Default mode network in the effects of Δ9-Tetrahydrocannabinol (THC) on human executive function.
Evidence is increasing for involvement of the endocannabinoid system in cognitive functions including attention and executive function, as well as in psychiatric disorders characterized by cognitive deficits, such as schizophrenia. Executive function appears to be associated with both modulation of active networks and inhibition of activity in the default mode network. In the present study, we examined the role of the endocannabinoid system in executive function, focusing on both the associated brain network and the default mode network. A pharmacological functional magnetic resonance imaging (fMRI) study was conducted with a placebo-controlled, cross-over design, investigating effects of the endocannabinoid agonist Δ9-tetrahydrocannabinol (THC) on executive function in 20 healthy volunteers, using a continuous performance task with identical pairs. Task performance was impaired after THC administration, reflected in both an increase in false alarms and a reduction in detected targets. This was associated with reduced deactivation in a set of brain regions linked to the default mode network, including posterior cingulate cortex and angular gyrus. Less deactivation was significantly correlated with lower performance after THC. Regions that were activated by the continuous performance task, notably bilateral prefrontal and parietal cortex, did not show effects of THC. These findings suggest an important role for the endocannabinoid system in both default mode modulation and executive function. This may be relevant for psychiatric disorders associated with executive function deficits, such as schizophrenia and ADHD.
Rudolf Magnus Institute of Neuroscience, Department of Neurology and Neurosurgery, University Medical Center Utrecht, Utrecht, The Netherlands. matthijs.bossong@kcl.ac.uk
Matthijs G
MG
Bossong
J Martijn
JM
Jansma
Hendrika H
HH
van Hell
Gerry
G
Jager
René S
RS
Kahn
Nick F
NF
Ramsey
D000293:Adolescent; D000328:Adult; D001921:Brain / Q000187:drug effects* / Q000502:physiology; D001931:Brain Mapping; D063386:Cannabinoid Receptor Agonists / Q000494:pharmacology; D018592:Cross-Over Studies; D004311:Double-Blind Method; D013759:Dronabinol / Q000494:pharmacology*; D056344:Executive Function / Q000187:drug effects* / Q000502:physiology; D006179:Gyrus Cinguli / Q000187:drug effects / Q000502:physiology; D064368:Healthy Volunteers; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D009415:Nerve Net / Q000187:drug effects* / Q000502:physiology; D011597:Psychomotor Performance / Q000187:drug effects / Q000502:physiology; D055815:Young Adult
D063386:Cannabinoid Receptor Agonists; D013759:Dronabinol