indirect pathway of the basal ganglia. Recent studies in dopamine-depleted and healthy rats indicate that the GP comprises two main types of pallidofugal neurons: the so-called "prototypic" and "arkypallidal" neurons. However, the reconstruction of complete arkypallidal neurons in healthy rats has not been reported. Here we visualized the entire axonal arborization of four single arkypallidal neurons and six single prototypic neurons in rat brain using labeling with a viral vector expressing membrane-targeted green fluorescent protein and examined the distribution of axon boutons in the target nuclei. Results revealed that not only the arkypallidal neurons but nearly all of the prototypic neurons projected to the striatum with numerous axon varicosities. Thus, the striatum is a major target nucleus for pallidal neurons. Arkypallidal and prototypic GP neurons located in the calbindin-positive and calbindin-negative regions mainly projected to the corresponding positive and negative regions in the striatum. Because the GP and striatum calbindin staining patterns reflect the topographic organization of the striatopallidal projection, the striatal neurons in the sensorimotor and associative regions constitute the reciprocal connection with the GP neurons in the corresponding regions.

  15. Neuron-derived IgG protects neurons from complement-dependent cytotoxicity.

    Science.gov (United States)

    Zhang, Jie; Niu, Na; Li, Bingjie; McNutt, Michael A

    2013-12-01

    Passive immunity of the nervous system has traditionally been thought to be predominantly due to the blood-brain barrier. This concept must now be revisited based on the existence of neuron-derived IgG. The conventional concept is that IgG is produced solely by mature B lymphocytes, but it has now been found to be synthesized by murine and human neurons. However, the function of this endogenous IgG is poorly understood. In this study, we confirm IgG production by rat cortical neurons at the protein and mRNA levels, with 69.0 ± 5.8% of cortical neurons IgG-positive. Injury to primary-culture neurons was induced by complement leading to increases in IgG production. Blockage of neuron-derived IgG resulted in more neuronal death and early apoptosis in the presence of complement. In addition, FcγRI was found in microglia and astrocytes. Expression of FcγR I in microglia was increased by exposure to neuron-derived IgG. Release of NO from microglia triggered by complement was attenuated by neuron-derived IgG, and this attenuation could be reversed by IgG neutralization. These data demonstrate that neuron-derived IgG is protective of neurons against injury induced by complement and microglial activation. IgG appears to play an important role in maintaining the stability of the nervous system.

  16. Role of neuronal activity in regulating the structure and function of auditory neurons

    International Nuclear Information System (INIS)

    Born, D.E.

    1986-01-01

    The role of afferent activity in maintaining neuronal structure and function was investigated in second order auditory neurons in nucleus magnocellularis (NM) of the chicken. The cochlea provides the major excitatory input to NM neurons via the eighth nerve. Removal of the cochlea causes dramatic changes in NM neurons. To determine if the elimination of neuronal activity is responsible for the changes in NM seen after cochlea removal, tetrodotoxin was used block action potentials in the cochlear ganglion cells. Tetrodotoxin injections into the perilymph reliably blocked neuronal activity in the cochlear nerve and NM. Far field recordings of sound-evoked potentials revealed that responses returned within 6 hours. Changes in amino acid incorporation in NM neurons were measured by giving intracardiac injections of 3 H-leucine and preparing tissue for autoradiographic demonstration of incorporated amino acid. Grain counts over individual neurons revealed that a single injection of tetrodotoxin produced a 40% decrease in grain density in ipsilateral NM neurons. It is concluded that neuronal activity plays an important contribution to the maintenance of the normal properties of NM neurons

  17. Antibacterial Compounds from Red Seaweeds (Rhodophyta

    Directory of Open Access Journals (Sweden)

    Noer Kasanah

    2015-07-01

    Full Text Available Seaweeds produce great variety of metabolites benefit for human. Red seaweeds (Rhodophyta are well known as producer of phycocolloids such agar, agarose, carragenan and great variety of secondary metabolites. This review discusses the red algal secondary metabolites with antibacterial activity. The chemical constituents of red algae are steroid, terpenoid, acetogenin and dominated by halogenated compounds mainly brominated compounds. Novel compounds with intriguing skeleton are also reported such as bromophycolides and neurymenolides. In summary, red seaweeds are potential sources for antibacterial agents and can serve as lead in synthesis of new natural medicines.

  18. Infra Red 3D Computer Mouse

    DEFF Research Database (Denmark)

    Harbo, Anders La-Cour; Stoustrup, Jakob

    2000-01-01

    The infra red 3D mouse is a three dimensional input device to a computer. It works by determining the position of an arbitrary object (like a hand) by emitting infra red signals from a number of locations and measuring the reflected intensities. To maximize stability, robustness, and use of bandw......The infra red 3D mouse is a three dimensional input device to a computer. It works by determining the position of an arbitrary object (like a hand) by emitting infra red signals from a number of locations and measuring the reflected intensities. To maximize stability, robustness, and use...

  19. MRI of neuronal migration disorders

    International Nuclear Information System (INIS)

    Engelbrecht, V.

    1996-01-01

    Twenty-one MRI examinations of the brain were performed in 19 children with neuronal migration disorders. Multiplanar oriented spin-echo sequences were on a scanner with 1.5 T. In 8 children we performed an additional turbo-inversion recovery (TIR) sequence. Results of sonography or CT from five children were compared with MRI scans. Using the actual nomenclature, we found the following migration disorders: Lissencephaly (n=6), cobblestone lissencephaly with Walker-Warbung syndrome (WWS) (n=2), polymicrogyria and schizencephaly (n=2), focal heterotopia (n=5), diffuse heterotopie (n=2) and hemimegalencephaly (n=2). MRI was superior to CT and sonography in all children. Except for the two boys with WWS, the TIR sequence was the best to demonstrate the changes in migration disorder because of the high contrast between gray and white matter. We demonstrate the characteristic features of the different migration disorders and compare them with the existing literature. (orig.) [de

  20. Neuronal responses to physiological stress

    DEFF Research Database (Denmark)

    Kagias, Konstantinos; Nehammer, Camilla; Pocock, Roger David John

    2012-01-01

    damage during aging that results in decline and eventual death. Studies have shown that the nervous system plays a pivotal role in responding to stress. Neurons not only receive and process information from the environment but also actively respond to various stresses to promote survival. These responses......Physiological stress can be defined as any external or internal condition that challenges the homeostasis of a cell or an organism. It can be divided into three different aspects: environmental stress, intrinsic developmental stress, and aging. Throughout life all living organisms are challenged...... by changes in the environment. Fluctuations in oxygen levels, temperature, and redox state for example, trigger molecular events that enable an organism to adapt, survive, and reproduce. In addition to external stressors, organisms experience stress associated with morphogenesis and changes in inner...

  1. Responses of neurons to extreme osmomechanical stress.

    Science.gov (United States)

    Wan, X; Harris, J A; Morris, C E

    1995-05-01

    Neurons are often regarded as fragile cells, easily destroyed by mechanical and osmotic insult. The results presented here demonstrate that this perception needs revision. Using extreme osmotic swelling, we show that molluscan neurons are astonishingly robust. In distilled water, a heterogeneous population of Lymnaea stagnalis CNS neurons swelled to several times their initial volume, yet had a ST50 (survival time for 50% of cells) > 60 min. Cells that were initially bigger survived longer. On return to normal medium, survivors were able, over the next 24 hr, to rearborize. Reversible membrane capacitance changes corresponding to about 0.7 muF/cm2 of apparent surface area accompanied neuronal swelling and shrinking in hypo- and hyperosmotic solutions; reversible changes in cell surface area evidently contributed to the neurons' ability to accommodate hydrostatic pressures then recover. The reversible membrane area/capacitance changes were not dependent on extracellular Ca2+. Neurons were monitored for potassium currents during direct mechanical inflation and during osmotically driven inflation. The latter but not the former stimulus routinely elicited small potassium currents, suggesting that tension increases activate the currents only if additional disruption of the cortex has occurred. Under stress in distilled water, a third of the neurons displayed a quite unexpected behavior: prolonged writhing of peripheral regions of the soma. This suggested that a plasma membrane-linked contractile machinery (presumably actomyosin) might contribute to the neurons' mechano-osmotic robustness by restricting water influx. Consistent with this possibility, 1 mM N-ethyl-maleimide, which inhibits myosin ATPase, decreased the ST50 to 18 min, rendered the survival time independent of initial size, and abolished writhing activity. For neurons, active mechanical resistance of the submembranous cortex, along with the mechanical compliance supplied by insertion or eversion of membrane

  2. Mirror neurons: from origin to function.

    Science.gov (United States)

    Cook, Richard; Bird, Geoffrey; Catmur, Caroline; Press, Clare; Heyes, Cecilia

    2014-04-01

    This article argues that mirror neurons originate in sensorimotor associative learning and therefore a new approach is needed to investigate their functions. Mirror neurons were discovered about 20 years ago in the monkey brain, and there is now evidence that they are also present in the human brain. The intriguing feature of many mirror neurons is that they fire not only when the animal is performing an action, such as grasping an object using a power grip, but also when the animal passively observes a similar action performed by another agent. It is widely believed that mirror neurons are a genetic adaptation for action understanding; that they were designed by evolution to fulfill a specific socio-cognitive function. In contrast, we argue that mirror neurons are forged by domain-general processes of associative learning in the course of individual development, and, although they may have psychological functions, they do not necessarily have a specific evolutionary purpose or adaptive function. The evidence supporting this view shows that (1) mirror neurons do not consistently encode action "goals"; (2) the contingency- and context-sensitive nature of associative learning explains the full range of mirror neuron properties; (3) human infants receive enough sensorimotor experience to support associative learning of mirror neurons ("wealth of the stimulus"); and (4) mirror neurons can be changed in radical ways by sensorimotor training. The associative account implies that reliable information about the function of mirror neurons can be obtained only by research based on developmental history, system-level theory, and careful experimentation.

  3. Contribution of synchronized GABAergic neurons to dopaminergic neuron firing and bursting.

    Science.gov (United States)

    Morozova, Ekaterina O; Myroshnychenko, Maxym; Zakharov, Denis; di Volo, Matteo; Gutkin, Boris; Lapish, Christopher C; Kuznetsov, Alexey

    2016-10-01

    In the ventral tegmental area (VTA), interactions between dopamine (DA) and γ-aminobutyric acid (GABA) neurons are critical for regulating DA neuron activity and thus DA efflux. To provide a mechanistic explanation of how GABA neurons influence DA neuron firing, we developed a circuit model of the VTA. The model is based on feed-forward inhibition and recreates canonical features of the VTA neurons. Simulations revealed that γ-aminobutyric acid (GABA) receptor (GABAR) stimulation can differentially influence the firing pattern of the DA neuron, depending on the level of synchronization among GABA neurons. Asynchronous activity of GABA neurons provides a constant level of inhibition to the DA neuron and, when removed, produces a classical disinhibition burst. In contrast, when GABA neurons are synchronized by common synaptic input, their influence evokes additional spikes in the DA neuron, resulting in increased measures of firing and bursting. Distinct from previous mechanisms, the increases were not based on lowered firing rate of the GABA neurons or weaker hyperpolarization by the GABAR synaptic current. This phenomenon was induced by GABA-mediated hyperpolarization of the DA neuron that leads to decreases in intracellular calcium (Ca 2+ ) concentration, thus reducing the Ca 2+ -dependent potassium (K + ) current. In this way, the GABA-mediated hyperpolarization replaces Ca 2+ -dependent K + current; however, this inhibition is pulsatile, which allows the DA neuron to fire during the rhythmic pauses in inhibition. Our results emphasize the importance of inhibition in the VTA, which has been discussed in many studies, and suggest a novel mechanism whereby computations can occur locally. Copyright © 2016 the American Physiological Society.

  4. The acute stress response of red porgy, Pagrus pagrus, kept on a red or white background

    NARCIS (Netherlands)

    Salm, A.L. van der; Pavlidis, M; Flik, G.; Wendelaar Bonga, S.E.

    2005-01-01

    The skin colour of red porgy, Pagrus pagrus, can be modified by exposure to different background colours. Red and white background colours brighten the dark skin colour that develops under common culture conditions in red porgy. To assess whether skin colour is also modified by aquaculture related

  5. When red means go : non-normative effects of red under sensation seeking

    NARCIS (Netherlands)

    Mehta, R.; Demmers, J.; van Dolen, W.M.; Weinberg, C.B.

    Although previous research has identified red as the color of compliance, the current work proposes that this effect of red may not hold under high sensation-seeking propensity conditions. It is argued that the color red has the capability to induce arousal, which in turn has been shown to enhance a

  6. Control of poultry red mites

    DEFF Research Database (Denmark)

    Kilpinen, Ole; Steenberg, Tove

    2008-01-01

    The poultry red mite (PRM), Dermanyssus gallinae, is the most important ectoparasite in European egg production. The mites hide in cracks and crevices in the near vicinity of the resting places of the birds, coming out to feed mainly during the night. Under favourable conditions the population can...... grow rapidly, leading to serious problems. Large mite populations may cause anaemia or even death to the poultry, but also in lower numbers mites may be a nuisance to the birds causing decreased egg production and egg quality. Furthermore, they may have the potential of acting as reservoir......-pathogenic fungi and desiccant dust. The dust is diatomaceous earth (of natural origin), synthetic silica products or combinations of the two. The progress of the work with desiccant dusts will be reported. So far, 7 different products have been tested in the laboratory with regard to their efficacy, speed...

  7. Stochastic multiresonance in coupled excitable FHN neurons

    Science.gov (United States)

    Li, Huiyan; Sun, Xiaojuan; Xiao, Jinghua

    2018-04-01

    In this paper, effects of noise on Watts-Strogatz small-world neuronal networks, which are stimulated by a subthreshold signal, have been investigated. With the numerical simulations, it is surprisingly found that there exist several optimal noise intensities at which the subthreshold signal can be detected efficiently. This indicates the occurrence of stochastic multiresonance in the studied neuronal networks. Moreover, it is revealed that the occurrence of stochastic multiresonance has close relationship with the period of subthreshold signal Te and the noise-induced mean period of the neuronal networks T0. In detail, we find that noise could induce the neuronal networks to generate stochastic resonance for M times if Te is not very large and falls into the interval ( M × T 0 , ( M + 1 ) × T 0 ) with M being a positive integer. In real neuronal system, subthreshold signal detection is very meaningful. Thus, the obtained results in this paper could give some important implications on detecting subthreshold signal and propagating neuronal information in neuronal systems.

  8. Neuronal medium that supports basic synaptic functions and activity of human neurons in vitro.

    Science.gov (United States)

    Bardy, Cedric; van den Hurk, Mark; Eames, Tameji; Marchand, Cynthia; Hernandez, Ruben V; Kellogg, Mariko; Gorris, Mark; Galet, Ben; Palomares, Vanessa; Brown, Joshua; Bang, Anne G; Mertens, Jerome; Böhnke, Lena; Boyer, Leah; Simon, Suzanne; Gage, Fred H

    2015-05-19

    Human cell reprogramming technologies offer access to live human neurons from patients and provide a new alternative for modeling neurological disorders in vitro. Neural electrical activity is the essence of nervous system function in vivo. Therefore, we examined neuronal activity in media widely used to culture neurons. We found that classic basal media, as well as serum, impair action potential generation and synaptic communication. To overcome this problem, we designed a new neuronal medium (BrainPhys basal + serum-free supplements) in which we adjusted the concentrations of inorganic salts, neuroactive amino acids, and energetic substrates. We then tested that this medium adequately supports neuronal activity and survival of human neurons in culture. Long-term exposure to this physiological medium also improved the proportion of neurons that were synaptically active. The medium was designed to culture human neurons but also proved adequate for rodent neurons. The improvement in BrainPhys basal medium to support neurophysiological activity is an important step toward reducing the gap between brain physiological conditions in vivo and neuronal models in vitro.

  9. Protocol for culturing low density pure rat hippocampal neurons supported by mature mixed neuron cultures.

    Science.gov (United States)

    Yang, Qian; Ke, Yini; Luo, Jianhong; Tang, Yang

    2017-02-01

    primary hippocampal neuron cultures allow for subcellular morphological dissection, easy access to drug treatment and electrophysiology analysis of individual neurons, and is therefore an ideal model for the study of neuron physiology. While neuron and glia mixed cultures are relatively easy to prepare, pure neurons are particular hard to culture at low densities which are suitable for morphology studies. This may be due to a lack of neurotrophic factors such as brain derived neurotrophic factor (BDNF), neurotrophin-3 (NT3) and Glial cell line-derived neurotrophic factor (GDNF). In this study we used a two step protocol in which neuron-glia mixed cultures were initially prepared for maturation to support the growth of young neurons plated at very low densities. Our protocol showed that neurotrophic support resulted in physiologically functional hippocampal neurons with larger cell body, increased neurite length and decreased branching and complexity compared to cultures prepared using a conventional method. Our protocol provides a novel way to culture highly uniformed hippocampal neurons for acquiring high quality, neuron based data. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Survival motor neuron protein in motor neurons determines synaptic integrity in spinal muscular atrophy.

    Science.gov (United States)

    Martinez, Tara L; Kong, Lingling; Wang, Xueyong; Osborne, Melissa A; Crowder, Melissa E; Van Meerbeke, James P; Xu, Xixi; Davis, Crystal; Wooley, Joe; Goldhamer, David J; Lutz, Cathleen M; Rich, Mark M; Sumner, Charlotte J

    2012-06-20

    The inherited motor neuron disease spinal muscular atrophy (SMA) is caused by deficient expression of survival motor neuron (SMN) protein and results in severe muscle weakness. In SMA mice, synaptic dysfunction of both neuromuscular junctions (NMJs) and central sensorimotor synapses precedes motor neuron cell death. To address whether this synaptic dysfunction is due to SMN deficiency in motor neurons, muscle, or both, we generated three lines of conditional SMA mice with tissue-specific increases in SMN expression. All three lines of mice showed increased survival, weights, and improved motor behavior. While increased SMN expression in motor neurons prevented synaptic dysfunction at the NMJ and restored motor neuron somal synapses, increased SMN expression in muscle did not affect synaptic function although it did improve myofiber size. Together these data indicate that both peripheral and central synaptic integrity are dependent on motor neurons in SMA, but SMN may have variable roles in the maintenance of these different synapses. At the NMJ, it functions at the presynaptic terminal in a cell-autonomous fashion, but may be necessary for retrograde trophic signaling to presynaptic inputs onto motor neurons. Importantly, SMN also appears to function in muscle growth and/or maintenance independent of motor neurons. Our data suggest that SMN plays distinct roles in muscle, NMJs, and motor neuron somal synapses and that restored function of SMN at all three sites will be necessary for full recovery of muscle power.

  11. Glass promotes the differentiation of neuronal and non-neuronal cell types in the Drosophila eye

    Science.gov (United States)

    Morrison, Carolyn A.; Chen, Hao; Cook, Tiffany; Brown, Stuart

    2018-01-01

    Transcriptional regulators can specify different cell types from a pool of equivalent progenitors by activating distinct developmental programs. The Glass transcription factor is expressed in all progenitors in the developing Drosophila eye, and is maintained in both neuronal and non-neuronal cell types. Glass is required for neuronal progenitors to differentiate as photoreceptors, but its role in non-neuronal cone and pigment cells is unknown. To determine whether Glass activity is limited to neuronal lineages, we compared the effects of misexpressing it in neuroblasts of the larval brain and in epithelial cells of the wing disc. Glass activated overlapping but distinct sets of genes in these neuronal and non-neuronal contexts, including markers of photoreceptors, cone cells and pigment cells. Coexpression of other transcription factors such as Pax2, Eyes absent, Lozenge and Escargot enabled Glass to induce additional genes characteristic of the non-neuronal cell types. Cell type-specific glass mutations generated in cone or pigment cells using somatic CRISPR revealed autonomous developmental defects, and expressing Glass specifically in these cells partially rescued glass mutant phenotypes. These results indicate that Glass is a determinant of organ identity that acts in both neuronal and non-neuronal cells to promote their differentiation into functional components of the eye. PMID:29324767

  12. Parkin Mutations Reduce the Complexity of Neuronal Processes in iPSC-derived Human Neurons

    Science.gov (United States)

    Ren, Yong; Jiang, Houbo; Hu, Zhixing; Fan, Kevin; Wang, Jun; Janoschka, Stephen; Wang, Xiaomin; Ge, Shaoyu; Feng, Jian

    2015-01-01

    Parkinson’s disease (PD) is characterized by the degeneration of nigral dopaminergic (DA) neurons and non-DA neurons in many parts of the brain. Mutations of parkin, an E3 ubiquitin ligase that strongly binds to microtubules, are the most frequent cause of recessively inherited Parkinson’s disease. The lack of robust PD phenotype in parkin knockout mice suggests a unique vulnerability of human neurons to parkin mutations. Here, we show that the complexity of neuronal processes as measured by total neurite length, number of terminals, number of branch points and Sholl analysis, was greatly reduced in induced pluripotent stem cell (iPSC)-derived TH+ or TH− neurons from PD patients with parkin mutations. Consistent with these, microtubule stability was significantly decreased by parkin mutations in iPSC-derived neurons. Overexpression of parkin, but not its PD-linked mutant nor GFP, restored the complexity of neuronal processes and the stability of microtubules. Consistent with these, the microtubule-depolymerizing agent colchicine mimicked the effect of parkin mutations by decreasing neurite length and complexity in control neurons while the microtubule-stabilizing drug taxol mimicked the effect of parkin overexpression by enhancing the morphology of parkin-deficient neurons. The results suggest that parkin maintains the morphological complexity of human neurons by stabilizing microtubules. PMID:25332110

  13. Context-aware modeling of neuronal morphologies

    Directory of Open Access Journals (Sweden)

    Benjamin eTorben-Nielsen

    2014-09-01

    Full Text Available Neuronal morphologies are pivotal for brain functioning: physical overlap between dendrites and axons constrain the circuit topology, and the precise shape and composition of dendrites determine the integration of inputs to produce an output signal. At the same time, morphologies are highly diverse and variant. The variance, presumably, originates from neurons developing in a densely packed brain substrate where they interact (e.g., repulsion or attraction with other actors in this substrate. However, when studying neurons their context is never part of the analysis and they are treated as if they existed in isolation.Here we argue that to fully understand neuronal morphology and its variance it is important to consider neurons in relation to each other and to other actors in the surrounding brain substrate, i.e., their context. We propose a context-aware computational framework, NeuroMaC, in which large numbers of neurons can be grown simultaneously according to growth rules expressed in terms of interactions between the developing neuron and the surrounding brain substrate.As a proof of principle, we demonstrate that by using NeuroMaC we can generate accurate virtual morphologies of distinct classes both in isolation and as part of neuronal forests. Accuracy is validated against population statistics of experimentally reconstructed morphologies. We show that context-aware generation of neurons can explain characteristics of variation. Indeed, plausible variation is an inherent property of the morphologies generated by context-aware rules. We speculate about the applicability of this framework to investigate morphologies and circuits, to classify healthy and pathological morphologies, and to generate large quantities of morphologies for large-scale modeling.

  14. Nitrogen depletion in field red giants

    DEFF Research Database (Denmark)

    Masseron, T.; Lagarde, N.; Miglio, A.

    2017-01-01

    , the behaviour of nitrogen data along the evolution confirms the existence of non-canonical extramixing on the red giant branch (RGB) for all low-mass stars in the field. But more surprisingly, the data indicate that nitrogen has been depleted between the RGB tip and the red clump. This may suggest that some...

  15. Mycobacterium bovis Infection of Red Fox, France.

    Science.gov (United States)

    Michelet, Lorraine; De Cruz, Krystel; Hénault, Sylvie; Tambosco, Jennifer; Richomme, Céline; Réveillaud, Édouard; Gares, Hélène; Moyen, Jean-Louis; Boschiroli, María Laura

    2018-06-01

    Mycobacterium bovis infection in wild red foxes was found in southern France, where livestock and other wildlife species are infected. Foxes frequently interact with cattle but have been underestimated as a reservoir of M. bovis. Our results suggest a possible role of the red fox in the epidemiology of bovine tuberculosis.

  16. Red blood cell alloimmunization after blood transfusion

    NARCIS (Netherlands)

    Schonewille, Henk

    2008-01-01

    Current pretransfusion policy requires the patients’ serum to be tested for the presence of irregular red blood cell antibodies. In case of an antibody, red blood cells lacking the corresponding antigen are transfused after an antiglobulin crossmatch. The aim of the studies in this thesis is

  17. Moving Forward with Computational Red Teaming

    Science.gov (United States)

    2012-07-01

    Red Teaming is used across both public and private sectors and is not the sole domain of the military. Red Team Consulting (2011) notes that “the use...open for review. Consider also the context of application. Oh (2009) explains how globalisation , the rise of emerging powers, environmental

  18. Seeing red to being red: conserved genetic mechanism for red cone oil droplets and co-option for red coloration in birds and turtles.

    Science.gov (United States)

    Twyman, Hanlu; Valenzuela, Nicole; Literman, Robert; Andersson, Staffan; Mundy, Nicholas I

    2016-08-17

    Avian ketocarotenoid pigments occur in both the red retinal oil droplets that contribute to colour vision and bright red coloration used in signalling. Turtles are the only other tetrapods with red retinal oil droplets, and some also display red carotenoid-based coloration. Recently, the CYP2J19 gene was strongly implicated in ketocarotenoid synthesis in birds. Here, we investigate CYP2J19 evolution in relation to colour vision and red coloration in reptiles using genomic and expression data. We show that turtles, but not crocodiles or lepidosaurs, possess a CYP2J19 orthologue, which arose via gene duplication before turtles and archosaurs split, and which is strongly and specifically expressed in the ketocarotenoid-containing retina and red integument. We infer that CYP2J19 initially functioned in colour vision in archelosaurs and conclude that red ketocarotenoid-based coloration evolved independently in birds and turtles via gene regulatory changes of CYP2J19 Our results suggest that red oil droplets contributed to colour vision in dinosaurs and pterosaurs. © 2016 The Author(s).

  19. Improving Mineral Nutrition of Micropropagated Red Raspberry

    Science.gov (United States)

    In vitro propagation is important for fast multiplication of a wide range of nursery crops, including red raspberry. The variation in genetic background of the many red raspberry cultivars makes it difficult to successfully use one growth medium for all. Although most cultivars will grow on Murashig...

  20. Red Sea as a source for bioprospecting

    KAUST Repository

    Kodzius, Rimantas

    2015-01-01

    King-Abdullah University of Science and Technology (KAUST) is located on the shores of the Red Sea in Saudi Arabia. The Red Sea is well known for its unique environment, harboring various microbes capable of surviving in salty brines. We collected

  1. The Austrian x red pine hybrid

    Science.gov (United States)

    W. B. Critchfield

    1963-01-01

    The genetic improvement of red pine (Pinus resinosa Ait.) presents tree breeders with one of their most difficult problems. Not only is this valuable species remarkably uniform, but until 1955 it resisted all attempts to cross it with other pines. In that year red pine and Austrian pine (P. nigra var. austriaca [...

  2. Red Dirt Thinking on Aspiration and Success

    Science.gov (United States)

    Osborne, Sam; Guenther, John

    2013-01-01

    This article sets the scene for the series of five articles on "red dirt thinking". It first introduces the idea behind red dirt thinking as opposed to "blue sky thinking". Both accept that there are any number of creative and expansive solutions and possibilities to identified challenges--in this case, the challenge of…

  3. Human Red Cells With Paroxysmal Nocturnal Haemoglobinuria ...

    African Journals Online (AJOL)

    The purified cells were used as hosts for the culture of P.falciparum in vitro. Results show that GPI-linked molecules on the red cell surface are not required for the efficient entry of the parasites, and that the PNH red cells are competent to sustain the growth of P.falciparum. Nigerian Quarterly Journal of Hospital Medicine Vol ...

  4. La red sobre trabajo infantil peligroso (Red Tip The hazardous child labor network (Red Tip

    Directory of Open Access Journals (Sweden)

    Walter Varillas

    2003-01-01

    Full Text Available En el mundo, aproximadamente 351.7 millones de niños entre 5 y 17 años realizaban algún tipo de actividad económica, de ellos 170.5 millones (48.5% realizaban algún tipo de trabajo considerado peligroso. Un alto porcentaje se encuentra en la agricultura, otros en minas, manufacturas, ladrilleras, predominantemente en la economía informal. El Convenio 138 (cobre la edad mínima de admisión en el empleo de la OIT y el Convenio 182 (sobre las peores formas de trabajo infantil, definen como trabajo infantil peligroso el que puede afectar la salud, seguridad y moralidad de los menores. Estudios específicos sobre los menores muestran su susceptibilidad particular frente a los riesgos laborales, aumentando la peligrosidad para su normal desarrollo y crecimiento: "los niños no son adultos pequeños". Los profesionales de la seguridad y salud en el trabajo pueden colaborar con los profesionales y las organizaciones especializadas en el trabajo infantil, en la definición y caracterización de lo que significa el trabajo infantil peligroso. Para ello se ha conformado la Red sobre Trabajo Infantil Peligroso (Red TIP, con la finalidad de articular estos dos espacios, orientados a eliminar el trabajo infantil peligroso y rescatar al menor y devolverle la oportunidad de sonreír ahora y en el futuro.In the world, approximately 351.7 millions children between 5 and 17 years old work. Of them, 170,5 millions (48.5% work at the hazardous child labor forms. A high percentage is in agriculture, others in mines, manufactures, brick makers, predominantly in informal economy. The 138 Convention of ILO and the 182 Convention, define as hazardous child labor activities that can affect the health, safety and morality of the children. Studies on the children at work point out their particular susceptibility to some occupational risks, increasing the danger for their normal development and growth. "They are not little adults". The occupational health

  5. 21 CFR 640.10 - Red Blood Cells.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 7 2010-04-01 2010-04-01 false Red Blood Cells. 640.10 Section 640.10 Food and... ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Red Blood Cells § 640.10 Red Blood Cells. The proper name of this product shall be Red Blood Cells. The product is defined as red blood cells remaining...

  6. White dwarf-red dwarf binaries in the Galaxy

    NARCIS (Netherlands)

    Besselaar, E.J.M. van den

    2007-01-01

    This PhD thesis shows several studies on white dwarf - red dwarf binaries. White dwarfs are the end products of most stars and red dwarfs are normal hydrogen burning low-mass stars. White dwarf - red dwarf binaries are both blue (white dwarf) and red (red dwarf). Together with the fact that they are

  7. Evoking prescribed spike times in stochastic neurons

    Science.gov (United States)

    Doose, Jens; Lindner, Benjamin

    2017-09-01

    Single cell stimulation in vivo is a powerful tool to investigate the properties of single neurons and their functionality in neural networks. We present a method to determine a cell-specific stimulus that reliably evokes a prescribed spike train with high temporal precision of action potentials. We test the performance of this stimulus in simulations for two different stochastic neuron models. For a broad range of parameters and a neuron firing with intermediate firing rates (20-40 Hz) the reliability in evoking the prescribed spike train is close to its theoretical maximum that is mainly determined by the level of intrinsic noise.

  8. Response of spiking neurons to correlated inputs

    International Nuclear Information System (INIS)

    Moreno, Ruben; Rocha, Jaime de la; Renart, Alfonso; Parga, Nestor

    2002-01-01

    The effect of a temporally correlated afferent current on the firing rate of a leaky integrate-and-fire neuron is studied. This current is characterized in terms of rates, autocorrelations, and cross correlations, and correlation time scale τ c of excitatory and inhibitory inputs. The output rate ν out is calculated in the Fokker-Planck formalism in the limit of both small and large τ c compared to the membrane time constant τ of the neuron. By simulations we check the analytical results, provide an interpolation valid for all τ c , and study the neuron's response to rapid changes in the correlation magnitude

  9. From red giants to planetary nebulae

    International Nuclear Information System (INIS)

    Kwok, S.

