Neurobiology of Nicotine and Non-nicotine Components of Tobacco Addiction

Completed · Phase 1 · Has a placebo group

Conditions studied: Smoking

In brief

In the present study the investigators will measure the effects of nicotine and non-nicotine factors on brain function during cognitive processes that are differentially sensitive to these factors. One process-continuous working memory (CWM)-is implemented via a network of frontal and parietal brain regions and is highly dopamine dependent. Smoking cessation results in significant deficits in CWM which can persist for weeks and are reversed by resumption of nicotine administration in the form of smoking or nicotine replacement. Additionally, CWM deficits are observed during smoking of denic cigarettes. Brain function during CWM is modulated by smoking abstinence and subsequent nicotine administration and activity in the dlPFC is implicated in these effects. Collectively, these data suggest that CWM is highly sensitive to the nicotine, but not non-nicotine components of smoking. Brain function during CWM is altered by smoking abstinence and nicotine, but the effect of smoking, in the absence of nicotine, has not been evaluated. Another process-cue-reactivity (CR)-results from the repeated pairing of otherwise neutral stimuli with nicotine administration. Acute smoking cessation has not been shown to have strong effects on CR in the form of cue-provoked craving, nor has nicotine replacement been shown to have robust effects on CR. Likewise, the direct effects of smoking abstinence on brain CR have been small; though craving has been shown to modulate relations between abstinence and CR. Moreover, recent data from our lab suggest larger 'doses' of abstinence (\~ 24 hrs) may amplify brain responses to cues. The effect of smoking in the absence of nicotine, on CR has not, to our knowledge, been evaluated. Collectively, these data suggest that CR in the form of cue-induced craving is not highly sensitive to the effects of short-term smoking abstinence or nicotine. Brain CR is modulated by abstinence-induced craving and longer-term abstinence, but it is unclear whether abstinence from nicotine or non-nicotine components is responsible for these effects. In the present study, we propose to evaluate the effects of non-nicotine and nicotine factors on CWM and CR using functional magnetic resonance imaging. This method allows for the non-invasive assessment of brain function. We will also examine the role of genes in moderating and mediating the effects of nicotine and non-nicotine factors on cognitive function

Key facts

Study ID

NCT01056926

Run by

Duke University

People needed

147

Starts

2009-03-01

Expected to finish

2011-11-01

Last updated by the study team

2017-01-31

Who can join

Age: 18 and older, up to 55. Sex: any. Healthy volunteers: accepted.

You may qualify if…

• generally healthy,
• between the ages of 18 and 55,
• smoking of at least 10 cigarettes/day of a brand delivering > 0.5 mg nicotine according to the standard Federal Trade Commission (FTC) method,
• an afternoon expired carbon monoxide concentration of at least 10 ppm (to confirm inhalation),
• no interest in quitting smoking as measured by self-report, and
• right-handed as measured by a three-item scale used in our laboratory.

You may not qualify if…

• inability to attend all required experimental sessions,
• significant health problems (e.g., chronic hypertension, emphysema, seizure disorder, history of significant heart problems),
• use of psychoactive medications,
• use of smokeless tobacco,
• current alcohol or drug abuse,
• use of illegal drugs as measured by urine drug screen,
• current use of nicotine replacement therapy or other smoking cessation treatment,
• presence of conditions that would make MRI unsafe (e.g., pacemaker),
• presence of conditions contraindicated for nicotine replacement therapy (e.g., skin allergies or disorders).

Where it is running

• Duke University Medical Center — Durham, North Carolina, United States

Full record on ClinicalTrials.gov

Trial information comes from ClinicalTrials.gov and is refreshed daily. TrialsForMe does not provide medical care and does not run the studies it lists.