Facilitatory actions of guanidine on synaptic transmission in mammalian brain slices

Guanidine administration may be beneficial in the treatment of amyotrophic lateral sclerosis and related diseases; however, the actions of guanidine on the mammalian central nervous system have not been investigated. We studied the effects of this compound on neuronal properties and synaptic transmission in isolated slices of guinea pig olfactory cortex using intra- and extracellular recording mothods. Addition of guanidine to the superfusate (≥300 μ ) produced the following effects. (a) Excitatory and inhibitory postsynaptic potentials, evoked by stimulation of the lateral olfactory tract, were increased in amplitude and duration; (b) the amplitude and frequency of spontaneously occurring postsynaptic potentials was significantly increased; (c) membrane potential and input resistance remained virtually unchanged; and (d) the duration of the lateral olfactory tract compound action potential was prolonged. These results suggest that guanidine enhances the release of excitatory and inhibitory neurotransmitters in the mammalian cortex and this effect may be beneficial in human central nervous system diseases in which the efficiency of synaptic transmission is reduced

Convulsant actions of 4-aminopyridine on the guinea-pig olfactory cortex slice

The effects of bath-applied 4-aminopyridine on neurones and extracellular potassium and calcium concentrations were recorded in slices of guinea-pig olfactory cortex. Neurones were orthodromically activated by stimulating the lateral olfactory tract. 4-Aminopyridine (3–10 μM) had the following effects: (1) an increase in the frequency and amplitude of spontaneous postsynaptic potentials: (2) a prolongation and oscillatory behaviour or orthodromically evoked postsynaptic potentials; (3) induction of spontaneous or stimulus-evoked seizure-type discharges which were accompanied by large rises in extracellular potassium and falls in calcium concentration; (4) a prolongation of the lateral olfactory tract population fibre spike. Prior to paroxysmal depolarization, membrane potential, input resistance and soma spike duration were unaffected. In the seconds before seizure discharges, a late hyperpolarizing potential (evoked by orthodromic stimulation) was reduced in amplitude or abolished. Diphenylhydantoin (50 μM) or magnesium ions (5 mM) prevented paroxysmal activity. Our results whow that 4-aminopyridine can produce seizure-type discharges in a brain slice preparation. The role of increased spontaneous potentials and possible loss of synaptic inhibition as causal factors for such discharges is discussed

A transient outward current in a mammalian central neurone blocked by 4-aminopyridine

It is becoming increasingly clear that nerve cells in the mammalian central nervous system (CNS) have a very complex electroresponsiveness. They exhibit not only time- and voltage-dependent Na+ and K+ conductances, analogous to those in the squid giant axon1, but also a variety of other conductances that have a significant role in the control of cell excitability. Of the outward currents, there are, in addition to the delayed rectifier, the Ca2+-activated K+ current2,3 which underlies the long-lasting spike afterhyperpolarization, and the M current4, a non-inactivating K+ current evoked by membrane depolarization and blocked by muscarinic, cholinergic agonists. We demonstrate here the existence in a mammalian central neurone (hip-pocampal CA3 pyramidal cells) of yet another outward current, which is transient and may be carried by K+ ions. Further, the experiments show that this current is substantially reduced by the convulsant 4-aminopyridine (4-AP)5, resulting in a marked increase in cell excitability

Trabajando hacia una integración educativa total: La discapacidad auditiva.