    1982-01-01

    The transition from red giants to planetary nebulae is studied by comparing the spectral characteristics of red giant envelopes and planetary nebulae. Observational and theoretical evidence both suggest that remnants of red giant envelopes may still be present in planetary nebula systems and should have significant effects on their formation. The dynamical effects of the interaction of stellar winds from central stars of planetary nebulae with the remnant red giant envelopes are evaluated and the mechanism found to be capable of producing the observed masses and momenta of planetary nebulae. The observed mass-radii relation of planetary nebulae may also be best explained by the interacting winds model. The possibility that red giant mass loss, and therefore the production of planetary nebulae, is different between Population I and II systems is also discussed

  10. Red algae and their use in papermaking.

    Science.gov (United States)

    Seo, Yung-Bum; Lee, Youn-Woo; Lee, Chun-Han; You, Hack-Chul

    2010-04-01

    Gelidialian red algae, that contain rhizoidal filaments, except the family Gelidiellaceae were processed to make bleached pulps, which can be used as raw materials for papermaking. Red algae consist of rhizoidal filaments, cortical cells usually reddish in color, and medullary cells filled with mucilaginous carbohydrates. Red algae pulp consists of mostly rhizoidal filaments. Red algae pulp of high brightness can be produced by extracting mucilaginous carbohydrates after heating the algae in an aqueous medium and subsequently treating the extracted with bleaching chemicals. In this study, we prepared paper samples from bleached pulps obtained from two red algae species (Gelidium amansii and Gelidium corneum) and compared their properties to those of bleached wood chemical pulps. Copyright 2009 Elsevier Ltd. All rights reserved.

  11. The Relevance of AgRP Neuron-Derived GABA Inputs to POMC Neurons Differs for Spontaneous and Evoked Release.

    Science.gov (United States)

    Rau, Andrew R; Hentges, Shane T

    2017-08-02

    Hypothalamic agouti-related peptide (AgRP) neurons potently stimulate food intake, whereas proopiomelanocortin (POMC) neurons inhibit feeding. Whether AgRP neurons exert their orexigenic actions, at least in part, by inhibiting anorexigenic POMC neurons remains unclear. Here, the connectivity between GABA-releasing AgRP neurons and POMC neurons was examined in brain slices from male and female mice. GABA-mediated spontaneous IPSCs (sIPSCs) in POMC neurons were unaffected by disturbing GABA release from AgRP neurons either by cell type-specific deletion of the vesicular GABA transporter or by expression of botulinum toxin in AgRP neurons to prevent vesicle-associated membrane protein 2-dependent vesicle fusion. Additionally, there was no difference in the ability of μ-opioid receptor (MOR) agonists to inhibit sIPSCs in POMC neurons when MORs were deleted from AgRP neurons, and activation of the inhibitory designer receptor hM4Di on AgRP neurons did not affect sIPSCs recorded from POMC neurons. These approaches collectively indicate that AgRP neurons do not significantly contribute to the strong spontaneous GABA input to POMC neurons. Despite these observations, optogenetic stimulation of AgRP neurons reliably produced evoked IPSCs in POMC neurons, leading to the inhibition of POMC neuron firing. Thus, AgRP neurons can potently affect POMC neuron function without contributing a significant source of spontaneous GABA input to POMC neurons. Together, these results indicate that the relevance of GABAergic inputs from AgRP to POMC neurons is state dependent and highlight the need to consider different types of transmitter release in circuit mapping and physiologic regulation. SIGNIFICANCE STATEMENT Agouti-related peptide (AgRP) neurons play an important role in driving food intake, while proopiomelanocortin (POMC) neurons inhibit feeding. Despite the importance of these two well characterized neuron types in maintaining metabolic homeostasis, communication between these

  12. Red and Green Fluorescence from Oral Biofilms.

    Science.gov (United States)

    Volgenant, Catherine M C; Hoogenkamp, Michel A; Krom, Bastiaan P; Janus, Marleen M; Ten Cate, Jacob M; de Soet, Johannes J; Crielaard, Wim; van der Veen, Monique H

    2016-01-01

    Red and green autofluorescence have been observed from dental plaque after excitation by blue light. It has been suggested that this red fluorescence is related to caries and the cariogenic potential of dental plaque. Recently, it was suggested that red fluorescence may be related to gingivitis. Little is known about green fluorescence from biofilms. Therefore, we assessed the dynamics of red and green fluorescence in real-time during biofilm formation. In addition, the fluorescence patterns of biofilm formed from saliva of eight different donors are described under simulated gingivitis and caries conditions. Biofilm formation was analysed for 12 hours under flow conditions in a microfluidic BioFlux flow system with high performance microscopy using a camera to allow live cell imaging. For fluorescence images dedicated excitation and emission filters were used. Both green and red fluorescence were linearly related with the total biomass of the biofilms. All biofilms displayed to some extent green and red fluorescence, with higher red and green fluorescence intensities from biofilms grown in the presence of serum (gingivitis simulation) as compared to the sucrose grown biofilms (cariogenic simulation). Remarkably, cocci with long chain lengths, presumably streptococci, were observed in the biofilms. Green and red fluorescence were not found homogeneously distributed within the biofilms: highly fluorescent spots (both green and red) were visible throughout the biomass. An increase in red fluorescence from the in vitro biofilms appeared to be related to the clinical inflammatory response of the respective saliva donors, which was previously assessed during an in vivo period of performing no-oral hygiene. The BioFlux model proved to be a reliable model to assess biofilm fluorescence. With this model, a prediction can be made whether a patient will be prone to the development of gingivitis or caries.

  13. Red and Green Fluorescence from Oral Biofilms.

    Directory of Open Access Journals (Sweden)

    Catherine M C Volgenant

    Full Text Available Red and green autofluorescence have been observed from dental plaque after excitation by blue light. It has been suggested that this red fluorescence is related to caries and the cariogenic potential of dental plaque. Recently, it was suggested that red fluorescence may be related to gingivitis. Little is known about green fluorescence from biofilms. Therefore, we assessed the dynamics of red and green fluorescence in real-time during biofilm formation. In addition, the fluorescence patterns of biofilm formed from saliva of eight different donors are described under simulated gingivitis and caries conditions. Biofilm formation was analysed for 12 hours under flow conditions in a microfluidic BioFlux flow system with high performance microscopy using a camera to allow live cell imaging. For fluorescence images dedicated excitation and emission filters were used. Both green and red fluorescence were linearly related with the total biomass of the biofilms. All biofilms displayed to some extent green and red fluorescence, with higher red and green fluorescence intensities from biofilms grown in the presence of serum (gingivitis simulation as compared to the sucrose grown biofilms (cariogenic simulation. Remarkably, cocci with long chain lengths, presumably streptococci, were observed in the biofilms. Green and red fluorescence were not found homogeneously distributed within the biofilms: highly fluorescent spots (both green and red were visible throughout the biomass. An increase in red fluorescence from the in vitro biofilms appeared to be related to the clinical inflammatory response of the respective saliva donors, which was previously assessed during an in vivo period of performing no-oral hygiene. The BioFlux model proved to be a reliable model to assess biofilm fluorescence. With this model, a prediction can be made whether a patient will be prone to the development of gingivitis or caries.

  14. Red Misfits in the Sloan Digital Sky Survey: properties of star-forming red galaxies

    Science.gov (United States)

    Evans, Fraser A.; Parker, Laura C.; Roberts, Ian D.

    2018-06-01

    We study Red Misfits, a population of red, star-forming galaxies in the local Universe. We classify galaxies based on inclination-corrected optical colours and specific star formation rates derived from the Sloan Digital Sky Survey Data Release 7. Although the majority of blue galaxies are star-forming and most red galaxies exhibit little to no ongoing star formation, a small but significant population of galaxies (˜11 per cent at all stellar masses) are classified as red in colour yet actively star-forming. We explore a number of properties of these galaxies and demonstrate that Red Misfits are not simply dusty or highly inclined blue cloud galaxies or quiescent red galaxies with poorly constrained star formation. The proportion of Red Misfits is nearly independent of environment, and this population exhibits both intermediate morphologies and an enhanced likelihood of hosting an active galactic nucleus. We conclude that Red Misfits are a transition population, gradually quenching on their way to the red sequence and this quenching is dominated by internal processes rather than environmentally driven processes. We discuss the connection between Red Misfits and other transition galaxy populations, namely S0s, red spirals, and green valley galaxies.

  15. Effect of correlating adjacent neurons for identifying communications: Feasibility experiment in a cultured neuronal network

    OpenAIRE

    Yoshi Nishitani; Chie Hosokawa; Yuko Mizuno-Matsumoto; Tomomitsu Miyoshi; Shinichi Tamura

    2017-01-01

    Neuronal networks have fluctuating characteristics, unlike the stable characteristics seen in computers. The underlying mechanisms that drive reliable communication among neuronal networks and their ability to perform intelligible tasks remain unknown. Recently, in an attempt to resolve this issue, we showed that stimulated neurons communicate via spikes that propagate temporally, in the form of spike trains. We named this phenomenon “spike wave propagation”. In these previous studies, using ...

  16. Reconstruction of phrenic neuron identity in embryonic stem cell-derived motor neurons.

    Science.gov (United States)

    Machado, Carolina Barcellos; Kanning, Kevin C; Kreis, Patricia; Stevenson, Danielle; Crossley, Martin; Nowak, Magdalena; Iacovino, Michelina; Kyba, Michael; Chambers, David; Blanc, Eric; Lieberam, Ivo

    2014-02-01

    Air breathing is an essential motor function for vertebrates living on land. The rhythm that drives breathing is generated within the central nervous system and relayed via specialised subsets of spinal motor neurons to muscles that regulate lung volume. In mammals, a key respiratory muscle is the diaphragm, which is innervated by motor neurons in the phrenic nucleus. Remarkably, relatively little is known about how this crucial subtype of motor neuron is generated during embryogenesis. Here, we used direct differentiation of motor neurons from mouse embryonic stem cells as a tool to identify genes that direct phrenic neuron identity. We find that three determinants, Pou3f1, Hoxa5 and Notch, act in combination to promote a phrenic neuron molecular identity. We show that Notch signalling induces Pou3f1 in developing motor neurons in vitro and in vivo. This suggests that the phrenic neuron lineage is established through a local source of Notch ligand at mid-cervical levels. Furthermore, we find that the cadherins Pcdh10, which is regulated by Pou3f1 and Hoxa5, and Cdh10, which is controlled by Pou3f1, are both mediators of like-like clustering of motor neuron cell bodies. This specific Pcdh10/Cdh10 activity might provide the means by which phrenic neurons are assembled into a distinct nucleus. Our study provides a framework for understanding how phrenic neuron identity is conferred and will help to generate this rare and inaccessible yet vital neuronal subtype directly from pluripotent stem cells, thus facilitating subsequent functional investigations.

  17. Fitting neuron models to spike trains

    Directory of Open Access Journals (Sweden)

    Cyrille eRossant

    2011-02-01

    Full Text Available Computational modeling is increasingly used to understand the function of neural circuitsin systems neuroscience.These studies require models of individual neurons with realisticinput-output properties.Recently, it was found that spiking models can accurately predict theprecisely timed spike trains produced by cortical neurons in response tosomatically injected currents,if properly fitted. This requires fitting techniques that are efficientand flexible enough to easily test different candidate models.We present a generic solution, based on the Brian simulator(a neural network simulator in Python, which allowsthe user to define and fit arbitrary neuron models to electrophysiological recordings.It relies on vectorization and parallel computing techniques toachieve efficiency.We demonstrate its use on neural recordings in the barrel cortex andin the auditory brainstem, and confirm that simple adaptive spiking modelscan accurately predict the response of cortical neurons. Finally, we show how a complexmulticompartmental model can be reduced to a simple effective spiking model.

  18. Toward functional classification of neuronal types.

    Science.gov (United States)

    Sharpee, Tatyana O

    2014-09-17

    How many types of neurons are there in the brain? This basic neuroscience question remains unsettled despite many decades of research. Classification schemes have been proposed based on anatomical, electrophysiological, or molecular properties. However, different schemes do not always agree with each other. This raises the question of whether one can classify neurons based on their function directly. For example, among sensory neurons, can a classification scheme be devised that is based on their role in encoding sensory stimuli? Here, theoretical arguments are outlined for how this can be achieved using information theory by looking at optimal numbers of cell types and paying attention to two key properties: correlations between inputs and noise in neural responses. This theoretical framework could help to map the hierarchical tree relating different neuronal classes within and across species. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. From quantum entanglement to mirror neuron

    International Nuclear Information System (INIS)

    Zak, Michail

    2007-01-01

    It is proposed that two fundamental phenomena: quantum entanglement in physics, and mirror neuron in biopsychology, can be described by using the same mathematical formalism, namely, the feedback from the Liouville equation to equation of motion

  20. Do enteric neurons make hypocretin? ☆

    Science.gov (United States)

    Baumann, Christian R.; Clark, Erika L.; Pedersen, Nigel P.; Hecht, Jonathan L.; Scammell, Thomas E.

    2008-01-01

    Hypocretins (orexins) are wake-promoting neuropeptides produced by hypothalamic neurons. These hypocretin-producing cells are lost in people with narcolepsy, possibly due to an autoimmune attack. Prior studies described hypocretin neurons in the enteric nervous system, and these cells could be an additional target of an autoimmune process. We sought to determine whether enteric hypocretin neurons are lost in narcoleptic subjects. Even though we tried several methods (including whole mounts, sectioned tissue, pre-treatment of mice with colchicine, and the use of various primary antisera), we could not identify hypocretin-producing cells in enteric nervous tissue collected from mice or normal human subjects. These results raise doubts about whether enteric neurons produce hypocretin. PMID:18191238

  1. Advances in 3D neuronal cell culture

    NARCIS (Netherlands)

    Frimat, Jean Philippe; Xie, Sijia; Bastiaens, Alex; Schurink, Bart; Wolbers, Floor; Den Toonder, Jaap; Luttge, Regina

    2015-01-01

    In this contribution, the authors present our advances in three-dimensional (3D) neuronal cell culture platform technology contributing to controlled environments for microtissue engineering and analysis of cellular physiological and pathological responses. First, a micromachined silicon sieving

  2. Review Paper: Polyphenolic Antioxidants and Neuronal Regeneration

    Directory of Open Access Journals (Sweden)

    Amin Ataie

    2016-05-01

    Full Text Available Many studies indicate that oxidative stress is involved in the pathophysiology of neurodegenerative diseases. Oxidative stress can induce neuronal damages, modulate intracellular signaling and ultimately leads to neuronal death by apoptosis or necrosis. To review antioxidants preventive effects on oxidative stress and neurodegenerative diseases we accumulated data from international medical journals and academic informations' sites. According to many studies, antioxidants could reduce toxic neuronal damages and many studies confirmed the efficacy of polyphenol antioxidants in fruits and vegetables to reduce neuronal death and to diminish oxidative stress. This systematic review showed the antioxidant activities of phytochemicals which play as natural neuroprotectives with low adverse effects against some neurodegenerative diseases as Parkinson or Alzheimer diseases.

  3. Review Paper: Polyphenolic Antioxidants and Neuronal Regeneration

    Directory of Open Access Journals (Sweden)

    Amin Ataie

    2016-04-01

    Full Text Available Many studies indicate that oxidative stress is involved in the pathophysiology of neurodegenerative diseases. Oxidative stress can induce neuronal damages, modulate intracellular signaling and ultimately leads to neuronal death by apoptosis or necrosis. To review antioxidants preventive effects on oxidative stress and neurodegenerative diseases we accumulated data from international medical journals and academic informations' sites. According to many studies, antioxidants could reduce toxic neuronal damages and many studies confirmed the efficacy of polyphenol antioxidants in fruits and vegetables to reduce neuronal death and to diminish oxidative stress. This systematic review showed the antioxidant activities of phytochemicals which play as natural neuroprotectives with low adverse effects against some neurodegenerative diseases as Parkinson or Alzheimer diseases.

  4. Proteomic Analysis of the Neurotrophic Effect of Gelidium amansii in Primary Cultured Neurons.

    Science.gov (United States)

    Hannan, Md Abdul; Mohibbullah, Md; Hong, Yong-Ki; Moon, Il Soo

    2017-03-01

    Gelidium amansii is an edible and economically important red alga consumed in South Eastern Asia. In previous studies, we reported that the ethanol extracts of G. amansii (GAE) has promising modulatory activity with respect to the morphological and functional maturation of hippocampal neurons in culture. In this study, we show that the chloroform (CHCl 3 ) subfraction of GAE and the ethyl acetate (EtOAc) fraction dose-dependently promoted neurite outgrowth, and their effects were comparable with that of GAE. We further assessed in cultured cortical neurons, proteins differentially expressed in the presence/absence of the GAE, CHCl 3 subfraction, and the EtOAc fraction by 2D-PAGE and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Proteomic data revealed that a number of proteins responsible for multiple cellular and biochemical functions vital for neuronal development and maturation were significantly upregulated in neurons treated with the GAE, CHCl 3 subfraction, and the EtOAc fraction. Of the identified proteins, profilin 2a, septin 7, cdc42, protein phosphatase 2A, DA11, eukaryotic translation initiation factor 5A-1, and γ-enolase are known to play important roles in neuritogenesis and dendritic arborization. Immunofluorescence data demonstrate that GAE-treated hippocampal neurons showed greater intensity ratios in the expressions of the septin 7 and cdc42 compared to vehicle control, validating their proteomic profiles. Together these results suggest that the GAE/CHCl 3 subfraction and EtOAc fraction promote neurite development by up or downregulating several key proteins.

  5. AgRP neurons regulate development of dopamine neuronal plasticity and nonfood-associated behaviors

    Science.gov (United States)

    Dietrich, Marcelo O; Bober, Jeremy; Ferreira, Jozélia G; Tellez, Luis A; Mineur, Yann S; Souza, Diogo O; Gao, Xiao-Bing; Picciotto, Marina R; Araújo, Ivan; Liu, Zhong-Wu; Horvath, Tamas L

    2012-01-01

    It is not known whether behaviors unrelated to feeding are affected by hypothalamic regulators of hunger. We found that impairment of Agouti-related protein (AgRP) circuitry by either Sirt1 knockdown in AgRP-expressing neurons or early postnatal ablation of these neurons increased exploratory behavior and enhanced responses to cocaine. In AgRP circuit–impaired mice, ventral tegmental dopamine neurons exhibited enhanced spike timing–dependent long-term potentiation, altered amplitude of miniature postsynaptic currents and elevated dopamine in basal forebrain. Thus, AgRP neurons determine the set point of the reward circuitry and associated behaviors. PMID:22729177

  6. Labeling of neuronal differentiation and neuron cells with biocompatible fluorescent nanodiamonds.

    Science.gov (United States)

    Hsu, Tzu-Chia; Liu, Kuang-Kai; Chang, Huan-Cheng; Hwang, Eric; Chao, Jui-I

    2014-05-16

    Nanodiamond is a promising carbon nanomaterial developed for biomedical applications. Here, we show fluorescent nanodiamond (FND) with the biocompatible properties that can be used for the labeling and tracking of neuronal differentiation and neuron cells derived from embryonal carcinoma stem (ECS) cells. The fluorescence intensities of FNDs were increased by treatment with FNDs in both the mouse P19 and human NT2/D1 ECS cells. FNDs were taken into ECS cells; however, FNDs did not alter the cellular morphology and growth ability. Moreover, FNDs did not change the protein expression of stem cell marker SSEA-1 of ECS cells. The neuronal differentiation of ECS cells could be induced by retinoic acid (RA). Interestingly, FNDs did not affect on the morphological alteration, cytotoxicity and apoptosis during the neuronal differentiation. Besides, FNDs did not alter the cell viability and the expression of neuron-specific marker β-III-tubulin in these differentiated neuron cells. The existence of FNDs in the neuron cells can be identified by confocal microscopy and flow cytometry. Together, FND is a biocompatible and readily detectable nanomaterial for the labeling and tracking of neuronal differentiation process and neuron cells from stem cells.

  7. Neuronal growth on L- and D-cysteine self-assembled monolayers reveals neuronal chiral sensitivity.

    Science.gov (United States)

    Baranes, Koby; Moshe, Hagay; Alon, Noa; Schwartz, Shmulik; Shefi, Orit

    2014-05-21

    Studying the interaction between neuronal cells and chiral molecules is fundamental for the design of novel biomaterials and drugs. Chirality influences all biological processes that involve intermolecular interaction. One common method used to study cellular interactions with different enantiomeric targets is the use of chiral surfaces. Based on previous studies that demonstrated the importance of cysteine in the nervous system, we studied the effect of L- and D-cysteine on single neuronal growth. L-Cysteine, which normally functions as a neuromodulator or a neuroprotective antioxidant, causes damage at elevated levels, which may occur post trauma. In this study, we grew adult neurons in culture enriched with L- and D-cysteine as free compounds or as self-assembled monolayers of chiral surfaces and examined the effect on the neuronal morphology and adhesion. Notably, we have found that exposure to the L-cysteine enantiomer inhibited, and even prevented, neuronal attachment more severely than exposure to the D-cysteine enantiomer. Atop the L-cysteine surfaces, neuronal growth was reduced and degenerated. Since the cysteine molecules were attached to the surface via the thiol groups, the neuronal membrane was exposed to the molecular chiral site. Thus, our results have demonstrated high neuronal chiral sensitivity, revealing chiral surfaces as indirect regulators of neuronal cells and providing a reference for studying chiral drugs.

  8. A neuron-astrocyte transistor-like model for neuromorphic dressed neurons.

    Science.gov (United States)

    Valenza, G; Pioggia, G; Armato, A; Ferro, M; Scilingo, E P; De Rossi, D

    2011-09-01

    Experimental evidences on the role of the synaptic glia as an active partner together with the bold synapse in neuronal signaling and dynamics of neural tissue strongly suggest to investigate on a more realistic neuron-glia model for better understanding human brain processing. Among the glial cells, the astrocytes play a crucial role in the tripartite synapsis, i.e. the dressed neuron. A well-known two-way astrocyte-neuron interaction can be found in the literature, completely revising the purely supportive role for the glia. The aim of this study is to provide a computationally efficient model for neuron-glia interaction. The neuron-glia interactions were simulated by implementing the Li-Rinzel model for an astrocyte and the Izhikevich model for a neuron. Assuming the dressed neuron dynamics similar to the nonlinear input-output characteristics of a bipolar junction transistor, we derived our computationally efficient model. This model may represent the fundamental computational unit for the development of real-time artificial neuron-glia networks opening new perspectives in pattern recognition systems and in brain neurophysiology. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. NBLAST: Rapid, Sensitive Comparison of Neuronal Structure and Construction of Neuron Family Databases.

    Science.gov (United States)

    Costa, Marta; Manton, James D; Ostrovsky, Aaron D; Prohaska, Steffen; Jefferis, Gregory S X E

    2016-07-20

    Neural circuit mapping is generating datasets of tens of thousands of labeled neurons. New computational tools are needed to search and organize these data. We present NBLAST, a sensitive and rapid algorithm, for measuring pairwise neuronal similarity. NBLAST considers both position and local geometry, decomposing neurons into short segments; matched segments are scored using a probabilistic scoring matrix defined by statistics of matches and non-matches. We validated NBLAST on a published dataset of 16,129 single Drosophila neurons. NBLAST can distinguish neuronal types down to the finest level (single identified neurons) without a priori information. Cluster analysis of extensively studied neuronal classes identified new types and unreported topographical features. Fully automated clustering organized the validation dataset into 1,052 clusters, many of which map onto previously described neuronal types. NBLAST supports additional query types, including searching neurons against transgene expression patterns. Finally, we show that NBLAST is effective with data from other invertebrates and zebrafish. VIDEO ABSTRACT. Copyright © 2016 MRC Laboratory of Molecular Biology. Published by Elsevier Inc. All rights reserved.

  10. Intrinsically active and pacemaker neurons in pluripotent stem cell-derived neuronal populations.

    Science.gov (United States)

    Illes, Sebastian; Jakab, Martin; Beyer, Felix; Gelfert, Renate; Couillard-Despres, Sébastien; Schnitzler, Alfons; Ritter, Markus; Aigner, Ludwig

    2014-03-11

    Neurons generated from pluripotent stem cells (PSCs) self-organize into functional neuronal assemblies in vitro, generating synchronous network activities. Intriguingly, PSC-derived neuronal assemblies develop spontaneous activities that are independent of external stimulation, suggesting the presence of thus far undetected intrinsically active neurons (IANs). Here, by using mouse embryonic stem cells, we provide evidence for the existence of IANs in PSC-neuronal networks based on extracellular multielectrode array and intracellular patch-clamp recordings. IANs remain active after pharmacological inhibition of fast synaptic communication and possess intrinsic mechanisms required for autonomous neuronal activity. PSC-derived IANs are functionally integrated in PSC-neuronal populations, contribute to synchronous network bursting, and exhibit pacemaker properties. The intrinsic activity and pacemaker properties of the neuronal subpopulation identified herein may be particularly relevant for interventions involving transplantation of neural tissues. IANs may be a key element in the regulation of the functional activity of grafted as well as preexisting host neuronal networks.

  11. Effects of weak electric fields on the activity of neurons and neuronal networks

    International Nuclear Information System (INIS)

    Jeffreys, J.G.R.; Deans, J.; Bikson, M.; Fox, J.

    2003-01-01

    Electric fields applied to brain tissue will affect cellular properties. They will hyperpolarise the ends of cells closest to the positive part of the field, and depolarise ends closest to the negative. In the case of neurons this affects excitability. How these changes in transmembrane potential are distributed depends on the length constant of the neuron, and on its geometry; if the neuron is electrically compact, the change in transmembrane potential becomes an almost linear function of distance in the direction of the field. Neurons from the mammalian hippocampus, maintained in tissue slices in vitro, are significantly affected by fields of around 1-5 Vm -1 . (author)

  12. Statistics of Visual Responses to Image Object Stimuli from Primate AIT Neurons to DNN Neurons.

    Science.gov (United States)

    Dong, Qiulei; Wang, Hong; Hu, Zhanyi

    2018-02-01

    Under the goal-driven paradigm, Yamins et al. ( 2014 ; Yamins & DiCarlo, 2016 ) have shown that by optimizing only the final eight-way categorization performance of a four-layer hierarchical network, not only can its top output layer quantitatively predict IT neuron responses but its penultimate layer can also automatically predict V4 neuron responses. Currently, deep neural networks (DNNs) in the field of computer vision have reached image object categorization performance comparable to that of human beings on ImageNet, a data set that contains 1.3 million training images of 1000 categories. We explore whether the DNN neurons (units in DNNs) possess image object representational statistics similar to monkey IT neurons, particularly when the network becomes deeper and the number of image categories becomes larger, using VGG19, a typical and widely used deep network of 19 layers in the computer vision field. Following Lehky, Kiani, Esteky, and Tanaka ( 2011 , 2014 ), where the response statistics of 674 IT neurons to 806 image stimuli are analyzed using three measures (kurtosis, Pareto tail index, and intrinsic dimensionality), we investigate the three issues in this letter using the same three measures: (1) the similarities and differences of the neural response statistics between VGG19 and primate IT cortex, (2) the variation trends of the response statistics of VGG19 neurons at different layers from low to high, and (3) the variation trends of the response statistics of VGG19 neurons when the numbers of stimuli and neurons increase. We find that the response statistics on both single-neuron selectivity and population sparseness of VGG19 neurons are fundamentally different from those of IT neurons in most cases; by increasing the number of neurons in different layers and the number of stimuli, the response statistics of neurons at different layers from low to high do not substantially change; and the estimated intrinsic dimensionality values at the low

  13. Layer 5 Callosal Parvalbumin-Expressing Neurons: A Distinct Functional Group of GABAergic Neurons.

    Science.gov (United States)

    Zurita, Hector; Feyen, Paul L C; Apicella, Alfonso Junior

    2018-01-01

    Previous studies have shown that parvalbumin-expressing neurons (CC-Parv neurons) connect the two hemispheres of motor and sensory areas via the corpus callosum, and are a functional part of the cortical circuit. Here we test the hypothesis that layer 5 CC-Parv neurons possess anatomical and molecular mechanisms which dampen excitability and modulate the gating of interhemispheric inhibition. In order to investigate this hypothesis we use viral tracing to determine the anatomical and electrophysiological properties of layer 5 CC-Parv and parvalbumin-expressing (Parv) neurons of the mouse auditory cortex (AC). Here we show that layer 5 CC-Parv neurons had larger dendritic fields characterized by longer dendrites that branched farther from the soma, whereas layer 5 Parv neurons had smaller dendritic fields characterized by shorter dendrites that branched nearer to the soma. The layer 5 CC-Parv neurons are characterized by delayed action potential (AP) responses to threshold currents, lower firing rates, and lower instantaneous frequencies compared to the layer 5 Parv neurons. Kv1.1 containing K + channels are the main source of the AP repolarization of the layer 5 CC-Parv and have a major role in determining both the spike delayed response, firing rate and instantaneous frequency of these neurons.

  14. Progranulin regulates neuronal outgrowth independent of Sortilin

    Directory of Open Access Journals (Sweden)

    Gass Jennifer

    2012-07-01

    Full Text Available Abstract Background Progranulin (PGRN, a widely secreted growth factor, is involved in multiple biological functions, and mutations located within the PGRN gene (GRN are a major cause of frontotemporal lobar degeneration with TDP-43-positive inclusions (FLTD-TDP. In light of recent reports suggesting PGRN functions as a protective neurotrophic factor and that sortilin (SORT1 is a neuronal receptor for PGRN, we used a Sort1-deficient (Sort1−/− murine primary hippocampal neuron model to investigate whether PGRN’s neurotrophic effects are dependent on SORT1. We sought to elucidate this relationship to determine what role SORT1, as a regulator of PGRN levels, plays in modulating PGRN’s neurotrophic effects. Results As the first group to evaluate the effect of PGRN loss in Grn knockout primary neuronal cultures, we show neurite outgrowth and branching are significantly decreased in Grn−/− neurons compared to wild-type (WT neurons. More importantly, we also demonstrate that PGRN overexpression can rescue this phenotype. However, the recovery in outgrowth is not observed following treatment with recombinant PGRN harboring missense mutations p.C139R, p.P248L or p.R432C, indicating that these mutations adversely affect the neurotrophic properties of PGRN. In addition, we also present evidence that cleavage of full-length PGRN into granulin peptides is required for increased neuronal outgrowth, suggesting that the neurotrophic functions of PGRN are contained within certain granulins. To further characterize the mechanism by which PGRN impacts neuronal morphology, we assessed the involvement of SORT1. We demonstrate that PGRN induced-outgrowth occurs in the absence of SORT1 in Sort1−/− cultures. Conclusion We demonstrate that loss of PGRN impairs proper neurite outgrowth and branching, and that exogenous PGRN alleviates this impairment. Furthermore, we determined that exogenous PGRN induces outgrowth independent of SORT1, suggesting another

  15. Action observation: Inferring intentions without mirror neurons

    DEFF Research Database (Denmark)

    Frith, Christopher; Kilner, James M

    2008-01-01

    A recent study has shown, using fMRI, that the mirror neuron system does not mediate action understanding when the observed action is novel or when it is hard to understand.......A recent study has shown, using fMRI, that the mirror neuron system does not mediate action understanding when the observed action is novel or when it is hard to understand....

  16. Unidirectional synchronization of Hodgkin-Huxley neurons

    Energy Technology Data Exchange (ETDEWEB)

    Cornejo-Perez, Octavio [Division de Matematicas Aplicadas y Sistemas, Computacionales, IPICYT, Apdo. Postal 3-74 Tangamanga, 78231 San Luis Potosi (Mexico)]. E-mail: octavio@ipicyt.edu.mx; Femat, Ricardo [Division de Matematicas Aplicadas y Sistemas, Computacionales, IPICYT, Apdo. Postal 3-74 Tangamanga, 78231 San Luis Potosi (Mexico)]. E-mail: rfemat@ipicyt.edu.mx

    2005-07-01

    Synchronization dynamics of two noiseless Hodgkin-Huxley (HH) neurons under the action of feedback control is studied. The spiking patterns of the action potentials evoked by periodic external modulations attain synchronization states under the feedback action. Numerical simulations for the synchronization dynamics of regular-irregular desynchronized spiking sequences are displayed. The results are discussed in context of generalized synchronization. It is also shown that the HH neurons can be synchronized in face of unmeasured states.

