Although neural plasticity has traditionally been studied within the brain, evidence indicates that the spinal cord is quite plastic as well. Spinal neurons can even support a simple form of instrumental learning (Grau et al., 1998), as indicated by spinally transected rats’ ability to exhibit an increase in hind limb flexion duration when limb extension is associated with shock (controllable shock). If limb extension is not associated with shock (uncontrollable shock), a learning deficit develops. Recent research indicates that other forms of plasticity, such as long-term potentiation and central sensitization, do not depend on neural activity alone, but also on glial cells. I examined whether glial cells are also necessary in spinal instrumental learning and the learning deficit. Therefore, two glial inhibitors were selected: minocycline and fluorocitrate. To examine the role of glial cells in spinal instrumental learning, rats received intrathecal minocycline, fluorocitrate, or saline prior to testing with 30-minutes of controllable leg-shock. Results indicate that both drugs dose-dependently reduced acquisition, with higher doses resulting in shorter response durations. Once the response was acquired, fluorocitrate did not alter response maintenance. This suggests that glial cells are involved in the acquisition, but not the maintenance, of spinal learning. To examine the role of glial cells in the spinal learning deficit rats were given intrathecal minocycline, fluorocitrate, or saline prior to testing with 6-minutes of uncontrollable tail shock or no shock. Twenty-four hours later all rats were tested with 30-minutes of controllable leg-shock. Results indicated the learning deficit induced by uncontrollable shock was prevented by prior administration of fluorocitrate. Minocycline did not prevent the deficit; moreover, it appears that even in the absence of shock, minocycline caused a learning deficit. Overall, this data indicate that glial cells are necessary for the acquisition of spinal instrumental learning and the learning deficit. Furthermore, it provides further evidence for the role of glial cells in plasticity.

Previous work has shown that the spinal cord is capable of supporting a simple form of instrumental learning. Subjects that receive controllable shock to an extended hind limb will increase the duration of limb flexion over time in order to reduce net shock exposure. Exposure to as little as 6 minutes of uncontrollable stimulation prior to instrumental testing can elicit a long-lasting learning deficit. Prior work has suggested that this deficit may reflect an overexcitation of spinal neurons akin to central sensitization, and that learning is inhibited by the saturation of plasticity. The experiments in this dissertation were designed to test the role of the cytokine tumor necrosis factor alpha (TNFa) in the induction and expression of the deficit. It is believed that the inflammatory properties of TNFa may mediate the excitatory processes that lead to maladaptive spinal functioning. Experiments 1 and 2 tested the necessity of endogenous TNFa in the deficit produced by uncontrollable shock. These experiments showed that the inhibition of endogenous TNFa blocks both the induction and expression of the shock-induced deficit, suggesting a necessary role for TNFa in mediating the inhibition of spinal learning. Conversely, Experiment 3 was designed to test the sufficiency for TNFa in producing a learning deficit. I found that treatment with exogenous TNFa undermined spinal learning in a dose-dependent fashion, whether given immediately, or 24 hours prior to testing. Experiment 4 demonstrated that the long-term TNFa-induced deficit is mediated by TNFa receptor activity, as a TNF inhibitor given prior to testing blocked the expression of this deficit. As TNFa has been shown to be predominantly of glial origin, I next assessed the role that glia play in the TNFa-induced deficit. Experiment 5 showed that inhibiting glial metabolism prior to TNFa treatment blocked the capacity for TNFa to produce a long-term deficit. Experiment 6 assessed the potential for TNFa inhibition to block the deficit induced by lipopolysaccharide (LPS), an agent known to induce TNFa. TNFa has also been shown to drive neural excitation by increasing the trafficking of calciumpermeable AMPA receptors to the active zone of the post-synaptic bouton. Experiment 7 showed that selectively antagonizing these receptors prior to testing blocked the TNFa- induced deficit, suggesting a possible post-synaptic mechanism by which TNFa exerts its effects. Finally, histological evidence was sought to reinforce the previous behavioral findings. Experiment 8 used quantitative RT-PCR to assess the differential expression of TNFa mRNA in uncontrollably shocked subjects as compared to those receiving controllable shock and no shock. To determine concentrations of TNFa protein, an ELISA was run in Experiment 9 comparing uncontrollably shocked subjects to unshocked controls.

