title: Methods of the pharmacological imaging of the cannabinoid system (PhICS) study: towards understanding the role of the brain endocannabinoid system in human cognition.
abstract: Various lines of (pre)clinical research indicate that cannabinoid agents carry the potential for therapeutic application to reduce symptoms in several psychiatric disorders. However, direct testing of the involvement of cannabinoid brain systems in psychiatric syndromes is essential for further development. In the Pharmacological Imaging of the Cannabinoid System (PhICS) study, the involvement of the endocannabinoid system in cognitive brain function is assessed by comparing acute effects of the cannabinoid agonist Δ9-tetrahydrocannabinol (THC) on brain function between healthy controls and groups of psychiatric patients showing cognitive dysfunction. This article describes the objectives and methods of the PhICS study and presents preliminary results of the administration procedure on subjective and neurophysiological parameters. Core elements in the methodology of PhICS are the administration method (THC is administered by inhalation using a vaporizing device) and a comprehensive use of pharmacological magnetic resonance imaging (phMRI) combining several types of MRI scans including functional MRI (fMRI), Arterial Spin Labeling (ASL) to measure brain perfusion, and resting-state fMRI. Additional methods like neuropsychological testing further specify the exact role of the endocannabinoid system in regulating cognition. Preliminary results presented in this paper indicate robust behavioral and subjective effects of THC. In addition, fMRI paradigms demonstrate activation of expected networks of brain regions in the cognitive domains of interest. The presented administration and assessment protocol provides a basis for further research on the involvement of the endocannabionoid systems in behavior and in psychopathology, which in turn may lead to development of therapeutic opportunities of cannabinoid ligands.
authors.affiliation: Department of Neurology and Neurosurgery, Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, The Netherlands. h.h.vanhell@umcutrecht.nl
authors.forename: Hendrika H
authors.initials: HH
authors.lastname: van Hell
authors.forename: Matthijs G
authors.initials: MG
authors.lastname: Bossong
authors.forename: Gerry
authors.initials: G
authors.lastname: Jager
authors.forename: René S
authors.initials: RS
authors.lastname: Kahn
authors.forename: Nick F
authors.initials: NF
authors.lastname: Ramsey
mesh_terms: D000704:Analysis of Variance; D001288:Attention / Q000187:drug effects; D001921:Brain / Q000098:blood supply* / Q000187:drug effects / Q000378:metabolism*; D001931:Brain Mapping; D063385:Cannabinoid Receptor Modulators / Q000378:metabolism*; D003071:Cognition / Q000187:drug effects / Q000502:physiology*; D004311:Double-Blind Method; D013759:Dronabinol / Q000097:blood / Q000627:therapeutic use; D004644:Emotions / Q000187:drug effects; D063388:Endocannabinoids; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007360:Intelligence; D008279:Magnetic Resonance Imaging / Q000379:methods; D001523:Mental Disorders / Q000097:blood / Q000188:drug therapy / Q000473:pathology / Q000503:physiopathology; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood; D010147:Pain Measurement; D010551:Personality / Q000187:drug effects; D011619:Psychotropic Drugs / Q000097:blood / Q000627:therapeutic use; D016032:Randomized Controlled Trials as Topic; D012201:Reward; D013113:Spin Labels; D013997:Time Factors
chemical_list: D063385:Cannabinoid Receptor Modulators; D063388:Endocannabinoids; D011619:Psychotropic Drugs; D013113:Spin Labels; D013759:Dronabinol; D010100:Oxygen