Spike-Timing Dependent Plasticity Beyond Synapse – Pre- and Post-Synaptic Plasticity of Intrinsic Neuronal Excitability

Long-lasting plasticity of synaptic transmission is classically thought to be the cellular substrate for information storage in the brain. Recent data indicate however that it is not the whole story and persistent changes in the intrinsic neuronal excitability have been shown to occur in parallel to the induction of long-term synaptic modifications. This form of plasticity depends on the regulation of voltage-gated ion channels. Here we review the experimental evidence for plasticity of neuronal excitability induced at pre- or postsynaptic sites when long-term plasticity of synaptic transmission is induced with Spike-Timing Dependent Plasticity (STDP) protocols. We describe the induction and expression mechanisms of the induced changes in excitability. Finally, the functional synergy between synaptic and non-synaptic plasticity and their spatial extent are discussed

El laberinto de la otredad. Sobre la propuesta de Pierre Bourdieu en torno a la cultura popular

El presente artículo hace una aproximación a la obra de Pierre Bourdieu, y se centraen aquellos trabajos que el autor destinó a la comprensión de la cultura popular.En esta tarea, resulta necesario recuperar sus nociones de cultura y sociedad, y larelación establecida entre ambas. Desde su teoría de los campos, se indaga sobreel modo de estructuración, de reproducción y de diferenciación en las sociedades.Finalmente, desde y contra su propuesta de cultura popular, se pretende avanzarhacia una concepción diferente, que reconozca las potencialidades de las clasessubalternas para romper con la dominación y subvertir, mediante la creación, el ordensimbólico de lo dado

Temporal Modulation of Spike-Timing-Dependent Plasticity

Spike-timing-dependent plasticity (STDP) has attracted considerable experimental and theoretical attention over the last decade. In the most basic formulation, STDP provides a fundamental unit – a spike pair – for quantifying the induction of long-term changes in synaptic strength. However, many factors, both pre- and postsynaptic, can affect synaptic transmission and integration, especially when multiple spikes are considered. Here we review the experimental evidence for multiple types of nonlinear temporal interactions in STDP, focusing on the contributions of individual spike pairs, overall spike rate, and precise spike timing for modification of cortical and hippocampal excitatory synapses. We discuss the underlying processes that determine the specific learning rules at different synapses, such as postsynaptic excitability and short-term depression. Finally, we describe the success of efforts toward building predictive, quantitative models of how complex and natural spike trains induce long-term synaptic modifications

How do electrical synapses regulate their strength?

International audienc

Effects of game location, quality of opposition, number of foreign players and anthropometric characteritics in elite handball games

The aims of this study were (1) to investigate the influence of game location, quality of opposition, age of players, and anthropometric characteristics of backcourt and pivot players as well as the number of foreign players in a team on goal difference between the teams in the French (LNH) and German (Bundesliga) national men’s professional leagues, and (2) to predict goal difference of match final scores in these two national leagues using a multiple regression model. Archival data were obtained from the open access official websites to collect a sample of 165 handball matches (LNH [N=89], and Bundesliga [N=76]) of the first part of the 2015/2016 regular season. The linear regression model predicted the winner in 79% of cases with a mean accuracy of four goals. The coefficients of determination found in both multiple regression models were r²=.67 and r²=.49 for the LNH and the Bundesliga, respectively. The models revealed a high contribution of the difference in the end-of-previous season goal-average per match ranking and a moderate contribution of the game location to goal difference. The models also highlighted differences in the way games were won in these leagues with a contribution of foreigners, anthropometric characteristics and age only in the Bundesliga

Modulation of spike-evoked synaptic transmission: The role of presynaptic calcium and potassium channels

AbstractAction potentials are usually considered as the smallest unit of neuronal information conveyed by presynaptic neurons to their postsynaptic target. Thus, neuronal signaling in brain circuits is all-or-none or digital. However, recent studies indicate that subthreshold analog variation in presynaptic membrane potential modulates spike-evoked transmission. The informational content of each presynaptic action potential is therefore greater than initially expected. This property constitutes a form of fast activity-dependent modulation of functional coupling. Therefore, it could have important consequences on information processing in neural networks in parallel with more classical forms of presynaptic short-term facilitation based on repetitive stimulation, modulation of presynaptic calcium or modifications of the release machinery. We discuss here how analog voltage shift in the presynaptic neuron may regulate spike-evoked release of neurotransmitter through the modulation of voltage-gated calcium and potassium channels in the axon and presynaptic terminal. This article is part of a Special Issue entitled: 13th European Symposium on Calcium

What are the mechanisms for analogue and digital signalling in the brain?

