Mechanisms underlying activation of neural stem cells in the adult central nervous system

À la fin du 19e siècle, Dr. Ramón y Cajal, un pionnier scientifique, a découvert les éléments cellulaires individuels, appelés neurones, composant le système nerveux. Il a également remarqué la complexité de ce système et a mentionné l’impossibilité de ces nouveaux neurones à être intégrés dans le système nerveux adulte. Une de ses citations reconnues : “Dans les centres adultes, les chemins nerveux sont fixes, terminés, immuables. Tout doit mourir, rien ne peut être régénérer” est représentative du dogme de l’époque (Ramón y Cajal 1928). D’importantes études effectuées dans les années 1960-1970 suggèrent un point de vue différent. Il a été démontré que les nouveaux neurones peuvent être générés à l’âge adulte, mais cette découverte a créé un scepticisme omniprésent au sein de la communauté scientifique. Il a fallu 30 ans pour que le concept de neurogenèse adulte soit largement accepté. Cette découverte, en plus de nombreuses avancées techniques, a ouvert la porte à de nouvelles cibles thérapeutiques potentielles pour les maladies neurodégénératives. Les cellules souches neurales (CSNs) adultes résident principalement dans deux niches du cerveau : la zone sous-ventriculaire des ventricules latéraux et le gyrus dentelé de l’hippocampe. En condition physiologique, le niveau de neurogenèse est relativement élevé dans la zone sous-ventriculaire contrairement à l’hippocampe où certaines étapes sont limitantes. En revanche, la moelle épinière est plutôt définie comme un environnement en quiescence. Une des principales questions qui a été soulevée suite à ces découvertes est : comment peut-on activer les CSNs adultes afin d’augmenter les niveaux de neurogenèse ? Dans l’hippocampe, la capacité de l’environnement enrichi (incluant la stimulation cognitive, l’exercice et les interactions sociales) à promouvoir la neurogenèse hippocampale a déjà été démontrée. La plasticité de cette région est importante, car elle peut jouer un rôle clé dans la récupération de déficits au niveau de la mémoire et l’apprentissage. Dans la moelle épinière, des études effectuées in vitro ont démontré que les cellules épendymaires situées autour du canal central ont des capacités d’auto-renouvellement et de multipotence (neurones, astrocytes, oligodendrocytes). Il est intéressant de noter qu’in vivo, suite à une lésion de la moelle épinière, les cellules épendymaires sont activées, peuvent s’auto-renouveller, mais peuvent seulement ii donner naissance à des cellules de type gliale (astrocytes et oligodendrocytes). Cette nouvelle fonction post-lésion démontre que la plasticité est encore possible dans un environnement en quiescence et peut être exploité afin de développer des stratégies de réparation endogènes dans la moelle épinière. Les CSNs adultes jouent un rôle important dans le maintien des fonctions physiologiques du cerveau sain et dans la réparation neuronale suite à une lésion. Cependant, il y a peu de données sur les mécanismes qui permettent l'activation des CSNs en quiescence permettant de maintenir ces fonctions. L'objectif général est d'élucider les mécanismes sous-jacents à l'activation des CSNs dans le système nerveux central adulte. Pour répondre à cet objectif, nous avons mis en place deux approches complémentaires chez les souris adultes : 1) L'activation des CSNs hippocampales par l'environnement enrichi (EE) et 2) l'activation des CSNs de la moelle épinière par la neuroinflammation suite à une lésion. De plus, 3) afin d’obtenir plus d’information sur les mécanismes moléculaires de ces modèles, nous utiliserons des approches transcriptomiques afin d’ouvrir de nouvelles perspectives. Le premier projet consiste à établir de nouveaux mécanismes cellulaires et moléculaires à travers lesquels l’environnement enrichi module la plasticité du cerveau adulte. Nous avons tout d’abord évalué la contribution de chacune des composantes de l’environnement enrichi à la neurogenèse hippocampale (Chapitre II). L’exercice volontaire promeut la neurogenèse, tandis que le contexte social augmente l’activation neuronale. Par la suite, nous avons déterminé l’effet de ces composantes sur les performances comportementales et sur le transcriptome à l’aide d’un labyrinthe radial à huit bras afin d’évaluer la mémoire spatiale et un test de reconnaissante d’objets nouveaux ainsi qu’un RNA-Seq, respectivement (Chapitre III). Les coureurs ont démontré une mémoire spatiale de rappel à court-terme plus forte, tandis que les souris exposées aux interactions sociales ont eu une plus grande flexibilité cognitive à abandonner leurs anciens souvenirs. Étonnamment, l’analyse du RNA-Seq a permis d’identifier des différences claires dans l’expression des transcripts entre les coureurs de courte et longue distance, en plus des souris sociales (dans l’environnement complexe). iii Le second projet consiste à découvrir comment les cellules épendymaires acquièrent les propriétés des CSNs in vitro ou la multipotence suite aux lésions in vivo (Chapitre IV). Une analyse du RNA-Seq a révélé que le transforming growth factor-β1 (TGF-β1) agit comme un régulateur, en amont des changements significatifs suite à une lésion de la moelle épinière. Nous avons alors confirmé la présence de cette cytokine suite à la lésion et caractérisé son rôle sur la prolifération, différentiation, et survie des cellules initiatrices de neurosphères de la moelle épinière. Nos résultats suggèrent que TGF-β1 régule l’acquisition et l’expression des propriétés de cellules souches sur les cellules épendymaires provenant de la moelle épinière.