  17. Arsenic Trioxide Modulates the Central Snail Neuron Action Potential

    Directory of Open Access Journals (Sweden)

    Guan-Ling Lu

    2009-09-01

    Conclusion: As2O3 at 10 mM elicits BoPs in central snail neurons and this effect may relate to the PLC activity of the neuron, rather than protein kinase A activity, or calcium influxes of the neuron. As2O3 at higher concentration irreversibly abolishes the spontaneous action potentials of the neuron.

  18. Reaching for the red planet

    Science.gov (United States)

    David, L

    1996-05-01

    The distant shores of Mars were reached by numerous U.S. and Russian spacecraft throughout the 1960s to mid 1970s. Nearly 20 years have passed since those successful missions which orbited and landed on the Martian surface. Two Soviet probes headed for the planet in July, 1988, but later failed. In August 1993, the U.S. Mars Observer suddenly went silent just three days before it was to enter orbit around the planet and was never heard from again. In late 1996, there will be renewed activity on the launch pads with three probes departing for the red planet: 1) The U.S. Mars Global Surveyor will be launched in November on a Delta II rocket and will orbit the planet for global mapping purposes; 2) Russia's Mars '96 mission, scheduled to fly in November on a Proton launcher, consists of an orbiter, two small stations which will land on the Martian surface, and two penetrators that will plow into the terrain; and finally, 3) a U.S. Discovery-class spacecraft, the Mars Pathfinder, has a December launch date atop a Delta II booster. The mission features a lander and a microrover that will travel short distances over Martian territory. These missions usher in a new phase of Mars exploration, setting the stage for an unprecedented volley of spacecraft that will orbit around, land on, drive across, and perhaps fly at low altitudes over the planet.

  19. A red-letter day !

    CERN Multimedia

    2008-01-01

    Today is a red-letter day for the LHC and CERN as a beam of protons has travelled around the LHC ring for the very first time! The start of LHC operation marks the end of a long period in which you have given your all, and this first particle beam circulating in the accelerator now paves the way for discoveries that will open up a whole new field of knowledge. The history of the LHC began in 1984 with a debate on the possible objectives of a future accelerator, based on the state of our knowledge at that time. The CERN Council then approved the single-stage construction of the LHC in 1996, giving the go-ahead for the work that has now reached completion. For the past twelve years, physicists, engineers and technicians from CERN and its associated institutes have been engaged in constructing the three pillars of the LHC: the accelerator (including the upgrade of the existing accelerator chain), the four experiments, and the computing ...

  20. Red Shifts and Existing Speculations

    Science.gov (United States)

    Aisenberg, Sol

    2009-03-01

    There are many current flaws, mysteries, and errors in the standard model of the universe - all based upon speculative interpretation of many excellent and verified observations. The most serious cause of some errors is the speculation about the meaning of the redshifts observed in the 1930s by Hubble. He ascribed the redshifts as due to ``an apparent Doppler effect''. This led to speculation that the remote stars were receding, and the universe was expanding -- although without observational proof of the actual receding velocity of the stars. The age of the universe, based upon the Hubble constant is pure speculation because of lack of velocity demonstration. The belief in expansion, the big bang, and of inflation should be reexamined. Also, the redshift cannot always be used as a distance measure, particularly for photons from quasars containing massive black holes that can reduce photon energy through gravitational attraction. If the linear Hubble constant is extrapolated to the most remote super novae and beyond, it would eventually require that the corresponding photon energy go to zero or become negative -- according to Hubble linear relationship. This should require a reexamination of the meaning of the red shift and the speculative consequences and give a model with fewer mysteries.

  1. Red Blood Cell Storage Lesion

    Directory of Open Access Journals (Sweden)

    Daryl J. Kor

    2009-10-01

    Full Text Available The past two decades have witnessed increased scrutiny regarding efficacy and risk of the once unquestioned therapy of red blood cell (RBC transfusion. Simultaneously, a variety of changes have been identified within the RBC and storage media during RBC preservation that are correlated with reduced tissue oxygenation and transfusion-associated adverse effects. These alterations are collectively termed the storage lesion and include extensive biochemical, biomechanical, and immunologic changes involving cells of diverse origin. Time-dependent falls is 2,3-diphosphoglycerate, intracellular RBC adenosine triphosphate, and nitric oxide have been shown to impact RBC deformability and delivery of oxygen to the end-organ. The accumulation of biologic response modifiers such as soluble CD40 ligand (sCD40L, lysophosphatidylcholine (lyso-PC, and Regulated on Activation, Normal T-cell Expressed and Secreted (RANTES have been associated with altered recipient immune function as well. This review will address the alterations occurring within the RBC and storage media during RBC preservation and will address the potential clinical consequence thereof.

  2. Decadal Stability of Red Sea Mangroves

    KAUST Repository

    Almahasheer, Hanan; Aljowair, Abdulaziz; Duarte, Carlos M.; Irigoien, Xabier

    2015-01-01

    Across the Earth, mangroves play an important role in coastal protection, both as nurseries and carbon sinks. However, due to various human and environmental impacts, the coverage of mangroves is declining on a global scale. The Red Sea is in the northern-most area of the distribution range of mangroves. Little is known about the surface covered by mangroves at this northern limit or about the changes experienced by Red Sea mangroves. We sought to study changes in the coverage of Red Sea mangroves by using multi-temporal Landsat data (1972, 2000 and 2013). Interestingly, our results show that there has been no decline in mangrove stands in the Red Sea but rather a slight increase. The area covered by mangroves is about 69 Km2 along the African shore and 51 Km2 along the Arabian Peninsula shore. From 1972 to 2013, the area covered by mangroves increased by about 0.29% y-1. We conclude that the trend exhibited by Red Sea mangroves departs from the general global decline of mangroves. Along the Red Sea, mangroves expanded by 12% over the 41 years from 1972 to 2013. Losses to Red Sea mangroves, mostly due to coastal development, have been compensated by afforestation projects.

  3. Uptake of carnitine by red blood cells

    International Nuclear Information System (INIS)

    Campa, M.; Borum, P.

    1986-01-01

    A significant amount of blood carnitine (70% of cord blood and 40% of blood from healthy adults) is partitioned into the red blood cell compartment of whole blood. Data indicate that the plasma compartment and the red blood cell compartment of whole blood represent different metabolic pools of carnitine. There are no data to indicate that red blood cells synthesize carnitine, but our understanding of the uptake of carnitine by red blood cells is negligible. Red blood cells were obtained from healthy adults, washed twice with normal saline, and used for uptake experiments. When the cells were incubated at 37 0 C in the presence of 14 C-carnitine, radioactivity was found both in the soluble cytosolic and membrane fractions of the cells following lysis. The uptake was dependent upon the time of incubation, temperature of incubation, and carnitine concentration in the incubation medium. Washed red blood cell membranes incubated with 14 C-carnitine showed specific binding of radioactivity. These data are consistent with the hypothesis that red blood cells have an uptake mechanism for L-carnitine

  4. Decadal Stability of Red Sea Mangroves

    KAUST Repository

    Almahasheer, Hanan

    2015-12-15

    Across the Earth, mangroves play an important role in coastal protection, both as nurseries and carbon sinks. However, due to various human and environmental impacts, the coverage of mangroves is declining on a global scale. The Red Sea is in the northern-most area of the distribution range of mangroves. Little is known about the surface covered by mangroves at this northern limit or about the changes experienced by Red Sea mangroves. We sought to study changes in the coverage of Red Sea mangroves by using multi-temporal Landsat data (1972, 2000 and 2013). Interestingly, our results show that there has been no decline in mangrove stands in the Red Sea but rather a slight increase. The area covered by mangroves is about 69 Km2 along the African shore and 51 Km2 along the Arabian Peninsula shore. From 1972 to 2013, the area covered by mangroves increased by about 0.29% y-1. We conclude that the trend exhibited by Red Sea mangroves departs from the general global decline of mangroves. Along the Red Sea, mangroves expanded by 12% over the 41 years from 1972 to 2013. Losses to Red Sea mangroves, mostly due to coastal development, have been compensated by afforestation projects.

  5. Information transmission with spiking Bayesian neurons

    International Nuclear Information System (INIS)

    Lochmann, Timm; Deneve, Sophie

    2008-01-01

    Spike trains of cortical neurons resulting from repeatedpresentations of a stimulus are variable and exhibit Poisson-like statistics. Many models of neural coding therefore assumed that sensory information is contained in instantaneous firing rates, not spike times. Here, we ask how much information about time-varying stimuli can be transmitted by spiking neurons with such input and output variability. In particular, does this variability imply spike generation to be intrinsically stochastic? We consider a model neuron that estimates optimally the current state of a time-varying binary variable (e.g. presence of a stimulus) by integrating incoming spikes. The unit signals its current estimate to other units with spikes whenever the estimate increased by a fixed amount. As shown previously, this computation results in integrate and fire dynamics with Poisson-like output spike trains. This output variability is entirely due to the stochastic input rather than noisy spike generation. As a result such a deterministic neuron can transmit most of the information about the time varying stimulus. This contrasts with a standard model of sensory neurons, the linear-nonlinear Poisson (LNP) model which assumes that most variability in output spike trains is due to stochastic spike generation. Although it yields the same firing statistics, we found that such noisy firing results in the loss of most information. Finally, we use this framework to compare potential effects of top-down attention versus bottom-up saliency on information transfer with spiking neurons

  6. The transfer function of neuron spike.

    Science.gov (United States)

    Palmieri, Igor; Monteiro, Luiz H A; Miranda, Maria D

    2015-08-01

    The mathematical modeling of neuronal signals is a relevant problem in neuroscience. The complexity of the neuron behavior, however, makes this problem a particularly difficult task. Here, we propose a discrete-time linear time-invariant (LTI) model with a rational function in order to represent the neuronal spike detected by an electrode located in the surroundings of the nerve cell. The model is presented as a cascade association of two subsystems: one that generates an action potential from an input stimulus, and one that represents the medium between the cell and the electrode. The suggested approach employs system identification and signal processing concepts, and is dissociated from any considerations about the biophysical processes of the neuronal cell, providing a low-complexity alternative to model the neuronal spike. The model is validated by using in vivo experimental readings of intracellular and extracellular signals. A computational simulation of the model is presented in order to assess its proximity to the neuronal signal and to observe the variability of the estimated parameters. The implications of the results are discussed in the context of spike sorting. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Endocannabinoids mediate neuron-astrocyte communication.

    Science.gov (United States)

    Navarrete, Marta; Araque, Alfonso

    2008-03-27

    Cannabinoid receptors play key roles in brain function, and cannabinoid effects in brain physiology and drug-related behavior are thought to be mediated by receptors present in neurons. Neuron-astrocyte communication relies on the expression by astrocytes of neurotransmitter receptors. Yet, the expression of cannabinoid receptors by astrocytes in situ and their involvement in the neuron-astrocyte communication remain largely unknown. We show that hippocampal astrocytes express CB1 receptors that upon activation lead to phospholipase C-dependent Ca2+ mobilization from internal stores. These receptors are activated by endocannabinoids released by neurons, increasing astrocyte Ca2+ levels, which stimulate glutamate release that activates NMDA receptors in pyramidal neurons. These results demonstrate the existence of endocannabinoid-mediated neuron-astrocyte communication, revealing that astrocytes are targets of cannabinoids and might therefore participate in the physiology of cannabinoid-related addiction. They also reveal the existence of an endocannabinoid-glutamate signaling pathway where astrocytes serve as a bridge for nonsynaptic interneuronal communication.

  8. Mechanical Dissociation of Retinal Neurons with Vibration

    Science.gov (United States)

    Motomura, Tamami; Hayashida, Yuki; Murayama, Nobuki

    The neuromorphic device, which implements the functions of biological neural circuits by means of VLSI technology, has been collecting much attention in the engineering fields in the last decade. Concurrently, progress in neuroscience research has revealed the nonlinear computation in single neuron levels, suggesting that individual neurons are not merely the circuit elements but computational units. Thus, elucidating the properties of neuronal signal processing is thought to be an essential step for developing the next generation of neuromorphic devices. In the present study, we developed a method for dissociating single neurons from specific sublayers of mammalian retinas with using no proteolytic enzymes but rather combining tissue incubation in a low-Ca2+ medium and the vibro-dissociation technique developed for the slices of brains and spinal cords previously. Our method took shorter time of the procedure, and required less elaborated skill, than the conventional enzymatic method did; nevertheless it yielded enough number of the cells available for acute electrophysiological experiments. The isolated retinal neurons were useful for measuring the nonlinear membrane conductances as well as the spike firing properties under the perforated-patch whole-cell configuration. These neurons also enabled us to examine the effects of proteolytic enzymes on the membrane excitability in those cells.

  9. Graphene foam as a biocompatible scaffold for culturing human neurons

    Science.gov (United States)

    Mattei, Cristiana; Nasr, Babak; Hudson, Emma J.; Alshawaf, Abdullah J.; Chana, Gursharan; Everall, Ian P.; Dottori, Mirella; Skafidas, Efstratios

    2018-01-01

    In this study, we explore the use of electrically active graphene foam as a scaffold for the culture of human-derived neurons. Human embryonic stem cell (hESC)-derived cortical neurons fated as either glutamatergic or GABAergic neuronal phenotypes were cultured on graphene foam. We show that graphene foam is biocompatible for the culture of human neurons, capable of supporting cell viability and differentiation of hESC-derived cortical neurons. Based on the findings, we propose that graphene foam represents a suitable scaffold for engineering neuronal tissue and warrants further investigation as a model for understanding neuronal maturation, function and circuit formation. PMID:29657752

  10. Neuron matters: electric activation of neuronal tissue is dependent on the interaction between the neuron and the electric field.

    Science.gov (United States)

    Ye, Hui; Steiger, Amanda

    2015-08-12

    In laboratory research and clinical practice, externally-applied electric fields have been widely used to control neuronal activity. It is generally accepted that neuronal excitability is controlled by electric current that depolarizes or hyperpolarizes the excitable cell membrane. What determines the amount of polarization? Research on the mechanisms of electric stimulation focus on the optimal control of the field properties (frequency, amplitude, and direction of the electric currents) to improve stimulation outcomes. Emerging evidence from modeling and experimental studies support the existence of interactions between the targeted neurons and the externally-applied electric fields. With cell-field interaction, we suggest a two-way process. When a neuron is positioned inside an electric field, the electric field will induce a change in the resting membrane potential by superimposing an electrically-induced transmembrane potential (ITP). At the same time, the electric field can be perturbed and re-distributed by the cell. This cell-field interaction may play a significant role in the overall effects of stimulation. The redistributed field can cause secondary effects to neighboring cells by altering their geometrical pattern and amount of membrane polarization. Neurons excited by the externally-applied electric field can also affect neighboring cells by ephaptic interaction. Both aspects of the cell-field interaction depend on the biophysical properties of the neuronal tissue, including geometric (i.e., size, shape, orientation to the field) and electric (i.e., conductivity and dielectricity) attributes of the cells. The biophysical basis of the cell-field interaction can be explained by the electromagnetism theory. Further experimental and simulation studies on electric stimulation of neuronal tissue should consider the prospect of a cell-field interaction, and a better understanding of tissue inhomogeneity and anisotropy is needed to fully appreciate the neural

  11. RED ONE kuvaajan työkaluna

    OpenAIRE

    Käki, Ossi

    2010-01-01

    Opinnäytetyöni projektiosa, 30-minuuttinen lyhytelokuva Huomisen Muisto – Memory of Tomorrow kuvattiin RED ONE -kameralla vuosina 2008-2009. Opinnäytetyöni kirjallinen osuus tutkii miten RED ONE soveltuu kuvaajan työvälineeksi lyhytelokuvassa. Huomisen Muisto oli ensimmäinen Tampereen ammattikorkeakoulussa RED ONE:lla kuvattu elokuva ja koko tekninen workflow piti kehittää lähes nollasta. Paljon kuvan digitaalista jälkikäsittelyä sisältävänä science fiction -elokuvana Huomisen Muisto asetti i...

  12. Psychology: red enhances human performance in contests.

    Science.gov (United States)

    Hill, Russell A; Barton, Robert A

    2005-05-19

    Red coloration is a sexually selected, testosterone-dependent signal of male quality in a variety of animals, and in some non-human species a male's dominance can be experimentally increased by attaching artificial red stimuli. Here we show that a similar effect can influence the outcome of physical contests in humans--across a range of sports, we find that wearing red is consistently associated with a higher probability of winning. These results indicate not only that sexual selection may have influenced the evolution of human response to colours, but also that the colour of sportswear needs to be taken into account to ensure a level playing field in sport.

  13. Adult neuronal ceroid-lipofuscinosis.

    Science.gov (United States)

    Goebel, H H; Braak, H

    1989-01-01

    Among the different clinical forms of neuronal ceroid-lipofuscinosis (NCL), the adult type is the least frequent, most sporadic and most difficult one to diagnose. Clinical symptomatology differs from the classical childhood NCL forms in that ocular symptoms are absent while changes of behavior, dementia and seizures dominate the clinical picture. Excessive accumulation of NCL-specific lipopigments has largely been explored in the nervous system, where pigmento-architectonic investigations disclose layer-specific cortical pathology similar to but less pronounced than that of juvenile and protracted juvenile NCL. Ultrastructural analysis of lipopigments in adult NCL reveals diversity of lipopigment fine structure, but less impressive than in the childhood forms of NCL. Abnormal accretion of lipopigments outside the nervous system has rarely been demonstrated and requires ampler documentation, making in vivo diagnosis of adult NCL often difficult and sometimes equivocal. Adult NCL is now frequently considered identical to "Kufs' disease". However, in the past, the latter term has comprised a heterogeneous spectrum of lipidoses the NCL-nature of which had not been unequivocally established. Thus, one may either speak of "Kufs' syndrome" or abandon this term altogether. Although patients afflicted with adult NCL may suffer from Kufs' disease, not all who have and had Kufs disease may have or have had adult NCL. The current debate on adult NCL centers around scepticism concerning many of the earlier reports, on incorporating diagnostic studies of non-CNS organs in presumptive patients and on distinguishing adult NCL from "atypical" patients or forms of NCL, as well as other disorders marked by non-specific abnormal accumulation of lipofuscin.

  14. Synchronization of Coupled Neurons Controlled by a Pacemaker

    International Nuclear Information System (INIS)

    Li Mei-Sheng; Zhang Hong-Hui; Zhao Yong; Shi Xia

    2011-01-01

    We investigate synchronization of Hindmarsh—Rose neurons with gap junctions under the control of a pacemaker. In a ring Hindmarsh—Rose neuronal network, the coupled neurons with the pacemaker can occur in synchronization more easily than those without the pacemaker. Furthermore, the pacemaker can induce phase synchronization or nearly-complete synchronization of nonidentical neurons. This synchronization can occur more easily when time delay is considered. Theses results can be helpful to understand the activities of the real neuronal system. (general)

  15. NeuronMetrics: software for semi-automated processing of cultured neuron images.

    Science.gov (United States)

    Narro, Martha L; Yang, Fan; Kraft, Robert; Wenk, Carola; Efrat, Alon; Restifo, Linda L

    2007-03-23

    Using primary cell culture to screen for changes in neuronal morphology requires specialized analysis software. We developed NeuronMetrics for semi-automated, quantitative analysis of two-dimensional (2D) images of fluorescently labeled cultured neurons. It skeletonizes the neuron image using two complementary image-processing techniques, capturing fine terminal neurites with high fidelity. An algorithm was devised to span wide gaps in the skeleton. NeuronMetrics uses a novel strategy based on geometric features called faces to extract a branch number estimate from complex arbors with numerous neurite-to-neurite contacts, without creating a precise, contact-free representation of the neurite arbor. It estimates total neurite length, branch number, primary neurite number, territory (the area of the convex polygon bounding the skeleton and cell body), and Polarity Index (a measure of neuronal polarity). These parameters provide fundamental information about the size and shape of neurite arbors, which are critical factors for neuronal function. NeuronMetrics streamlines optional manual tasks such as removing noise, isolating the largest primary neurite, and correcting length for self-fasciculating neurites. Numeric data are output in a single text file, readily imported into other applications for further analysis. Written as modules for ImageJ, NeuronMetrics provides practical analysis tools that are easy to use and support batch processing. Depending on the need for manual intervention, processing time for a batch of approximately 60 2D images is 1.0-2.5 h, from a folder of images to a table of numeric data. NeuronMetrics' output accelerates the quantitative detection of mutations and chemical compounds that alter neurite morphology in vitro, and will contribute to the use of cultured neurons for drug discovery.

  16. Leptin signaling in GABA neurons, but not glutamate neurons, is required for reproductive function.

    Science.gov (United States)

    Zuure, Wieteke A; Roberts, Amy L; Quennell, Janette H; Anderson, Greg M

    2013-11-06

    The adipocyte-derived hormone leptin acts in the brain to modulate the central driver of fertility: the gonadotropin releasing hormone (GnRH) neuronal system. This effect is indirect, as GnRH neurons do not express leptin receptors (LEPRs). Here we test whether GABAergic or glutamatergic neurons provide the intermediate pathway between the site of leptin action and the GnRH neurons. Leptin receptors were deleted from GABA and glutamate neurons using Cre-Lox transgenics, and the downstream effects on puberty onset and reproduction were examined. Both mouse lines displayed the expected increase in body weight and region-specific loss of leptin signaling in the hypothalamus. The GABA neuron-specific LEPR knock-out females and males showed significantly delayed puberty onset. Adult fertility observations revealed that these knock-out animals have decreased fecundity. In contrast, glutamate neuron-specific LEPR knock-out mice displayed normal fertility. Assessment of the estrogenic hypothalamic-pituitary-gonadal axis regulation in females showed that leptin action on GABA neurons is not necessary for estradiol-mediated suppression of tonic luteinizing hormone secretion (an indirect measure of GnRH neuron activity) but is required for regulation of a full preovulatory-like luteinizing hormone surge. In conclusion, leptin signaling in GABAergic (but not glutamatergic neurons) plays a critical role in the timing of puberty onset and is involved in fertility regulation throughout adulthood in both sexes. These results form an important step in explaining the role of central leptin signaling in the reproductive system. Limiting the leptin-to-GnRH mediators to GABAergic cells will enable future research to focus on a few specific types of neurons.

  17. A novel perspective on neuron study: damaging and promoting effects in different neurons induced by mechanical stress.

    Science.gov (United States)

    Wang, Yazhou; Wang, Wei; Li, Zong; Hao, Shilei; Wang, Bochu

    2016-10-01

    A growing volume of experimental evidence demonstrates that mechanical stress plays a significant role in growth, proliferation, apoptosis, gene expression, electrophysiological properties and many other aspects of neurons. In this review, first, the mechanical microenvironment and properties of neurons under in vivo conditions are introduced and analyzed. Second, research works in recent decades on the effects of different mechanical forces, especially compression and tension, on various neurons, including dorsal root ganglion neurons, retinal ganglion cells, cerebral cortex neurons, hippocampus neurons, neural stem cells, and other neurons, are summarized. Previous research results demonstrate that mechanical stress can not only injure neurons by damaging their morphology, impacting their electrophysiological characteristics and gene expression, but also promote neuron self-repair. Finally, some future perspectives in neuron research are discussed.

  18. Synthetic biology as red herring.

    Science.gov (United States)

    Preston, Beth

    2013-12-01

    It has become commonplace to say that with the advent of technologies like synthetic biology the line between artifacts and living organisms, policed by metaphysicians since antiquity, is beginning to blur. But that line began to blur 10,000 years ago when plants and animals were first domesticated; and has been thoroughly blurred at least since agriculture became the dominant human subsistence pattern many millennia ago. Synthetic biology is ultimately only a late and unexceptional offshoot of this prehistoric development. From this perspective, then, synthetic biology is a red herring, distracting us from more thorough philosophical consideration of the most truly revolutionary human practice-agriculture. In the first section of this paper I will make this case with regard to ontology, arguing that synthetic biology crosses no ontological lines that were not crossed already in the Neolithic. In the second section I will construct a parallel case with regard to cognition, arguing that synthetic biology as biological engineering represents no cognitive advance over what was required for domestication and the new agricultural subsistence pattern it grounds. In the final section I will make the case with regard to human existence, arguing that synthetic biology, even if wildly successful, is not in a position to cause significant existential change in what it is to be human over and above the massive existential change caused by the transition to agriculture. I conclude that a longer historical perspective casts new light on some important issues in philosophy of technology and environmental philosophy. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Nonenzymatic glucosylation of neuronal calmodulin and its functional consequences

    International Nuclear Information System (INIS)

    Kowluru, R.A.; Kowluru, A.; Bitensky, M.W.

    1986-01-01

    Glucosylation (NEG) (nonenzymatic) of proteins is a posttranslational protein modification that occurs readily in the diabetic environment. As a consequence of NEG some proteins are known to undergo a change in function. Their studies of red blood cell (RBC) cytoskeletal proteins indicate that calmodulin is glucosylated in the diabetic RBC and this is followed by a change in function. Here they present new data in support of their earlier findings. Purified bovine brain calmodulin was glucosylated in vitro in the presence of 28 mM glucose. After six days of incubation at room temperature 2.75 moles of glucose were incorporated per mole of calmodulin. Glucosylated calmodulin exhibited a marked reduction in calcium dependent functions. Its ability to stimulate neuronal phosphodiesterase (PDE) and adenylate cyclase was reduced by 65 and 80% respectively. Its ability to stimulate rat brain protein kinase was reduced by 40%. Glucosylated calmodulin exhibited a 56% drop in its 45 Ca binding as compared with unmodified calmodulin. These data provide an additional example in which NEG markedly alters protein function

  20. Red Wine Polyphenols for Cancer Prevention

    Science.gov (United States)

    He, Shan; Sun, Cuirong; Pan, Yuanjiang

    2008-01-01

    Conventional cancer therapies, the second leading cause of death worldwide, result in serious side effects and, at best, merely extend the patient's lifespan by a few years. Searching for effective prevention is of high priority in both basic and clinical sciences. In recent decades natural products have been considered to be an important source of cancer chemopreventive agents. Red wine polyphenols, which consisted of various powerful antioxidants such as flavonoids and stilbenes, have been implicated in cancer prevention and that promote human health without recognizable side effects. Since resveratrol, a major component of red wine polyphenols, has been studied and reviewed extensively for its chemopreventive activity to interfere with the multi-stage carcinogenesis, this review focuses on recent progress in studies on cancer chemopreventive activities of red wine polyphenol extracts and fractions as well as other red wine polyphenols, like procyanidin B5 analogues and myricetin. PMID:19325788

  1. Red Wine Polyphenols for Cancer Prevention

    Directory of Open Access Journals (Sweden)

    Yuanjiang Pan

    2008-05-01

    Full Text Available Conventional cancer therapies, the second leading cause of death worldwide, result in serious side effects and, at best, merely extend the patient's lifespan by a few years. Searching for effective prevention is of high priority in both basic and clinical sciences. In recent decades natural products have been considered to be an important source of cancer chemopreventive agents. Red wine polyphenols, which consisted of various powerful antioxidants such as flavonoids and stilbenes, have been implicated in cancer prevention and that promote human health without recognizable side effects. Since resveratrol, a major component of red wine polyphenols, has been studied and reviewed extensively for its chemopreventive activity to interfere with the multi-stage carcinogenesis, this review focuses on recent progress in studies on cancer chemopreventive activities of red wine polyphenol extracts and fractions as well as other red wine polyphenols, like procyanidin B5 analogues and myricetin.

  2. sample data Red River_2011-2013

    Data.gov (United States)

    U.S. Environmental Protection Agency — OK Fish Kill data from Red River 2011-2013. This dataset is associated with the following publication: Jones-Lepp, T., V. Taguchi, W. Sovocool, D. Betowski, P....

  3. Raoul Kurvitz esitleb : "Armastusest" & "RED" / Heie Treier

    Index Scriptorium Estoniae

    Treier, Heie, 1963-

    2000-01-01

    Näitus "Armastusest" Vaal-galeriis, näituse avamine toimus kunstniku performance'iga. Sõnumina mainitakse Raoul Kurvitza kuraatoriprojekti "RED" Mustpeade Maja valges saalis, loetletud eksponeeritud kunstnikud

  4. Li'l Red Schoolhouse workshops

    Science.gov (United States)

    1993-01-01

    Education specialists at Stennis conduct staff development workshops for elementary and secondary teachers of math, science and technology and other subjects as well as specialized workshops conducted in the NASA Li'l Red Schoolhouse.

  5. Red in the Face: Understanding Rosacea

    Science.gov (United States)

    ... causing them to lose work or to have low self-esteem,” says Dr. Richard Gallo, a skin expert at the University of California, San Diego. “Many psychological problems are the consequence of having this red, puffy ...

  6. Doppler interpretation of quasar red shifts.

    Science.gov (United States)

    Zapolsky, H S

    1966-08-05

    The hypothesis that the quasistellar sources (quasars) are local objects moving with velocities close to the speed of light is examined. Provided there is no observational cutoff on apparent bolometric magnitude for the quasars, the transverse Doppler effect leads to the expectation of fewer blue shifts than red shifts for an isotropic distribution of velocities. Such a distribution also yields a function N(z), the number of objects with red shift less than z which is not inconsistent with the present data. On the basis of two extreme assumptions concerning the origin of such rapidly moving sources, we computed curves of red shift plotted against magnitude. In particular, the curve obtained on the assumption that the quasars originated from an explosion in or nearby our own galaxy is in as good agreement with the observations as the curve of cosmological red shift plotted against magnitude.

  7. NOAA NCCOS: New England Red Tide Research

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Alexandrium blooms are one of several algal bloom types often called "red tides," but more correctly referred to as Harmful Algal Blooms (HABs). Alexandrium produces...

  8. Avoiding Anemia: Boost Your Red Blood Cells

    Science.gov (United States)

    ... Issues Subscribe January 2014 Print this issue Avoiding Anemia Boost Your Red Blood Cells En español Send ... Disease When Blood Cells Bend Wise Choices Preventing Anemia To prevent or treat iron-deficiency anemia: Eat ...

  9. Comparative metagenomics of the Red Sea

    KAUST Repository

    Mineta, Katsuhiko

    2016-01-26

    Metagenome produces a tremendous amount of data that comes from the organisms living in the environments. This big data enables us to examine not only microbial genes but also the community structure, interaction and adaptation mechanisms at the specific location and condition. The Red Sea has several unique characteristics such as high salinity, high temperature and low nutrition. These features must contribute to form the unique microbial community during the evolutionary process. Since 2014, we started monthly samplings of the metagenomes in the Red Sea under KAUST-CCF project. In collaboration with Kitasato University, we also collected the metagenome data from the ocean in Japan, which shows contrasting features to the Red Sea. Therefore, the comparative metagenomics of those data provides a comprehensive view of the Red Sea microbes, leading to identify key microbes, genes and networks related to those environmental differences.

  10. Dipeptides from the red alga Acanthopora spicifera

    Digital Repository Service at National Institute of Oceanography (India)

    Wahidullah, S.; De; Kamat, S.Y.

    An investigation of red alga Acanthophora spicifera afforded the known peptide, aurantiamide acetate and a new diastereoisomer of this dipeptide (dia-aurantiamide acetate). This is a first report of aurantiamide acetate from a marine source...

  11. Signals and Circuits in the Purkinje Neuron

    Directory of Open Access Journals (Sweden)

    Ze'ev R Abrams

    2011-09-01

    Full Text Available Purkinje neurons in the cerebellum have over 100,000 inputs organized in an orthogonal geometry, and a single output channel. As the sole output of the cerebellar cortex layer, their complex firing pattern has been associated with motor control and learning. As such they have been extensively modeled and measured using tools ranging from electrophysiology and neuroanatomy, to dynamic systems and artificial intelligence methods. However, there is an alternative approach to analyze and describe the neuronal output of these cells using concepts from Electrical Engineering, particularly signal processing and digital/analog circuits. By viewing the Purkinje neuron as an unknown circuit to be reverse-engineered, we can use the tools that provide the foundations of today’s integrated circuits and communication systems to analyze the Purkinje system at the circuit level. We use Fourier transforms to analyze and isolate the inherent frequency modes in the Purkinje neuron and define 3 unique frequency ranges associated with the cells’ output. Comparing the Purkinje neuron to a signal generator that can be externally modulated adds an entire level of complexity to the functional role of these neurons both in terms of data analysis and information processing, relying on Fourier analysis methods in place of statistical ones. We also re-describe some of the recent literature in the field, using the nomenclature of signal processing. Furthermore, by comparing the experimental data of the past decade with basic electronic circuitry, we can resolve the outstanding controversy in the field, by recognizing that the Purkinje neuron can act as a multivibrator circuit.

