Biophysical foundation and function of depolarizing afterpotentials in principal cells of the medial entorhinal cortex

Neurons in layer II of the rodent medial entorhinal cortex (MEC) encode spatial information. One particular type, grid cells, tends to fire at specific spatial locations that form hexagonal lattices covering the explored environment. Within these firing fields grid cells frequently show short high-frequency spike sequences. Such bursts have received little attention but may contribute substantially to encoding spatial information. On the other hand, in vitro recordings of MEC principal cells have revealed that action potentials are followed by prominent depolarizing afterpotentials (DAP). Their biophysical foundation and function, however, are poorly understood. The objective of this study is to understand the mechanism behind the DAP by creating a biophysical realistic model of a stellate cell and to draw a connection between DAPs and burst firing in vivo. The developed single-compartment model reproduced the main electrophysi- ological characteristics of stellate cells in the MEC layer II, that are a DAP, sag, tonic firing in response to positive step currents and resonance. Using virtual blocking experiments, it was found that for the generation of the DAP only a NaP , KDR and leak current were necessary whereby the NaP current also exhibited a resurgent component. This suggests that for the generation of the DAP a balance between several currents is needed. In addition, the persistent and resurgent sodium current might play an important role. We analyzed the relevance of DAPs in vivo using whole-cell recordings of grid cells from Domnisoru et al. (2013). We found that around 20% of the cells exhibited a DAP. However, the percentage of cells was much lower than estimates from in vitro recordings. We showed that this is partly due to the quality of the recording as selecting APs from presumably good parts of the recording improved the visibility of DAPs. To investigate the relationship between DAPs and burst firing all cells were classified into bursty and non-bursty based on the spike-time autocorrelation. All cells with a DAP were bursty except the cell with the smallest DAP. Moreover, taking the mean of the spike-triggered average of the membrane potential for all bursty and non-bursty cells respectively showed a clear DAP for bursty but not for non-bursty cells. In summary, we found that the DAP can be realized in a single-compartment model by a NaP , KDR and leak current and provided evidence for the relevance of DAPs for burst firing in vivo

Pratique d'une activité physique régulière après la période post-partum: principaux facteurs influents et implications pour la prise en charge physiothérapeutique : travail de Bachelor

Introduction : Par ses spécificités physiques, psychiques et sociales, la période suivant une naissance est considérée à risque pour le développement d’habitudes sédentaires chez la femme. L'objectif de cette revue de la littérature est d'identifier les croyances et les barrières déterminant un mode de vie actif ou non, ceci afin d'optimiser le message de promotion de l'activité physique auprès de cette population. Méthodes : Après avoir établi des équations de recherche et un ensemble de critères d’inclusion et d’exclusion, 3 articles ont été sélectionnés à partir de différentes bases de données. Ceux-ci ont été analysés selon la synthèse thématique qualitative tirée de la méthode de Thomas & Harden (2008). Résultats : Les 5 thèmes analytiques suivants ont été déterminés à partir de codes et de thèmes descriptifs : représentation de ce que devrait être une « bonne » mère/femme, perception de sa propre santé et rapport à l’activité physique, contraintes organisationnelles du nouveau mode de vie et place de l’activité physique, message de l’entourage et du corps médical en lien avec la pratique de l’activité physique et finalement, adéquation du type d’activité physique avec la situation. Discussion : Les pressions sociales jouent un rôle important dans l’intégration de l’activité physique dans le quotidien. Notamment, le temps consacré à sa pratique peut engendrer de la culpabilité. Un grand nombre de facteurs exterieurs tiennent aussi une place importante. Le soignant doit trouver des stratégies et adapter son discours, par exemple lors d’entretiens motivationels. Cependant, l’information venant du corps médical n’est que peu mentionnée dans les 3 articles sélectionnés. Les soignants devraient saisir l’opportunité de mettre l’accent sur la prévention durant cette période de la vie synonyme de renouveau

The impact of digitalization in the public sector: A systematic literature review