El presente Trabajo de Fin de Grado consiste en un proyecto de innovación para mejorar la integración del alumnado con discapacidad auditiva en la comunidad educativa. Nuestro proyecto consiste por un lado en profundizar y mostrar todos los aspectos que engloba la discapacidad auditiva, para posteriormente centrarnos en cómo actuar utilizando diferentes estrategias y metodologías, que resulten exitosas con todo el alumnado. Si hablamos de discapacidad auditiva, hacemos referencia a una pérdida de capacidad sensorial en la que el individuo necesita de ayuda o apoyo constante para la comunicación en su día a día. Por tanto, la discapacidad auditiva es un trastorno que no debe confundirse con la simple pérdida de audición, que es frecuente en la población normal, aunque en la mayoría de los casos las personas siguen disfrutando de una vida normalizada. Así, investigamos y analizamos diferentes propuestas de actuación en el aula, para favorecer la inclusión del alumnado con discapacidad auditiva junto con el resto de sus compañeros.This final degree project consists of an innovation project to improve the integration of students with hearing disabilities in the educational community. Our project consists on the one hand in deepening and showing all aspects of hearing impairment, and then focusing on how to act using different strategies and methodologies that are successful with all students. Hearing impairment refers to a loss of sensory capacity in which the individual needs constant help or support for everyday communication. Therefore, hearing impairment is a disorder that should not be confused with simple hearing loss, which is common in the normal population, although in most cases people enjoy a normal life. In this way, we researched and analysed different options for action in the classroom, to assist the inclusion of hearing impaired students alongside their classmates

La neutralidad de red y las libertades comunicativas en el contexto de la pandemia, Lima Metropolitana, 2020

La presente investigación denominada “La neutralidad de red y las libertades comunicativas en el contexto de la pandemia, Lima Metropolitana, 2020“; tuvo como objetivo determinar si la neutralidad de red, regulada en la Resolución Nº 165-2016- CD/OSIPTEL, garantiza las libertades comunicativas en el contexto de la pandemia, Lima Metropolitana, 2020. La metodología empleada en esta investigación ha sido de enfoque cualitativo y tipo básico; establecido con un diseño de teoría fundamentada. Del mismo modo, se utilizaron como instrumentos de recolección de datos a la guía de entrevista y guía de análisis documental para asegurar un mayor sustento a la investigación. La conclusión a la que se llegó fue que, la neutralidad de red no garantiza las libertades comunicativas en una situación de emergencia nacional, debido a que el marco jurídico de las telecomunicaciones, específicamente el de neutralidad de red, establece una consideración desfavorable a las personas contratantes del servicio de internet como usuarios o clientes habituales y no como personas que ejercen sus derechos y obligaciones; por ello, no se refleja en la política regulatoria del OSIPTEL la protección jurídica de las libertades de expresión e información que son derechos constitucionalmente reconocidos

Cutaneous metastases of breast carcinoma: a case report

© 2009 Vano-Galvan et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

The germination of a world: for a volcanic cosmopolitics

La compañía (2017-2019) es una muestra del artista mexicano Daniel Lezama en donde se narra visualmente algunos mecanismos de explotación intensiva en relación con la reproducción biótica de las especies, a la vez que pone en tensión una visión náhuatl, diversos cuerpos-máquina y la permanencia actante de los volcanes Popocatépetl e Iztaccíhuatl. Dicho lo anterior, a través del análisis de algunos materiales de la muestra sostenemos dos hipótesis. La primera tiene que ver con pensar La compañía como un imaginario antiedípico que muestra cómo los mecanismos de la colonización capitalista operan a través de la captura de múltiples intensidades pulsionales que crean realidades-mundo. La segunda hipótesis despliega que el inconsciente está estructurado según mecánicas extractivistas, en donde La compañía esboza un imaginario de germen-mundo y posibilita otra imagen pensamiento sobre la naturaleza en relación con sus geografías y sus lenguajesLa compañía (2017-2019) is an exhibition by the Mexican artist Daniel Lezama where some mechanisms of intensive exploitation in relation to the biotic reproduction of species are visually narrated, while it mobilizes a náhuatl imaginary, various body-machines, and the actant permanence of the Popocatépetl and Iztaccíhuatl volcanoes. Through the analysis of some of these materials, our essay advances two main hypotheses. The first posits La compañía as an anti-Oedipal imaginary that shows how the mechanisms of capitalist colonization operate through the capture of instinctual intensities that create world realities. The second hypothesis postulates that the unconscious is structured according to extractivist mechanics, while La compañía outlines an imaginary of a germ-world, enabling another thought-image about nature in relation to its geographies and its languages.Fil: Hernandez Galvan, Francisco. Benemérita Universidad Autónoma de Puebla; México. Consejo Nacional de Ciencia y Tecnología; MéxicoFil: de Mauro Rucovsky, Martin Adrian de Mauro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Humanidades. Universidad Nacional de Córdoba. Instituto de Humanidades; Argentina. Universidad Autónoma del Estado de México; Méxic

