Roelof Peter Soeter1,2, Linda E. Klumpers3,
Naj Khalili-Mahani1,2, Mark A. van Buchem1,2, Serge
A.R.B. Rombouts1,2, Joop M.A. van Gerven, 3,4
1Department of Radiology, Leiden
University Medical Center (LUMC), Leiden, Netherlands; 2Leiden
Institute for Brain and Cognition (LIBC), Leiden, Netherlands; 3Centre
for Human Drug Research, Leiden, Netherlands; 4Department of Neurology,
Leiden University Medical Center (LUMC), Leiden, Netherlands
Resting
state FMRI is a promising technique for drug studies, because it allows a
repeated task-independent assessment of functional interactions between brain
regions (functional connectivity). Here we investigate the effects of THC,
the psychoactive compound of cannabis, on functional brain connectivity. Nine
healthy male volunteers participated in a randomised, double blind,
placebo-controlled trial in which 8 RS-FMRI scans were obtained in each
treatment occasion. THC administration decreased connectivity in different
brain regions, including cerebellum and several cortical regions. Functional
connectivity using RS-FMRI is a promising new technique to study
pharmacologically induced changes in brain activity.