International audienceSynaptic transmission in the brain generally depends on action potentials. However, recent studies indicate that subthreshold variation in the presynaptic membrane potential also determines spike-evoked transmission. The informational content of each presynaptic action potential is therefore greater than initially expected. The contribution of this synaptic property, which is a fast (from 0.01 to 10 s) and state-dependent modulation of functional coupling, has been largely underestimated and could have important consequences for our understanding of information processing in neural networks. We discuss here how the membrane voltage of the presynaptic terminal might modulate neurotransmitter release by mechanisms that do not involve a change in presynaptic Ca2+ influx

Long-Term Plasticity of Intrinsic Excitability: Learning Rules and Mechanisms 456 Learning & Memory

International audienceSpatio-temporal configurations of distributed activity in the brain is thought to contribute to the coding of neuronal information and synaptic contacts between nerve cells could play a central role in the formation of privileged pathways of activity. Synaptic plasticity is not the exclusive mode of regulation of information processing in the brain, and persistent regulations of ionic conductances in some specialized neuronal areas such as the dendrites, the cell body, and the axon could also modulate, in the long-term, the propagation of neuronal information. Persistent changes in intrinsic excitability have been reported in several brain areas in which activity is elevated during a classical conditioning. The role of synaptic activity seems to be a determinant in the induction, but the learning rules and the underlying mechanisms remain to be defined. We discuss here the role of synaptic activity in the induction of intrinsic plasticity in cortical, hippocampal, and cerebellar neurons. Activation of glutamate receptors initiates a long-term modification in neuronal excitability that may represent a parallel, synergistic substrate for learning and memory. Similar to synaptic plasticity, long-lasting intrinsic plasticity appears to be bidirectional and to express a certain level of input or cell specificity. These nonsynaptic forms of plasticity affect the signal propagation in the axon, the dendrites, and the soma. They not only share common learning rules and induction pathways with the better-known synaptic plasticity such as NMDA receptor dependent LTP and LTD, but also contribute in synergy with these synaptic changes to the formation of a coherent engram

Prise de décisions de cadres confrontés à un environnement dynamique, coopératif et compétitif. Une approche en ergonomie cognitive (application à l'entraînement professionnel de handball de match)

Ce travail, adossé au paradigme de la prise de décision en situation (Klein, Orasanu, Calderwood, & Zsambok, 1993) porte sur le processus de prise de décisions d entraîneurs de handball au cours du match. La situation de match, caractérisée par ses aspects dynamiques, coopératifs et compétitifs, donne une conception chaotique de ce processus (Bowes & Jones, 2006). C est pourquoi, son étude nécessite de mobiliser plusieurs approches et modèles théoriques (e.g., cognition collective, théorie du focus régulateur [Higgins, 1997], théorie du contrôle [Carver & Scheier, 1982], modèles de persuasion [Chaiken, 1980 ; Petty & Cacioppo, 1986], communication dialogique [Goffman, 1961], modèle de l activité coopérative [Hoc, 2001]). Les données, issues de situations réelles de matchs (protocoles verbaux, choix de système défensif) ou d entretiens (e.g., auto-confrontations avec technique de rappel stimulé) font l objet d analyses quantitatives ou qualitatives. Les résultats révèlent les connaissances procédurales des entraîneurs concernant : la gestion de l équipe, les informations permettant aux joueurs d acquérir ou de mettre à jour des structures de connaissances adaptées à la situation, et les tentatives d influence des arbitres. Ces connaissances procédurales sont fonction des conditions du match (notamment le rapport d opposition entre les deux équipes) et influencées par des connaissances sur le jeu et les caractéristiques des joueurs. Différents modes de contrôle cognitif et styles de coaching sont aussi mis en évidence. Ainsi, le processus de prise de décisions d entraîneurs experts possède des régularités et suit des règles génériques, des heuristiques ou patterns.This work, based on naturalistic decision-making paradigm (Klein, Orasanu, Calderwood, & Zsambok, 1993) is focused on team sport (handball) coaches decision-making during match. The coaching activity is dynamic and chaotic (Bowes & Jones, 2006) and generated by on-going events, especially during match. Therefore, coaches decision-making studies require to use many theoretical approaches and models (e.g., team cognition, regulatory focus theory [Higgins, 1997], control theory [Carver & Scheier, 1982], persuasive models [Chaiken, 1980 ; Petty & Cacioppo, 1986], dialogic communication [Goffman, 1961], cooperative activity model [Hoc, 2001]). Data have been collected from official games (verbal protocols, defense system choices) or interviews (self-confrontation with stimulated technique recall) and analysed with quantitative and qualitative approach. Results highlight procedural knowledge concerning team management, information allowing players to acquire or update knowledge structures, and influence referee. This procedural knowledge varied depending on the game conditions and is influenced by the coach s deep knowledge of the game and player profiles. Results highlight also different cognitive control modes, and different coaching styles. There exist contextual factors effects on procedural knowledge and cognitive control modes. Among these factors, ratio of strength between the two teams appears especially salient. Therefore, our empirical studies show that expert coaches decision-making process have some regularity and follow generic rules, heuristics or patternsPARIS11-SCD-Bib. électronique (914719901) / SudocSudocFranceF

Nacer para comenzar. Acción y libertad en Hannah Arendt

El objetivo de este artículo es analizar el concepto de acción en la propuesta de Hannah Arendt, vinculándolo a sus desarrollos sobre política y revolución. Para ello se estudió el conjunto de producciones en el que la autora aborda estas temáticas. La intención de este trabajo es establecer un recorrido por la obra de Arendt a partir del cual derive una compresión del sentido necesario de la libertad en la acción de los hombres para la realización de la condición humana. En este marco, el análisis de nociones-pares como acción y discurso, público y privado, silencio y violencia, perdón y promesa, abren la posibilidad a pensar procesos culturales donde comunicación y política se encuentren y pongan al servicio de procesos emancipadores de transformación social.Fil: Debanne, Luciano. Universidad Nacional de Córdoba. Centro de Estudios Avanzados; ArgentinaFil: Meirovich, Valeria. Universidad Nacional de Córdoba. Centro de Estudios Avanzados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin