View clinical trials related to Dopamine.
Filter by:Developing theoretical, quantitative models of the basic cognitive mechanisms underlying human social decision-making, and understanding the influence of neuromodulators such as dopamine on these mechanisms, has important ramifications for both healthy and patient populations. In this proposal the investigators combine quantitative social measures, computational models, neuroimaging, and a pharmacological intervention to define the mechanisms of social decision-making.
The dopamine agonist pramipexole has recently been suggested as a potential novel antidepressant drug. While preliminary clinical data hint at its efficacy in treating depressive symptoms, our current understanding of its impact on neurocognitive processes is relatively limited. This is in part because mechanistic studies have largely focused on the effects of single-dose treatments. However, such acute administration of dopaminergic drugs likely has different cognitive effects than the more prolonged administration that is used clinically. This study therefore aims to explore and characterise the neurocognitive effects of more prolonged pramipexole treatment. Forty healthy volunteers will be randomly allocated to 12 to 15 days of treatment with either pramipexole or placebo. Study participants as well as researchers will be blinded as to which treatment is used. Before and after treatment all participants will perform a set of psychological tasks and questionnaires evaluating reward-based learning, emotional information processing, motivational vigour and subjective experience. Furthermore, functional magnetic resonance imaging (fMRI) will be used to compare neural activity during emotion and reward processing between the two treatment groups. We hypothesises that pramipexole might enhance reward sensitivity, motivational vigour, and pleasure experience and could induce positive biases in emotional information processing.
This observational study will investigate whether differences in birth events and oxygen levels during the newborn period affects the brain activity of children during the middle childhood years.
Transcranial direct current stimulation (tDCS) is a technique that is emerging as a prospective therapy for neurologic, psychiatric and addictive disorders. Specifically, anodal tDCS applied over the dorsolateral prefrontal cortex (DLPFC) is associated with improvement of cognitive functions and mood. Despite an increased use in clinical settings, tDCS suffers from limitations, especially regarding the strength and the duration of therapeutic effects. Strategies to optimize the conditions for tDCS application suffer from the lack of knowledge about its neurophysiological impact. Moreover, tDCS is increasingly used in private settings through commercial apparatus and tutorials to make a "do-it-yourself" device delivering tDCS now available on the Internet. This private use worries neuroscientists and health authorities. Even if the general impression is that, in controlled conditions, tDCS is safe with only mild and transient adverse effects, whether and how tDCS could be used for enhancing cognition in healthy subjects are needed to investigate in more detail. The investigators believe that a better understanding of some neurobiological effects of tDCS is crucial to further tailor tDCS for experimental and therapeutic applications and to define recommendations for a private use. As the cortex is densely connected with basal ganglia areas, including dopaminergic areas, tDCS is probably not only capable to target cortical but also subcortical structures remote from the stimulation sites. Some studies suggest that cortical stimulation by other approaches, such as transcranial magnetic stimulation (rTMS) leads to an increased dopaminergic transmission. The involvement of dopaminergic systems in tDCS effects has been investigated only indirectly in pharmacological studies. Thus, the direct effect of the DLPFC stimulation by tDCS on dopaminergic transmission is still unknown. The aim of this project is to reveal the online impact of a single-session of tDCS applied bilaterally over the DLPFC in healthy subjects on the dopaminergic transmission measured by PET, combined with the [11C]raclopride bolus-plus-continuous-infusion method.