  12. Resveratrol stimulates AMP kinase activity in neurons.

    Science.gov (United States)

    Dasgupta, Biplab; Milbrandt, Jeffrey

    2007-04-24

    Resveratrol is a polyphenol produced by plants that has multiple beneficial activities similar to those associated with caloric restriction (CR), such as increased life span and delay in the onset of diseases associated with aging. CR improves neuronal health, and the global beneficial effects of CR have been postulated to be mediated by the nervous system. One key enzyme thought to be activated during CR is the AMP-activated kinase (AMPK), a sensor of cellular energy levels. AMPK is activated by increases in the cellular AMP:ATP ratio, whereupon it functions to help preserve cellular energy. In this regard, the regulation of dietary food intake by hypothalamic neurons is mediated by AMPK. The suppression of nonessential energy expenditure by activated AMPK along with the CR mimetic and neuroprotective properties of resveratrol led us to hypothesize that neuronal activation of AMPK could be an important component of resveratrol activity. Here, we show that resveratrol activated AMPK in Neuro2a cells and primary neurons in vitro as well as in the brain. Resveratrol and the AMPK-activating compound 5-aminoimidazole-4-carboxamide-1-beta-D-ribofuranoside (AICAR) promoted robust neurite outgrowth in Neuro2a cells, which was blocked by genetic and pharmacologic inhibition of AMPK. Resveratrol also stimulated mitochondrial biogenesis in an AMPK-dependent manner. Resveratrol-stimulated AMPK activity in neurons depended on LKB1 activity but did not require the NAD-dependent protein deacetylase SIRT1 during this time frame. These findings suggest that neuronal activation of AMPK by resveratrol could affect neuronal energy homeostasis and contribute to the neuroprotective effects of resveratrol.

  13. Channel properties of Nax expressed in neurons.

    Directory of Open Access Journals (Sweden)

    Masahito Matsumoto

    Full Text Available Nax is a sodium-concentration ([Na+]-sensitive Na channel with a gating threshold of ~150 mM for extracellular [Na+] ([Na+]o in vitro. We previously reported that Nax was preferentially expressed in the glial cells of sensory circumventricular organs including the subfornical organ, and was involved in [Na+] sensing for the control of salt-intake behavior. Although Nax was also suggested to be expressed in the neurons of some brain regions including the amygdala and cerebral cortex, the channel properties of Nax have not yet been adequately characterized in neurons. We herein verified that Nax was expressed in neurons in the lateral amygdala of mice using an antibody that was newly generated against mouse Nax. To investigate the channel properties of Nax expressed in neurons, we established an inducible cell line of Nax using the mouse neuroblastoma cell line, Neuro-2a, which is endogenously devoid of the expression of Nax. Functional analyses of this cell line revealed that the [Na+]-sensitivity of Nax in neuronal cells was similar to that expressed in glial cells. The cation selectivity sequence of the Nax channel in cations was revealed to be Na+ ≈ Li+ > Rb+ > Cs+ for the first time. Furthermore, we demonstrated that Nax bound to postsynaptic density protein 95 (PSD95 through its PSD95/Disc-large/ZO-1 (PDZ-binding motif at the C-terminus in neurons. The interaction between Nax and PSD95 may be involved in promoting the surface expression of Nax channels because the depletion of endogenous PSD95 resulted in a decrease in Nax at the plasma membrane. These results indicated, for the first time, that Nax functions as a [Na+]-sensitive Na channel in neurons as well as in glial cells.

  14. Bax regulates neuronal Ca2+ homeostasis.

    Science.gov (United States)

    D'Orsi, Beatrice; Kilbride, Seán M; Chen, Gang; Perez Alvarez, Sergio; Bonner, Helena P; Pfeiffer, Shona; Plesnila, Nikolaus; Engel, Tobias; Henshall, David C; Düssmann, Heiko; Prehn, Jochen H M

    2015-01-28

    Excessive Ca(2+) entry during glutamate receptor overactivation ("excitotoxicity") induces acute or delayed neuronal death. We report here that deficiency in bax exerted broad neuroprotection against excitotoxic injury and oxygen/glucose deprivation in mouse neocortical neuron cultures and reduced infarct size, necrotic injury, and cerebral edema formation after middle cerebral artery occlusion in mice. Neuronal Ca(2+) and mitochondrial membrane potential (Δψm) analysis during excitotoxic injury revealed that bax-deficient neurons showed significantly reduced Ca(2+) transients during the NMDA excitation period and did not exhibit the deregulation of Δψm that was observed in their wild-type (WT) counterparts. Reintroduction of bax or a bax mutant incapable of proapoptotic oligomerization equally restored neuronal Ca(2+) dynamics during NMDA excitation, suggesting that Bax controlled Ca(2+) signaling independently of its role in apoptosis execution. Quantitative confocal imaging of intracellular ATP or mitochondrial Ca(2+) levels using FRET-based sensors indicated that the effects of bax deficiency on Ca(2+) handling were not due to enhanced cellular bioenergetics or increased Ca(2+) uptake into mitochondria. We also observed that mitochondria isolated from WT or bax-deficient cells similarly underwent Ca(2+)-induced permeability transition. However, when Ca(2+) uptake into the sarco/endoplasmic reticulum was blocked with the Ca(2+)-ATPase inhibitor thapsigargin, bax-deficient neurons showed strongly elevated cytosolic Ca(2+) levels during NMDA excitation, suggesting that the ability of Bax to support dynamic ER Ca(2+) handling is critical for cell death signaling during periods of neuronal overexcitation. Copyright © 2015 the authors 0270-6474/15/351706-17$15.00/0.

  15. Estradiol Protects Proopiomelanocortin Neurons Against Insulin Resistance.

    Science.gov (United States)

    Qiu, Jian; Bosch, Martha A; Meza, Cecilia; Navarro, Uyen-Vy; Nestor, Casey C; Wagner, Edward J; Rønnekleiv, Oline K; Kelly, Martin J

    2018-02-01

    Insulin resistance is at the core of the metabolic syndrome, and men exhibit a higher incidence of metabolic syndrome than women in early adult life, but this sex advantage diminishes sharply when women reach the postmenopausal state. Because 17β-estradiol (E2) augments the excitability of the anorexigenic proopiomelanocortin (POMC) neurons, we investigated the neuroprotective effects of E2 against insulin resistance in POMC neurons from diet-induced obese (DIO) female and male mice. The efficacy of insulin to activate canonical transient receptor potential 5 (TRPC5) channels and depolarize POMC neurons was significantly reduced in DIO male mice but not in DIO female mice. However, the insulin response in POMC neurons was abrogated in ovariectomized DIO females but restored with E2 replacement. E2 increased T-type calcium channel Cav3.1 messenger RNA (mRNA) expression and whole-cell currents but downregulated stromal-interaction molecule 1 mRNA, which rendered POMC neurons more excitable and responsive to insulin-mediated TRPC5 channel activation. Moreover, E2 prevented the increase in suppressor of cytokine signaling-3 mRNA expression with DIO as seen in DIO males. As proof of principle, insulin [intracerebroventricular injection into the third ventricle (ICV)] decreased food intake and increased metabolism in female but not male guinea pigs fed a high-fat diet. The uncoupling of the insulin receptor from its downstream effector system was corroborated by the reduced expression of phosphorylated protein kinase B in the arcuate nucleus of male but not female guinea pigs following insulin. Therefore, E2 protects female POMC neurons from insulin resistance by enhancing POMC neuronal excitability and the coupling of insulin receptor to TRPC5 channel activation. Copyright © 2018 Endocrine Society.

  16. Metagenomic studies of the Red Sea.

    Science.gov (United States)

    Behzad, Hayedeh; Ibarra, Martin Augusto; Mineta, Katsuhiko; Gojobori, Takashi

    2016-02-01

    Metagenomics has significantly advanced the field of marine microbial ecology, revealing the vast diversity of previously unknown microbial life forms in different marine niches. The tremendous amount of data generated has enabled identification of a large number of microbial genes (metagenomes), their community interactions, adaptation mechanisms, and their potential applications in pharmaceutical and biotechnology-based industries. Comparative metagenomics reveals that microbial diversity is a function of the local environment, meaning that unique or unusual environments typically harbor novel microbial species with unique genes and metabolic pathways. The Red Sea has an abundance of unique characteristics; however, its microbiota is one of the least studied among marine environments. The Red Sea harbors approximately 25 hot anoxic brine pools, plus a vibrant coral reef ecosystem. Physiochemical studies describe the Red Sea as an oligotrophic environment that contains one of the warmest and saltiest waters in the world with year-round high UV radiations. These characteristics are believed to have shaped the evolution of microbial communities in the Red Sea. Over-representation of genes involved in DNA repair, high-intensity light responses, and osmoregulation were found in the Red Sea metagenomic databases suggesting acquisition of specific environmental adaptation by the Red Sea microbiota. The Red Sea brine pools harbor a diverse range of halophilic and thermophilic bacterial and archaeal communities, which are potential sources of enzymes for pharmaceutical and biotechnology-based application. Understanding the mechanisms of these adaptations and their function within the larger ecosystem could also prove useful in light of predicted global warming scenarios where global ocean temperatures are expected to rise by 1-3°C in the next few decades. In this review, we provide an overview of the published metagenomic studies that were conducted in the Red Sea, and

  17. Neuronal medium that supports basic synaptic functions and activity of human neurons in vitro

    NARCIS (Netherlands)

    Bardy, C.; Hurk, M. van den; Eames, T.; Marchand, C.; Hernandez, R.V.; Kellogg, M.; Gorris, M.A.J.; Galet, B.; Palomares, V.; Brown, J.; Bang, A.G.; Mertens, J.; Bohnke, L.; Boyer, L.; Simon, S.; Gage, F.H.

    2015-01-01

    Human cell reprogramming technologies offer access to live human neurons from patients and provide a new alternative for modeling neurological disorders in vitro. Neural electrical activity is the essence of nervous system function in vivo. Therefore, we examined neuronal activity in media widely

  18. Morphine disinhibits glutamatergic input to VTA dopamine neurons and promotes dopamine neuron excitation.

    Science.gov (United States)

    Chen, Ming; Zhao, Yanfang; Yang, Hualan; Luan, Wenjie; Song, Jiaojiao; Cui, Dongyang; Dong, Yi; Lai, Bin; Ma, Lan; Zheng, Ping

    2015-07-24

    One reported mechanism for morphine activation of dopamine (DA) neurons of the ventral tegmental area (VTA) is the disinhibition model of VTA-DA neurons. Morphine inhibits GABA inhibitory neurons, which shifts the balance between inhibitory and excitatory input to VTA-DA neurons in favor of excitation and then leads to VTA-DA neuron excitation. However, it is not known whether morphine has an additional strengthening effect on excitatory input. Our results suggest that glutamatergic input to VTA-DA neurons is inhibited by GABAergic interneurons via GABAB receptors and that morphine promotes presynaptic glutamate release by removing this inhibition. We also studied the contribution of the morphine-induced disinhibitory effect on the presynaptic glutamate release to the overall excitatory effect of morphine on VTA-DA neurons and related behavior. Our results suggest that the disinhibitory action of morphine on presynaptic glutamate release might be the main mechanism for morphine-induced increase in VTA-DA neuron firing and related behaviors.

  19. Transgenic tools to characterize neuronal properties of discrete populations of zebrafish neurons.

    Science.gov (United States)

    Satou, Chie; Kimura, Yukiko; Hirata, Hiromi; Suster, Maximiliano L; Kawakami, Koichi; Higashijima, Shin-ichi

    2013-09-01

    The developing nervous system consists of a variety of cell types. Transgenic animals expressing reporter genes in specific classes of neuronal cells are powerful tools for the study of neuronal network formation. We generated a wide variety of transgenic zebrafish that expressed reporter genes in specific classes of neurons or neuronal progenitors. These include lines in which neurons of specific neurotransmitter phenotypes expressed fluorescent proteins or Gal4, and lines in which specific subsets of the dorsal progenitor domain in the spinal cord expressed fluorescent proteins. Using these, we examined domain organization in the developing dorsal spinal cord, and found that there are six progenitor domains in zebrafish, which is similar to the domain organization in mice. We also systematically characterized neurotransmitter properties of the neurons that are produced from each domain. Given that reporter gene expressions occurs in a wide area of the nervous system in the lines generated, these transgenic fish should serve as powerful tools for the investigation of not only the neurons in the dorsal spinal cord but also neuronal structures and functions in many other regions of the nervous system.

  20. CRISPR Epigenome Editing of AKAP150 in DRG Neurons Abolishes Degenerative IVD-Induced Neuronal Activation.

    Science.gov (United States)

    Stover, Joshua D; Farhang, Niloofar; Berrett, Kristofer C; Gertz, Jason; Lawrence, Brandon; Bowles, Robby D

    2017-09-06

    Back pain is a major contributor to disability and has significant socioeconomic impacts worldwide. The degenerative intervertebral disc (IVD) has been hypothesized to contribute to back pain, but a better understanding of the interactions between the degenerative IVD and nociceptive neurons innervating the disc and treatment strategies that directly target these interactions is needed to improve our understanding and treatment of back pain. We investigated degenerative IVD-induced changes to dorsal root ganglion (DRG) neuron activity and utilized CRISPR epigenome editing as a neuromodulation strategy. By exposing DRG neurons to degenerative IVD-conditioned media under both normal and pathological IVD pH levels, we demonstrate that degenerative IVDs trigger interleukin (IL)-6-induced increases in neuron activity to thermal stimuli, which is directly mediated by AKAP and enhanced by acidic pH. Utilizing this novel information on AKAP-mediated increases in nociceptive neuron activity, we developed lentiviral CRISPR epigenome editing vectors that modulate endogenous expression of AKAP150 by targeted promoter histone methylation. When delivered to DRG neurons, these epigenome-modifying vectors abolished degenerative IVD-induced DRG-elevated neuron activity while preserving non-pathologic neuron activity. This work elucidates the potential for CRISPR epigenome editing as a targeted gene-based pain neuromodulation strategy. Copyright © 2017 The American Society of Gene and Cell Therapy. Published by Elsevier Inc. All rights reserved.

  1. BigNeuron: Large-Scale 3D Neuron Reconstruction from Optical Microscopy Images

    NARCIS (Netherlands)

    H. Peng (Hanchuan); M. Hawrylycz (Michael); J. Roskams (Jane); S. Hill (Sean); N. Spruston (Nelson); E. Meijering (Erik); G.A. Ascoli (Giorgio A.)

    2015-01-01

    textabstractUnderstanding the structure of single neurons is critical for understanding how they function within neural circuits. BigNeuron is a new community effort that combines modern bioimaging informatics, recent leaps in labeling and microscopy, and the widely recognized need for openness and

  2. Photometry of Southern Hemisphere red dwarf stars

    Science.gov (United States)

    Weistrop, D.

    1980-01-01

    Results are presented for a photometric investigation of a spectroscopically selected sample of red dwarf stars in the Southern Hemisphere. Absolute magnitudes and distances for the stars are estimated from broadband red colors. Three stars which may be subluminous are identified, as are several stars which may be within 25 pc. The tangential velocity and velocity dispersion of the sample are similar to values found in other studies of nearby late-type stars.

  3. Red Wine, Resveratrol and Atrial Fibrillation

    OpenAIRE

    Stephan, Laura Siga; Almeida, Eduardo Dytz; Markoski, Melissa Medeiros; Garavaglia, Juliano; Marcadenti, Aline

    2017-01-01

    Atrial fibrillation (AF) is a common cardiac arrhythmia that is associated with increased risk for cardiovascular disease and overall mortality. Excessive alcohol intake is a well-known risk factor for AF, but this correlation is less clear with light and moderate drinking. Besides, low doses of red wine may acutely prolong repolarization and slow cardiac conduction. Resveratrol, a bioactive polyphenol found in grapes and red wine, has been linked to antiarrhythmic properties and may act as a...

  4. Causes of Red Eye-Uveitis

    OpenAIRE

    Selçuk Sızmaz

    2012-01-01

    Uveitis, being an important cause of ocular morbidity, must be taken into consideration in the differential diagnosis and the management of patients with red eye. Uveitis entities can demonstrate variable clinical features. Patients presenting with uveitis must undergo careful systemic evaluation for exact diagnosis and treatment. Studies for standardization of uveitis with variable clinical pictures are emerging. Acute anterior uveitis and panuveitis can cause red eye. The purpose o...

  5. Clinical implications of The Red Book.

    Science.gov (United States)

    Culliford, Penny

    2012-09-01

    This presentation stresses the uniqueness of both the therapist's and patient's personal experience in clinical work and relates this to the significance of The Red Book as Jung's personal odyssey and for me personally as an analyst. I consider The Red Book's enduring relevance alongside recent psychological theories, neuroscience and early mystical writings, and conclude with a clinical vignette of a patient's response to a piece of choral music and subsequent use of active imagination. © 2012, The Society of Analytical Psychology.

  6. Red Teaming of Advanced Information Assurance Concepts

    International Nuclear Information System (INIS)

    DUGGAN, RUTH A.; WOOD, BRADLEY

    1999-01-01

    Red Teaming is an advanced form of assessment that can be used to identify weaknesses in a variety of cyber systems. it is especially beneficial when the target system is still in development when designers can readily affect improvements. This paper discusses the red team analysis process and the author's experiences applying this process to five selected Information Technology Office (ITO) projects. Some detail of the overall methodology, summary results from the five projects, and lessons learned are contained within this paper

  7. Protective effects of plant seed extracts against amyloid β-induced neurotoxicity in cultured hippocampal neurons

    Directory of Open Access Journals (Sweden)

    Yoshinori Okada

    2013-01-01

    Full Text Available Aim: Alzheimer′s disease (AD is characterized by large deposits of amyloid β (Aβ peptide. Aβ is known to increase reactive oxygen species (ROS production in neurons, leading to cell death. In this study, we screened 15 plant seeds′ aqueous extracts (PSAE for inhibitory effects on Aβ (25-35-induced cell death using hippocampus neurons (HIPN. Materials and Methods: Fifteen chosen plants were nine medical herbs (Japanese honeywort, luffa, rapeseed, Chinese colza, potherb mustard, Japanese radish, bitter melon, red shiso, corn, and kaiware radish and six general commercial plants (common bean, komatsuna, Qing geng cai, bell pepper, kale, and lettuce. PSAE were measured for total phenolic content (TPC with the Folin-Ciocalteu method, and the 2-diphenyl-1-picryl-hydrazyl (DPPH radical scavenging effect of each seed extract was measured. To find a protectant against Aβ-induced oxidative stress, we screened 15 PSAE using a 2′, 7′-dichlorofluorescein diacetate assay. To further unravel the anti-inflammatory effects of PSAE on Aβ-induced inflammation, PSAE were added to HIPN. The neuroprotective effects of the PSAE were evaluated by Cell Counting Kit-8 assay, measuring the cell viability in Aβ-induced HIPN. Results: TPC of 15 PSAE was in the range of 0.024-1.96 mg of chlorogenic acid equivalents/gram. The aqueous extracts showed antioxidant activities. Furthermore, intracellular ROS accumulation resulting from Aβ treatment was reduced when cells were treated with some PSAE. Kale, bitter melon, kaiware radish, red shiso, and corn inhibited tumor necrosis factor-alpha secretion by the Aβ-stimulated neurons and all samples except Japanese honeywort showed enhancement of cell survival. Conclusion: From these results, we suggest that some plant seed extracts offer protection against Aβ-mediated cell death.

  8. Protective effects of plant seed extracts against amyloid β-induced neurotoxicity in cultured hippocampal neurons.

    Science.gov (United States)

    Okada, Yoshinori; Okada, Mizue

    2013-04-01

    Alzheimer's disease (AD) is characterized by large deposits of amyloid β (Aβ) peptide. Aβ is known to increase reactive oxygen species (ROS) production in neurons, leading to cell death. In this study, we screened 15 plant seeds' aqueous extracts (PSAE) for inhibitory effects on Aβ (25-35)-induced cell death using hippocampus neurons (HIPN). Fifteen chosen plants were nine medical herbs (Japanese honeywort, luffa, rapeseed, Chinese colza, potherb mustard, Japanese radish, bitter melon, red shiso, corn, and kaiware radish) and six general commercial plants (common bean, komatsuna, Qing geng cai, bell pepper, kale, and lettuce). PSAE were measured for total phenolic content (TPC) with the Folin-Ciocalteu method, and the 2-diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging effect of each seed extract was measured. To find a protectant against Aβ-induced oxidative stress, we screened 15 PSAE using a 2', 7'-dichlorofluorescein diacetate assay. To further unravel the anti-inflammatory effects of PSAE on Aβ-induced inflammation, PSAE were added to HIPN. The neuroprotective effects of the PSAE were evaluated by Cell Counting Kit-8 assay, measuring the cell viability in Aβ-induced HIPN. TPC of 15 PSAE was in the range of 0.024-1.96 mg of chlorogenic acid equivalents/gram. The aqueous extracts showed antioxidant activities. Furthermore, intracellular ROS accumulation resulting from Aβ treatment was reduced when cells were treated with some PSAE. Kale, bitter melon, kaiware radish, red shiso, and corn inhibited tumor necrosis factor-alpha secretion by the Aβ-stimulated neurons and all samples except Japanese honeywort showed enhancement of cell survival. From these results, we suggest that some plant seed extracts offer protection against Aβ-mediated cell death.

  9. The Red Book through the ages.

    Science.gov (United States)

    Pickering, Larry K; Peter, Georges; Shulman, Stanford T

    2013-11-01

    The first edition of the Red Book was published in 1938. Since then, there have been numerous advances in the fields of infectious diseases and public health that have decreased morbidity and mortality of infants, children, and adolescents. Over the years, emerging pathogens and disease complexes have been described, sophisticated diagnostic techniques developed, advances in antimicrobial therapy have occurred, and immunizations have been implemented to prevent previously deadly diseases. Of the 18 diseases or organisms in the 1938 edition, 13 are now vaccine-preventable. Since inception of the Red Book, the aims of the editors have been to keep pace with these innovations and to continue to inform the medical community. These goals have made the Red Book a fundamental resource for pediatricians and other health care professionals in terms of guiding diagnosis, therapy, and prevention of infectious diseases. The list of 18 diseases or organisms originally described in the 1938 Red Book has expanded to include over 160 diseases or organisms in the 2012 edition. The pace of biomedical discovery, as well as the amount of information available and the number of methods for its delivery, will continue to accelerate in the future. Integration of information into future editions of the Red Book will ensure that practitioners continue to rely on the Red Book in its various electronic formats for clinical guidance and support.

  10. All-optical recording and stimulation of retinal neurons in vivo in retinal degeneration mice

    Science.gov (United States)

    Strazzeri, Jennifer M.; Williams, David R.; Merigan, William H.

    2018-01-01

    Here we demonstrate the application of a method that could accelerate the development of novel therapies by allowing direct and repeatable visualization of cellular function in the living eye, to study loss of vision in animal models of retinal disease, as well as evaluate the time course of retinal function following therapeutic intervention. We use high-resolution adaptive optics scanning light ophthalmoscopy to image fluorescence from the calcium sensor GCaMP6s. In mice with photoreceptor degeneration (rd10), we measured restored visual responses in ganglion cell layer neurons expressing the red-shifted channelrhodopsin ChrimsonR over a six-week period following significant loss of visual responses. Combining a fluorescent calcium sensor, a channelrhodopsin, and adaptive optics enables all-optical stimulation and recording of retinal neurons in the living eye. Because the retina is an accessible portal to the central nervous system, our method also provides a novel non-invasive method of dissecting neuronal processing in the brain. PMID:29596518

  11. Optogenetic identification of hypothalamic orexin neuron projections to paraventricular spinally projecting neurons.

    Science.gov (United States)

    Dergacheva, Olga; Yamanaka, Akihiro; Schwartz, Alan R; Polotsky, Vsevolod Y; Mendelowitz, David

    2017-04-01

    Orexin neurons, and activation of orexin receptors, are generally thought to be sympathoexcitatory; however, the functional connectivity between orexin neurons and a likely sympathetic target, the hypothalamic spinally projecting neurons (SPNs) in the paraventricular nucleus of the hypothalamus (PVN) has not been established. To test the hypothesis that orexin neurons project directly to SPNs in the PVN, channelrhodopsin-2 (ChR2) was selectively expressed in orexin neurons to enable photoactivation of ChR2-expressing fibers while examining evoked postsynaptic currents in SPNs in rat hypothalamic slices. Selective photoactivation of orexin fibers elicited short-latency postsynaptic currents in all SPNs tested ( n = 34). These light-triggered responses were heterogeneous, with a majority being excitatory glutamatergic responses (59%) and a minority of inhibitory GABAergic (35%) and mixed glutamatergic and GABAergic currents (6%). Both glutamatergic and GABAergic responses were present in the presence of tetrodotoxin and 4-aminopyridine, suggesting a monosynaptic connection between orexin neurons and SPNs. In addition to generating postsynaptic responses, photostimulation facilitated action potential firing in SPNs (current clamp configuration). Glutamatergic, but not GABAergic, postsynaptic currents were diminished by application of the orexin receptor antagonist almorexant, indicating orexin release facilitates glutamatergic neurotransmission in this pathway. This work identifies a neuronal circuit by which orexin neurons likely exert sympathoexcitatory control of cardiovascular function. NEW & NOTEWORTHY This is the first study to establish, using innovative optogenetic approaches in a transgenic rat model, that there are robust heterogeneous projections from orexin neurons to paraventricular spinally projecting neurons, including excitatory glutamatergic and inhibitory GABAergic neurotransmission. Endogenous orexin release modulates glutamatergic, but not

  12. Energy-efficient neural information processing in individual neurons and neuronal networks.

    Science.gov (United States)

    Yu, Lianchun; Yu, Yuguo

    2017-11-01

    Brains are composed of networks of an enormous number of neurons interconnected with synapses. Neural information is carried by the electrical signals within neurons and the chemical signals among neurons. Generating these electrical and chemical signals is metabolically expensive. The fundamental issue raised here is whether brains have evolved efficient ways of developing an energy-efficient neural code from the molecular level to the circuit level. Here, we summarize the factors and biophysical mechanisms that could contribute to the energy-efficient neural code for processing input signals. The factors range from ion channel kinetics, body temperature, axonal propagation of action potentials, low-probability release of synaptic neurotransmitters, optimal input and noise, the size of neurons and neuronal clusters, excitation/inhibition balance, coding strategy, cortical wiring, and the organization of functional connectivity. Both experimental and computational evidence suggests that neural systems may use these factors to maximize the efficiency of energy consumption in processing neural signals. Studies indicate that efficient energy utilization may be universal in neuronal systems as an evolutionary consequence of the pressure of limited energy. As a result, neuronal connections may be wired in a highly economical manner to lower energy costs and space. Individual neurons within a network may encode independent stimulus components to allow a minimal number of neurons to represent whole stimulus characteristics efficiently. This basic principle may fundamentally change our view of how billions of neurons organize themselves into complex circuits to operate and generate the most powerful intelligent cognition in nature. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  13. Crosstalks between kisspeptin neurons and somatostatin neurons are not photoperiod dependent in the ewe hypothalamus.

    Science.gov (United States)

    Dufourny, Laurence; Lomet, Didier

    2017-12-01

    Seasonal reproduction is under the control of gonadal steroid feedback, itself synchronized by day-length or photoperiod. As steroid action on GnRH neurons is mostly indirect and therefore exerted through interneurons, we looked for neuroanatomical interactions between kisspeptin (KP) neurons and somatostatin (SOM) neurons, two populations targeted by sex steroids, in three diencephalic areas involved in the central control of ovulation and/or sexual behavior: the arcuate nucleus (ARC), the preoptic area (POA) and the ventrolateral part of the ventromedial hypothalamus (VMHvl). KP is the most potent secretagogue of GnRH secretion while SOM has been shown to centrally inhibit LH pulsatile release. Notably, hypothalamic contents of these two neuropeptides vary with photoperiod in specific seasonal species. Our hypothesis is that SOM inhibits KP neuron activity and therefore indirectly modulate GnRH release and that this effect may be seasonally regulated. We used sections from ovariectomized estradiol-replaced ewes killed after photoperiodic treatment mimicking breeding or anestrus season. We performed triple immunofluorescent labeling to simultaneously detect KP, SOM and synapsin, a marker for synaptic vesicles. Sections from the POA and from the mediobasal hypothalamus were examined using a confocal microscope. Randomly selected KP or SOM neurons were observed in the POA and ARC. SOM neurons were also observed in the VMHvl. In both the ARC and POA, nearly all KP neurons presented numerous SOM contacts. SOM neurons presented KP terminals more frequently in the ARC than in the POA and VMHvl. Quantitative analysis failed to demonstrate major seasonal variations of KP and SOM interactions. Our data suggest a possible inhibitory action of SOM on all KP neurons in both photoperiodic statuses. On the other hand, the physiological significance of KP modulation of SOM neuron activity and vice versa remain to be determined. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Binding by asynchrony: the neuronal phase code

    Directory of Open Access Journals (Sweden)

    Zoltan Nadasdy

    2010-09-01

    Full Text Available Neurons display continuous subthreshold oscillations and discrete action potentials. When action potentials are phase-locked to the subthreshold oscillation, we hypothesize they represent two types of information: the presence/absence of a sensory feature and the phase of subthreshold oscillation. If subthreshold oscillation phases are neuron-specific, then the sources of action potentials can be recovered based on the action potential times. If the spatial information about the stimulus is converted to action potential phases, then action potentials from multiple neurons can be combined into a single axon and the spatial configuration reconstructed elsewhere. For the reconstruction to be successful, we introduce two assumptions: that a subthreshold oscillation field has a constant phase gradient and that coincidences between action potentials and intracellular subthreshold oscillations are neuron-specific as defined by the "interference principle." Under these assumptions, a phase coding model enables information transfer between structures and reproduces experimental phenomenons such as phase precession, grid cell architecture, and phase modulation of cortical spikes. This article reviews a recently proposed neuronal algorithm for information encoding and decoding from the phase of action potentials (Nadasdy 2009. The focus is given to the principles common across different systems instead of emphasizing system specific differences.

  15. Synchronous behavior of two coupled electronic neurons

    International Nuclear Information System (INIS)

    Pinto, R. D.; Varona, P.; Volkovskii, A. R.; Szuecs, A.; Abarbanel, Henry D. I.; Rabinovich, M. I.

