This study will examine the relationship between variations in a gene called OPRM1 and the response to alcohol. The OPRM1 (Mu-opioid Receptor-1) gene helps regulate brain pathways involved in experiencing pleasure. Brain pathways use a chemical called dopamine. Different forms of the OPRM1 gene may lead to differences in how dopamine is released and subsequently to differences in a person's response to alcohol. Healthy non-smokers between 21 and 45 years of age may be eligible for this study. Candidates are screened with a medical and psychiatric history and physical examination, blood and urine tests, and breathalyzer (breath alcohol test). A blood test is also done to determine the variant of OPRM1 gene. Participants undergo the following procedures in three study sessions: Session 1 " Breathalyzer test, urine test for illicit drugs and pregnancy test for women who can become pregnant. " Insertion of catheters (plastic tubes) into a vein in one arm for infusing alcohol and into the other arm for drawing blood samples. " Completion of questionnaires on how intoxicated the subject feels. " Blood draw for research studies. " Eye movement test (a visor with a digital camera tracks the subject's eye movements while he or she watches lights on a computer screen). " 45-minute alcohol infusion (up to 0,08 grams per deciliter - a level considered in most states as driving under the influence of alcohol). " Repeat breathalyzer, questionnaires, eye movement test and blood draw every 15 minutes during the infusion and again after the infusion is complete. " Subjects remain in the clinic until their blood alcohol content falls below 0.02 g/dL, determined by a breathalyzer test done every 15 minutes. Subjects can usually return home about 3 to 4 hours after the alcohol infusion stops. Sessions 2 and 3 The procedure is the same as for session 1, except subjects receive an infusion of alcohol one session and an infusion of saline (salt water) the other. Also, subjects undergo positron emission tomography (PET) scanning during the infusions. For this test, the subject lies on a bed that slides in and out of a doughnut-shaped scanner. A custom-molded mask is used to support the head and prevent it from moving during the scanning. A small amount of radioactive substance called C-11 raclopride is injected through one of the catheters to trace brain dopamine activity. ...
There is one SNP
OPRM1 A118G SNP, Alcohol Response, and Striatal Dopamine. --- A118G ---
OPRM1 A118G SNP, Alcohol Response, and Striatal Dopamine This study will examine the relationship between variations in a gene called OPRM1 and the response to alcohol. --- A118G ---
A functional mu-opioid receptor (OPRM1) A118G single nucleotide polymorphism (SNP) alters the affinity of the mu-opioid receptor for its endogenous ligand, is in some studies associated with increased risk for alcohol and heroin addiction, and confers differential pain sensitivity and subjective responses to alcohol. --- A118G ---
This prompts the question whether the differential subjective response to alcohol observed as a function of the OPRM1 A118G genotype reflects differential activation of the mesolimbic DA release. --- A118G ---
The objective of this study is to examine the role of the A118G OPRM1 polymorphism for responses to a highly standardized intravenous alcohol challenge, with regard to psycho-physiological variables measured in the laboratory, and for brain dopamine release measured by 11C raclopride PET. --- A118G ---