In this qualitative case study, self-directed learning theory was used as the lens to explore experiences of nine women entrepreneurs during the first four years of business ownership as they sought to acquire skills necessary to run their businesses. Data were collected over six months through in-person 90-minute interviews and follow-up questions posed by telephone and email. Qualitative data software was used for coding and thematic analysis, resulting in five broad conclusions related to learning, with additional unanticipated findings. Study participants engaged in a variety of self-directed learning activities, mostly through trial and error experimentation, and possessed varying motivations for learning. Educational level and reliance on past industry experience limited openness to new experiences and commitment to learning for some, particularly those with high school degrees or limited college experience. The majority of learning was pursued “just-in-time” as the need mandated when a challenge presented itself rather than in a pre-planned manner. Learning was heavily reliant on other people: most sought the advice of paid professionals, former co-workers, or friends and family. The use of a mentor for learning was identified by one participant, while three employed business coaches for professional guidance. Much of their learning was highly instrumental in nature, focused on here-and-now problem solving related to managing employees, handling legal issues in establishing the business, and learning to market themselves. While extremely self-confident in their abilities, most of the women struggled with issues of family and work-life balance, and several described guilt over neglecting one aspect of their lives for the other. Study conclusions emphasize the importance of knowing how to learn in the entrepreneurial context and suggest ways entrepreneurs can access knowledge and new experiences for learning, with implications for entrepreneurship programs, government agencies, and educators.

Prior work from our laboratory has shown that the spinal cord is capable of supporting a simple form of instrumental (response-outcome) learning. In a typical experiment, animals are given a spinal transection at the second thoracic vertebra, and tested 24 h after surgery. If animals are given shock when their leg is in a resting position (controllable shock), they quickly learn to maintain the leg in a flexed position, thereby minimizing shock exposure. Animals exposed to shock that is independent of leg position (uncontrollable shock) fail to learn. This learning deficit can be induced by as little as 6 minutes of shock to either limb or to the tail, and lasts for up to 48 h. The aim of this dissertation was to explore whether the deficit shares behavioral features and pharmacological mechanisms similar to those involved in the induction of neuropathic pain. Work within the pain literature has identified a spinal hyperexcitability that is induced by intense stimulation of pain fibers. This phenomenon, known as central sensitization, is characterized by an increase in tactile reactivity (allodynia) that can be induced by shock or peripheral inflammation. Pharmacological findings have revealed that central sensitization depends on the activation of the N-methyl-D-aspartate (NMDA) and group I metabotropic glutamate receptors (mGluRs). Experiment 1 showed that uncontrollable shock induces a tactile allodynia similar to that observed in central sensitization. Experiment 2 showed that peripheral inflammation caused by a subcutaneous injection of formalin generates a dose-dependent deficit. Experiment 3 indicated that the formalin-induced deficit was observed 24 h after delivery of the stimulus. Experiments 4-8 revealed that the NMDA and group I mGluRs are involved in the deficit. The NMDA receptor was found to be necessary (Experiment 4), but only sufficient to induce a deficit at neurotoxic doses (Experiment 5). Both of the group I mGluRs (subtypes, mGluR1 and mGluR5) were found to be necessary (Experiments 6 & 7). A general group I mGluR agonist summated with a subthreshold intensity of shock to produce a robust deficit (Experiment 8), suggesting shock and mGluR activation produce a deficit through a common mechanism.

Prior work from our laboratory has shown that the spinal cord is capable of supporting a simple form of instrumental (response-outcome) learning. In a typical experiment, animals are given a spinal transection at the second thoracic vertebra, and tested 24 h after surgery. If animals are given shock when their leg is in a resting position (controllable shock), they quickly learn to maintain the leg in a flexed position, thereby minimizing shock exposure. Animals exposed to shock that is independent of leg position (uncontrollable shock) fail to learn. This learning deficit can be induced by as little as 6 minutes of shock to either limb or to the tail, and lasts for up to 48 h. The aim of this dissertation was to explore whether the deficit shares behavioral features and pharmacological mechanisms similar to those involved in the induction of neuropathic pain. Work within the pain literature has identified a spinal hyperexcitability that is induced by intense stimulation of pain fibers. This phenomenon, known as central sensitization, is characterized by an increase in tactile reactivity (allodynia) that can be induced by shock or peripheral inflammation. Pharmacological findings have revealed that central sensitization depends on the activation of the N-methyl-D-aspartate (NMDA) and group I metabotropic glutamate receptors (mGluRs). Experiment 1 showed that uncontrollable shock induces a tactile allodynia similar to that observed in central sensitization. Experiment 2 showed that peripheral inflammation caused by a subcutaneous injection of formalin generates a dose-dependent deficit. Experiment 3 indicated that the formalin-induced deficit was observed 24 h after delivery of the stimulus. Experiments 4-8 revealed that the NMDA and group I mGluRs are involved in the deficit. The NMDA receptor was found to be necessary (Experiment 4), but only sufficient to induce a deficit at neurotoxic doses (Experiment 5). Both of the group I mGluRs (subtypes, mGluR1 and mGluR5) were found to be necessary (Experiments 6 & 7). A general group I mGluR agonist summated with a subthreshold intensity of shock to produce a robust deficit (Experiment 8), suggesting shock and mGluR activation produce a deficit through a common mechanism.