    2000-01-01

    We report on experimental studies of synchronization phenomena in a pair of analog electronic neurons (ENs). The ENs were designed to reproduce the observed membrane voltage oscillations of isolated biological neurons from the stomatogastric ganglion of the California spiny lobster Panulirus interruptus. The ENs are simple analog circuits which integrate four-dimensional differential equations representing fast and slow subcellular mechanisms that produce the characteristic regular/chaotic spiking-bursting behavior of these cells. In this paper we study their dynamical behavior as we couple them in the same configurations as we have done for their counterpart biological neurons. The interconnections we use for these neural oscillators are both direct electrical connections and excitatory and inhibitory chemical connections: each realized by analog circuitry and suggested by biological examples. We provide here quantitative evidence that the ENs and the biological neurons behave similarly when coupled in the same manner. They each display well defined bifurcations in their mutual synchronization and regularization. We report briefly on an experiment on coupled biological neurons and four-dimensional ENs, which provides further ground for testing the validity of our numerical and electronic models of individual neural behavior. Our experiments as a whole present interesting new examples of regularization and synchronization in coupled nonlinear oscillators. (c) 2000 The American Physical Society

  16. Doubly stochastic coherence in complex neuronal networks

    Science.gov (United States)

    Gao, Yang; Wang, Jianjun

    2012-11-01

    A system composed of coupled FitzHugh-Nagumo neurons with various topological structures is investigated under the co-presence of two independently additive and multiplicative Gaussian white noises, in which particular attention is paid to the neuronal networks spiking regularity. As the additive noise intensity and the multiplicative noise intensity are simultaneously adjusted to optimal values, the temporal periodicity of the output of the system reaches the maximum, indicating the occurrence of doubly stochastic coherence. The network topology randomness exerts different influences on the temporal coherence of the spiking oscillation for dissimilar coupling strength regimes. At a small coupling strength, the spiking regularity shows nearly no difference in the regular, small-world, and completely random networks. At an intermediate coupling strength, the temporal periodicity in a small-world neuronal network can be improved slightly by adding a small fraction of long-range connections. At a large coupling strength, the dynamical behavior of the neurons completely loses the resonance property with regard to the additive noise intensity or the multiplicative noise intensity, and the spiking regularity decreases considerably with the increase of the network topology randomness. The network topology randomness plays more of a depressed role than a favorable role in improving the temporal coherence of the spiking oscillation in the neuronal network research study.

  17. Bursting synchronization in clustered neuronal networks

    International Nuclear Information System (INIS)

    Yu Hai-Tao; Wang Jiang; Deng Bin; Wei Xi-Le

    2013-01-01

    Neuronal networks in the brain exhibit the modular (clustered) property, i.e., they are composed of certain subnetworks with differential internal and external connectivity. We investigate bursting synchronization in a clustered neuronal network. A transition to mutual-phase synchronization takes place on the bursting time scale of coupled neurons, while on the spiking time scale, they behave asynchronously. This synchronization transition can be induced by the variations of inter- and intracoupling strengths, as well as the probability of random links between different subnetworks. Considering that some pathological conditions are related with the synchronization of bursting neurons in the brain, we analyze the control of bursting synchronization by using a time-periodic external signal in the clustered neuronal network. Simulation results show a frequency locking tongue in the driving parameter plane, where bursting synchronization is maintained, even in the presence of external driving. Hence, effective synchronization suppression can be realized with the driving parameters outside the frequency locking region. (interdisciplinary physics and related areas of science and technology)

  18. Epigenetic Basis of Neuronal and Synaptic Plasticity.

    Science.gov (United States)

    Karpova, Nina N; Sales, Amanda J; Joca, Samia R

    2017-01-01

    Neuronal network and plasticity change as a function of experience. Altered neural connectivity leads to distinct transcriptional programs of neuronal plasticity-related genes. The environmental challenges throughout life may promote long-lasting reprogramming of gene expression and the development of brain disorders. The modifications in neuronal epigenome mediate gene-environmental interactions and are required for activity-dependent regulation of neuronal differentiation, maturation and plasticity. Here, we highlight the latest advances in understanding the role of the main players of epigenetic machinery (DNA methylation and demethylation, histone modifications, chromatin-remodeling enzymes, transposons, and non-coding RNAs) in activity-dependent and long- term neural and synaptic plasticity. The review focuses on both the transcriptional and post-transcriptional regulation of gene expression levels, including the processes of promoter activation, alternative splicing, regulation of stability of gene transcripts by natural antisense RNAs, and alternative polyadenylation. Further, we discuss the epigenetic aspects of impaired neuronal plasticity and the pathogenesis of neurodevelopmental (Rett syndrome, Fragile X Syndrome, genomic imprinting disorders, schizophrenia, and others), stressrelated (mood disorders) and neurodegenerative Alzheimer's, Parkinson's and Huntington's disorders. The review also highlights the pharmacological compounds that modulate epigenetic programming of gene expression, the potential treatment strategies of discussed brain disorders, and the questions that should be addressed during the development of effective and safe approaches for the treatment of brain disorders.

  19. Spin orbit torque based electronic neuron

    Energy Technology Data Exchange (ETDEWEB)

    Sengupta, Abhronil, E-mail: asengup@purdue.edu; Choday, Sri Harsha; Kim, Yusung; Roy, Kaushik [School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907 (United States)

    2015-04-06

    A device based on current-induced spin-orbit torque (SOT) that functions as an electronic neuron is proposed in this work. The SOT device implements an artificial neuron's thresholding (transfer) function. In the first step of a two-step switching scheme, a charge current places the magnetization of a nano-magnet along the hard-axis, i.e., an unstable point for the magnet. In the second step, the SOT device (neuron) receives a current (from the synapses) which moves the magnetization from the unstable point to one of the two stable states. The polarity of the synaptic current encodes the excitatory and inhibitory nature of the neuron input and determines the final orientation of the magnetization. A resistive crossbar array, functioning as synapses, generates a bipolar current that is a weighted sum of the inputs. The simulation of a two layer feed-forward artificial neural network based on the SOT electronic neuron shows that it consumes ∼3× lower power than a 45 nm digital CMOS implementation, while reaching ∼80% accuracy in the classification of 100 images of handwritten digits from the MNIST dataset.

  20. Spin orbit torque based electronic neuron

    International Nuclear Information System (INIS)

    Sengupta, Abhronil; Choday, Sri Harsha; Kim, Yusung; Roy, Kaushik

    2015-01-01

    A device based on current-induced spin-orbit torque (SOT) that functions as an electronic neuron is proposed in this work. The SOT device implements an artificial neuron's thresholding (transfer) function. In the first step of a two-step switching scheme, a charge current places the magnetization of a nano-magnet along the hard-axis, i.e., an unstable point for the magnet. In the second step, the SOT device (neuron) receives a current (from the synapses) which moves the magnetization from the unstable point to one of the two stable states. The polarity of the synaptic current encodes the excitatory and inhibitory nature of the neuron input and determines the final orientation of the magnetization. A resistive crossbar array, functioning as synapses, generates a bipolar current that is a weighted sum of the inputs. The simulation of a two layer feed-forward artificial neural network based on the SOT electronic neuron shows that it consumes ∼3× lower power than a 45 nm digital CMOS implementation, while reaching ∼80% accuracy in the classification of 100 images of handwritten digits from the MNIST dataset

  1. Large-scale modelling of neuronal systems

    International Nuclear Information System (INIS)

    Castellani, G.; Verondini, E.; Giampieri, E.; Bersani, F.; Remondini, D.; Milanesi, L.; Zironi, I.

    2009-01-01

    The brain is, without any doubt, the most, complex system of the human body. Its complexity is also due to the extremely high number of neurons, as well as the huge number of synapses connecting them. Each neuron is capable to perform complex tasks, like learning and memorizing a large class of patterns. The simulation of large neuronal systems is challenging for both technological and computational reasons, and can open new perspectives for the comprehension of brain functioning. A well-known and widely accepted model of bidirectional synaptic plasticity, the BCM model, is stated by a differential equation approach based on bistability and selectivity properties. We have modified the BCM model extending it from a single-neuron to a whole-network model. This new model is capable to generate interesting network topologies starting from a small number of local parameters, describing the interaction between incoming and outgoing links from each neuron. We have characterized this model in terms of complex network theory, showing how this, learning rule can be a support For network generation.

  2. Memristors Empower Spiking Neurons With Stochasticity

    KAUST Repository

    Al-Shedivat, Maruan

    2015-06-01

    Recent theoretical studies have shown that probabilistic spiking can be interpreted as learning and inference in cortical microcircuits. This interpretation creates new opportunities for building neuromorphic systems driven by probabilistic learning algorithms. However, such systems must have two crucial features: 1) the neurons should follow a specific behavioral model, and 2) stochastic spiking should be implemented efficiently for it to be scalable. This paper proposes a memristor-based stochastically spiking neuron that fulfills these requirements. First, the analytical model of the memristor is enhanced so it can capture the behavioral stochasticity consistent with experimentally observed phenomena. The switching behavior of the memristor model is demonstrated to be akin to the firing of the stochastic spike response neuron model, the primary building block for probabilistic algorithms in spiking neural networks. Furthermore, the paper proposes a neural soma circuit that utilizes the intrinsic nondeterminism of memristive switching for efficient spike generation. The simulations and analysis of the behavior of a single stochastic neuron and a winner-take-all network built of such neurons and trained on handwritten digits confirm that the circuit can be used for building probabilistic sampling and pattern adaptation machinery in spiking networks. The findings constitute an important step towards scalable and efficient probabilistic neuromorphic platforms. © 2011 IEEE.

  3. Effects of Tannic Acid, Green Tea and Red Wine on hERG Channels Expressed in HEK293 Cells.

    Directory of Open Access Journals (Sweden)

    Xi Chu

    Full Text Available Tannic acid presents in varying concentrations in plant foods, and in relatively high concentrations in green teas and red wines. Human ether-à-go-go-related gene (hERG channels expressed in multiple tissues (e.g. heart, neurons, smooth muscle and cancer cells, and play important roles in modulating cardiac action potential repolarization and tumor cell biology. The present study investigated the effects of tannic acid, green teas and red wines on hERG currents. The effects of tannic acid, teas and red wines on hERG currents stably transfected in HEK293 cells were studied with a perforated patch clamp technique. In this study, we demonstrated that tannic acid inhibited hERG currents with an IC50 of 3.4 μM and ~100% inhibition at higher concentrations, and significantly shifted the voltage dependent activation to more positive potentials (Δ23.2 mV. Remarkably, a 100-fold dilution of multiple types of tea (green tea, oolong tea and black tea or red wine inhibited hERG currents by ~90%, and significantly shifted the voltage dependent activation to more positive potentials (Δ30.8 mV and Δ26.0 mV, respectively. Green tea Lung Ching and red wine inhibited hERG currents, with IC50 of 0.04% and 0.19%, respectively. The effects of tannic acid, teas and red wine on hERG currents were irreversible. These results suggest tannic acid is a novel hERG channel blocker and consequently provide a new mechanistic evidence for understanding the effects of tannic acid. They also revealed the potential pharmacological basis of tea- and red wine-induced biology activities.

  4. Effects of Tannic Acid, Green Tea and Red Wine on hERG Channels Expressed in HEK293 Cells

    Science.gov (United States)

    Xu, Bingyuan; Li, Wenya; Lin, Yue; Sun, Xiaorun; Ding, Chunhua; Zhang, Xuan

    2015-01-01

    Tannic acid presents in varying concentrations in plant foods, and in relatively high concentrations in green teas and red wines. Human ether-à-go-go-related gene (hERG) channels expressed in multiple tissues (e.g. heart, neurons, smooth muscle and cancer cells), and play important roles in modulating cardiac action potential repolarization and tumor cell biology. The present study investigated the effects of tannic acid, green teas and red wines on hERG currents. The effects of tannic acid, teas and red wines on hERG currents stably transfected in HEK293 cells were studied with a perforated patch clamp technique. In this study, we demonstrated that tannic acid inhibited hERG currents with an IC50 of 3.4 μM and ~100% inhibition at higher concentrations, and significantly shifted the voltage dependent activation to more positive potentials (Δ23.2 mV). Remarkably, a 100-fold dilution of multiple types of tea (green tea, oolong tea and black tea) or red wine inhibited hERG currents by ~90%, and significantly shifted the voltage dependent activation to more positive potentials (Δ30.8 mV and Δ26.0 mV, respectively). Green tea Lung Ching and red wine inhibited hERG currents, with IC50 of 0.04% and 0.19%, respectively. The effects of tannic acid, teas and red wine on hERG currents were irreversible. These results suggest tannic acid is a novel hERG channel blocker and consequently provide a new mechanistic evidence for understanding the effects of tannic acid. They also revealed the potential pharmacological basis of tea- and red wine-induced biology activities. PMID:26625122

  5. Synchronization of motor neurons during locomotion in the neonatal rat

    DEFF Research Database (Denmark)

    Tresch, Matthew C.; Kiehn, Ole

    2002-01-01

    We describe here the robust synchronization of motor neurons at a millisecond time scale during locomotor activity in the neonatal rat. Action potential activity of motor neuron pairs was recorded extracellularly using tetrodes during locomotor activity in the in vitro neonatal rat spinal cord....... Approximately 40% of motor neuron pairs recorded in the same spinal segment showed significant synchronization, with the duration of the central peak in cross-correlograms between motor neurons typically ranging between ∼ 30 and 100 msec. The percentage of synchronized motor neuron pairs was considerably higher...... between motor neurons persisted. On the other hand, both local and distant coupling between motor neurons were preserved after antagonism of gap junction coupling between motor neurons. These results demonstrate that motor neuron activity is strongly synchronized at a millisecond time scale during...

  6. Neuronal replacement therapy: previous achievements and challenges ahead

    Science.gov (United States)

    Grade, Sofia; Götz, Magdalena

    2017-10-01

    Lifelong neurogenesis and incorporation of newborn neurons into mature neuronal circuits operates in specialized niches of the mammalian brain and serves as role model for neuronal replacement strategies. However, to which extent can the remaining brain parenchyma, which never incorporates new neurons during the adulthood, be as plastic and readily accommodate neurons in networks that suffered neuronal loss due to injury or neurological disease? Which microenvironment is permissive for neuronal replacement and synaptic integration and which cells perform best? Can lost function be restored and how adequate is the participation in the pre-existing circuitry? Could aberrant connections cause malfunction especially in networks dominated by excitatory neurons, such as the cerebral cortex? These questions show how important connectivity and circuitry aspects are for regenerative medicine, which is the focus of this review. We will discuss the impressive advances in neuronal replacement strategies and success from exogenous as well as endogenous cell sources. Both have seen key novel technologies, like the groundbreaking discovery of induced pluripotent stem cells and direct neuronal reprogramming, offering alternatives to the transplantation of fetal neurons, and both herald great expectations. For these to become reality, neuronal circuitry analysis is key now. As our understanding of neuronal circuits increases, neuronal replacement therapy should fulfill those prerequisites in network structure and function, in brain-wide input and output. Now is the time to incorporate neural circuitry research into regenerative medicine if we ever want to truly repair brain injury.

  7. Autapse-induced synchronization in a coupled neuronal network

    International Nuclear Information System (INIS)

    Ma, Jun; Song, Xinlin; Jin, Wuyin; Wang, Chuni

    2015-01-01

    Highlights: • The functional effect of autapse on neuronal activity is detected. • Autapse driving plays active role in regulating electrical activities as pacemaker. • It confirms biological experimental results for rhythm synchronization between heterogeneous cells. - Abstract: The effect of autapse on coupled neuronal network is detected. In our studies, three identical neurons are connected with ring type and autapse connected to one neuron of the network. The autapse connected to neuron can impose time-delayed feedback in close loop on the neuron thus the dynamics of membrane potentials can be changed. Firstly, the effect of autapse driving on single neuron is confirmed that negative feedback can calm down the neuronal activity while positive feedback can excite the neuronal activity. Secondly, the collective electrical behaviors of neurons are regulated by a pacemaker, which associated with the autapse forcing. By using appropriate gain and time delay in the autapse, the neurons can reach synchronization and the membrane potentials of all neurons can oscillate with the same rhythm under mutual coupling. It indicates that autapse forcing plays an important role in changing the collective electric activities of neuronal network, and appropriate electric modes can be selected due to the switch of feedback type(positive or negative) in autapse. And the autapse-induced synchronization in network is also consistent with some biological experiments about synchronization between nonidentical neurons.

  8. A Review of Prevention, Diagnosis and Treatment of Relative Energy Deficiency in Sport (RED-S) in Artistic (Synchronized) Swimming.

    Science.gov (United States)

    Robertson, Sherry; Mountjoy, Margo

    2018-05-03

    The syndrome Relative Energy Deficiency in Sport (RED-S) is a clinical entity characterized by low energy availability (LEA), which can negatively affect the health and performance of both male and female athletes. The underlying mechanism of RED-S is an inadequacy of dietary energy to support optimal health and performance. This syndrome refers to impaired physiological function including metabolic rate, menstrual function, bone health, immunity, protein synthesis, and cardiovascular health, with psychological consequences which can either precede (through restrictive dietary habits) or result from RED-S. The term RED-S extends beyond the condition termed the "Female Athlete Triad". Formerly known as synchronized swimming, artistic swimming is an Olympic sport requiring a high level of fitness as well as technical skill and artistry. The risk of RED-S is high in artistic swimming as it is an aesthetic, judged sport with an emphasis on a lean physique. RED-S is of significant concern in the sport of artistic swimming because of the potential negative effects on physical and mental health as well as consequences on athletic performance. This paper reviews health and performance consequences associated with LEA resulting in RED-S in artistic swimming. Medical and nutritional considerations specific to artistic swimming are reviewed and methods to help detect and manage RED-S are discussed. Prevention and management of RED-S in this athlete population should be a priority for coaches and the sport medicine professionals working with artistic swimming athletes should utilize the RED-S CAT, a Clinical Assessment Tool for screening and managing RED-S.

  9. 27 CFR 9.190 - Red Hill Douglas County, Oregon.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Red Hill Douglas County... Areas § 9.190 Red Hill Douglas County, Oregon. (a) Name. The name of the viticultural area described in this section is “Red Hill Douglas County, Oregon”. For purposes of part 4 of this chapter, “Red Hill...

  10. What makes red quasars red?. Observational evidence for dust extinction from line ratio analysis

    Science.gov (United States)

    Kim, Dohyeong; Im, Myungshin

    2018-02-01

    Red quasars are very red in the optical through near-infrared (NIR) wavelengths, which is possibly due to dust extinction in their host galaxies as expected in a scenario in which red quasars are an intermediate population between merger-driven star-forming galaxies and unobscured type 1 quasars. However, alternative mechanisms also exist to explain their red colors: (i) an intrinsically red continuum; (ii) an unusual high covering factor of the hot dust component, that is, CFHD = LHD/Lbol, where the LHD is the luminosity from the hot dust component and the Lbol is the bolometric luminosity; and (iii) a moderate viewing angle. In order to investigate why red quasars are red, we studied optical and NIR spectra of 20 red quasars at z 0.3 and 0.7, where the usage of the NIR spectra allowed us to look into red quasar properties in ways that are little affected by dust extinction. The Paschen to Balmer line ratios were derived for 13 red quasars and the values were found to be 10 times higher than unobscured type 1 quasars, suggesting a heavy dust extinction with AV > 2.5 mag. Furthermore, the Paschen to Balmer line ratios of red quasars are difficult to explain with plausible physical conditions without adopting the concept of the dust extinction. The CFHD of red quasars are similar to, or marginally higher than, those of unobscured type 1 quasars. The Eddington ratios, computed for 19 out of 20 red quasars, are higher than those of unobscured type 1 quasars (by factors of 3-5), and hence the moderate viewing angle scenario is disfavored. Consequently, these results strongly suggest the dust extinction that is connected to an enhanced nuclear activity as the origin of the red color of red quasars, which is consistent with the merger-driven quasar evolution scenario. Full Table A.1 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/610/A31

  11. Decoding spikes in a spiking neuronal network

    Energy Technology Data Exchange (ETDEWEB)

    Feng Jianfeng [Department of Informatics, University of Sussex, Brighton BN1 9QH (United Kingdom); Ding, Mingzhou [Department of Mathematics, Florida Atlantic University, Boca Raton, FL 33431 (United States)

    2004-06-04

    We investigate how to reliably decode the input information from the output of a spiking neuronal network. A maximum likelihood estimator of the input signal, together with its Fisher information, is rigorously calculated. The advantage of the maximum likelihood estimation over the 'brute-force rate coding' estimate is clearly demonstrated. It is pointed out that the ergodic assumption in neuroscience, i.e. a temporal average is equivalent to an ensemble average, is in general not true. Averaging over an ensemble of neurons usually gives a biased estimate of the input information. A method on how to compensate for the bias is proposed. Reconstruction of dynamical input signals with a group of spiking neurons is extensively studied and our results show that less than a spike is sufficient to accurately decode dynamical inputs.

  12. Dynamics of a structured neuron population

    International Nuclear Information System (INIS)

    Pakdaman, Khashayar; Salort, Delphine; Perthame, Benoît

    2010-01-01

    We study the dynamics of assemblies of interacting neurons. For large fully connected networks, the dynamics of the system can be described by a partial differential equation reminiscent of age-structure models used in mathematical ecology, where the 'age' of a neuron represents the time elapsed since its last discharge. The nonlinearity arises from the connectivity J of the network. We prove some mathematical properties of the model that are directly related to qualitative properties. On the one hand, we prove that it is well-posed and that it admits stationary states which, depending upon the connectivity, can be unique or not. On the other hand, we study the long time behaviour of solutions; both for small and large J, we prove the relaxation to the steady state describing asynchronous firing of the neurons. In the middle range, numerical experiments show that periodic solutions appear expressing re-synchronization of the network and asynchronous firing

  13. Current Source Density Estimation for Single Neurons

    Directory of Open Access Journals (Sweden)

    Dorottya Cserpán

    2014-03-01

    Full Text Available Recent developments of multielectrode technology made it possible to measure the extracellular potential generated in the neural tissue with spatial precision on the order of tens of micrometers and on submillisecond time scale. Combining such measurements with imaging of single neurons within the studied tissue opens up new experimental possibilities for estimating distribution of current sources along a dendritic tree. In this work we show that if we are able to relate part of the recording of extracellular potential to a specific cell of known morphology we can estimate the spatiotemporal distribution of transmembrane currents along it. We present here an extension of the kernel CSD method (Potworowski et al., 2012 applicable in such case. We test it on several model neurons of progressively complicated morphologies from ball-and-stick to realistic, up to analysis of simulated neuron activity embedded in a substantial working network (Traub et al, 2005. We discuss the caveats and possibilities of this new approach.

  14. Runx transcription factors in neuronal development

    Directory of Open Access Journals (Sweden)

    Shiga Takashi

    2008-08-01

    Full Text Available Abstract Runt-related (Runx transcription factors control diverse aspects of embryonic development and are responsible for the pathogenesis of many human diseases. In recent years, the functions of this transcription factor family in the nervous system have just begun to be understood. In dorsal root ganglion neurons, Runx1 and Runx3 play pivotal roles in the development of nociceptive and proprioceptive sensory neurons, respectively. Runx appears to control the transcriptional regulation of neurotrophin receptors, numerous ion channels and neuropeptides. As a consequence, Runx contributes to diverse aspects of the sensory system in higher vertebrates. In this review, we summarize recent progress in determining the role of Runx in neuronal development.

  15. GABAergic actions on cholinergic laterodorsal tegmental neurons

    DEFF Research Database (Denmark)

    Kohlmeier, K A; Kristiansen, Uffe

    2010-01-01

    Cholinergic neurons of the pontine laterodorsal tegmentum (LDT) play a critical role in regulation of behavioral state. Therefore, elucidation of mechanisms that control their activity is vital for understanding of how switching between wakefulness, sleep and anesthetic states is effectuated....... In vivo studies suggest that GABAergic mechanisms within the pons play a critical role in behavioral state switching. However, the postsynaptic, electrophysiological actions of GABA on LDT neurons, as well as the identity of GABA receptors present in the LDT mediating these actions is virtually unexplored...... neurons. Post-synaptic location of GABA(A) receptors was demonstrated by persistence of muscimol-induced inward currents in TTX and low Ca(2+) solutions. THIP, a selective GABA(A) receptor agonist with a preference for d-subunit containing GABA(A) receptors, induced inward currents, suggesting...

  16. Decoding spikes in a spiking neuronal network

    International Nuclear Information System (INIS)

    Feng Jianfeng; Ding, Mingzhou

    2004-01-01

    We investigate how to reliably decode the input information from the output of a spiking neuronal network. A maximum likelihood estimator of the input signal, together with its Fisher information, is rigorously calculated. The advantage of the maximum likelihood estimation over the 'brute-force rate coding' estimate is clearly demonstrated. It is pointed out that the ergodic assumption in neuroscience, i.e. a temporal average is equivalent to an ensemble average, is in general not true. Averaging over an ensemble of neurons usually gives a biased estimate of the input information. A method on how to compensate for the bias is proposed. Reconstruction of dynamical input signals with a group of spiking neurons is extensively studied and our results show that less than a spike is sufficient to accurately decode dynamical inputs

  17. Mechanosensor Channels in Mammalian Somatosensory Neurons

    Directory of Open Access Journals (Sweden)

    Patrick Delmas

    2007-09-01

    Full Text Available Mechanoreceptive sensory neurons innervating the skin, skeletal muscles andviscera signal both innocuous and noxious information necessary for proprioception, touchand pain. These neurons are responsible for the transduction of mechanical stimuli intoaction potentials that propagate to the central nervous system. The ability of these cells todetect mechanical stimuli impinging on them relies on the presence of mechanosensitivechannels that transduce the external mechanical forces into electrical and chemical signals.Although a great deal of information regarding the molecular and biophysical properties ofmechanosensitive channels in prokaryotes has been accumulated over the past two decades,less is known about the mechanosensitive channels necessary for proprioception and thesenses of touch and pain. This review summarizes the most pertinent data onmechanosensitive channels of mammalian somatosensory neurons, focusing on theirproperties, pharmacology and putative identity.

  18. MR imaging of neuronal migration anomaly

    International Nuclear Information System (INIS)

    Hong, Hyun Sook; Choi, Eun Wan; Kim, Dae Ho; Chung, Moo Chan; Kwon, Kuy Hyang; Kim, Ki Jung

    1991-01-01

    Abnormalities of neuronal migration are characterized by anectopic location of neurons in the cerebral cortex. This broad group of anomalies includes agyria, pachygyria, schizencephaly, unilateral megalencephaly, and gray matter heterotopia. Patients with this anomaly present clinically with a variety of symptoms which are proportional to the extent of the brain involved. These abnormalities have characterized pathologically in vivo by sonography and CT scan. MR appears to be an imaging technique of choice in evaluating these anomalies because it is capable of exceptionally good differentiation between gray and white matter, high contrast resolution, multiplanar display of the anatomy, and lack of overlying bone artifac. The purpose of this paper is to describe the MR findings of neuronal migration anomaly. The results of our study support that MR appears to be the imaging method of choice for diagnosing migration anomalies and the primary screening method for infants or children who have seisure/and delayed development

  19. Mirror Neurons and Mirror-Touch Synesthesia.

    Science.gov (United States)

    Linkovski, Omer; Katzin, Naama; Salti, Moti

    2016-05-30

    Since mirror neurons were introduced to the neuroscientific community more than 20 years ago, they have become an elegant and intuitive account for different cognitive mechanisms (e.g., empathy, goal understanding) and conditions (e.g., autism spectrum disorders). Recently, mirror neurons were suggested to be the mechanism underlying a specific type of synesthesia. Mirror-touch synesthesia is a phenomenon in which individuals experience somatosensory sensations when seeing someone else being touched. Appealing as it is, careful delineation is required when applying this mechanism. Using the mirror-touch synesthesia case, we put forward theoretical and methodological issues that should be addressed before relying on the mirror-neurons account. © The Author(s) 2016.

  20. Merkel cells and neurons keep in touch

    Science.gov (United States)

    Woo, Seung-Hyun; Lumpkin, Ellen A.; Patapoutian, Ardem

    2014-01-01

    The Merkel cell-neurite complex is a unique vertebrate touch receptor comprising two distinct cell types in the skin. Its presence in touch-sensitive skin areas was recognized more than a century ago, but the functions of each cell type in sensory transduction have been unclear. Three recent studies demonstrate that Merkel cells are mechanosensitive cells that function in touch transduction via Piezo2. One study concludes that Merkel cells rather than sensory neurons are principal sites of mechanotransduction, whereas the other two studies report that both Merkel cells and neurons encode mechanical inputs. Together, these studies settle a longstanding debate on whether Merkel cells are mechanosensory cells, and enable future investigations of how these skin cells communicate with neurons. PMID:25480024

  1. Descending Command Neurons in the Brainstem that Halt Locomotion

    DEFF Research Database (Denmark)

    Bouvier, Julien; Caggiano, Vittorio; Leiras, Roberto

    2015-01-01

    identifiable brainstem populations to a potential locomotor stop signal, we used developmental genetics and considered a discrete neuronal population in the reticular formation: the V2a neurons. We find that those neurons constitute a major excitatory pathway to locomotor areas of the ventral spinal cord....... Selective activation of V2a neurons of the rostral medulla stops ongoing locomotor activity, owing to an inhibition of premotor locomotor networks in the spinal cord. Moreover, inactivation of such neurons decreases spontaneous stopping in vivo. Therefore, the V2a "stop neurons" represent a glutamatergic...

  2. Mirror neurons: Enigma of the metaphysical modular brain.

    Science.gov (United States)

    Acharya, Sourya; Shukla, Samarth

    2012-07-01

    Mirror neurons are one of the most important discoveries in the last decade of neuroscience. These are a variety of visuospatial neurons which indicate fundamentally about human social interaction. Essentially, mirror neurons respond to actions that we observe in others. The interesting part is that mirror neurons fire in the same way when we actually recreate that action ourselves. Apart from imitation, they are responsible for myriad of other sophisticated human behavior and thought processes. Defects in the mirror neuron system are being linked to disorders like autism. This review is a brief introduction to the neurons that shaped our civilization.

  3. The Red Sea Modeling and Forecasting System

    KAUST Repository

    Hoteit, Ibrahim

    2015-04-01

    Despite its importance for a variety of socio-economical and political reasons and the presence of extensive coral reef gardens along its shores, the Red Sea remains one of the most under-studied large marine physical and biological systems in the global ocean. This contribution will present our efforts to build advanced modeling and forecasting capabilities for the Red Sea, which is part of the newly established Saudi ARAMCO Marine Environmental Research Center at KAUST (SAMERCK). Our Red Sea modeling system compromises both regional and nested costal MIT general circulation models (MITgcm) with resolutions varying between 8 km and 250 m to simulate the general circulation and mesoscale dynamics at various spatial scales, a 10-km resolution Weather Research Forecasting (WRF) model to simulate the atmospheric conditions, a 4-km resolution European Regional Seas Ecosystem Model (ERSEM) to simulate the Red Sea ecosystem, and a 1-km resolution WAVEWATCH-III model to simulate the wind driven surface waves conditions. We have also implemented an oil spill model, and a probabilistic dispersion and larval connectivity modeling system (CMS) based on a stochastic Lagrangian framework and incorporating biological attributes. We are using the models outputs together with available observational data to study all aspects of the Red Sea circulations. Advanced monitoring capabilities are being deployed in the Red Sea as part of the SAMERCK, comprising multiple gliders equipped with hydrographical and biological sensors, high frequency (HF) surface current/wave mapping, buoys/ moorings, etc, complementing the available satellite ocean and atmospheric observations and Automatic Weather Stations (AWS). The Red Sea models have also been equipped with advanced data assimilation capabilities. Fully parallel ensemble-based Kalman filtering (EnKF) algorithms have been implemented with the MITgcm and ERSEM for assimilating all available multivariate satellite and in-situ data sets. We

  4. The Red Sea Modeling and Forecasting System

    KAUST Repository

    Hoteit, Ibrahim; Gopalakrishnan, Ganesh; Latif, Hatem; Toye, Habib; Zhan, Peng; Kartadikaria, Aditya R.; Viswanadhapalli, Yesubabu; Yao, Fengchao; Triantafyllou, George; Langodan, Sabique; Cavaleri, Luigi; Guo, Daquan; Johns, Burt

    2015-01-01

    Despite its importance for a variety of socio-economical and political reasons and the presence of extensive coral reef gardens along its shores, the Red Sea remains one of the most under-studied large marine physical and biological systems in the global ocean. This contribution will present our efforts to build advanced modeling and forecasting capabilities for the Red Sea, which is part of the newly established Saudi ARAMCO Marine Environmental Research Center at KAUST (SAMERCK). Our Red Sea modeling system compromises both regional and nested costal MIT general circulation models (MITgcm) with resolutions varying between 8 km and 250 m to simulate the general circulation and mesoscale dynamics at various spatial scales, a 10-km resolution Weather Research Forecasting (WRF) model to simulate the atmospheric conditions, a 4-km resolution European Regional Seas Ecosystem Model (ERSEM) to simulate the Red Sea ecosystem, and a 1-km resolution WAVEWATCH-III model to simulate the wind driven surface waves conditions. We have also implemented an oil spill model, and a probabilistic dispersion and larval connectivity modeling system (CMS) based on a stochastic Lagrangian framework and incorporating biological attributes. We are using the models outputs together with available observational data to study all aspects of the Red Sea circulations. Advanced monitoring capabilities are being deployed in the Red Sea as part of the SAMERCK, comprising multiple gliders equipped with hydrographical and biological sensors, high frequency (HF) surface current/wave mapping, buoys/ moorings, etc, complementing the available satellite ocean and atmospheric observations and Automatic Weather Stations (AWS). The Red Sea models have also been equipped with advanced data assimilation capabilities. Fully parallel ensemble-based Kalman filtering (EnKF) algorithms have been implemented with the MITgcm and ERSEM for assimilating all available multivariate satellite and in-situ data sets. We

  5. Neuronal glycogen synthesis contributes to physiological aging.

    Science.gov (United States)

    Sinadinos, Christopher; Valles-Ortega, Jordi; Boulan, Laura; Solsona, Estel; Tevy, Maria F; Marquez, Mercedes; Duran, Jordi; Lopez-Iglesias, Carmen; Calbó, Joaquim; Blasco, Ester; Pumarola, Marti; Milán, Marco; Guinovart, Joan J

    2014-10-01

    Glycogen is a branched polymer of glucose and the carbohydrate energy store for animal cells. In the brain, it is essentially found in glial cells, although it is also present in minute amounts in neurons. In humans, loss-of-function mutations in laforin and malin, proteins involved in suppressing glycogen synthesis, induce the presence of high numbers of insoluble polyglucosan bodies in neuronal cells. Known as Lafora bodies (LBs), these deposits result in the aggressive neurodegeneration seen in Lafora's disease. Polysaccharide-based aggregates, called corpora amylacea (CA), are also present in the neurons of aged human brains. Despite the similarity of CA to LBs, the mechanisms and functional consequences of CA formation are yet unknown. Here, we show that wild-type laboratory mice also accumulate glycogen-based aggregates in the brain as they age. These structures are immunopositive for an array of metabolic and stress-response proteins, some of which were previously shown to aggregate in correlation with age in the human brain and are also present in LBs. Remarkably, these structures and their associated protein aggregates are not present in the aged mouse brain upon genetic ablation of glycogen synthase. Similar genetic intervention in Drosophila prevents the accumulation of glycogen clusters in the neuronal processes of aged flies. Most interestingly, targeted reduction of Drosophila glycogen synthase in neurons improves neurological function with age and extends lifespan. These results demonstrate that neuronal glycogen accumulation contributes to physiological aging and may therefore constitute a key factor regulating age-related neurological decline in humans. © 2014 The Authors. Aging cell published by the Anatomical Society and John Wiley & Sons Ltd.

