[18F]MK‐9470 PET measurement of cannabinoid CB1 receptor availability in chronic cannabis users. (27th December 2013)

• Record Type: Journal Article
• Authors: Ceccarini, Jenny; Kuepper, Rebecca; Kemels, Dieter; van Os, Jim; Henquet, Cécile; Van Laere, Koen
• Is Part Of: Addiction biology. Volume 20:Number 2(2015:Mar.)
• Page Start: 357
• Page End: 367
• Publication Date: 2013-12-27
• Subjects: Substance abuse -- Periodicals; Substance abuse -- Physiological aspects -- Periodicals; Substance-Related Disorders -- periodicals; 616.86
• DOI: 10.1111/adb.12116
• Languages: English
• ISSNs: 1355-6215

Abstract

<abstract abstract-type="main"> <title>Abstract</title> <p>Δ<sup>9</sup>‐Tetrahydrocannabinol, the main psychoactive component of cannabis, exerts its central effects through activation of the cerebral type 1 cannabinoid (CB<sub>1</sub>) receptor. Pre‐clinical studies have provided evidence that chronic cannabis exposure is linked to decreased CB<sub>1</sub> receptor expression and this is thought to be a component underlying drug tolerance and dependence. In this study, we make first use of the selective high‐affinity positron emission tomography (PET) ligand [<sup>18</sup>F]MK‐9470 to obtain <italic>in vivo</italic> measurements of cerebral CB<sub>1</sub> receptor availability in 10 chronic cannabis users (age = 26.0 ± 4.1 years). Each patient underwent [<sup>18</sup>F]MK‐9470 PET within the first week following the last cannabis consumption. A population of 10 age‐matched healthy subjects (age = 23.0 ± 2.9 years) was used as control group. Parametric modified standardized uptake value images, reflecting CB<sub>1</sub> receptor availability, were calculated. Statistical parametric mapping and volume‐of‐interest (VOI) analyses of CB<sub>1</sub> receptor availability were performed. Compared with controls, cannabis users showed a global decrease in CB<sub>1</sub> receptor availability (−11.7 percent). VOI‐based analysis demonstrated that the CB<sub>1</sub> receptor decrease was significant in the temporal lobe (−12.7 percent), anterior (−12.6 percent) and posterior cingulate cortex (−13.5 percent) and nucleus accumbens (−11.2 percent). Voxel‐based analysis confirmed this decrease and regional pattern in CB<sub>1</sub> receptor availability in cannabis users. These findings revealed that chronic cannabis use may alter specific regional CB<sub>1</sub> receptor expression through neuroadaptive changes in CB<sub>1</sub> receptor availability, opening the way for the examination of specific CB<sub>1</sub>‐cannabis addiction interactions which may predict future cannabis‐related treatment outcome.</p> </abstract>