mecamylamine precipitated withdrawal. Consistent with the results of Jackson and colleagues, the lack of the α5 subunit abolished the somatic symptoms of withdrawal to levels exhibited by saline-treated mice, suggesting that the α5 subunit mediates some physical symptoms of nicotine withdrawal (Jackson et al. 2008; Salas et al. 2009). However, because physical symptoms are a less significant component of the withdrawal syndrome in human smokers compared to affective and cognitive signs, the relevance in humans must be evaluated.