When theories become practice - a metaphorical analysis of adult-education school-leaders’ talk

Marketization has changed the education system. If we say that education is a market, this transforms the understanding of education and influences how people act. In this paper, adult-education school-leaders’ talk is analysed and seven metaphors for education are found: education as administration, market, matching, democracy, policy work, integration and learning. Exploring empirical metaphors provides a rich illustration of coinciding meanings. In line with studies on policy texts, economic metaphors are found to dominate. This should be understood not only as representing liberal ideology, as is often discussed in analyses of policy papers, but also as representing economic theory. In other words, contemporary adult education can be understood as driven by economic theories. The difference and relation between ideology and theory should be further examined since they have an impact on our society and on our everyday lives. (DIPF/Orig.)

Marketising Slovene adult education policies and practices using mechanisms of the Europeanisation of education

This article addresses the issue of marketisation in the field of adult education by reflecting on the Europeanisation of education currently taking place through the establishment of European adult education policies. The article argues that Europeanisation fosters marketisation of adult education and commodifies valuable knowledge and desirable forms of neoliberal subjectivity. An analysis of Slovene adult education policies from 2004-2015 reveals how a European economised vocabulary is being implemented in Slovene adult education policies and practices. The main argument of this article is that these practices are shaped through financial mechanisms that marketise the adult education field. This results in new relationships between governing bodies within the field, the unstable and decreasing role of public adult education institutions and the prevailing role of private providers of adult education, who offer training programmes to meet labour market needs. (DIPF/Orig.)

Editorial. Marketization and commodification of adult education

The editorial presents the articles of this issue on the topic of marketization and commodification of adult education of which some are conceptual and some empirical. (DIPF/Orig.)

The interaction of economic and pedagogical ideals in the context of workplace learning in Germany: a framework for empirical research – inspired by business ethics

As an effect of marketisation, the importance of workplace learning in Germany has increased. The article follows up on the long-standing discourse around the question of how economic and pedagogical ideals interact in this context. In order to develop a theoretical framework for empirical research, three major positions of the discipline of business ethics are introduced. Business ethics in more abstract ways deals with the very same question, namely how do ideas such as profit orientation interact with other norms and values? The new perspectives show that the discourse has been hitherto based on a specific understanding of economy. In order to derive an empirical answer to the research question, the question is re-formulated as follows: Which values are inherent in the decisions taken? Consequently, it suggests using the concept of ‘rationalities of justification’ for empirical research. The article shows how this concept can be applied by conducting a test run. (DIPF/Orig.)

Mind the gap! An exploration of the role of lifelong learning in promoting co-production and citizenship within social care for older people

Contemporary themes in public policy have emphasised co-productive approaches within both the access and provision of support services to older people. This paper provides a cross disciplinary exploration from its respective authors perspectives on social work and educational gerontology to examine the potential for lifelong learning and learning interventions from which co-production with those using social care services in later life might be better facilitated. Using an example from the UK, we specifically elicit how co-produced care can enhance the horizon of learning and learning research. The synthesis of ideas across these two disciplines could enrich understanding and provide essential levers for moving towards empowerment and emancipation by engaging with a more co-productive approach in social care for older people. (DIPF/Orig.)

