Abstract
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.
Highlights
The endocannabinoid system is a retrograde messenger system that regulates both excitatory and inhibitory neurotransmission, and consists of cannabinoid receptors and accompanying endogenous ligands [1]
Goal-oriented behavior has recently been associated with reduced neural activity in the default mode network (DMN), which mainly consists of the posterior cingulate cortex, medial prefrontal cortex, and bilateral inferior parietal lobules [9,10,11]
The role of the eCB system in executive function was studied in an functional magnetic resonance imaging (fMRI) study with a THC challenge, focusing on processing of continuously updated information and the role of DMN
Summary
The endocannabinoid (eCB) system is a retrograde messenger system that regulates both excitatory and inhibitory neurotransmission, and consists of cannabinoid receptors and accompanying endogenous ligands [1]. Failure to reduce DMN activity impairs performance on various cognitive tasks [12,13,14,15] Psychiatric patients such as patients with schizophrenia or attention-deficit hyperactivity disorder (ADHD), who exhibit a strong decline in cognitive function, display an inability to deactivate the DMN during performance of executive function paradigms [11,16,17,18,19,20,21,22,23]. This suggests a role for the DMN in cognitive function deficits
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