  6. Nuclear Calcium Buffering Capacity Shapes Neuronal Architecture*

    Science.gov (United States)

    Mauceri, Daniela; Hagenston, Anna M.; Schramm, Kathrin; Weiss, Ursula; Bading, Hilmar

    2015-01-01

    Calcium-binding proteins (CaBPs) such as parvalbumin are part of the cellular calcium buffering system that determines intracellular calcium diffusion and influences the spatiotemporal dynamics of calcium signals. In neurons, CaBPs are primarily localized to the cytosol and function, for example, in nerve terminals in short-term synaptic plasticity. However, CaBPs are also expressed in the cell nucleus, suggesting that they modulate nuclear calcium signals, which are key regulators of neuronal gene expression. Here we show that the calcium buffering capacity of the cell nucleus in mouse hippocampal neurons regulates neuronal architecture by modulating the expression levels of VEGFD and the complement factor C1q-c, two nuclear calcium-regulated genes that control dendrite geometry and spine density, respectively. Increasing the levels of nuclear calcium buffers by means of expression of a nuclearly targeted form of parvalbumin fused to mCherry (PV.NLS-mC) led to a reduction in VEGFD expression and, as a result, to a decrease in total dendritic length and complexity. In contrast, mRNA levels of the synapse pruning factor C1q-c were increased in neurons expressing PV.NLS-mC, causing a reduction in the density and size of dendritic spines. Our results establish a close link between nuclear calcium buffering capacity and the transcription of genes that determine neuronal structure. They suggest that the development of cognitive deficits observed in neurological conditions associated with CaBP deregulation may reflect the loss of necessary structural features of dendrites and spines. PMID:26231212

  7. Nuclear Calcium Buffering Capacity Shapes Neuronal Architecture.

    Science.gov (United States)

    Mauceri, Daniela; Hagenston, Anna M; Schramm, Kathrin; Weiss, Ursula; Bading, Hilmar

    2015-09-18

    Calcium-binding proteins (CaBPs) such as parvalbumin are part of the cellular calcium buffering system that determines intracellular calcium diffusion and influences the spatiotemporal dynamics of calcium signals. In neurons, CaBPs are primarily localized to the cytosol and function, for example, in nerve terminals in short-term synaptic plasticity. However, CaBPs are also expressed in the cell nucleus, suggesting that they modulate nuclear calcium signals, which are key regulators of neuronal gene expression. Here we show that the calcium buffering capacity of the cell nucleus in mouse hippocampal neurons regulates neuronal architecture by modulating the expression levels of VEGFD and the complement factor C1q-c, two nuclear calcium-regulated genes that control dendrite geometry and spine density, respectively. Increasing the levels of nuclear calcium buffers by means of expression of a nuclearly targeted form of parvalbumin fused to mCherry (PV.NLS-mC) led to a reduction in VEGFD expression and, as a result, to a decrease in total dendritic length and complexity. In contrast, mRNA levels of the synapse pruning factor C1q-c were increased in neurons expressing PV.NLS-mC, causing a reduction in the density and size of dendritic spines. Our results establish a close link between nuclear calcium buffering capacity and the transcription of genes that determine neuronal structure. They suggest that the development of cognitive deficits observed in neurological conditions associated with CaBP deregulation may reflect the loss of necessary structural features of dendrites and spines. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  8. Determination of the rate constant for neuronal and extra-neuronal monoamine oxidase

    International Nuclear Information System (INIS)

    Cassis, L.; Ludwig, J.; Trendelenburg, U.

    1986-01-01

    In the rat vas deferens, neuronal deamination of 3 H-(-) noradrenaline ( 3 H-NA) to 3 H-dihydroxyphenethylglycol ( 3 HDOPEG) cannot be inhibited by pretreatment with a monoamine oxidase (MAO) inhibitor. However, in the extraneuronal compartment of the rat heart, inhibition of MAO abolishes the formation of 3 HDOPEG. To clarify this discrepancy, the authors determined the rate constant for MAO (/sup k/mao/) neuronally (rat vas deferens) and extraneuronally (rat heart). For neuronal /sup k/mao, vasa deferentia were incubated with 3 HNA for 300 minutes, and the cumulative formation of 3 HDOPEG measured. The delay in time before 3 HDOPEG achieves steady state (/sup tau/system), is inversely proportional to /sup k/mao. Because /sup tau/system is very short for neuronal MAO, an appreciable delay was only achieved after partial inhibition of MAO with various parglyline concentrations. To relate to the uninhibited enzyme, the percentage inhibition by pargyline was then determined in homogenate preparations. For extraneuronal MAO, a similar procedure was performed in perfused rat hearts. Results show a significantly greater /sup k/mao of neuronal origin, (/sup k/mao = .57min - 1) which when related to the fractional size of the neuronal compartment suggests a very high activity of neuronal MAO

  9. Direct Neuronal Reprogramming for Disease Modeling Studies Using Patient-Derived Neurons: What Have We Learned?

    Directory of Open Access Journals (Sweden)

    Janelle Drouin-Ouellet

    2017-09-01

    Full Text Available Direct neuronal reprogramming, by which a neuron is formed via direct conversion from a somatic cell without going through a pluripotent intermediate stage, allows for the possibility of generating patient-derived neurons. A unique feature of these so-called induced neurons (iNs is the potential to maintain aging and epigenetic signatures of the donor, which is critical given that many diseases of the CNS are age related. Here, we review the published literature on the work that has been undertaken using iNs to model human brain disorders. Furthermore, as disease-modeling studies using this direct neuronal reprogramming approach are becoming more widely adopted, it is important to assess the criteria that are used to characterize the iNs, especially in relation to the extent to which they are mature adult neurons. In particular: i what constitutes an iN cell, ii which stages of conversion offer the earliest/optimal time to assess features that are specific to neurons and/or a disorder and iii whether generating subtype-specific iNs is critical to the disease-related features that iNs express. Finally, we discuss the range of potential biomedical applications that can be explored using patient-specific models of neurological disorders with iNs, and the challenges that will need to be overcome in order to realize these applications.

  10. Identification of neuronal network properties from the spectral analysis of calcium imaging signals in neuronal cultures.

    Science.gov (United States)

    Tibau, Elisenda; Valencia, Miguel; Soriano, Jordi

    2013-01-01

    Neuronal networks in vitro are prominent systems to study the development of connections in living neuronal networks and the interplay between connectivity, activity and function. These cultured networks show a rich spontaneous activity that evolves concurrently with the connectivity of the underlying network. In this work we monitor the development of neuronal cultures, and record their activity using calcium fluorescence imaging. We use spectral analysis to characterize global dynamical and structural traits of the neuronal cultures. We first observe that the power spectrum can be used as a signature of the state of the network, for instance when inhibition is active or silent, as well as a measure of the network's connectivity strength. Second, the power spectrum identifies prominent developmental changes in the network such as GABAA switch. And third, the analysis of the spatial distribution of the spectral density, in experiments with a controlled disintegration of the network through CNQX, an AMPA-glutamate receptor antagonist in excitatory neurons, reveals the existence of communities of strongly connected, highly active neurons that display synchronous oscillations. Our work illustrates the interest of spectral analysis for the study of in vitro networks, and its potential use as a network-state indicator, for instance to compare healthy and diseased neuronal networks.

  11. Axonal regeneration and neuronal function are preserved in motor neurons lacking ß-actin in vivo.

    Directory of Open Access Journals (Sweden)

    Thomas R Cheever

    2011-03-01

    Full Text Available The proper localization of ß-actin mRNA and protein is essential for growth cone guidance and axon elongation in cultured neurons. In addition, decreased levels of ß-actin mRNA and protein have been identified in the growth cones of motor neurons cultured from a mouse model of Spinal Muscular Atrophy (SMA, suggesting that ß-actin loss-of-function at growth cones or pre-synaptic nerve terminals could contribute to the pathogenesis of this disease. However, the role of ß-actin in motor neurons in vivo and its potential relevance to disease has yet to be examined. We therefore generated motor neuron specific ß-actin knock-out mice (Actb-MNsKO to investigate the function of ß-actin in motor neurons in vivo. Surprisingly, ß-actin was not required for motor neuron viability or neuromuscular junction maintenance. Skeletal muscle from Actb-MNsKO mice showed no histological indication of denervation and did not significantly differ from controls in several measurements of physiologic function. Finally, motor axon regeneration was unimpaired in Actb-MNsKO mice, suggesting that ß-actin is not required for motor neuron function or regeneration in vivo.

  12. Direct projections from hypothalamic orexin neurons to brainstem cardiac vagal neurons.

    Science.gov (United States)

    Dergacheva, Olga; Yamanaka, Akihiro; Schwartz, Alan R; Polotsky, Vsevolod Y; Mendelowitz, David

    2016-12-17

    Orexin neurons are known to augment the sympathetic control of cardiovascular function, however the role of orexin neurons in parasympathetic cardiac regulation remains unclear. To test the hypothesis that orexin neurons contribute to parasympathetic control we selectively expressed channelrhodopsin-2 (ChR2) in orexin neurons in orexin-Cre transgenic rats and examined postsynaptic currents in cardiac vagal neurons (CVNs) in the dorsal motor nucleus of the vagus (DMV). Simultaneous photostimulation and recording in ChR2-expressing orexin neurons in the lateral hypothalamus resulted in reliable action potential firing as well as large whole-cell currents suggesting a strong expression of ChR2 and reliable optogenetic excitation. Photostimulation of ChR2-expressing fibers in the DMV elicited short-latency (ranging from 3.2ms to 8.5ms) postsynaptic currents in 16 out of 44 CVNs tested. These responses were heterogeneous and included excitatory glutamatergic (63%) and inhibitory GABAergic (37%) postsynaptic currents. The results from this study suggest different sub-population of orexin neurons may exert diverse influences on brainstem CVNs and therefore may play distinct functional roles in parasympathetic control of the heart. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

  13. Power laws from linear neuronal cable theory

    DEFF Research Database (Denmark)

    Pettersen, Klas H; Lindén, Henrik Anders; Tetzlaff, Tom

    2014-01-01

    suggested to be at the root of this phenomenon, we here demonstrate a possible origin of such power laws in the biophysical properties of single neurons described by the standard cable equation. Taking advantage of the analytical tractability of the so called ball and stick neuron model, we derive general...... are homogeneously distributed across the neural membranes and themselves exhibit pink ([Formula: see text]) noise distributions. While the PSD noise spectra at low frequencies may be dominated by synaptic noise, our findings suggest that the high-frequency power laws may originate in noise from intrinsic ion...

  14. An introduction to modeling neuronal dynamics

    CERN Document Server

    Börgers, Christoph

    2017-01-01

    This book is intended as a text for a one-semester course on Mathematical and Computational Neuroscience for upper-level undergraduate and beginning graduate students of mathematics, the natural sciences, engineering, or computer science. An undergraduate introduction to differential equations is more than enough mathematical background. Only a slim, high school-level background in physics is assumed, and none in biology. Topics include models of individual nerve cells and their dynamics, models of networks of neurons coupled by synapses and gap junctions, origins and functions of population rhythms in neuronal networks, and models of synaptic plasticity. An extensive online collection of Matlab programs generating the figures accompanies the book. .

  15. Neuronal release of proBDNF

    OpenAIRE

    Yang, Jianmin; Siao, Chia-Jen; Nagappan, Guhan; Marinic, Tina; Jing, Deqiang; McGrath, Kelly; Chen, Zhe-Yu; Mark, Willie; Tessarollo, Lino; Lee, Francis S; Lu, Bai; Hempstead, Barbara L

    2009-01-01

    Pro–brain-derived neurotrophic factor (proBDNF) and mature BDNF utilize distinct receptors to mediate divergent neuronal actions. Using new tools to quantitate endogenous BDNF isoforms, we found that mouse neurons secrete both proBDNF and mature BDNF. The highest levels of proBDNF and p75 were observed perinatally and declined, but were still detectable, in adulthood. Thus, BDNF actions are developmentally regulated by secretion of proBDNF or mature BDNF and by local expression of p75 and Trk...

  16. Intrinsic neuromodulation: altering neuronal circuits from within.

    Science.gov (United States)

    Katz, P S; Frost, W N

    1996-02-01

    There are two sources of neuromodulation for neuronal circuits: extrinsic inputs and intrinsic components of the circuits themselves. Extrinsic neuromodulation is known to be pervasive in nervous systems, but intrinsic neuromodulation is less recognized, despite the fact that it has now been demonstrated in sensory and neuromuscular circuits and in central pattern generators. By its nature, intrinsic neuromodulation produces local changes in neuronal computation, whereas extrinsic neuromodulation can cause global changes, often affecting many circuits simultaneously. Studies in a number of systems are defining the different properties of these two forms of neuromodulation.

  17. Insights into the role of neuronal glucokinase.

    Science.gov (United States)

    De Backer, Ivan; Hussain, Sufyan S; Bloom, Stephen R; Gardiner, James V

    2016-07-01

    Glucokinase is a key component of the neuronal glucose-sensing mechanism and is expressed in brain regions that control a range of homeostatic processes. In this review, we detail recently identified roles for neuronal glucokinase in glucose homeostasis and counterregulatory responses to hypoglycemia and in regulating appetite. We describe clinical implications from these advances in our knowledge, especially for developing novel treatments for diabetes and obesity. Further research required to extend our knowledge and help our efforts to tackle the diabetes and obesity epidemics is suggested. Copyright © 2016 the American Physiological Society.

  18. Insights into the role of neuronal glucokinase

    Science.gov (United States)

    De Backer, Ivan; Hussain, Sufyan S.; Gardiner, James V.

    2016-01-01

    Glucokinase is a key component of the neuronal glucose-sensing mechanism and is expressed in brain regions that control a range of homeostatic processes. In this review, we detail recently identified roles for neuronal glucokinase in glucose homeostasis and counterregulatory responses to hypoglycemia and in regulating appetite. We describe clinical implications from these advances in our knowledge, especially for developing novel treatments for diabetes and obesity. Further research required to extend our knowledge and help our efforts to tackle the diabetes and obesity epidemics is suggested. PMID:27189932

  19. Temporal characteristics of gustatory responses in rat parabrachial neurons vary by stimulus and chemosensitive neuron type.

    Science.gov (United States)

    Geran, Laura; Travers, Susan

    2013-01-01

    It has been demonstrated that temporal features of spike trains can increase the amount of information available for gustatory processing. However, the nature of these temporal characteristics and their relationship to different taste qualities and neuron types are not well-defined. The present study analyzed the time course of taste responses from parabrachial (PBN) neurons elicited by multiple applications of "sweet" (sucrose), "salty" (NaCl), "sour" (citric acid), and "bitter" (quinine and cycloheximide) stimuli in an acute preparation. Time course varied significantly by taste stimulus and best-stimulus classification. Across neurons, the ensemble code for the three electrolytes was similar initially but quinine diverged from NaCl and acid during the second 500 ms of stimulation and all four qualities became distinct just after 1s. This temporal evolution was reflected in significantly broader tuning during the initial response. Metric space analyses of quality discrimination by individual neurons showed that increases in information (H) afforded by temporal factors was usually explained by differences in rate envelope, which had a greater impact during the initial 2s (22.5% increase in H) compared to the later response (9.5%). Moreover, timing had a differential impact according to cell type, with between-quality discrimination in neurons activated maximally by NaCl or citric acid most affected. Timing was also found to dramatically improve within-quality discrimination (80% increase in H) in neurons that responded optimally to bitter stimuli (B-best). Spikes from B-best neurons were also more likely to occur in bursts. These findings suggest that among PBN taste neurons, time-dependent increases in mutual information can arise from stimulus- and neuron-specific differences in response envelope during the initial dynamic period. A stable rate code predominates in later epochs.

  20. Neuron-to-neuron transmission of α-synuclein fibrils through axonal transport

    Science.gov (United States)

    Freundt, Eric C.; Maynard, Nate; Clancy, Eileen K.; Roy, Shyamali; Bousset, Luc; Sourigues, Yannick; Covert, Markus; Melki, Ronald; Kirkegaard, Karla; Brahic, Michel

    2012-01-01

    Objective The lesions of Parkinson's disease spread through the brain in a characteristic pattern that corresponds to axonal projections. Previous observations suggest that misfolded α-synuclein could behave as a prion, moving from neuron to neuron and causing endogenous α-synuclein to misfold. Here, we characterized and quantified the axonal transport of α-synuclein fibrils and showed that fibrils could be transferred from axons to second-order neurons following anterograde transport. Methods We grew primary cortical mouse neurons in microfluidic devices to separate soma from axonal projections in fluidically isolated microenvironments. We used live-cell imaging and immunofluorescence to characterize the transport of fluorescent α-synuclein fibrils and their transfer to second-order neurons. Results Fibrillar α-synuclein was internalized by primary neurons and transported in axons with kinetics consistent with slow component-b of axonal transport (fast axonal transport with saltatory movement). Fibrillar α-synuclein was readily observed in the cell bodies of second-order neurons following anterograde axonal transport. Axon-to-soma transfer appeared not to require synaptic contacts. Interpretation These results support the hypothesis that the progression of Parkinson's disease can be caused by neuron-to-neuron spread of α-synuclein aggregates and that the anatomical pattern of progression of lesions between axonally connected areas results from the axonal transport of such aggregates. That the transfer did not appear to be transsynaptic gives hope that α-synuclein fibrils could be intercepted by drugs during the extra-cellular phase of their journey. PMID:23109146

  1. Recurrently connected and localized neuronal communities initiate coordinated spontaneous activity in neuronal networks

    Science.gov (United States)

    Amin, Hayder; Maccione, Alessandro; Nieus, Thierry

    2017-01-01

    Developing neuronal systems intrinsically generate coordinated spontaneous activity that propagates by involving a large number of synchronously firing neurons. In vivo, waves of spikes transiently characterize the activity of developing brain circuits and are fundamental for activity-dependent circuit formation. In vitro, coordinated spontaneous spiking activity, or network bursts (NBs), interleaved within periods of asynchronous spikes emerge during the development of 2D and 3D neuronal cultures. Several studies have investigated this type of activity and its dynamics, but how a neuronal system generates these coordinated events remains unclear. Here, we investigate at a cellular level the generation of network bursts in spontaneously active neuronal cultures by exploiting high-resolution multielectrode array recordings and computational network modelling. Our analysis reveals that NBs are generated in specialized regions of the network (functional neuronal communities) that feature neuronal links with high cross-correlation peak values, sub-millisecond lags and that share very similar structural connectivity motifs providing recurrent interactions. We show that the particular properties of these local structures enable locally amplifying spontaneous asynchronous spikes and that this mechanism can lead to the initiation of NBs. Through the analysis of simulated and experimental data, we also show that AMPA currents drive the coordinated activity, while NMDA and GABA currents are only involved in shaping the dynamics of NBs. Overall, our results suggest that the presence of functional neuronal communities with recurrent local connections allows a neuronal system to generate spontaneous coordinated spiking activity events. As suggested by the rules used for implementing our computational model, such functional communities might naturally emerge during network development by following simple constraints on distance-based connectivity. PMID:28749937

  2. Recurrently connected and localized neuronal communities initiate coordinated spontaneous activity in neuronal networks.

    Directory of Open Access Journals (Sweden)

    Davide Lonardoni

    2017-07-01

    Full Text Available Developing neuronal systems intrinsically generate coordinated spontaneous activity that propagates by involving a large number of synchronously firing neurons. In vivo, waves of spikes transiently characterize the activity of developing brain circuits and are fundamental for activity-dependent circuit formation. In vitro, coordinated spontaneous spiking activity, or network bursts (NBs, interleaved within periods of asynchronous spikes emerge during the development of 2D and 3D neuronal cultures. Several studies have investigated this type of activity and its dynamics, but how a neuronal system generates these coordinated events remains unclear. Here, we investigate at a cellular level the generation of network bursts in spontaneously active neuronal cultures by exploiting high-resolution multielectrode array recordings and computational network modelling. Our analysis reveals that NBs are generated in specialized regions of the network (functional neuronal communities that feature neuronal links with high cross-correlation peak values, sub-millisecond lags and that share very similar structural connectivity motifs providing recurrent interactions. We show that the particular properties of these local structures enable locally amplifying spontaneous asynchronous spikes and that this mechanism can lead to the initiation of NBs. Through the analysis of simulated and experimental data, we also show that AMPA currents drive the coordinated activity, while NMDA and GABA currents are only involved in shaping the dynamics of NBs. Overall, our results suggest that the presence of functional neuronal communities with recurrent local connections allows a neuronal system to generate spontaneous coordinated spiking activity events. As suggested by the rules used for implementing our computational model, such functional communities might naturally emerge during network development by following simple constraints on distance-based connectivity.

  3. 7X performance results - final report : ASCI Red vs Red Storm.

    Energy Technology Data Exchange (ETDEWEB)

    Dinge, Dennis C. (Cray Inc., Albuquerque, NM); Davis, Michael E. (Cray Inc., Albuquerque, NM); Haskell, Karen H.; Ballance, Robert A.; Gardiner, Thomas Anthony; Stevenson, Joel O.; Noe, John P.

    2011-04-01

    The goal of the 7X performance testing was to assure Sandia National Laboratories, Cray Inc., and the Department of Energy that Red Storm would achieve its performance requirements which were defined as a comparison between ASCI Red and Red Storm. Our approach was to identify one or more problems for each application in the 7X suite, run those problems at multiple processor sizes in the capability computing range, and compare the results between ASCI Red and Red Storm. The first part of this report describes the two computer systems, the applications in the 7X suite, the test problems, and the results of the performance tests on ASCI Red and Red Storm. During the course of the testing on Red Storm, we had the opportunity to run the test problems in both single-core mode and dual-core mode and the second part of this report describes those results. Finally, we reflect on lessons learned in undertaking a major head-to-head benchmark comparison.

  4. Understanding metal homeostasis in primary cultured neurons. Studies using single neuron subcellular and quantitative metallomics.

    Science.gov (United States)

    Colvin, Robert A; Lai, Barry; Holmes, William R; Lee, Daewoo

    2015-07-01

    The purpose of this study was to demonstrate how single cell quantitative and subcellular metallomics inform us about both the spatial distribution and cellular mechanisms of metal buffering and homeostasis in primary cultured neurons from embryonic rat brain, which are often used as models of human disease involving metal dyshomeostasis. The present studies utilized synchrotron radiation X-ray fluorescence (SRXRF) and focused primarily on zinc and iron, two abundant metals in neurons that have been implicated in the pathogenesis of neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease. Total single cell contents for calcium, iron, zinc, copper, manganese, and nickel were determined. Resting steady state zinc showed a diffuse distribution in both soma and processes, best defined by the mass profile of the neuron with an enrichment in the nucleus compared with the cytoplasm. Zinc buffering and homeostasis was studied using two modes of cellular zinc loading - transporter and ionophore (pyrithione) mediated. Single neuron zinc contents were shown to statistically significantly increase by either loading method - ionophore: 160 million to 7 billion; transporter 160 million to 280 million atoms per neuronal soma. The newly acquired and buffered zinc still showed a diffuse distribution. Soma and processes have about equal abilities to take up zinc via transporter mediated pathways. Copper levels are distributed diffusely as well, but are relatively higher in the processes relative to zinc levels. Prior studies have observed iron puncta in certain cell types, but others have not. In the present study, iron puncta were characterized in several primary neuronal types. The results show that iron puncta could be found in all neuronal types studied and can account for up to 50% of the total steady state content of iron in neuronal soma. Although other metals can be present in iron puncta, they are predominantly iron containing and do not appear to be

  5. Neurons of self-defence: neuronal innervation of the exocrine defence glands in stick insects.

    Science.gov (United States)

    Stolz, Konrad; von Bredow, Christoph-Rüdiger; von Bredow, Yvette M; Lakes-Harlan, Reinhard; Trenczek, Tina E; Strauß, Johannes

    2015-01-01

    Stick insects (Phasmatodea) use repellent chemical substances (allomones) for defence which are released from so-called defence glands in the prothorax. These glands differ in size between species, and are under neuronal control from the CNS. The detailed neural innervation and possible differences between species are not studied so far. Using axonal tracing, the neuronal innervation is investigated comparing four species. The aim is to document the complexity of defence gland innervation in peripheral nerves and central motoneurons in stick insects. In the species studied here, the defence gland is innervated by the intersegmental nerve complex (ISN) which is formed by three nerves from the prothoracic (T1) and suboesophageal ganglion (SOG), as well as a distinct suboesophageal nerve (Nervus anterior of the suboesophageal ganglion). In Carausius morosus and Sipyloidea sipylus, axonal tracing confirmed an innervation of the defence glands by this N. anterior SOG as well as N. anterior T1 and N. posterior SOG from the intersegmental nerve complex. In Peruphasma schultei, which has rather large defence glands, only the innervation by the N. anterior SOG was documented by axonal tracing. In the central nervous system of all species, 3-4 neuron types are identified by axonal tracing which send axons in the N. anterior SOG likely innervating the defence gland as well as adjacent muscles. These neurons are mainly suboesophageal neurons with one intersegmental neuron located in the prothoracic ganglion. The neuron types are conserved in the species studied, but the combination of neuron types is not identical. In addition, the central nervous system in S. sipylus contains one suboesophageal and one prothoracic neuron type with axons in the intersegmental nerve complex contacting the defence gland. Axonal tracing shows a very complex innervation pattern of the defence glands of Phasmatodea which contains different neurons in different nerves from two adjacent body segments

  6. Red mud characterization using nuclear analytical techniques

    International Nuclear Information System (INIS)

    Obhodas, J.; Sudac, D.; Matjacic, L.; Valkovic, V.

    2011-01-01

    Red mud is a toxic waste left as a byproduct in aluminum production Bayer process. Since it contains significant concentrations of other chemical elements interesting for industry, including REE, it is also potential secondary ore source. Recent events in some countries have shown that red mud presents a serious environmental hazard if not properly stored. The subject of our study is the red mud from an ex-aluminum plant in Obrovac, Croatia, left from processing of bauxite mined during late 70's and early 80's at the eastern Adriatic coast and since than stored in open concrete basins for more than 30 years. We have used energy dispersive x-ray fluorescence analysis (both tube and radioactive source excitation), fast neutron activation analysis and passive gamma spectrometry to identify a number of elements present in the red mud, their concentration levels and radioactivity in the red mud. The high concentrations of Al, Si, Ca, Ti and Fe have been measured. Chemical elements Sc, Cr, Mn, Co, Ni, Cu, Zn, Ga, As, Se, Br, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Pb, Th and U were found in lower concentrations. No significant levels of radioactivity have been measured. (authors)

  7. Features of Red Sea Water Masses

    Science.gov (United States)

    Kartadikaria, Aditya; Hoteit, Ibrahim

    2015-04-01

    Features of Red Sea water mass can be divided into three types but best to be grouped into two different classes that are split at the potential density line σθ=27.4. The surface water (0-50 m) and the intermediate water (50-200 m) have nearly identical types of water mass. They appear as a maxima salinity layer for the water mass that has σθ > 26.0, and as a minimum salinity layer for water mass that has σθ water masses are strongly affected by mixing that is controlled by seasonal variability, fresh water intrusion of the Gulf of Aden Intermediate Water (GAIW), and eddies variability. Two types of mixing; isopycnal and diapycnal mixing are part of important physical phenomena that explain the change of water mass in the Red Sea. The isopycnal mixing occurs at the neutral potential density line, connecting the Red Sea with its adjacent channel, the Gulf of Aden. Diapycnal mixing is found as a dominant mixing mode in the surface of the Red Sea Water and mainly due to energetic eddy activity. Density gradients, across which diapycnal mixing occurs, in the Red Sea are mainly due to large variations in salinity. The isolation of an extreme haline water mass below the thermocline contributes to the generation of the latitudinal shift and low diapycnal mixing. This finding further explains the difference of spatial kinetic mixing between the RSW and the Indian Ocean basin.

  8. Shape memory of human red blood cells.

    Science.gov (United States)

    Fischer, Thomas M

    2004-05-01

    The human red cell can be deformed by external forces but returns to the biconcave resting shape after removal of the forces. If after such shape excursions the rim is always formed by the same part of the membrane, the cell is said to have a memory of its biconcave shape. If the rim can form anywhere on the membrane, the cell would have no shape memory. The shape memory was probed by an experiment called go-and-stop. Locations on the membrane were marked by spontaneously adhering latex spheres. Shape excursions were induced by shear flow. In virtually all red cells, a shape memory was found. After stop of flow and during the return of the latex spheres to the original location, the red cell shape was biconcave. The return occurred by a tank-tread motion of the membrane. The memory could not be eliminated by deforming the red cells in shear flow up to 4 h at room temperature as well as at 37 degrees C. It is suggested that 1). the characteristic time of stress relaxation is >80 min and 2). red cells in vivo also have a shape memory.

  9. Features of Red Sea Water Masses

    KAUST Repository

    Kartadikaria, Aditya R.