Community School of São Miguel de Machede: A decade of Learning

the Community School of São Miguel de Machede exists since 1998. A model of Community Education has been developed in this decade of existence, which not being confined to the frequent profiles of the most common approaches in Adult Education, has been the result of a process of symbiosis between a practice that normally precedes the conceptualization and a thought which has always expressed the concern of interpreting and enrich that practice. Setting on a model of learning based on the PADéCA – Program of Helping the Development of the Capacity to Learn, proposed by Berbaum (1988), the Community School of São Miguel de Machede has been developing several activities centred on a fundamental concern: to create easy and qualified accesses, in this community (council of Evora), so that the respective members can learn to exercise their principal rights of citizenship, in the territory where they live and in a circumstance of equality of opportunities in relation to the remaining fellow countrymen. Being a project with a decade of life, it is now possible to speak of a history full of stories and learning experiences, which occurred as a result of a rich interaction between the initial thoughts and impulses of the theoretical approaches and a reality full of unexpectedness, mutability and humanity resulting from the complexity that a living community presents, with a history and a present, but not always with clear and positive idea about the respective future.

Propofol causes neuronal degeneration in neonatal mice and long-term neurocognitive consequences in adult mice

Purpose: To investigate the effect of propofol on brain development in neonatal mice and long-term neurocognitive impact in adult mice. Method: The offspring of female C57Bl/6 and male CD-1 mice were administered propofol at concentrations of 2.5 and 5.0 mg/kg (treatment group) or normal saline (control) on postnatal day 7. Thereafter, histological and immunohistochemical examinations were performed on the mice brain. Apoptotic assay, neuronal nuclei antigen immunohistochemistry (to assess neuron density), and behavioral and neurocognitive tests were conducted on the adult mice. Results: Propofol induced cellular degeneration and apoptosis in the brains of neonatal mice. It also modulated physiological parameters (pH, PO2, glucose and lactate), among which decreased blood glucose might be associated with cellular degeneration in the brain. Propofol also caused long-term neuronal deficits in adults, which showed impaired neurocognitive functions. Upon reaching adulthood, propofol-treated mice showed slow learning response and poor memory compared to controls. Conclusion: Propofol causes neurodegeneration in neonatal mice and has long-term neurocognitive consequences in adults, indicating that the use of propofol anesthetics in neonates requires careful consideration.

Part-time and fractional staff in the learning and skills sector

This Universities and College Union Launch Event presentation reported on the findings of Learning and Skills Research Network (LSRN) London and South East (LSE) Regional Research Project. The presentation reflected on research carried out during 2002-06 on the development and deployment of part-time staff in the Learning and Skills Sector. Although the lifelong learning sector is the largest UK education sector, little attention has as yet been paid to the role of LSC sector part-time staff. Worrying trends of an increasing casualisation of staffing have been reported. The role of part-timers as highly committed (philanthropic) but generally underpaid and exploited staff (ragged-trousered) emerged from the data collected by this investigation, which examined the role of part-timers in several colleges and adult education institutions in London and the South East. The metaphor of the 'ragged-trousered philanthropist' was consciously selected to investigate the interactivity between philantrophy, employment practices for PT staff, and education as social action, in addressing the need for good practice to achieve quality outcomes in learning and teaching. The results are to some extent transferable to other education and training sectors employing part-time staff, e.g. higher education institutions and work-based training organisations.

A trial of e-simulation of sudden patient deterioration (FIRST2ACT WEB) on student learning

BACKGROUND: High-fidelity simulation pedagogy is of increasing importance in health professional education; however, face-to-face simulation programs are resource intensive and impractical to implement across large numbers of students. OBJECTIVES: To investigate undergraduate nursing students' theoretical and applied learning in response to the e-simulation program-FIRST2ACT WEBTM, and explore predictors of virtual clinical performance. DESIGN AND SETTING: Multi-center trial of FIRST2ACT WEBTM accessible to students in five Australian universities and colleges, across 8 campuses. PARTICIPANTS: A population of 489 final-year nursing students in programs of study leading to license to practice. METHODS: Participants proceeded through three phases: (i) pre-simulation-briefing and assessment of clinical knowledge and experience; (ii) e-simulation-three interactive e-simulation clinical scenarios which included video recordings of patients with deteriorating conditions, interactive clinical tasks, pop up responses to tasks, and timed performance; and (iii) post-simulation feedback and evaluation. Descriptive statistics were followed by bivariate analysis to detect any associations, which were further tested using standard regression analysis. RESULTS: Of 409 students who commenced the program (83% response rate), 367 undergraduate nursing students completed the web-based program in its entirety, yielding a completion rate of 89.7%; 38.1% of students achieved passing clinical performance across three scenarios, and the proportion achieving passing clinical knowledge increased from 78.15% pre-simulation to 91.6% post-simulation. Knowledge was the main independent predictor of clinical performance in responding to a virtual deteriorating patient R(2)=0.090, F(7, 352)=4.962, p<0.001. DISCUSSION: The use of web-based technology allows simulation activities to be accessible to a large number of participants and completion rates indicate that 'Net Generation' nursing students were highly engaged with this mode of learning. CONCLUSION: The web-based e-simulation program FIRST2ACTTM effectively enhanced knowledge, virtual clinical performance, and self-assessed knowledge, skills, confidence, and competence in final-year nursing students.

