The airway sensory impact of nicotine contributes to the conditioned reinforcing effects of individual puffs from cigarettes

Abstract

Puffs from cigarettes are the fundamental unit of smoking reward. Here, we examined the extent to which reward from puffs can be derived from the airway sensory effect of nicotine, in the absence of a direct central nervous system effect of nicotine. We did this by assessing the self-reported reward obtained from individual puffs from nicotinized, denicotinized and unlit cigarettes within 7 s of inhalation, which is before nicotine had an opportunity to reach the brain. We also assessed the self-reported strength of airway sensations elicited by the puffs. We found that nicotinized puffs were rated as both stronger and more rewarding than denicotinized and unlit puffs. We also found that the extent to which nicotine elicited reward was directly correlated with the extent to which nicotine elicited airway sensations. This indicates that the airway sensory effects of nicotine contribute to the reward from puffs, above and beyond the reward derived from the airway sensory effects of non-nicotine constituents. These findings have implications for the interpretation of studies that use puffs as experimental units to examine nicotine reward. They also have implications for the use of denicotinized and low nicotine cigarettes as aids to smoking cessation.

Ventral Striatal Dopamine Release in Response to Smoking a Regular vs a Denicotinized Cigarette

“…In tobacco-dependent smokers, smoking denicotinized cigarettes has been found to result in a degree of withdrawal relief that is similar to smoking regular cigarettes (Pickworth et al, 1999;Buchhalter et al, 2001;Dallery et al, 2003;Donny et al, 2007); however, denicotinized cigarettes provide less satisfaction (Butschky et al, 1995;Gross et al, 1997), reward (Naqvi and Bechara, 2005;Donny et al, 2007), and anxiety reduction (Pomerleau et al, 1984;Buckley et al, 2007) than regular cigarettes. Denicotinized cigarettes also do not elevate heart rate like regular cigarettes (Butschky et al, 1995;Pickworth et al, 1999;Schuh et al, 2001;Buchhalter et al, 2001), but both cigarette types increase skin conductance responses (Naqvi and Bechara, 2006).…”

“…Denicotinized cigarettes also do not elevate heart rate like regular cigarettes (Butschky et al, 1995;Pickworth et al, 1999;Schuh et al, 2001;Buchhalter et al, 2001), but both cigarette types increase skin conductance responses (Naqvi and Bechara, 2006). Furthermore, a recent study directly demonstrated that the airway sensation from nicotinized cigarette puffs were more rewarding than such sensations from denicotinized cigarette puffs (though both cigarette types produced greater reward than unlit puffs) (Naqvi and Bechara, 2005). Taken together, these studies indicate that sensory factors associated with smoking are important for relief of withdrawal, but that nicotine may be necessary for the rewarding properties of smoking.…”

Skin conductance responses are elicited by the airway sensory effects of puffs from cigarettes

“…Work by others (Pritchard et al, 1996;Rose et al, 1999) has shown that nicotine's airway sensory effects are a source of hedonic impact from smoking. An earlier study by our laboratory (Naqvi and Bechara, 2005) in which hedonic impact was assessed before nicotine reached the brain showed that nicotinized puffs elicit more hedonic impact than denicotinized puffs in large measure because nicotinized puffs stimulate more intense airway sensations than denicotinized puffs. Though one cannot exclude the contribution of nicotine's pharmacologic (i.e.…”

“…Recent smoking may also have acted to reduce the pharmacologic effects of nicotine from individual puffs as a result of acute tolerance, which lasts for up to 2 h following nicotine exposure (Perkins et al, 1995). Previous results (Naqvi and Bechara, 2005) have shown that, despite a diminished pharmacologic effect of nicotine due to recent smoking, nicotine still exerts airway sensory effects.…”

“…We measured subjective hedonic impact and SCRs elicited by individual puffs from nicotinized, denicotinized and unlit cigarettes. Previous findings have shown that the airway sensory effects of nicotine give rise to hedonic impact (Pritchard et al, 1996;Rose et al, 1999) and that this contributes significantly to the difference in hedonic impact between nicotinized and denicotinized puffs (Naqvi and Bechara, 2005). We therefore predicted that SCR would be larger for nicotinized puffs than for denicotinized and unlit puffs, since more hedonic impact is derived from the airway sensory effects of nicotinized puffs than from the airway sensory effects of denicotinized puffs.…”