    2015-04-01

    Features of Red Sea water mass can be divided into three types but best to be grouped into two different classes that are split at the potential density line σθ=27.4. The surface water (0-50 m) and the intermediate water (50-200 m) have nearly identical types of water mass. They appear as a maxima salinity layer for the water mass that has σθ > 26.0, and as a minimum salinity layer for water mass that has σθ < 26.0. These types of water masses are strongly affected by mixing that is controlled by seasonal variability, fresh water intrusion of the Gulf of Aden Intermediate Water (GAIW), and eddies variability. Two types of mixing; isopycnal and diapycnal mixing are part of important physical phenomena that explain the change of water mass in the Red Sea. The isopycnal mixing occurs at the neutral potential density line, connecting the Red Sea with its adjacent channel, the Gulf of Aden. Diapycnal mixing is found as a dominant mixing mode in the surface of the Red Sea Water and mainly due to energetic eddy activity. Density gradients, across which diapycnal mixing occurs, in the Red Sea are mainly due to large variations in salinity. The isolation of an extreme haline water mass below the thermocline contributes to the generation of the latitudinal shift and low diapycnal mixing. This finding further explains the difference of spatial kinetic mixing between the RSW and the Indian Ocean basin.

  10. Live imaging of dense-core vesicles in primary cultured hippocampal neurons.

    Science.gov (United States)

    Kwinter, David M; Silverman, Michael A; Kwinter, David; Michael, Silverman

    2009-05-29

    Observing and characterizing dynamic cellular processes can yield important information about cellular activity that cannot be gained from static images. Vital fluorescent probes, particularly green fluorescent protein (GFP) have revolutionized cell biology stemming from the ability to label specific intracellular compartments and cellular structures. For example, the live imaging of GFP (and its spectral variants) chimeras have allowed for a dynamic analysis of the cytoskeleton, organelle transport, and membrane dynamics in a multitude of organisms and cell types [1-3]. Although live imaging has become prevalent, this approach still poses many technical challenges, particularly in primary cultured neurons. One challenge is the expression of GFP-tagged proteins in post-mitotic neurons; the other is the ability to capture fluorescent images while minimizing phototoxicity, photobleaching, and maintaining general cell health. Here we provide a protocol that describes a lipid-based transfection method that yields a relatively low transfection rate (~0.5%), however is ideal for the imaging of fully polarized neurons. A low transfection rate is essential so that single axons and dendrites can be characterized as to their orientation to the cell body to confirm directionality of transport, i.e., anterograde v. retrograde. Our approach to imaging GFP expressing neurons relies on a standard wide-field fluorescent microscope outfitted with a CCD camera, image capture software, and a heated imaging chamber. We have imaged a wide variety of organelles or structures, for example, dense-core vesicles, mitochondria, growth cones, and actin without any special optics or excitation requirements other than a fluorescent light source. Additionally, spectrally-distinct, fluorescently labeled proteins, e.g., GFP and dsRed-tagged proteins, can be visualized near simultaneously to characterize co-transport or other coordinated cellular events. The imaging approach described here is

  11. Male red ornamentation is associated with female red sensitivity in sticklebacks.

    Directory of Open Access Journals (Sweden)

    Ingolf P Rick

    Full Text Available Sexual selection theory proposes correlated evolutionary changes in mating preferences and secondary sexual characters based on a positive genetic correlation between preference and the preferred trait. Empirical work has provided support for a genetic covariation between female preference and male attractiveness in several taxa. Here, we study parent and offspring visual traits in threespine sticklebacks, Gasterosteus aculeatus. While focusing on the proximate basis of mating preferences, we compare the red breeding coloration of males, which strongly contributes to female choice, with their daughters' red sensitivity measured by optomotor response thresholds. We show that the red color expression of fathers correlates well with their daughters' red sensitivity. Given that a within-population genetic correlation between signal and preference was experimentally confirmed for the red coloration in sticklebacks, our results indicate a proximate mechanism in terms of perceptual sensitivity being involved in the co-evolution of female preferences and male mating signals.

  12. Complete synchronization in coupled type-I neurons

    Indian Academy of Sciences (India)

    Keywords. Complete synchronization; noise; coupled type-I neurons. Abstract. For a system of type-I neurons bidirectionally coupled through a nonlinear feedback mechanism, we discuss the issue of ... Pramana – Journal of Physics | News.

  13. Synaptic glutamate release by postnatal rat serotonergic neurons in microculture.

    Science.gov (United States)

    Johnson, M D

    1994-02-01

    Serotonergic neurons are thought to play a role in depression and obsessive compulsive disorder. However, their functional transmitter repertoire is incompletely known. To investigate this repertoire, intracellular recordings were obtained from 132 cytochemically identified rat mesopontine serotonergic neurons that had re-established synapses in microcultures. Approximately 60% of the neurons evoked excitatory glutamatergic potentials in themselves or in target neurons. Glutamatergic transmission was frequently observed in microcultures containing a solitary serotonergic neuron. Evidence for co-release of serotonin and glutamate from single raphe neurons was also obtained. However, evidence for gamma-aminobutyric acid release by serotonergic neurons was observed in only two cases. These findings indicate that many cultured serotonergic neurons form glutamatergic synapses and may explain several observations in slices and in vivo.

  14. Protective effect of parvalbumin on excitotoxic motor neuron death

    DEFF Research Database (Denmark)

    Van den Bosch, L.; Schwaller, B.; Vleminckx, V.

    2002-01-01

    Amyotrophic lateral sclerosis, ALS, AMPA receptor, calcium-binding proteins, calcium buffering, excitotoxity, kainic acid, motor neuron, parvalbumin......Amyotrophic lateral sclerosis, ALS, AMPA receptor, calcium-binding proteins, calcium buffering, excitotoxity, kainic acid, motor neuron, parvalbumin...

  15. Neuron-glia metabolic coupling: Role in plasticity and neuroprotection

    KAUST Repository

    Magistretti, Pierre J.

    2017-01-01

    A tight metabolic coupling between astrocytes and neurons is a key feature of brain energy metabolism (Magistretti and Allaman, Neuron, 2015). Over the years we have described two basic mechanisms of neurometabolic coupling. First the glycogenolytic

  16. GABAA receptor-expressing neurons promote consumption in Drosophila melanogaster.

    Science.gov (United States)

    Cheung, Samantha K; Scott, Kristin

    2017-01-01

    Feeding decisions are highly plastic and bidirectionally regulated by neurons that either promote or inhibit feeding. In Drosophila melanogaster, recent studies have identified four GABAergic interneurons that act as critical brakes to prevent incessant feeding. These GABAergic neurons may inhibit target neurons that drive consumption. Here, we tested this hypothesis by examining GABA receptors and neurons that promote consumption. We find that Resistance to dieldrin (RDL), a GABAA type receptor, is required for proper control of ingestion. Knockdown of Rdl in a subset of neurons causes overconsumption of tastants. Acute activation of these neurons is sufficient to drive consumption of appetitive substances and non-appetitive substances and acute silencing of these neurons decreases consumption. Taken together, these studies identify GABAA receptor-expressing neurons that promote Drosophila ingestive behavior and provide insight into feeding regulation.

  17. Great red spot dependence on solar activity

    International Nuclear Information System (INIS)

    Schatten, K.H.

    1979-01-01

    A new inquiry has been made into the question of whether Jupiter's Great Red Spot shows a solar activity dependence. From 1892 to 1947 a clear correlation was present. A dearth of sightings in the seventeenth century, along with the Maunder Minimum, further supports the relation. An anticorrelation, however, from l948 to l967 removed support for such an effect. The old observations have reexamined and recent observations have also been studied. The author reexamines this difficult question and suggests a possible physical mechanism for a Sun-Jovian weather relation. Prinn and Lewis' conversion reaction of Phosphine gas to triclinic red phosphorous crystals is a reaction dependent upon solar radiation. It may explain the dependence found, as well as the striking appearance of the Great Red Spot in the UV

  18. Seasonal Overturning Circulation in the Red Sea

    Science.gov (United States)

    Yao, F.; Hoteit, I.; Koehl, A.

    2010-12-01

    The Red Sea exhibits a distinct seasonal overturning circulation. In winter, a typical two-layer exchange structure, with a fresher inflow from the Gulf of Aden on top of an outflow from the Red Sea, is established. In summer months (June to September) this circulation pattern is changed to a three-layer structure: a surface outflow from the Red Sea on top of a subsurface intrusion of the Gulf of Aden Intermediate Water and a weakened deep outflow. This seasonal variability is studied using a general circulation model, MITgcm, with 6 hourly NCEP atmospheric forcing. The model is able to reproduce the observed seasonal variability very well. The forcing mechanisms of the seasonal variability related to seasonal surface wind stress and buoyancy flux, and water mass transformation processes associated with the seasonal overturning circulation are analyzed and presented.

  19. 'Rosy Red' Soil in Phoenix's Scoop

    Science.gov (United States)

    2008-01-01

    This image shows fine-grained material inside the Robotic Arm scoop as seen by the Robotic Arm Camera (RAC) aboard NASA's Phoenix Mars Lander on June 25, 2008, the 30th Martian day, or sol, of the mission. The image shows fine, fluffy, red soil particles collected in a sample called 'Rosy Red.' The sample was dug from the trench named 'Snow White' in the area called 'Wonderland.' Some of the Rosy Red sample was delivered to Phoenix's Optical Microscope and Wet Chemistry Laboratory for analysis. The RAC provides its own illumination, so the color seen in RAC images is color as seen on Earth, not color as it would appear on Mars. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  20. Red textures and the work of juxtaposition

    Directory of Open Access Journals (Sweden)

    Corinne A. Kratz

    Full Text Available Simon Gush's evocative work Red is an installation, an exhibit, a film, a website, and a provocation to think about what these different forms convey and do, and how they do so. What kinds of engagement, work and knowledge production are involved in curating, designing and creating work in different formats, each of which combines varied media and forms of expression? This article considers the design and interpretive possibilities of Red's different forms, paying particular attention to juxtaposition as a fundamental technique in designing and constructing exhibits, films and websites. The analysis examines the layerings, interactions, timings and textures involved and draws in other exhibitions to highlight the ways that Red and history museums approach their work and relations to time, history and historiography.

  1. Infrared Model Spectra for Evolving Red Supergiants

    Directory of Open Access Journals (Sweden)

    Kyung-Won Suh

    1993-06-01

    Full Text Available The space and ground based infrared spectra of red supergiants are modeled and arranged in order of their evolutionary status with their theoretical model parameters. The chemical compositions of the dust shells around red supergiants are affected by the nuclear reaction and dredge-up processes of the cental stars. The processes are sensitively dependent on the initial mass, the initial chemical composition, and the evolutionary status. Miras, infrared carbon stars, and OH/IR stars have close link in their evolution in manu aspects, i,e., the chemical composition, the optical depths and the mass loss rates. The evolutionary tracks for the three classes of red supergiants on infrared two-color diagrams have been made from model calculations and IRAS observational data.

  2. Overexpression of miR-183/-96/-182 triggers neuronal cell fate in Human Retinal Pigment Epithelial (hRPE) cells in culture.

    Science.gov (United States)

    Davari, Maliheh; Soheili, Zahra-Soheila; Samiei, Shahram; Sharifi, Zohreh; Pirmardan, Ehsan Ranaei

    2017-01-29

    miR-183 cluster, composed of miR-183/-96/-182 genes, is highly expressed in the adult retina, particularly in photoreceptors. It involves in development, maturation and normal function of neuroretina. Ectopic overexpression of miR-183/-96/-182 genes was performed to assess reprogramming of hRPE cells. They were amplified from genomic DNA and cloned independently or in tandem configuration into pAAV.MCS vector. hRPE cells were then transfected with the recombinant constructs. Real-Time PCR was performed to measure the expression levels of miR-183/-96/-182 and that of several retina-specific neuronal genes such as OTX2, NRL, PDC and DCT. The transfected cells also were immunocytochemically examined for retina-specific neuronal markers, including Rhodopsin, red opsin, CRX, Thy1, CD73, recoverin and PKCα, to determine the cellular fate of the transfected hRPE cells. Data showed that upon miR-183/-96/-182 overexpression in hRPE cultures, the expression of neuronal genes including OTX2, NRL, PDC and DCT was also upregulated. Moreover, miR-183 cluster-treated hRPE cells were immunoreactive for neuronal markers such as Rhodopsin, red opsin, CRX and Thy1. Both transcriptional and translational upregulation of neuronal genes in miR-183 cluster-treated hRPE cells suggests that in vitro overexpression of miR-183 cluster could trigger reprogramming of hRPE cells to retinal neuron fate. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Bayesian population decoding of spiking neurons.

    Science.gov (United States)

    Gerwinn, Sebastian; Macke, Jakob; Bethge, Matthias

    2009-01-01

    The timing of action potentials in spiking neurons depends on the temporal dynamics of their inputs and contains information about temporal fluctuations in the stimulus. Leaky integrate-and-fire neurons constitute a popular class of encoding models, in which spike times depend directly on the temporal structure of the inputs. However, optimal decoding rules for these models have only been studied explicitly in the noiseless case. Here, we study decoding rules for probabilistic inference of a continuous stimulus from the spike times of a population of leaky integrate-and-fire neurons with threshold noise. We derive three algorithms for approximating the posterior distribution over stimuli as a function of the observed spike trains. In addition to a reconstruction of the stimulus we thus obtain an estimate of the uncertainty as well. Furthermore, we derive a 'spike-by-spike' online decoding scheme that recursively updates the posterior with the arrival of each new spike. We use these decoding rules to reconstruct time-varying stimuli represented by a Gaussian process from spike trains of single neurons as well as neural populations.

  4. Bayesian population decoding of spiking neurons

    Directory of Open Access Journals (Sweden)

    Sebastian Gerwinn

    2009-10-01

    Full Text Available The timing of action potentials in spiking neurons depends on the temporal dynamics of their inputs and contains information about temporal fluctuations in the stimulus. Leaky integrate-and-fire neurons constitute a popular class of encoding models, in which spike times depend directly on the temporal structure of the inputs. However, optimal decoding rules for these models have only been studied explicitly in the noiseless case. Here, we study decoding rules for probabilistic inference of a continuous stimulus from the spike times of a population of leaky integrate-and-fire neurons with threshold noise. We derive three algorithms for approximating the posterior distribution over stimuli as a function of the observed spike trains. In addition to a reconstruction of the stimulus we thus obtain an estimate of the uncertainty as well. Furthermore, we derive a `spike-by-spike' online decoding scheme that recursively updates the posterior with the arrival of each new spike. We use these decoding rules to reconstruct time-varying stimuli represented by a Gaussian process from spike trains of single neurons as well as neural populations.

  5. Adrenal Steroids: Biphasic Effects on Neurons

    NARCIS (Netherlands)

    Joels, M.; Karst, H.; Squire, L.R.

    2009-01-01

    Corticosteroid hormones are released from the adrenal gland after stress. They enter the brain and bind to high-affinity mineralocorticoid and lower affinity glucocorticoid receptors. Through these nuclear receptors, corticosteroids exert long-lasting effects on essential properties of neurons, such

  6. Asynchronous Rate Chaos in Spiking Neuronal Circuits.

    Directory of Open Access Journals (Sweden)

    Omri Harish

    2015-07-01

    Full Text Available The brain exhibits temporally complex patterns of activity with features similar to those of chaotic systems. Theoretical studies over the last twenty years have described various computational advantages for such regimes in neuronal systems. Nevertheless, it still remains unclear whether chaos requires specific cellular properties or network architectures, or whether it is a generic property of neuronal circuits. We investigate the dynamics of networks of excitatory-inhibitory (EI spiking neurons with random sparse connectivity operating in the regime of balance of excitation and inhibition. Combining Dynamical Mean-Field Theory with numerical simulations, we show that chaotic, asynchronous firing rate fluctuations emerge generically for sufficiently strong synapses. Two different mechanisms can lead to these chaotic fluctuations. One mechanism relies on slow I-I inhibition which gives rise to slow subthreshold voltage and rate fluctuations. The decorrelation time of these fluctuations is proportional to the time constant of the inhibition. The second mechanism relies on the recurrent E-I-E feedback loop. It requires slow excitation but the inhibition can be fast. In the corresponding dynamical regime all neurons exhibit rate fluctuations on the time scale of the excitation. Another feature of this regime is that the population-averaged firing rate is substantially smaller in the excitatory population than in the inhibitory population. This is not necessarily the case in the I-I mechanism. Finally, we discuss the neurophysiological and computational significance of our results.

  7. Observability and synchronization of neuron models

    Science.gov (United States)

    Aguirre, Luis A.; Portes, Leonardo L.; Letellier, Christophe

    2017-10-01

    Observability is the property that enables recovering the state of a dynamical system from a reduced number of measured variables. In high-dimensional systems, it is therefore important to make sure that the variable recorded to perform the analysis conveys good observability of the system dynamics. The observability of a network of neuron models depends nontrivially on the observability of the node dynamics and on the topology of the network. The aim of this paper is twofold. First, to perform a study of observability using four well-known neuron models by computing three different observability coefficients. This not only clarifies observability properties of the models but also shows the limitations of applicability of each type of coefficients in the context of such models. Second, to study the emergence of phase synchronization in networks composed of neuron models. This is done performing multivariate singular spectrum analysis which, to the best of the authors' knowledge, has not been used in the context of networks of neuron models. It is shown that it is possible to detect phase synchronization: (i) without having to measure all the state variables, but only one (that provides greatest observability) from each node and (ii) without having to estimate the phase.

  8. Neuron-glia metabolic coupling and plasticity.

    Science.gov (United States)

    Magistretti, Pierre J

    2006-06-01

    The coupling between synaptic activity and glucose utilization (neurometabolic coupling) is a central physiological principle of brain function that has provided the basis for 2-deoxyglucose-based functional imaging with positron emission tomography (PET). Astrocytes play a central role in neurometabolic coupling, and the basic mechanism involves glutamate-stimulated aerobic glycolysis; the sodium-coupled reuptake of glutamate by astrocytes and the ensuing activation of the Na-K-ATPase triggers glucose uptake and processing via glycolysis, resulting in the release of lactate from astrocytes. Lactate can then contribute to the activity-dependent fuelling of the neuronal energy demands associated with synaptic transmission. An operational model, the 'astrocyte-neuron lactate shuttle', is supported experimentally by a large body of evidence, which provides a molecular and cellular basis for interpreting data obtained from functional brain imaging studies. In addition, this neuron-glia metabolic coupling undergoes plastic adaptations in parallel with adaptive mechanisms that characterize synaptic plasticity. Thus, distinct subregions of the hippocampus are metabolically active at different time points during spatial learning tasks, suggesting that a type of metabolic plasticity, involving by definition neuron-glia coupling, occurs during learning. In addition, marked variations in the expression of genes involved in glial glycogen metabolism are observed during the sleep-wake cycle, with in particular a marked induction of expression of the gene encoding for protein targeting to glycogen (PTG) following sleep deprivation. These data suggest that glial metabolic plasticity is likely to be concomitant with synaptic plasticity.

  9. Beyond the frontiers of neuronal types

    Science.gov (United States)

    Battaglia, Demian; Karagiannis, Anastassios; Gallopin, Thierry; Gutch, Harold W.; Cauli, Bruno

    2012-01-01

    Cortical neurons and, particularly, inhibitory interneurons display a large diversity of morphological, synaptic, electrophysiological, and molecular properties, as well as diverse embryonic origins. Various authors have proposed alternative classification schemes that rely on the concomitant observation of several multimodal features. However, a broad variability is generally observed even among cells that are grouped into a same class. Furthermore, the attribution of specific neurons to a single defined class is often difficult, because individual properties vary in a highly graded fashion, suggestive of continua of features between types. Going beyond the description of representative traits of distinct classes, we focus here on the analysis of atypical cells. We introduce a novel paradigm for neuronal type classification, assuming explicitly the existence of a structured continuum of diversity. Our approach, grounded on the theory of fuzzy sets, identifies a small optimal number of model archetypes. At the same time, it quantifies the degree of similarity between these archetypes and each considered neuron. This allows highlighting archetypal cells, which bear a clear similarity to a single model archetype, and edge cells, which manifest a convergence of traits from multiple archetypes. PMID:23403725

  10. Beyond the frontiers of neuronal types

    Directory of Open Access Journals (Sweden)

    Demian eBattaglia

    2013-02-01

    Full Text Available Cortical neurons and, particularly, inhibitory interneurons display a large diversity of morphological, synaptic, electrophysiological and molecular properties, as well as diverse embryonic origins. Various authors have proposed alternative classification schemes that rely on the concomitant observation of several multimodal features. However, a broad variability is generally observed even among cells that are grouped into a same class. Furthermore, the attribution of specific neurons to a single defined class is often difficult, because individual properties vary in a highly graded fashion, suggestive of continua of features between types. Going beyond the description of representative traits of distinct classes, we focus here on the analysis of atypical cells. We introduce a novel paradigm for neuronal type classification, assuming explicitly the existence of a structured continuum of diversity. Our approach, grounded on the theory of fuzzy sets, identifies a small optimal number of model archetypes. At the same time, it quantifies the degree of similarity between these archetypes and each considered neuron. This allows highlighting archetypal cells, which bear a clear similarity to a single model archetype, and edge cells, which manifest a convergence of traits from multiple archetypes.

  11. Motor neuron, nerve, and neuromuscular junction disease.

    Science.gov (United States)

    Finsterer, Josef; Papić, Lea; Auer-Grumbach, Michaela

    2011-10-01

    The aim is to review the most relevant findings published during the last year concerning clinical, genetic, pathogenic, and therapeutic advances in motor neuron disease, neuropathies, and neuromuscular junction disorders. Studies on animal and cell models have improved the understanding of how mutated survival motor neuron protein in spinal muscular atrophy governs the pathogenetic processes. New phenotypes of SOD1 mutations have been described. Moreover, animal models enhanced the insight into the pathogenetic background of sporadic and familial amyotrophic lateral sclerosis. Novel treatment options for motor neuron disease have been described in humans and animal models. Considerable progress has been achieved also in elucidating the genetic background of many forms of inherited neuropathies and high clinical and genetic heterogeneity has been demonstrated. Mutations in MuSK and GFTP1 have been shown to cause new types of congenital myasthenic syndromes. A third type of autoantibodies (Lrp4) has been detected to cause myasthenia gravis. Advances in the clinical and genetic characterization of motor neuron diseases, neuropathies, and neuromuscular transmission defects have important implications on the fundamental understanding, diagnosis, and management of these disorders. Identification of crucial steps of the pathogenetic process may provide the basis for the development of novel therapeutic strategies.

  12. GaAs optoelectronic neuron arrays

    Science.gov (United States)

    Lin, Steven; Grot, Annette; Luo, Jiafu; Psaltis, Demetri

    1993-01-01

    A simple optoelectronic circuit integrated monolithically in GaAs to implement sigmoidal neuron responses is presented. The circuit integrates a light-emitting diode with one or two transistors and one or two photodetectors. The design considerations for building arrays with densities of up to 10,000/sq cm are discussed.

  13. Managing Brain Extracellular K(+) during Neuronal Activity

    DEFF Research Database (Denmark)

    Larsen, Brian Roland; Stoica, Anca; MacAulay, Nanna

    2016-01-01

    characteristics required to fulfill their distinct physiological roles in clearance of K(+) from the extracellular space in the face of neuronal activity. Understanding the nature, impact and effects of the various Na(+)/K(+)-ATPase isoform combinations in K(+) management in the central nervous system might...... understanding of the pathological events occurring during disease....

  14. Modulation of neuronal network activity with ghrelin

    NARCIS (Netherlands)

    Stoyanova, Irina; Rutten, Wim; le Feber, Jakob

    2012-01-01

    Ghrelin is a neuropeptide regulating multiple physiological processes, including high brain functions such as learning and memory formation. However, the effect of ghrelin on network activity patterns and developments has not been studied yet. Therefore, we used dissociated cortical neurons plated

  15. Characterization of astrocytic and neuronal benzodiazepine receptors

    Energy Technology Data Exchange (ETDEWEB)

    Bender, A.S.

    1988-01-01

    Primary cultures of astrocytes and neurons express benzodiazepine receptors. Neuronal benzodiazepine receptors were of high-affinity, K{sub D} values were 7.5-43 nM and the densities of receptors (B{sub max}) were 924-4131 fmol/mg protein. Astrocytes posses a high-affinity benzodiazepine receptor, K{sub D} values were 6.6-13 nM. The B{sub max} values were 6,033-12,000 fmol/mg protein. The pharmacological profile of the neuronal benzodiazepine receptor was that of the central-type benzodiazepine receptor, where clonazepam has a high-affinity and Ro 5-4864 (4{prime}-chlorodiazepam) has a low-affinity. Whereas astrocytic benzoidazepine receptor was characteristic of the so called peripheral-type benzodiazepine receptors, which shows a high-affinity towards Ro 5-4863, and a low-affinity towards clonazepam. The astrocytic benzodiazepine receptors was functionally correlated with voltage dependent calcium channels, since dihydropyridines and benzodiazepines interacted with ({sup 3}H) diazepam and ({sup 3}H) nitrendipine receptors with the same rank order of potency, showing a statistically significant correlation. No such correlation was observed in neurons.

  16. Taurine Biosynthesis by Neurons and Astrocytes*

    Science.gov (United States)

    Vitvitsky, Victor; Garg, Sanjay K.; Banerjee, Ruma

    2011-01-01

    The physiological roles of taurine, a product of cysteine degradation and one of the most abundant amino acids in the body, remain elusive. Taurine deficiency leads to heart dysfunction, brain development abnormalities, retinal degradation, and other pathologies. The taurine synthetic pathway is proposed to be incomplete in astrocytes and neurons, and metabolic cooperation between these cell types is reportedly needed to complete the pathway. In this study, we analyzed taurine synthesis capability as reported by incorporation of radioactivity from [35S]cysteine into taurine, in primary murine astrocytes and neurons, and in several transformed cell lines (human (SH-SY5Y) and murine (N1E-115) neuroblastoma, human astrocytoma (U-87MG and 1321 N1), and rat glioma (C6)). Extensive incorporation of radioactivity from [35S]cysteine into taurine was observed in rat glioma cells as well as in primary mouse astrocytes and neurons, establishing the presence of an intact taurine synthesis pathway in these cells. Interestingly, exposure of cells to cysteine or cysteamine resulted in elevated intracellular hypotaurine without a corresponding increase in taurine levels, suggesting that oxidation of hypotaurine limits taurine synthesis in cells. Consistent with its role as an organic osmolyte, taurine synthesis was stimulated under hypertonic conditions in neurons. PMID:21778230

  17. Astrocytic actions on extrasynaptic neuronal currents

    Directory of Open Access Journals (Sweden)

    Balazs ePal

    2015-12-01

    Full Text Available In the last few decades, knowledge about astrocytic functions has significantly increased. It was demonstrated that astrocytes are not passive elements of the central nervous system, but active partners of neurons. There is a growing body of knowledge about the calcium excitability of astrocytes, the actions of different gliotransmitters and their release mechanisms, as well as the participation of astrocytes in the regulation of synaptic functions and their contribution to synaptic plasticity. However, astrocytic functions are even more complex than being a partner of the 'tripartite synapse', as they can influence extrasynaptic neuronal currents either by releasing substances or regulating ambient neurotransmitter levels. Several types of currents or changes of membrane potential with different kinetics and via different mechanisms can be elicited by astrocytic activity. Astrocyte-dependent phasic or tonic, inward or outward currents were described in several brain areas. Such currents, together with the synaptic actions of astrocytes, can contribute to neuromodulatory mechanisms, neurosensory and –secretory processes, cortical oscillatory activity, memory and learning or overall neuronal excitability. This mini-review is an attempt to give a brief summary of astrocyte-dependent extrasynaptic neuronal currents and their possible functional significance.

  18. Coupling Perception with Actions via Mirror Neurons

    Czech Academy of Sciences Publication Activity Database

    Wiedermann, Jiří

    č. 55 (2003), s. 11-12 ISSN 0926-4981 R&D Projects: GA ČR GA201/02/1456 Institutional research plan: AV0Z1030915 Keywords : mirror neurons * cognitive agents * neural nets Subject RIV: BA - General Mathematics http://www.ercim.eu/publication/Ercim_News/enw55/wiedermann.html

  19. Daidzein induces neuritogenesis in DRG neuronal cultures

    Directory of Open Access Journals (Sweden)

    Yang Shih-Hung

    2012-08-01

    Full Text Available Absract Background Daidzein, a phytoestrogen found in isoflavone, is known to exert neurotrophic and neuroprotective effects on the nervous system. Using primary rat dorsal root ganglion (DRG neuronal cultures, we have examined the potential neurite outgrowth effect of daidzein. Methods Dissociated dorsal root ganglia (DRG cultures were used to study the signaling mechanism of daidzein-induced neuritogenesis by immunocytochemistry and Western blotting. Results In response to daidzein treatment, DRG neurons showed a significant increase in total neurite length and in tip number per neuron. The neuritogenic effect of daidzein was significantly hampered by specific blockers for Src, protein kinase C delta (PKCδ and mitogen-activated protein kinase/extracellular signal-regulated kinase kinases (MEK/ERK, but not by those for estrogen receptor (ER. Moreover, daidzein induced phosphorylation of Src, PKCδ and ERK. The activation of PKCδ by daidzein was attenuated in the presence of a Src kinase inhibitor, and that of ERK by daidzein was diminished in the presence of either a Src or PKCδ inhibitor. Conclusion Daidzein may stimulate neurite outgrowth of DRG neurons depending on Src kinase, PKCδ and ERK signaling pathway.

  20. Magnocellular Neurons and Posterior Pituitary Function.

    Science.gov (United States)

    Brown, Colin H

    2016-09-15

    The posterior pituitary gland secretes oxytocin and vasopressin (the antidiuretic hormone) into the blood system. Oxytocin is required for normal delivery of the young and for delivery of milk to the young during lactation. Vasopressin increases water reabsorption in the kidney to maintain body fluid balance and causes vasoconstriction to increase blood pressure. Oxytocin and vasopressin secretion occurs from the axon terminals of magnocellular neurons whose cell bodies are principally found in the hypothalamic supraoptic nucleus and paraventricular nucleus. The physiological functions of oxytocin and vasopressin depend on their secretion, which is principally determined by the pattern of action potentials initiated at the cell bodies. Appropriate secretion of oxytocin and vasopressin to meet the challenges of changing physiological conditions relies mainly on integration of afferent information on reproductive, osmotic, and cardiovascular status with local regulation of magnocellular neurons by glia as well as intrinsic regulation by the magnocellular neurons themselves. This review focuses on the control of magnocellular neuron activity with a particular emphasis on their regulation by reproductive function, body fluid balance, and cardiovascular status. © 2016 American Physiological Society. Compr Physiol 6:1701-1741, 2016. Copyright © 2016 John Wiley & Sons, Inc.

  1. C1 neurons: the body's EMTs.

    Science.gov (United States)

    Guyenet, Patrice G; Stornetta, Ruth L; Bochorishvili, Genrieta; Depuy, Seth D; Burke, Peter G R; Abbott, Stephen B G

    2013-08-01

    The C1 neurons reside in the rostral and intermediate portions of the ventrolateral medulla (RVLM, IVLM). They use glutamate as a fast transmitter and synthesize catecholamines plus various neuropeptides. These neurons regulate the hypothalamic pituitary axis via direct projections to the paraventricular nucleus and regulate the autonomic nervous system via projections to sympathetic and parasympathetic preganglionic neurons. The presympathetic C1 cells, located in the RVLM, are probably organized in a roughly viscerotopic manner and most of them regulate the circulation. C1 cells are variously activated by hypoglycemia, infection or inflammation, hypoxia, nociception, and hypotension and contribute to most glucoprivic responses. C1 cells also stimulate breathing and activate brain stem noradrenergic neurons including the locus coeruleus. Based on the various effects attributed to the C1 cells, their axonal projections and what is currently known of their synaptic inputs, subsets of C1 cells appear to be differentially recruited by pain, hypoxia, infection/inflammation, hemorrhage, and hypoglycemia to produce a repertoire of stereotyped autonomic, metabolic, and neuroendocrine responses that help the organism survive physical injury and its associated cohort of acute infection, hypoxia, hypotension, and blood loss. C1 cells may also contribute to glucose and cardiovascular homeostasis in the absence of such physical stresses, and C1 cell hyperactivity may contribute to the increase in sympathetic nerve activity associated with diseases such as hypertension.

