Elevated Plus-Maze Test

The elevated plus-maze test was carried out as described previously (Nawata et al., 2012). The apparatus (Neuroscience, Tokyo) was constructed from black plastic and consisted of 2 open arms (50×10 cm) and 2 enclosed arms (50×10×50 cm) that extended from a central platform (10×10 cm). The maze was elevated 50 cm above the floor. Experiments began by placing a single rat on the central platform facing a closed arm. During the 10 minutes of free exploration, time spent on the open arms (defined as the animal placing its forepaws onto an arm) was recorded manually. In addition, the ambulation was measured with a digital tracking and computerized scoring system (LimeLight2, Actimetrics, Wilmette, IL). The maze was cleaned thoroughly with water between animals. This examination was carried out in 3 groups: control (measured 24 hours before the first day of METH self-administration), METH WD (measured on withdrawal day 10 after METH self-administration), and JZL184. JZL184 (40 mg/kg) was injected once on the test day. A different subject was used in each group.