Smoking-induced Dopamine Release: a [11C]-(+)-PHNO PET Study in Humans
This study will evaluate effects of smoking on the dopaminergic system by using PET tomography with new radioligand, [11C]-(+)-PHNO. Our primary hypothesis is that smoking a cigarette will produce dopamine release and this release can be measured using PET imaging and the [11C]-(+)-PHNO radiotracer. The secondary hypothesis is that this smoking induced dopamine release will be correlated with subjective craving and anxiety ratings.
Tobacco Use Disorder
|Study Design:||Time Perspective: Prospective|
|Official Title:||Does the Insula Control Smoking-induced Dopamine Release? A TMS/[11C]-PHNO Study in Humans. Part I: Smoking-induced Dopamine Release: a [11C]-(+)-PHNO PET Study in Humans.|
- [11C]-(+)-PHNO binding potential [ Time Frame: Up to 14 days between PET scans ] [ Designated as safety issue: No ]The process of imaging requires the injection of a positron-emitting radiotracer (here, [11C]-(+)-PHNO) that binds to the protein of interest (here, dopamine receptor DRD2/3) followed by the measurement of this binding using the PET scanner. Dopamine release increases DRD 2/3 occcupancy which results in decreased radiotracer's binding potential, and vice versa. [11C]-(+)-PHNO binding potential will be measured on two different conditions (Smoking vs. Non-smoking) on two separate days.
- Subjective reports of craving [ Time Frame: Up to 14 days between PET scans ] [ Designated as safety issue: No ]Levels of subjective craving will be assessed prior to and after each condition (Smoking vs. Non-smoking) on two separate days. Minnesota Nicotine Withdrawal Scale, Tiffany Questionnaire of Smoking Urges, The Urge to Smoke scale, Tobacco Craving Questionnaire, and 21-item Visual Analogue Scale will be used.
- Subjective reports of anxiety [ Time Frame: Up to 14 days between PET scans ] [ Designated as safety issue: No ]Subjective reports of anxiety will be collected prior to and after each condition (Smoking vs. Non-smoking) on two separate days. State anxiety questions from the Spielberg State-Trait Anxiety Inventory will be used.
Biospecimen Retention: Samples With DNA
Whole blood (15mL)
|Study Start Date:||February 2011|
|Study Completion Date:||March 2013|
|Primary Completion Date:||February 2013 (Final data collection date for primary outcome measure)|
Healthy male and female smokers. Each subject will undergo PET scan (along with craving and anxiety questionnaires) on two conditions - Smoking and Non-smoking - on two separate visits.
This will be a within-subjects study in healthy male and female smokers. There will be one within factor condition: Smoking and Non Smoking. Therefore, there will be a repeated measure of PET scans using [11C]-(+)-PHNO under two different conditions. Ten subjects (n=5 male and n=5 female) included in the study will come on two different days and will have a Smoking or Non smoking session performed just before the PET study. Subjective assessments will be conducted at each experimental condition.
|Centre for Addiction and Mental Health - 33 Russell St|
|Toronto, Ontario, Canada, M5S 2S1|
|Principal Investigator:||Bernard Le Foll, MD||Centre for Addiction and Mental Health|