A Comparison of the Effects of Classroom and Multi-User Virtual Environments on the Perceived Speaking Anxiety of Adult Post-Secondary English Language Learners

The population of English Language Learners (ELLs) globally has been increasing substantially every year. In the United States alone, adult ELLs are the fastest growing portion of learners in adult education programs (Yang, 2005). There is a significant need to improve the teaching of English to ELLs in the United States and other English-speaking dominant countries. However, for many ELLs, speaking, especially to Native English Speakers (NESs), causes considerable language anxiety, which in turn plays a vital role in hindering their language development and academic progress (Pichette, 2009; Woodrow, 2006). Task-based Language Teaching (TBLT), such as simulation activities, has long been viewed as an effective approach for second-language development. The current advances in technology and rapid emergence of Multi-User Virtual Environments (MUVEs) have provided an opportunity for educators to consider conducting simulations online for ELLs to practice speaking English to NESs. Yet to date, empirical research on the effects of MUVEs on ELLs’ language development and speaking is limited (Garcia-Ruiz, Edwards, & Aquino-Santos, 2007). This study used a true experimental treatment control group repeated measures design to compare the perceived speaking anxiety levels (as measured by an anxiety scale administered per simulation activity) of 11 ELLs (5 in the control group, 6 in the experimental group) when speaking to Native English Speakers (NESs) during 10 simulation activities. Simulations in the control group were done face-to-face, while those in the experimental group were done in the MUVE of Second Life. The results of the repeated measures ANOVA revealed after the Huynh-Feldt epsilon correction, demonstrated for both groups a significant decrease in anxiety levels over time from the first simulation to the tenth and final simulation. When comparing the two groups, the results revealed a statistically significant difference, with the experimental group demonstrating a greater anxiety reduction. These results suggests that language instructors should consider including face-to-face and MUVE simulations with ELLs paired with NESs as part of their language instruction. Future investigations should investigate the use of other multi-user virtual environments and/or measure other dimensions of the ELL/NES interactions.

When theories become practice—a metaphorical analysis of adult-education school-leaders’ talk

Marketization has changed the education system. If we say that education is a market, this transforms the understanding of education and influences how people act. In this paper, adult-education school-leaders’ talk is analysed and seven metaphors for education are found: education as administration, market, matching, democracy, policy work, integration and learning. Exploring empirical metaphors provides a rich illustration of coinciding meanings. In line with studies on policy texts, economic metaphors are found to dominate. This should be understood not only as representing liberal ideology, as is often discussed in analyses of policy papers, but also as representing economic theory. In other words, contemporary adult education can be understood as driven by economic theories. The difference and relation between ideology and theory should be further examined since they have an impact on our society and on our everyday lives.

‘‘Model age-based” and ‘‘copy when uncertain” biases in children’s social learning of a novel task

Theoretical models of social learning predict that individuals can benefit from using strategies that specify when and whom to copy. Here the interaction of two social learning strategies, model age-based biased copying and copy when uncertain, was investigated. Uncertainty was created via a systematic manipulation of demonstration efficacy (completeness) and efficiency (causal relevance of some actions). The participants, 4- to 6-year-old children (N = 140), viewed both an adult model and a child model, each of whom used a different tool on a novel task. They did so in a complete condition, a near-complete condition, a partial demonstration condition, or a no-demonstration condition. Half of the demonstrations in each condition incorporated causally irrelevant actions by the models. Social transmission was assessed by first responses but also through children’s continued fidelity, the hallmark of social traditions. Results revealed a bias to copy the child model both on first response and in continued interactions. Demonstration efficacy and efficiency did not affect choice of model at first response but did influence solution exploration across trials, with demonstrations containing causally irrelevant actions decreasing exploration of alternative methods. These results imply that uncertain environments can result in canalized social learning from specific classes of mode