Does Sweet Taste Potentiate Nicotine Cue Reactivity?

Alternative tobacco products are becoming increasingly available in the US market and are
promoted as potentially less deleterious compared to cigarettes. These products are
increasing in usage as either a substitution for cigarette smoking or in addition to
smoking. One particular appeal is that they often combine nicotine with sweet taste and
flavors, which are themselves reinforcing. The primary goal of this project is to determine
if sweet taste can potentiate the reinforcing properties of nicotine. Similar to nicotine,
cues predicting the availability of carbohydrates can stimulate intake, even in the absence
of hunger. The investigators have developed a novel flavor-nutrient conditioning paradigm to
study the reinforcing properties of carbohydrates. Novel flavors are paired with 0 or 113
kcal carbohydrate and increases in flavor-cue reactivity (change in liking and brain
response) when later sampled in the absence of the carbohydrate provide a measure of the
reinforcing potency. For smokers, the aroma of tobacco is a potent cue that can promote
smoking behavior. Using a modified version of our conditioning paradigm, our specific aim is
to test the prediction that sweet taste perception enhances the ability of nicotine to
induce neural plastic changes in brain reward circuits to increase the saliency, liking and
brain reactivity to the sight and vaporized flavor of electronic cigarettes (e-cigarettes).
Participants will smoke e-cigarettes that contain nicotine and an unsweetened vaporized
flavor, nicotine and a sweet vaporized flavor or only a sweet vaporized flavor (no
nicotine). The investigators predict that response in the nucleus accumbens and hypothalamus
to the sight and vaporized flavor of the e-cigarette that was paired with nicotine and sweet
taste will be greater than the responses to the sight and vaporized flavors associated with
the other e-cigarettes. The investigators further predict that liking and wanting will
increase more for the sight and vaporized flavor associated with both nicotine and sweet
taste. This finding would provide strong evidence that sweet taste potentiates the
reinforcement potency of nicotine and could therefore promote use.

Inclusion Criteria:

- right handed

- non-daily smoker

- english speaking

Exclusion Criteria:

- serious or unstable medical illness (e.g., cancer);

- past or current history of alcoholism or consistent drug use;

- current and history of major psychiatric illness as defined by the DSM-IV criteria
including eating disorders,

- medications that affect alertness (e.g., barbiturates, benzodiazepines, chloral
hydrate, haloperidol, lithium, carbamazepine, phenytoin, etc.) and any psychoactive
drugs or anti-obesity agents;

- history of major head trauma with loss of consciousness;

- ongoing pregnancy;

- known taste or smell dysfunction;

- a diagnosis of diabetes;

- any known allergies or sensitivity, including to food, vapors or odors;

- pregnant or nursing women,

- history of metalworking, injury with shrapnel or metal slivers, and major surgery;

- history of pacemaker or neurostimulator implantation m) asthma, chronic obstructive
pulmonary disease, bronchitis or any other lung disease.