Methylphenidate boosts choices of mental labor over leisure depending on striatal dopamine synthesis capacity

Description: Unthresholded t-statistic maps of the linear relationship between dopamine synthesis capacity ([18F]DOPA influx constant per minute, Ki) and cognitive motivation and choice latency i) under placebo, ii) under methylphenidate minus placebo, iii) under sulpiride minus placebo, and iv) under methylphenidate minus sulpiride. Additionally, linear relationship between dopamine synthesis capacity and working memory performance on the color wheel task (placebo session, although drug was administered after the working memory task). PET scans of participants (N=46, ages 18-43, 23 women) were acquired on a Siemens PET/CT-scanner at the Department of Nuclear Medicine of the Radboudumc, using an [18F]DOPA radiotracer (185MBq; approximately 5mCi; bolus injection). Participants received 150mg carbidopa and 400mg entacapone 50 minutes before scanning, to minimize peripheral metabolism of [18F]DOPA by decarboxylase and COMT, respectively, thereby increasing signal to noise ratio in the brain. Cognitive motivation is calculated as the proportion of trials on which participants chose the redo option (redo a working memory task) over the no-redo option (rest option).

Related article: http://doi.org/10.1038/s41386-020-00834-1