831 resultados para eco-plasticity
Motor unit synchronization between the vasti muscles: Physiology, pathophysiology and and plasticity
Resumo:
O design de joias apresenta grandes possibilidades de inserção no mercado atual, devido à grande procura por parte do consumidor, de um acessório que seja revelador de um significado especial e que esteja em perfeita sintonia com as mais recentes tendências do mercado. O Designer de joias além das tendências, necessita conhecer em profundidade as distintas técnicas de produção, os diferentes materiais, para assim responder aos mais variados requisitos. Deve ainda revelar a sua marca pessoal, demonstrando assim a sua criatividade e o domínio dos processos exigidos para a produção de joias. A joia sendo um artefacto que utiliza como referência o corpo e que além disso, reflete o tempo em que foi concebido, é um objeto pessoal que carrega uma mensagem simbólica e emocional. Deste modo, tendo como ponto de partida a simbiose da Joalharia Tradicional Portuguesa e o Traje Popular, anterior ao séc. XX, foi nossa intenção desenvolver este estudo, visando a compreensão da simbologia e função destas duas áreas, bem como, compreender o seu papel perante a sociedade, no que diz respeito aos materiais e técnicas utilizados no período anterior ao Séc. XX comparativamente com o que se produz na nossa contemporaneidade. Ambiciona-se nesta dissertação, desenvolver um projeto ecológico na joalharia, guiado pelos princípios do eco design e pela tecnologia da prototipagem rápida. É nossa intenção demostrar que esta junção potencia a inserção de novas técnicas, como a prototipagem rápida na confeção de novos conceitos na joalharia, desta vez, idealizados para uma abordagem contemporânea
Resumo:
Layer 5 contains the major projection neurons of the neocortex and is composed of two major cell types: regular spiking (RS) cells, which have cortico-cortical projections, and intrinsic bursting cells (IB), which have subcortical projections. Little is known about the plasticity processes and specifically the molecular mechanisms by which these two cell classes develop and maintain their unique integrative properties. In this study, we find that RS and IB cells show fundementally different experience-dependent plasticity processes and integrate Hebbian and homeostatic components of plasticity differently. Both RS and IB cells showed TNFα-dependent homeostatic plasticity in response to sensory deprivation, but IB cells were capable of a much faster synaptic depression and homeostatic rebound than RS cells. Only IB cells showed input-specific potentiation that depended on CaMKII autophosphorylation. Our findings demonstrate that plasticity mechanisms are not uniform within the neocortex, even within a cortical layer, but are specialized within subcircuits.
Resumo:
Synaptic plasticity is the dynamic regulation of the strength of synaptic communication between nerve cells. It is central to neuronal development as well as experience-dependent remodeling of the adult nervous system as occurs during memory formation. Aberrant forms of synaptic plasticity also accompany a variety of neurological and psychiatric diseases, and unraveling the biological basis of synaptic plasticity has been a major goal in neurobiology research. The biochemical and structural mechanisms underlying different forms of synaptic plasticity are complex, involving multiple signaling cascades, reconfigurations of structural proteins and the trafficking of synaptic proteins. As such, proteomics should be a valuable tool in dissecting the molecular events underlying normal and disease-related forms of plasticity. In fact, progress in this area has been disappointingly slow. We discuss the particular challenges associated with proteomic interrogation of synaptic plasticity processes and outline ways in which we believe proteomics may advance the field over the next few years. We pay particular attention to technical advances being made in small sample proteomics and the advent of proteomic imaging in studying brain plasticity.
Resumo:
Development of the cerebral cortex is influenced by sensory experience during distinct phases of postnatal development known as critical periods. Disruption of experience during a critical period produces neurons that lack specificity for particular stimulus features, such as location in the somatosensory system. Synaptic plasticity is the agent by which sensory experience affects cortical development. Here, we describe, in mice, a developmental critical period that affects plasticity itself. Transient neonatal disruption of signaling via the C-terminal domain of "disrupted in schizophrenia 1" (DISC1)-a molecule implicated in psychiatric disorders-resulted in a lack of long-term potentiation (LTP) (persistent strengthening of synapses) and experience-dependent potentiation in adulthood. Long-term depression (LTD) (selective weakening of specific sets of synapses) and reversal of LTD were present, although impaired, in adolescence and absent in adulthood. These changes may form the basis for the cognitive deficits associated with mutations in DISC1 and the delayed onset of a range of psychiatric symptoms in late adolescence.