The surgical procedure and behavioral tests were performed as previously described (Hodes, Rosen et al. 2016). Briefly, mice were randomly divided into four groups of eight animals each: Control (IgG + saline), Anti-ouabain antibodies (anti-ouabain antibodies + saline), AMPH (IgG + AMPH) and anti-ouabain antibodies + AMPH. The mice received an IP injection of AMPH or saline (10 mL/kg) and an ICV injection of anti-ouabain antibodies or IgG. After 15 min, the mice were placed individually in a 50 × 50 cm open-field arena, which they were allowed to explore for 6 min. The behavioral tests were performed during the light phase (10:00-14:00) under dimmed halogen lights (about 35 lux), as described by Gould et al. (Gould, O'Donnell et al. 2007). Activity levels were monitored and quantified by an automated camera-based computer tracking system Ethovision XT (Noldus Information Technologies, Wageningen, The Netherlands).