Brain connectivity
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Randomized Controlled Trial
Effects of L-dopa and oxazepam on resting-state functional magnetic resonance imaging connectivity: a randomized, cross-sectional placebo study.
Pharmacological functional brain imaging has traditionally focused on neuropharmacological modulations of event-related responses. The current study is a randomized, cross-sectional resting-state functional magnetic resonance imaging study where a single dose of commonly prescribed amounts of either benzodiazepine (oxazepam), L-dopa, or placebo was given to 81 healthy subjects. It was hypothesized that the connectivity in resting-state networks would be altered, and that the strength of connectivity in areas rich in target receptors would be particularly affected. ⋯ L-dopa mainly decreased connectivity between the Am and bilateral inferior frontal gyri and between midline regions of the DMN. The fALFF analysis revealed that L-dopa decreased low-frequency fluctuations in the cerebellum. It was concluded that the overall effects of single administrations of oxazepam and L-dopa on resting-state connectivity were small both in strength and in spatial extent, and were on par with placebo effects as revealed by comparing the two placebo groups.