A similar procedure has been developed for mice and produces reliable increases in ethanol self-administration during withdrawal. Now termed chronic intermittent exposure (CIE), C57BL/6 mice are exposed to intermittent durations of ethanol vapor (three cycles of 16 h of vapor and 8 h of air) and then tested in a 2 h limited access ethanol preference drinking test during the circadian dark period (Becker and Lopez 2004; Lopez and Becker 2005; Finn et al. 2007). Intermittent ethanol vapor exposure significantly increased 15% (v/v) ethanol intake by 30–50% in the post-vapor period, usually after multiple cycles and usually after 24 h of withdrawal (Finn et al. 2007). Similar results have been reported using an operant response in mice in 60 min test sessions for 10% (w/v) ethanol with intermittent vapor exposure of 14 h on/10 h off (Chu et al. 2007).