No description available.

No description available.

Made available in DSpace on 2016-06-02T19:39:49Z (GMT). No. of bitstreams: 1 6364.pdf: 2296877 bytes, checksum: 75407583e9c073a28f0009813d36ad60 (MD5) Previous issue date: 2014-02-28 / Financiadora de Estudos e Projetos / This paper presents a bibliographic review of scientific publications in the educational field which addresses teaching and learning processes of school subjects related to different theoretical perspectives of Psychology. This work derives from a broader research which investigated the presence of theoretical support of areas such as Sociology and Psychology in publications of three Brazilian scientific journals over the past three decades, they are, Educação & Sociedade, Revista Brasileira de Educação and Cadernos de Pesquisa. From the findings in the broader research which indicate that the presence of psychological science in these publications has decreased in the last decade, our work focuses on the relationship between the instrumental dimension of learning and psychology. Two assumptions pervade this work. The first regards the prospect that social changes in recent decades accelerate the processes of knowledge production and circulation, which also affect academic institutions. In this context, school knowledge gains a central focus in social processes, which is an important tool for people to have social protection and the conditions to strive for better living standards. The second assumption acknowledges that historically school education represents an important area of influence from psychology, addressing topics such as learning educational contents and student behavior, and the same relationship occurred between Brazil s Research in Education and Psychology. Educational Psychology generated many elements that provided the basis for teaching and learning theories, a contribution we believe may also be put into effect in the current context of society. Given these considerations, this research investigates the theoretical elements generated by Psychology for the discussions about the instrumental dimension of education, in the publications of Cadernos de Pesquisa from 1980 to 2012. The methodology included a bibliographical review of the publications on the study object followed by a Content Analysis of the 70 corresponding articles. The most common themes and the psychological theories were analyzed for each decade. The results showed that in the 1980s school failure was often discussed in the publications analyzed, reporting much concern with regards to the learning of school subjects by children of more disadvantaged classes, mainly based on the theory of Piaget and Social Psychology. In the 1990s, Piaget s theory was influential in the discussions about school learning, as was the comparison of this theoretical chain with postulates of the Historical-Cultural theory. The articles analyzed of the year 2000 exhibit discussions about skills and abilities, other knowledge elements that include education, in addition to classroom contents. In the last decade a decrease in the support to psychology-related discussions was also found. We discuss the progression of the presence of Psychology in the last three decades in the Cadernos de Pesquisa, together with possible theoretical implications when considering the assurance of instrumental learning for all students. / Este trabalho apresenta pesquisa bibliográfica realizada a partir de publicações científicas da área educacional que abordam processos de ensino e aprendizagem de conteúdos escolares, vinculados a diferentes correntes teóricas da Psicologia. O trabalho partiu de pesquisa maior que investigou a presença do suporte teórico de áreas como a Sociologia e a Psicologia em publicações de três revistas científicas do país, nas últimas três décadas, são elas, a Educação & Sociedade, Revista Brasileira de Educação e os Cadernos de Pesquisa. A partir de evidências encontradas na pesquisa maior de que a presença da ciência psicológica em tais publicações vem diminuindo na última década, o presente trabalho teve como foco a relação entre a dimensão instrumental da aprendizagem e a Psicologia. Dois pressupostos permeiam este trabalho. O primeiro diz respeito à consideração de que mudanças sociais nas últimas décadas aceleram processos de produção e circulação do conhecimento, afetando também a instituição escolar. Neste contexto, o conhecimento escolar ganha centralidade nos processos sociais, sendo um importante instrumento a ser adquirido para que as pessoas tenham proteção social e condições de lutar por melhores condições de vida. O segundo pressuposto concebe que historicamente a educação escolar se configura como importante área de influência da Psicologia, tratando temas como a aprendizagem de conteúdos escolares e comportamento de estudantes, e o mesmo vínculo se deu entre a Pesquisa em Educação no Brasil e a Psicologia. A Psicologia educacional trouxe diversos elementos que deram base para teorias de ensino e aprendizagem, contribuição que consideramos possível de se efetivar também no atual contexto da sociedade. A partir destas considerações, teve-se por objetivo na presente pesquisa investigar os elementos teóricos que a Psicologia trouxe para as discussões sobre a dimensão instrumental da educação, nas publicações dos Cadernos de Pesquisa, no período de 1980 a 2012. Como metodologia, foi realizado um levantamento bibliográfico das publicações referentes ao objeto de estudo e foi feita Análise de Conteúdo dos 70 artigos correspondentes. Para cada década foram analisados os temas mais frequentes, bem como as teorias psicológicas presentes. Como resultados, foi verificado que na década de 1980 o fracasso escolar foi frequentemente discutido nas publicações analisadas, com forte preocupação sobre a aprendizagem dos conteúdos escolares por parte das crianças de classes populares, principalmente com base na teoria de Piaget e na Psicologia Social. Na década de 1990, a teoria de Piaget se mostrou influente nas discussões sobre aprendizagem escolar, assim como a comparação desta corrente teórica com postulados da teoria Histórico-Cultural. Nos artigos analisados da década de 2000 são presentes discussões sobre as competências e habilidades, outros conhecimentos que envolvem a educação escolar, além dos conteúdos escolares. Na última década, também se verificou uma diminuição do suporte da Psicologia às discussões. Discutimos o movimento da presença da Psicologia nas últimas três décadas nos Cadernos de Pesquisa, aliado a possíveis implicações teóricas quando se pensa a garantia da aprendizagem instrumental para todos(as) os estudantes.

