title: Positron emission tomography shows elevated cannabinoid CB1 receptor binding in men with alcohol dependence.
abstract: BACKGROUND
  Several lines of evidence link cannabinoid (CB) type 1 (CB (1) ) receptor-mediated endogenous CB (eCB) signaling to the etiology of alcohol dependence (AD). However, to date, only peripheral measures of eCB function have been collected in living humans with AD and no human in vivo data on the potentially critical role of the brain CB (1)  receptor in AD have been published. This is an important gap in the literature, because recent therapeutic developments suggest that these receptors could be targeted for the treatment for AD.
  
  
  METHODS
  Medication-free participants were scanned during early abstinence 4 weeks after their last drink. Using positron emission tomography (PET) with a high-resolution research tomograph and the CB (1)  receptor selective radiotracer [(11)  C]OMAR, we determined [(11)  C]OMAR volume of distribution ( V (T) ) values, a measure of CB (1)  receptor density, in a priori selected brain regions in men with AD (n = 8, age 37.4 ± 7.9 years; 5 smokers) and healthy control (HC) men (n = 8, age 32.5 ± 6.9 years; all nonsmokers). PET images reconstructed using the MOLAR algorithm with hardware motion correction were rigidly aligned to the subject-specific magnetic resonance (MR) image, which in turn was warped to an MR template. Time-activity curves (TACs) were extracted from the dynamic PET data using a priori selected regions of interest delineated in the MR template space.
  
  
  RESULTS
  In AD relative to HC, [(11)  C]OMAR V (T)  values were elevated by approximately 20% (p = 0.023) in a circuit, including the amygdala, hippocampus, putamen, insula, anterior and posterior cingulate cortices, and orbitofrontal cortex. Age, body mass index, or smoking status did not influence the outcome.
  
  
  CONCLUSIONS
  These findings agree with preclinical evidence and provide the first, albeit still preliminary in vivo evidence suggesting a role for brain CB (1)  receptors in AD. The current study design does not answer the important question of whether elevated CB (1)  receptors are a preexisting vulnerability factor for AD or whether elevations develop as a consequence of AD.
authors.affiliation: Molecular Imaging Program, Department of Psychiatry and Radiology, New York University School of Medicine, New York, New York 10016, USA. alexander.neumeister@nyumc.org
authors.forename: Alexander
authors.initials: A
authors.lastname: Neumeister
authors.forename: Marc D
authors.initials: MD
authors.lastname: Normandin
authors.forename: James W
authors.initials: JW
authors.lastname: Murrough
authors.forename: Shannan
authors.initials: S
authors.lastname: Henry
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Bailey
authors.forename: David A
authors.initials: DA
authors.lastname: Luckenbaugh
authors.forename: Keri
authors.initials: K
authors.lastname: Tuit
authors.forename: Ming-Qiang
authors.initials: MQ
authors.lastname: Zheng
authors.forename: Isaac R
authors.initials: IR
authors.lastname: Galatzer-Levy
authors.forename: Rajita
authors.initials: R
authors.lastname: Sinha
authors.forename: Richard E
authors.initials: RE
authors.lastname: Carson
authors.forename: Marc N
authors.initials: MN
authors.lastname: Potenza
authors.forename: Yiyun
authors.initials: Y
authors.lastname: Huang
mesh_terms: D000328:Adult; D000437:Alcoholism / Q000378:metabolism*; D000679:Amygdala / Q000378:metabolism; D001921:Brain / Q000378:metabolism*; D016022:Case-Control Studies; D002540:Cerebral Cortex / Q000378:metabolism; D005625:Frontal Lobe / Q000378:metabolism; D006179:Gyrus Cinguli / Q000378:metabolism; D006624:Hippocampus / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D059906:Neuroimaging; D049268:Positron-Emission Tomography; D011699:Putamen / Q000378:metabolism; D043884:Receptor, Cannabinoid, CB1 / Q000378:metabolism*; D055815:Young Adult
chemical_list: D043884:Receptor, Cannabinoid, CB1