Appetite. 2013 Oct 23. pii: S0195-6663(13)00412-1. doi: 10.1016/j.appet.2013.10.003. [Epub ahead of print]
Department of Psychology, Doshisha University, Kyotanabe-shi, Kyoto 602-8580, Japan. Electronic address: [email protected]
Time-dependent increases in cue-induced sucrose seeking after forced abstinence have been described in rats with a history of sucrose self-administration, suggesting sucrose craving “incubates”. In the present study, we examined whether the incubation of craving generalizes to the artificial sweetener, saccharin.
Thirty-one male Long-Evans rats lever pressed for 0.3% saccharin solution 1h/day for 10days. On either Day 1 or 30 of forced abstinence, rats responded for 1h for presentation of a tone+light cue previously presented with every saccharin delivery during self-administration training.
Rats responded more during this cue-reactivity test session following 30 vs. 1day of forced abstinence (“incubation of craving”). This result is the first demonstration of the “incubation of saccharin craving” and suggests that a post-ingestive caloric consequence of self-administration is not a necessary condition for the development of incubation of sucrose craving. We also examined the time course (within-session decreases) of active-lever responding during the 1-h cue-reactivity test session.
Rats in the Day 30 group responded more than rats in the Day 1 group from the beginning of the test session. In addition, within-session decreases in responding were shallower in slope in the Day 30 than the Day 1 group. These results indicate that “incubation of saccharin craving” enhances the persistence of seeking behavior.