No description available.

L’objectif de cette thèse était de caractériser les relations entre tempérament et performances cognitives chez le cheval et leur modulation par le stress. Le tempérament était évalué selon cinq dimensions: la peur, la réactivité à l’Homme, la grégarité, la sensibilité tactile et l’activité locomotrice. Les relations entre ces dimensions et les performances lors de tâches instrumentales et de mémoire de travail ont été recherchées. La dimension de peur semble particulièrement essentielle et son influence dépend du stress : elle aurait un effet positif sur les performances cognitives en cas de stress intrinsèque, c’est-à-dire lorsque la tâche est elle-même source de stress, et un effet négatif en cas de stress extrinsèque. En l’absence de facteur de stress, ces relations sont plus contrastées. Dans une moindre mesure, des relations entre performances cognitives et les autres dimensions de tempérament ont été observées. L’activité locomotrice a une influence positive sur les performances qui ne ressort qu’en présence de facteurs de stress, qu’ils soient extrinsèques ou intrinsèques. Ce travail de thèse permet de contribuer à la caractérisation des liens entre tempérament et cognition, qui est un champ d’étude en pleine expansion, et met en évidence l’importance du stress dans la compréhension ces relations. / The aim of the current thesis was to characterize the relationships between temperament and cognitive performances in horses and their modulation when influenced by stress. The temperament was evaluated considering five dimensions: fearfulness, reactivity to humans, gregariousness, tactile sensitivity and locomotor activity. The relationships between these dimensions and performances during instrumental learning tasks as well as working memory tests have been investigated. The dimension of fearfulness seems particularly important and its influence depends on the presence or absence of stressor. Fearfulness has a positive effect on performances in case of intrinsic stress, i.e. the cognitive task is the source of stress; and a negative effect in case of extrinsic stress. Without any stressor, these relationships are more contrasted. To a lesser extent, relationships between cognitive performances and the other dimensions of temperament have been found. Especially, the dimension of locomotor activity has a positive effect on performances that stands out only in presence of stressors, whether they are intrinsic or extrinsic. This thesis contributes to the characterization of links between temperament and cognition, which is a field of study in a wide expansion, and shows the importance of stress in order to understand these relations.