View clinical trials related to Neuronal Plasticity.
Filter by:Background: Neuronal plasticity is the brain's ability to continuously adapt to experiences and learning of new skills. Although this affects multiple characteristics of the brain such as structure, function and metabolism, direct interactions between these aspects are largely missing. Aim: Using recent advancements in neuroimaging we aim to identify novel relationships how neuronal plasticity is related across these characteristics. Design: 40 healthy subjects will undergo two simultaneous PET/MR measurements at baseline and after 4 weeks. During the measurements a cognitively challenging task will be performed and the training group (20 subjects) will practice during the 4-week period. Implications: We combine simultaneous PET/MR and novel task-specific PET imaging to study brain metabolism, structure and function in a single measurement session. This provides optimal sensitivity for assessment of multimodal neuroplasticity associations. Knowledge how cognitive training affects multiple characteristics of the brain will also increase our understanding of disorders like depression, dementia and brain injuries, since these are diagnosed with cognitive evaluations. Considering the vast usage of the applied imaging procedures in diagnosis and therapy monitoring, the thorough investigation of multimodal associations offers benefit for the interpretability of neuroimaging in clinical routine.
Background: Conclusive evidence states that the serotonergic system mediates neuroplasticity from early embryonic development until brain maturation in adulthood. This study aims to demonstrate that selective serotonin reuptake inhibitors (SSRIs) enhance learning-dependent neuroplasticity in vivo, hereby contributing to the investigators understanding of the mechanism of action of therapy with SSRIs. Objectives: 1. To prove a positive influence of SSRIs on structural remodeling during learning, reflected by enhancements of gray and white matter microstructure, connectivity and functionality in brain regions involved in learning processes. 2. To show that this effect is topologically specific, i.e. that enhancements of plasticity markers are found in different regions depending on their involvement during the performance of specific learning tasks. Study design: Randomized, double-blind, placebo-controlled, longitudinal mono-center study. 80 healthy subjects will undergo three MRI scanning sessions: 1. baseline, at study entry, 2. after 3 weeks of facial/emotional (n=40) or Chinese character-meaning learning (n=40) and 3. after 3 weeks learning of new associations under administration of an SSRI or placebo. Methods: MRI measurements will be performed on a 3 Tesla PRISMA MAGNETOM MR scanner. Changes in gray matter microstructure will be assessed using high-resolution structural MRI and analyzed with voxel-based morphometry (VBM). Diffusion tensor imaging (DTI) enables non-invasive investigation of neuroplasticity in the human brain based on the reduction in mean diffusivity associated with swelling of astrocytes after increased synaptic activity. Resting-state functional MRI (fMRI) will allow for the measurement of changes in functional coupling between brain regions, and fMRI during tasks will assess differential activity in brain regions during learning. Relevance and implications: This study aims to provide evidence that SSRIs facilitate cytoarchitectonical restructuring. In addition to expanding the investigators current knowledge on the trophic effects of SSRIs, the results of this study will also elucidate interactions between the serotonergic system and changes to neuronal networks during learning as well as their behavioral consequences. By probing the neurobiological correlates of the antidepressant and anti-anxiety effects of SSRIs, this study will provide a rationale for targeted interventions that harness the neuroplasticity enhancing properties of SSRIs to facilitate therapeutic processes.