  2. Asynchronous Rate Chaos in Spiking Neuronal Circuits

    Science.gov (United States)

    Harish, Omri; Hansel, David

    2015-01-01

    The brain exhibits temporally complex patterns of activity with features similar to those of chaotic systems. Theoretical studies over the last twenty years have described various computational advantages for such regimes in neuronal systems. Nevertheless, it still remains unclear whether chaos requires specific cellular properties or network architectures, or whether it is a generic property of neuronal circuits. We investigate the dynamics of networks of excitatory-inhibitory (EI) spiking neurons with random sparse connectivity operating in the regime of balance of excitation and inhibition. Combining Dynamical Mean-Field Theory with numerical simulations, we show that chaotic, asynchronous firing rate fluctuations emerge generically for sufficiently strong synapses. Two different mechanisms can lead to these chaotic fluctuations. One mechanism relies on slow I-I inhibition which gives rise to slow subthreshold voltage and rate fluctuations. The decorrelation time of these fluctuations is proportional to the time constant of the inhibition. The second mechanism relies on the recurrent E-I-E feedback loop. It requires slow excitation but the inhibition can be fast. In the corresponding dynamical regime all neurons exhibit rate fluctuations on the time scale of the excitation. Another feature of this regime is that the population-averaged firing rate is substantially smaller in the excitatory population than in the inhibitory population. This is not necessarily the case in the I-I mechanism. Finally, we discuss the neurophysiological and computational significance of our results. PMID:26230679

  3. The mirror neuron system : New frontiers

    NARCIS (Netherlands)

    Keysers, Christian; Fadiga, Luciano

    2008-01-01

    Since the discovery of mirror neurons, much effort has been invested into Studying their location and properties in the human brain. Here we review these original findings and introduce the Main topics of this special issue of Social Neuroscience. What does the mirror system code? How is the mirror

  4. Unbroken Mirror Neurons in Autism Spectrum Disorders

    Science.gov (United States)

    Fan, Yang-Teng; Decety, Jean; Yang, Chia-Yen; Liu, Ji-Lin; Cheng, Yawei

    2010-01-01

    Background: The "broken mirror" theory of autism, which proposes that a dysfunction of the human mirror neuron system (MNS) is responsible for the core social and cognitive deficits in individuals with autism spectrum disorders (ASD), has received considerable attention despite weak empirical evidence. Methods: In this electroencephalographic…

  5. Geometrical Determinants of Neuronal Actin Waves.

    Science.gov (United States)

    Tomba, Caterina; Braïni, Céline; Bugnicourt, Ghislain; Cohen, Floriane; Friedrich, Benjamin M; Gov, Nir S; Villard, Catherine

    2017-01-01

    Hippocampal neurons produce in their early stages of growth propagative, actin-rich dynamical structures called actin waves. The directional motion of actin waves from the soma to the tip of neuronal extensions has been associated with net forward growth, and ultimately with the specification of neurites into axon and dendrites. Here, geometrical cues are used to control actin wave dynamics by constraining neurons on adhesive stripes of various widths. A key observable, the average time between the production of consecutive actin waves, or mean inter-wave interval (IWI), was identified. It scales with the neurite width, and more precisely with the width of the proximal segment close to the soma. In addition, the IWI is independent of the total number of neurites. These two results suggest a mechanistic model of actin wave production, by which the material conveyed by actin waves is assembled in the soma until it reaches the threshold leading to the initiation and propagation of a new actin wave. Based on these observations, we formulate a predictive theoretical description of actin wave-driven neuronal growth and polarization, which consistently accounts for different sets of experiments.

  6. C1 neurons: the body's EMTs

    Science.gov (United States)

    Stornetta, Ruth L.; Bochorishvili, Genrieta; DePuy, Seth D.; Burke, Peter G. R.; Abbott, Stephen B. G.

    2013-01-01

    The C1 neurons reside in the rostral and intermediate portions of the ventrolateral medulla (RVLM, IVLM). They use glutamate as a fast transmitter and synthesize catecholamines plus various neuropeptides. These neurons regulate the hypothalamic pituitary axis via direct projections to the paraventricular nucleus and regulate the autonomic nervous system via projections to sympathetic and parasympathetic preganglionic neurons. The presympathetic C1 cells, located in the RVLM, are probably organized in a roughly viscerotopic manner and most of them regulate the circulation. C1 cells are variously activated by hypoglycemia, infection or inflammation, hypoxia, nociception, and hypotension and contribute to most glucoprivic responses. C1 cells also stimulate breathing and activate brain stem noradrenergic neurons including the locus coeruleus. Based on the various effects attributed to the C1 cells, their axonal projections and what is currently known of their synaptic inputs, subsets of C1 cells appear to be differentially recruited by pain, hypoxia, infection/inflammation, hemorrhage, and hypoglycemia to produce a repertoire of stereotyped autonomic, metabolic, and neuroendocrine responses that help the organism survive physical injury and its associated cohort of acute infection, hypoxia, hypotension, and blood loss. C1 cells may also contribute to glucose and cardiovascular homeostasis in the absence of such physical stresses, and C1 cell hyperactivity may contribute to the increase in sympathetic nerve activity associated with diseases such as hypertension. PMID:23697799

  7. Efficient information transfer by Poisson neurons

    Czech Academy of Sciences Publication Activity Database

    Košťál, Lubomír; Shinomoto, S.

    2016-01-01

    Roč. 13, č. 3 (2016), s. 509-520 ISSN 1547-1063 R&D Projects: GA ČR(CZ) GA15-08066S Institutional support: RVO:67985823 Keywords : information capacity * Poisson neuron * metabolic cost * decoding error Subject RIV: BD - Theory of Information Impact factor: 1.035, year: 2016

  8. Achalasia: virus-induced euthanasia of neurons?

    NARCIS (Netherlands)

    Boeckxstaens, Guy E.

    2008-01-01

    Achalasia, a motor disorder of the esophagus, is characterized by myenteric plexitis leading to neuronal loss. Cytotoxic T cells, isolated from the lower esophageal sphincter of achalasia patients, respond to human herpes virus-1 (HSV-1) with gamma-IFN (and to a lesser extent IL-2) production and

  9. Lógicas para la red

    Directory of Open Access Journals (Sweden)

    Antonia HUERTAS

    2009-09-01

    Full Text Available RESUMEN: Tim Berners-Lee y sus colegas del World Wide Web Consortium (W3C llamaron «Semantic Web» al que sería el siguiente estadio de desarrollo de la red (inevitablemente traducido al castellano como Web Semántica. La idea detrás de esta evolución de la red es extender con metadatos y reglas lógicas la red basada en el lenguaje html, con el objetivo de que la infraestructura resultante permita a las máquinas entender los datos de la red de la misma forma que los entendemos los humanos. Así, añadir lógica a la red permitiría a los ordenadores tomar decisiones, hacer inferencias y responder preguntas. En este texto se pretende revisar las lógicas que han sido propuestas para permitir esta nueva web inteligente y repasar las cuestiones teóricas y pragmáticas más importantes de la corta pero intensa historia de las lógicas para la red.ABSTRACT: Tim Berners-Lee and their colleagues of the World Wide Web Consortium (W3C called «Semantic Web» the next development of the Web. The idea behind this evolution of the Web is to extend the present network based on the HTML language with metadata and logical rules, with the aim of the resulting infrastructure allowing machines to understand Web data in the same way that human beings understand them. Thus, adding logic to the Web would allow the computers to take decisions, to do inferences and to answer questions. In this paper it is intended to revise the logics that have been suggested to allow this new intelligent Web and to revise the most important theoretical and pragmatic questions of the short but intense history of logics for the Web.

  10. PYRETHROID MODULATION OF SPONTANEOUS NEURONAL EXCITABILITY AND NEUROTRANSMISSION IN HIPPOCAMPAL NEURONS IN CULTURE

    Science.gov (United States)

    Pyrethroid insecticides have potent actions on voltage-gated sodium channels, inhibiting inactivation and increasing channel open times. These are thought to underlie, at least in part, the clinical symptoms of pyrethroid intoxication. However, disruption of neuronal activity at ...

  11. Additivity of Pyrethroid Actions on Sodium Influx in Cortical Neurons in Cerebrocortical Neurons in Primary Culture

    Science.gov (United States)

    BACKGROUND: Pyrethroid insecticides bind to voltage-gated sodium channels and modify their gating kinetics, thereby disrupting neuronal function. Although previous work has tested the additivity of pyrethroids in vivo, this has not been assessed directly at the primary molecular ...

  12. Population coding in sparsely connected networks of noisy neurons

    OpenAIRE

    Tripp, Bryan P.; Orchard, Jeff

    2012-01-01

    This study examines the relationship between population coding and spatial connection statistics in networks of noisy neurons. Encoding of sensory information in the neocortex is thought to require coordinated neural populations, because individual cortical neurons respond to a wide range of stimuli, and exhibit highly variable spiking in response to repeated stimuli. Population coding is rooted in network structure, because cortical neurons receive information only from other neurons, and be...

  13. Gene Expression and the Diversity of Identified Neurons

    OpenAIRE

    Buck, L.; Stein, R.; Palazzolo, M.; Anderson, D. J.; Axel, R.

    1983-01-01

    Nervous systems consist of diverse populations of neurons that are anatomically and functionally distinct. The diversity of neurons and the precision with which they are interconnected suggest that specific genes or sets of genes are activated in some neurons but not expressed in others. Experimentally, this problem may be considered at two levels. First, what is the total number of genes expressed in the brain, and how are they distributed among the different populations of neurons? Second, ...

  14. Rapid shift in substrate utilization driven by hypothalamic Agrp neurons

    OpenAIRE

    Cavalcanti-De-Albuquerque, Joao; Dietrich, Marcelo; Bober, Jeremy; Zimmer, Marcelo

    2016-01-01

    Agrp neurons drive feeding. To what extend these neurons participate in the regulation of other homeostatic processes is not well understood. We investigated the role of Agrp neurons in substrate utilization in mice. Activation of Agrp neurons was sufficient to rapidly increase RER and carbohydrate utilization, while decreasing fat utilization. These metabolic changes were linearly correlated with carbohydrates ingested, but not protein or fat ingestion. However, even in the absence of ingest...

  15. Mirror neurons: Enigma of the metaphysical modular brain

    OpenAIRE

    Acharya, Sourya; Shukla, Samarth

    2012-01-01

    Mirror neurons are one of the most important discoveries in the last decade of neuroscience. These are a variety of visuospatial neurons which indicate fundamentally about human social interaction. Essentially, mirror neurons respond to actions that we observe in others. The interesting part is that mirror neurons fire in the same way when we actually recreate that action ourselves. Apart from imitation, they are responsible for myriad of other sophisticated human behavior and thought process...

  16. Mirror Neurons, Embodied Cognitive Agents and Imitation Learning

    OpenAIRE

    Wiedermann, Jiří

    2003-01-01

    Mirror neurons are a relatively recent discovery; it has been conjectured that these neurons play an important role in imitation learning and other cognitive phenomena. We will study a possible place and role of mirror neurons in the neural architecture of embodied cognitive agents. We will formulate and investigate the hypothesis that mirror neurons serve as a mechanism which coordinates the multimodal (i.e., motor, perceptional and proprioceptive) information and completes it so that the ag...

  17. Effect of different glucose supply conditions on neuronal energy metabolism

    OpenAIRE

    Zheng, Hongwen; Wang, Rubin; Qu, Jingyi

    2016-01-01

    The glucose-excited neurons in brain can sense blood glucose levels and reflect different firing states, which are mainly associated with regulation of blood glucose and energy demand in the brain. In this paper, a new model of glucose-excited neuron in hypothalamus is proposed. The firing properties and energy consumption of this type of neuron under conditions of different glucose levels are simulated and analyzed. The results show that the firing rate and firing duration of the neuron both...

  18. Radio universitaria: trabajo en red como imperativo

    Directory of Open Access Journals (Sweden)

    Tiziana Cavallo

    2014-01-01

    Full Text Available Trabajo en red es un concepto clave en la radio universitaria, tanto desde el punto de vista individual como del colectivo. A través de dos estudios de caso, enfocados en la radio universitaria de Italia y de Colombia, este artículo muestra cómo el trabajo en red ha sido decisivo para el fortalecimiento de su función, la ampliación de su impacto, la conformación de su identidad y el crecimiento de su visibilidad en las sociedades en las cuales desarrollan su labor.

  19. Oenology: red wine procyanidins and vascular health.

    Science.gov (United States)

    Corder, R; Mullen, W; Khan, N Q; Marks, S C; Wood, E G; Carrier, M J; Crozier, A

    2006-11-30

    Regular, moderate consumption of red wine is linked to a reduced risk of coronary heart disease and to lower overall mortality, but the relative contribution of wine's alcohol and polyphenol components to these effects is unclear. Here we identify procyanidins as the principal vasoactive polyphenols in red wine and show that they are present at higher concentrations in wines from areas of southwestern France and Sardinia, where traditional production methods ensure that these compounds are efficiently extracted during vinification. These regions also happen to be associated with increased longevity in the population.

  20. Causes of Red Eye-Uveitis

    Directory of Open Access Journals (Sweden)

    Selçuk Sızmaz

    2012-12-01

    Full Text Available Uveitis, being an important cause of ocular morbidity, must be taken into consideration in the differential diagnosis and the management of patients with red eye. Uveitis entities can demonstrate variable clinical features. Patients presenting with uveitis must undergo careful systemic evaluation for exact diagnosis and treatment. Studies for standardization of uveitis with variable clinical pictures are emerging. Acute anterior uveitis and panuveitis can cause red eye. The purpose of this current study is to summarize the clinical features and laboratory investigations that could help the differential diagnosis of acute anterior uveitis and panuveitis cases. (Turk J Ophthalmol 2012; 42: Supplement 57-62

  1. Incorporation of flat glass in red ceramic

    International Nuclear Information System (INIS)

    Caldas, T.C.C.; Morais, A.S.C.; Pereira, P.S.; Monteiro, S.N.; Vieira, C.M.F.

    2011-01-01

    This work have as objective evaluate the effect of incorporation of up to 10% by weight of powdered flat glass , from civil industry, in red ceramic. The bodies were obtained by uniaxial pressing at 20 MPa and fired at temperatures of 850 ° C and 1050 ° C. The parameters studied were linear firing shrinkage, apparent density, water absorption and flexural rupture stress for the evaluation of the mechanical physical properties. The microstructure was observed by scanning electron microscopy and phase identification was performed by X-ray diffraction. The results showed that the waste changes the microstructure and properties of red ceramics. (author)

  2. Pseudoepitheliomatous Hyperplasia in a Red Pigment Tattoo

    Science.gov (United States)

    Kazlouskaya, Viktoryia

    2015-01-01

    Red pigment tattoos are known to cause pseudoepitheliomatous hyperplasia in the skin, frequently simulating squamous cell carcinoma or keratoacanthoma. Herein, the authors present two additional cases of red pigment tattoo pseudoepitheliomatous hyperplasia in which they noted a lichenoid tissue reaction. They reviewed the previously published cases and observed a lichenoid reaction in the histopathological images similar to hypertrophic lichen planus. The authors suggest that these reactions might best be referred to as “lichenoid reaction with pseudoepitheliomatous hyperplasia” or “hypertrophic lichen planus-like reaction.” Accordingly, recognition of an inflammatory component may allow additional treatment options. PMID:26705448

  3. Recovery of rare earths from red mud

    International Nuclear Information System (INIS)

    Bautista, R.G.

    1992-01-01

    The prospect for the recovery of rare earths from red mud, the bauxite tailings from the production of alumina is examined. The Jamaican red mud by far has the higher trace concentrations of lanthanum, cerium, neodymium, and yttrium. Scandium is also present. The dissolution of the rare earth is a major extraction problem because of the large volume of other materials. The recovery processes that have been proposed include the production of co-products such as iron, alumina, and titanium concentrates, with the rare earths going with the titanium. In this paper a critical examination of the possible processes are presented with the recommended research projects to be carried out

  4. A MULTI-STAGE COLOR MODEL REVISITED: IMPLICATIONS FOR A GENE THERAPY CURE FOR RED-GREEN COLORBLINDNESS

    OpenAIRE

    Mancuso, Katherine; Mauck, Matthew C.; Kuchenbecker, James A.; Neitz, Maureen; Neitz, Jay

    2010-01-01

    In 1993, DeValois and DeValois proposed a “multi-stage color model” to explain how the cortex is ultimately able to deconfound the responses of neurons receiving input from three cone types in order to produce separate red-green and blue-yellow systems, as well as segregate luminance percepts (black-white) from color. This model extended the biological implementation of Hurvich and Jameson’s Opponent-Process Theory of color vision, a two-stage model encompassing the three cone types combined ...

  5. Proteomic Analysis of the Effect of Korean Red Ginseng in the Striatum of a Parkinson?s Disease Mouse Model

    OpenAIRE

    Kim, Dongsoo; Jeon, Hyongjun; Ryu, Sun; Koo, Sungtae; Ha, Ki-Tae; Kim, Seungtae

    2016-01-01

    Recent studies have shown that Korean Red Ginseng (KRG) suppresses dopaminergic neuronal death in the brain of a Parkinson's disease (PD) mouse model, but the mechanism is still elusive. Using a 2-dimensional electrophoresis technique, we investigated whether KRG can restore the changes in protein expressions in the striatum (ST) of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-injected mice. Male C57BL/6 mice (9 weeks old) were injected with 20 mg/kg MPTP intraperitoneally four times a...

  6. Chemical reactivation of resin-embedded pHuji adds red for simultaneous two-color imaging with EGFP

    Science.gov (United States)

    Guo, Wenyan; Liu, Xiuli; Liu, Yurong; Gang, Yadong; He, Xiaobin; Jia, Yao; Yin, Fangfang; Li, Pei; Huang, Fei; Zhou, Hongfu; Wang, Xiaojun; Gong, Hui; Luo, Qingming; Xu, Fuqiang; Zeng, Shaoqun

    2017-01-01

    The pH-sensitive fluorescent proteins enabling chemical reactivation in resin are useful tools for fluorescence microimaging. EGFP or EYFP is good for such applications. For simultaneous two-color imaging, a suitable red fluorescent protein is an urgent need. Here a pH-sensitive red fluorescent protein, pHuji, is selected and verified to remain pH-sensitive in HM20 resin. We observe 183% fluorescence intensity of pHuji in resin-embeded mouse brain and 29.08-fold fluorescence intensity of reactivated pHuji compared to the quenched state. pHuji and EGFP can be quenched and chemically reactivated simultaneously in resin, thus enabling simultaneous two-color micro-optical sectioning tomography of resin-embedded mouse brain. This method may greatly facilitate the visualization of neuronal morphology and neural circuits to promote understanding of the structure and function of the brain. PMID:28717566

  7. ALS and other motor neuron diseases.

    Science.gov (United States)

    Tiryaki, Ezgi; Horak, Holli A

    2014-10-01

    This review describes the most common motor neuron disease, ALS. It discusses the diagnosis and evaluation of ALS and the current understanding of its pathophysiology, including new genetic underpinnings of the disease. This article also covers other motor neuron diseases, reviews how to distinguish them from ALS, and discusses their pathophysiology. In this article, the spectrum of cognitive involvement in ALS, new concepts about protein synthesis pathology in the etiology of ALS, and new genetic associations will be covered. This concept has changed over the past 3 to 4 years with the discovery of new genes and genetic processes that may trigger the disease. As of 2014, two-thirds of familial ALS and 10% of sporadic ALS can be explained by genetics. TAR DNA binding protein 43 kDa (TDP-43), for instance, has been shown to cause frontotemporal dementia as well as some cases of familial ALS, and is associated with frontotemporal dysfunction in ALS. The anterior horn cells control all voluntary movement: motor activity, respiratory, speech, and swallowing functions are dependent upon signals from the anterior horn cells. Diseases that damage the anterior horn cells, therefore, have a profound impact. Symptoms of anterior horn cell loss (weakness, falling, choking) lead patients to seek medical attention. Neurologists are the most likely practitioners to recognize and diagnose damage or loss of anterior horn cells. ALS, the prototypical motor neuron disease, demonstrates the impact of this class of disorders. ALS and other motor neuron diseases can represent diagnostic challenges. Neurologists are often called upon to serve as a "medical home" for these patients: coordinating care, arranging for durable medical equipment, and leading discussions about end-of-life care with patients and caregivers. It is important for neurologists to be able to identify motor neuron diseases and to evaluate and treat patients affected by them.

  8. Discrimination of Communication Vocalizations by Single Neurons and Groups of Neurons in the Auditory Midbrain

    OpenAIRE

    Schneider, David M.; Woolley, Sarah M. N.

    2010-01-01

    Many social animals including songbirds use communication vocalizations for individual recognition. The perception of vocalizations depends on the encoding of complex sounds by neurons in the ascending auditory system, each of which is tuned to a particular subset of acoustic features. Here, we examined how well the responses of single auditory neurons could be used to discriminate among bird songs and we compared discriminability to spectrotemporal tuning. We then used biologically realistic...

  9. GABAergic inhibition through synergistic astrocytic neuronal interaction transiently decreases vasopressin neuronal activity during hypoosmotic challenge.

    Science.gov (United States)

    Wang, Yu-Feng; Sun, Min-Yu; Hou, Qiuling; Hamilton, Kathryn A

    2013-04-01

    The neuropeptide vasopressin is crucial to mammalian osmotic regulation. Local hypoosmotic challenge transiently decreases and then increases vasopressin secretion. To investigate mechanisms underlying this transient response, we examined the effects of hypoosmotic challenge on the electrical activity of rat hypothalamic supraoptic nucleus (SON) vasopressin neurons using patch-clamp recordings. We found that 5 min exposure of hypothalamic slices to hypoosmotic solution transiently increased inhibitory postsynaptic current (IPSC) frequency and reduced the firing rate of vasopressin neurons. Recovery occurred by 10 min of exposure, even though the osmolality remained low. The γ-aminobutyric acid (GABA)A receptor blocker, gabazine, blocked the IPSCs and the hypoosmotic suppression of firing. The gliotoxin l-aminoadipic acid blocked the increase in IPSC frequency at 5 min and the recovery of firing at 10 min, indicating astrocytic involvement in hypoosmotic modulation of vasopressin neuronal activity. Moreover, β-alanine, an osmolyte of astrocytes and GABA transporter (GAT) inhibitor, blocked the increase in IPSC frequency at 5 min of hypoosmotic challenge. Confocal microscopy of immunostained SON sections revealed that astrocytes and magnocellular neurons both showed positive staining of vesicular GATs (VGAT). Hypoosmotic stimulation in vivo reduced the number of VGAT-expressing neurons, and increased co-localisation and molecular association of VGAT with glial fibrillary acidic protein that increased significantly by 10 min. By 30 min, neuronal VGAT labelling was partially restored, and astrocytic VGAT was relocated to the ventral portion while it decreased in the somatic zone of the SON. Thus, synergistic astrocytic and neuronal GABAergic inhibition could ensure that vasopressin neuron firing is only transiently suppressed under hypoosmotic conditions. © 2013 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

  10. Evaluation of Red Light Camera Enforcement at Signalized Intersections

    Directory of Open Access Journals (Sweden)

    Abdulrahman AlJanahi

    2007-12-01

    Full Text Available The study attempts to find the effectiveness of adopting red light cameras in reducing red light violators. An experimental approach was adopted to investigate the use of red light cameras at signalized intersections in the Kingdom of Bahrain. The study locations were divided into three groups. The first group was related to the approaches monitored with red light cameras. The second group was related to approaches without red light cameras, but located within an intersection that had one of its approaches monitored with red light cameras. The third group was related to intersection approaches located at intersection without red light cameras (controlled sites. A methodology was developed for data collection. The data were then tested statistically by Z-test using proportion methods to compare the proportion of red light violations occurring at different sites. The study found that the proportion of red light violators at approaches monitored with red light cameras was significantly less than those at the controlled sites for most of the time. Approaches without red light cameras located within intersections having red light cameras showed, in general, fewer violations than controlled sites, but the results were not significant for all times of the day. The study reveals that red light cameras have a positive effect on reducing red light violations. However, these conclusions need further evaluations to justify their safe and economic use.

  11. Developmental time windows for axon growth influence neuronal network topology.

    Science.gov (United States)

    Lim, Sol; Kaiser, Marcus

    2015-04-01

    Early brain connectivity development consists of multiple stages: birth of neurons, their migration and the subsequent growth of axons and dendrites. Each stage occurs within a certain period of time depending on types of neurons and cortical layers. Forming synapses between neurons either by growing axons starting at similar times for all neurons (much-overlapped time windows) or at different time points (less-overlapped) may affect the topological and spatial properties of neuronal networks. Here, we explore the extreme cases of axon formation during early development, either starting at the same time for all neurons (parallel, i.e., maximally overlapped time windows) or occurring for each neuron separately one neuron after another (serial, i.e., no overlaps in time windows). For both cases, the number of potential and established synapses remained comparable. Topological and spatial properties, however, differed: Neurons that started axon growth early on in serial growth achieved higher out-degrees, higher local efficiency and longer axon lengths while neurons demonstrated more homogeneous connectivity patterns for parallel growth. Second, connection probability decreased more rapidly with distance between neurons for parallel growth than for serial growth. Third, bidirectional connections were more numerous for parallel growth. Finally, we tested our predictions with C. elegans data. Together, this indicates that time windows for axon growth influence the topological and spatial properties of neuronal networks opening up the possibility to a posteriori estimate developmental mechanisms based on network properties of a developed network.

  12. First-spike latency in Hodgkin's three classes of neurons.

    Science.gov (United States)

    Wang, Hengtong; Chen, Yueling; Chen, Yong

    2013-07-07

    We study the first-spike latency (FSL) in Hodgkin's three classes of neurons with the Morris-Lecar neuron model. It is found that all the three classes of neurons can encode an external stimulus into FSLs. With DC inputs, the FSLs of all of the neurons decrease with input intensity. With input current decreased to the threshold, class 1 neurons show an arbitrary long FSL whereas class 2 and 3 neurons exhibit the short-limit FSLs. When the input current is sinusoidal, the amplitude, frequency and initial phase can be encoded by all the three classes of neurons. The FSLs of all of the neurons decrease with the input amplitude and frequency. When the input frequency is too high, all of the neurons respond with infinite FSLs. When the initial phase increases, the FSL decreases and then jumps to a maximal value and finally decreases linearly. With changes in the input parameters, the FSLs of the class 1 and 2 neurons exhibit similar properties. However, the FSL of the class 3 neurons became slightly longer and only produces responses for a narrow range of initial phase if input frequencies are low. Moreover, our results also show that the FSL and firing rate responses are mutually independent processes and that neurons can encode an external stimulus into different FSLs and firing rates simultaneously. This finding is consistent with the current theory of dual or multiple complementary coding mechanisms. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Multiple Modes of Communication between Neurons and Oligodendrocyte Precursor Cells

    NARCIS (Netherlands)

    Maldonado, Paloma P; Angulo, María Cecilia

    The surprising discovery of bona fide synapses between neurons and oligodendrocytes precursor cells (OPCs) 15 years ago placed these progenitors as real partners of neurons in the CNS. The role of these synapses has not been established yet, but a main hypothesis is that neuron-OPC synaptic activity

  14. THE MITOCHONDRIAL DERANGEMENTS IN NEURONAL DEGENER ATION AND NEURODEGENERATIVE DISEASES

    Institute of Scientific and Technical Information of China (English)

    Xue, Qi-ming; Gao, Feng; Chen, Qin-tang

    2000-01-01

    @@There are diverse concepts on the pathogenesis of neuronal degeneration and the neurodegenerative diseases. Among them there are different factors which might influence the initiation of neuronal degeneration as well as the pathogenesis of neurodegenerative diseases, such as Alzheimer′s disease, Parkinson′s disease, motor neuron disease, and so on.

  15. What is happening to motor neuron disease in Nigeria? | Imam ...

    African Journals Online (AJOL)

    Background: Systematic studies of motor neuron disease were last reported from Ibadan, Nigeria, more than two decades ago. Since then, information about motor neuron disease has become limited making it necessary to review the current status of the disease. Methods: The clinical records of all cases of motor neuron ...

  16. Social interaction in robotic agents emulating the mirror neuron function

    NARCIS (Netherlands)

    Barakova, E.I.; Mira, J.; Álvarez, J.R.

    2007-01-01

    Emergent interactions that are expressed by the movements of two agents are discussed in this paper. The common coding principle is used to show how the mirror neuron system may facilitate interaction behaviour. Synchronization between neuron groups in different structures of the mirror neuron

  17. Dcc regulates asymmetric outgrowth of forebrain neurons in zebrafish.

    Directory of Open Access Journals (Sweden)

    Jingxia Gao

    Full Text Available The guidance receptor DCC (deleted in colorectal cancer ortholog UNC-40 regulates neuronal asymmetry development in Caenorhabditis elegans, but it is not known whether DCC plays a role in the specification of neuronal polarity in vertebrates. To examine the roles of DCC in neuronal asymmetry regulation in vertebrates, we studied zebrafish anterior dorsal telencephalon (ADt neuronal axons. We generated transgenic zebrafish animals expressing the photo-convertible fluorescent protein Kaede in ADt neurons and then photo-converted Kaede to label specifically the ADt neuron axons. We found that ADt axons normally project ventrally. Knock down of Dcc function by injecting antisense morpholino oligonucleotides caused the ADt neurons to project axons dorsally. To examine the axon projection pattern of individual ADt neurons, we labeled single ADt neurons using a forebrain-specific promoter to drive fluorescent protein expression. We found that individual ADt neurons projected axons dorsally or formed multiple processes after morpholino knock down of Dcc function. We further found that knock down of the Dcc ligand, Netrin1, also caused ADt neurons to project axons dorsally. Knockdown of Neogenin1, a guidance receptor closely related to Dcc, enhanced the formation of aberrant dorsal axons in embryos injected with Dcc morpholino. These experiments provide the first evidence that Dcc regulates polarized axon initiation and asymmetric outgrowth of forebrain neurons in vertebrates.

  18. The origin and function of mirror neurons: the missing link.

    Science.gov (United States)

    Lingnau, Angelika; Caramazza, Alfonso

    2014-04-01

    We argue, by analogy to the neural organization of the object recognition system, that demonstration of modulation of mirror neurons by associative learning does not imply absence of genetic adaptation. Innate connectivity defines the types of processes mirror neurons can participate in while allowing for extensive local plasticity. However, the proper function of these neurons remains to be worked out.

  19. The role of mirror neurons in language acquisition and evolution.

    Science.gov (United States)

    Behme, Christina

    2014-04-01

    I argue that Cook et al.'s attack of the genetic hypothesis of mirror neurons misses its target because the authors miss the point that genetics may specify how neurons may learn, not what they learn. Paying more attention to recent work linking mirror neurons to language acquisition and evolution would strengthen Cook et al.'s arguments against a rigid genetic hypothesis.

  20. Reliable activation of immature neurons in the adult hippocampus.

    Directory of Open Access Journals (Sweden)

    Lucas A Mongiat

    Full Text Available Neurons born in the adult dentate gyrus develop, mature, and connect over a long interval that can last from six to eight weeks. It has been proposed that, during this period, developing neurons play a relevant role in hippocampal signal processing owing to their distinctive electrical properties. However, it has remained unknown whether immature neurons can be recruited into a network before synaptic and functional maturity have been achieved. To address this question, we used retroviral expression of green fluorescent protein to identify developing granule cells of the adult mouse hippocampus and investigate the balance of afferent excitation, intrinsic excitability, and firing behavior by patch clamp recordings in acute slices. We found that glutamatergic inputs onto young neurons are significantly weaker than those of mature cells, yet stimulation of cortical excitatory axons elicits a similar spiking probability in neurons at either developmental stage. Young neurons are highly efficient in transducing ionic currents into membrane depolarization due to their high input resistance, which decreases substantially in mature neurons as the inward rectifier potassium (Kir conductance increases. Pharmacological blockade of Kir channels in mature neurons mimics the high excitability characteristic of young neurons. Conversely, Kir overexpression induces mature-like firing properties in young neurons. Therefore, the differences in excitatory drive of young and mature neurons are compensated by changes in membrane excitability that render an equalized firing activity. These observations demonstrate that the adult hippocampus continuously generates a population of highly excitable young neurons capable of information processing.