, 2002). Aside from replication of these results, further research should examine the mechanisms of nicotine��s actions on reinforced responding, Ceritinib cancer as well as the actions of acute abstinence. For example, nicotine lowers intracranial self-stimulation (ICSS) threshold, indicating increased reward sensitivity (Kenny & Markou, 2006), and cessation of nicotine may do the opposite (increase ICSS threshold), under certain conditions, coinciding with somatic signs of withdrawal (Paterson et al. 2008). However, the fact that we saw no significant correlation of withdrawal severity with reinforced responding suggests the effects of nicotine cessation on reward sensitivity may not be closely tied to withdrawal per se. Further research also should explore bupropion��s possible effects on reinforced responding, such as actions at alpha-adrenergic receptors (Palmatier et al.

, 2009). In summary, these exploratory findings suggest quitting smoking may not only remove the primary and secondary reinforcing effects of nicotine, but also these reinforcement enhancing effects of nicotine. These effects would decrease overall reinforcement from other rewards in the smoker��s environment, especially those sensory in nature. Consequently, a lapse could restore overall reinforcement from rewarding activities, perhaps in a manner similar to the attenuated decline observed with bupropion (Figure 2). Our findings suggest other cessation medications may also prevent loss of reinforced responding after quitting, especially varenicline (Levin et al., 2012), perhaps helping explain their efficacy in maintaining abstinence.

FUNDING This research was supported by National Institutes of Health Grants CA143187 and DA031218. DECLARATION OF INTERESTS Dr. KAP has consulted with Embera Neurotherapeutics on the development of smoking cessation medications unrelated to this article. No other authors have any disclosures. ACKNOWLEDGMENTS The authors thank Carolyn Fonte, Jacqueline Sun, and Tiona Jones for their helpful assistance during sessions.
Cigars, cigarillos, and little cigars (CCLC) are the most widely consumed tobacco products second to cigarettes among adolescents aged 12�C17. Surveys indicate that approximately 13.1% of all students in the United States report past month CCLC use, with use increasing over the course of high school (e.g., 9th grade: 9.0%; 12th grade: 17.

3%; Centers for Disease Control and Prevention (CDC), 2012). Current surveillance reports may be an underestimation of CCLC prevalence rates given that many CCLC users, Entinostat particularly those who also smoke cigarettes, incorrectly identify themselves as nonsmokers (Nasim, Blank, Berry, & Eissenberg, 2012). Notably, sales of cigar products in the United States have recently surged (Kozlowski, Dollar, & Giovino, 2008); annual sales of CCLC increased by up to 316% from 1995 to 2008 (Maxwell, 2008), which may be attributable to lower barriers to consumption including federal excise taxation rates that are 3.