Benthic diversity and assemblage structure of a north Patagonian rocky shore: a monitoring legacy of the NaGISA project

The rocky shore of Punta Este, Golfo Nuevo (Patagonia, Argentina), was sampled using the standardized NaGISA (CoML) protocol aimed to generate biodiversity baseline data in 6 levels, from high intertidal to 10m depth. Based on the generated data, we studied the benthic assemblage structure, species richness, mean abundance and the distribution pattern of invertebrate functional groups, typifying species in each intertidal and subtidal level. The rocky shore studied, as other in north Patagonia is understudied, factors driven its assemblage structure are not clear yet. The intertidal sampled is exposed to extreme physical conditions higher than any other studied rocky shore systems, with air temperature variation of 40°C during the year, maximum winds of 90 km/h and semidiurnal tides of 5m amplitude; on the other hand subtidal presents less thermal variation (DeltaT 10°C along the year) and more homogeneous physical conditions. We identified 65 taxa represented by six animal phyla: Mollusca, Arthropoda, Annelida (Polychaeta), Echinodermata, Cnidaria and Nemertea; and three algal phyla: Chlorophyta, Rhodophyta and Heterokontophyta (class: Phaeophyceae). Ordination nMDS plots showed three different assemblages in terms of species composition (intertidal, subtidal 1m level and subtidal 5-10m samples). The intertidal was represented by suspension feeders mainly Mollusca. The tiny mussels Brachidontes rodriguezii and Brachidontes purpuratus, and the algae Corallina officinalis dominated the intertidal and acts as a buffer that prevent other species for physical stress. The subtidal was mainly represented by grazers. Our results showed a tendency of suspension feeders decreasing and increasing of grazers and predators from high intertidal to subtidal, probably driven by decreasing in physical stress. The gastropod Tegula patagonica, the sea urchins Arbacia dufresnii and Pseudechinus magellanicus and the non native algae Undaria pinnatifida were the most abundant in 1m-10m level. Based on previous works performed in the region, we hypothesize that the differences registered between intertidal and subtidal samples could be explained in part by an increase in physical stress in the intertidal with low predation pressure that promotes positive interactions, while in the subtidal the increasing in consumers and decreasing of physical stress could lead to associational defenses. Competition for primary substrate at the intertidal and subtidal must be explored in future experiments. Our results could be useful to compare data and to develop a sustainable network for long-term monitoring benthic community changes due to anthropogenic activities.Fil: Rechimont, Maria Emilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Galvan, David Edgardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Sueiro, Maria Cruz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Casas, Graciela Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Piriz, Maria Luz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Diez, María Emilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Primost, Monica Angelina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Zabala, Maria Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Marquez, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Brogger, Martin Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales; ArgentinaFil: Fernandez Alfaya, Jose Elias. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Bigatti, Gregorio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentin

Young children's interpersonal trust consistency as a predictor of future school adjustment

Young children’s interpersonal trust consistency was examined as a predictor of future school adjustment. One hundred and ninety two (95 male and 97 female, M age = 6 years 2 months, SD age = 6 months) children from school years 1 and 2 in the United Kingdom were tested twice over one-year. Children completed measures of peer trust and school adjustment and teachers completed the Short-Form Teacher Rating Scale of School Adjustment. Longitudinal quadratic relationships emerged between consistency of children’s peer trust beliefs and peer-reported trustworthiness and school adjustment and these varied according to social group, facet of trust, and indictor of school adjustment. The findings support the conclusion that interpersonal trust consistency, especially for secret-keeping, predicts aspects of young children’s school adjustment