The digitalization of public administration is increasingly moving forward. This systematic literature review analyzes empirical studies that explore the impacts of digitalization projects (n=93) in the public sector. Bibliometrically, only a few authors have published several times on this topic so far. Most studies focusing on impact come from the US or China, and are related to Computer Science. In terms of content, the majority of examined articles studies services to citizens, and therefore consider them when measuring impact. A classification of the investigated effects by dimensions of public value shows that the analysis of utilitarian-instrumental values, such as efficiency or performance, is prevalent. More interdisciplinary cooperation is needed to research the impact of digitalization in the public sector. The different dimensions of impact should be linked more closely. In addition, research should focus more on the effects of digitalization within administration.Die Digitalisierung der öffentlichen Verwaltung schreitet zunehmend voran. Dieser systematische Literaturüberblick analysiert empirische Studien, die sich auf Auswirkungen von Digitalisierungsprojekten konzentrieren (n=93). Dabei wird aus bibliometrischer Sicht deutlich, dass bisher nur wenige Autor:innen mehrfach zu diesem Thema publiziert haben. Die meisten Studien mit dem Schwerpunkt Wirkung stammen aus den USA oder China und sind disziplinär größtenteils der Informatik zuzuordnen. Inhaltlich fokussiert der Großteil der untersuchten Artikel auf Dienstleistungen für Bürger:innen und nimmt daher diese auch in der Wirkungsmessung in den Blick. Die Einordnung der untersuchten Auswirkungen in Dimensionen von public value zeigt, dass die meisten Studien sich auf die Analyse utilitaristisch-instrumenteller Werte konzentrieren, wie etwa Effizienz oder Performanz. Unsere Ergebnisse weisen darauf hin, dass eine stärkere interdisziplinäre Zusammenarbeit bei der Erforschung der Wirkungen von Digitalisierung im öffentlichen Sektor nötig ist. Hier sollten stärker auch unterschiedliche Wirkungsdimensionen miteinander verknüpft werden. Zudem sollte sich die Forschung intensiver mit Auswirkungen von Digitalisierung innerhalb der Verwaltung auseinandersetzen

Biophysical foundation and function of depolarizing afterpotentials in principal cells of the medial entorhinal cortex

Neurons in layer II of the rodent medial entorhinal cortex (MEC) encode spatial information. One particular type, grid cells, tends to fire at specific spatial locations that form hexagonal lattices covering the explored environment. Within these firing fields grid cells frequently show short high-frequency spike sequences. Such bursts have received little attention but may contribute substantially to encoding spatial information. On the other hand, in vitro recordings of MEC principal cells have revealed that action potentials are followed by prominent depolarizing afterpotentials (DAP). Their biophysical foundation and function, however, are poorly understood. The objective of this study is to understand the mechanism behind the DAP by creating a biophysical realistic model of a stellate cell and to draw a connection between DAPs and burst firing in vivo. The developed single-compartment model reproduced the main electrophysi- ological characteristics of stellate cells in the MEC layer II, that are a DAP, sag, tonic firing in response to positive step currents and resonance. Using virtual blocking experiments, it was found that for the generation of the DAP only a NaP , KDR and leak current were necessary whereby the NaP current also exhibited a resurgent component. This suggests that for the generation of the DAP a balance between several currents is needed. In addition, the persistent and resurgent sodium current might play an important role. We analyzed the relevance of DAPs in vivo using whole-cell recordings of grid cells from Domnisoru et al. (2013). We found that around 20% of the cells exhibited a DAP. However, the percentage of cells was much lower than estimates from in vitro recordings. We showed that this is partly due to the quality of the recording as selecting APs from presumably good parts of the recording improved the visibility of DAPs. To investigate the relationship between DAPs and burst firing all cells were classified into bursty and non-bursty based on the spike-time autocorrelation. All cells with a DAP were bursty except the cell with the smallest DAP. Moreover, taking the mean of the spike-triggered average of the membrane potential for all bursty and non-bursty cells respectively showed a clear DAP for bursty but not for non-bursty cells. In summary, we found that the DAP can be realized in a single-compartment model by a NaP , KDR and leak current and provided evidence for the relevance of DAPs for burst firing in vivo

Dante intermédial : une introduction

Expressions like ‘intermedial Dante’, ‘Dante and intermediality’ or ‘Dante’s reception across media’ open up a field so immensely vast that one cannot even begin to describe it within the limits of a journal article. The notes that follow attempt to provide a point of departure for those who are just approaching the study of Dante’s intermedial reception.Expressions like ‘intermedial Dante’, ‘Dante and intermediality’ or ‘Dante’s reception across media’ open up a field so immensely vast that one cannot even begin to describe it within the limits of a journal article. The notes that follow attempt to provide a point of departure for those who are just approaching the study of Dante’s intermedial reception