Amphetamine-induced hyperlocomotion test of lithium-responsive behavior in mice

AIH assays were performed as described in Gould et al.⁴⁹. The following compounds were administered to mice either intraperitoneally (IP), subcutaneously (SC), or by gavage (per os, PO) in a volume of 0.01 ml/g body weight as following: methamphetamine 3.5 mg/kg, IP in saline (Sigma-Aldrich); LiCl 85 mg/kg, IP in saline (Sigma-Aldrich); ropinirole 10 mg/kg, IP in dH₂O (Sigma-Aldrich); oxiracetam 100 mg/kg, IP in dH₂O (BOC Sciences, Shirley, NY, USA); Huperzine A 1 mg/kg, PO in dH₂O with 40% volume 0.1 M HCl (Sigma-Aldrich); sulpiride 10 mg/kg, IP in saline with three drops of Tween-80 (Tocris Bioscience, Bristol, UK); ganaxolone 10 mg/kg, IP in 20% 2-hydroxypropyl-beta-cyclodextrin (Tocris Bioscience); forskolin 1 mg/kg, SC suspended in 10% cremaphor (Tocris Bioscience); NNC-711 5 mg/kg, IP in saline and sonicated (Tocris Bioscience). A cohort of 32 C57BL/6J mice and another one of 32 DBA/2J mice were used to test huperzine A, oxiracetam, and ropinirole. A third cohort of 32 C57BL/6J mice was used to test forskolin, ganaloxone, NNC-711, and sulpiride. Each cohort was tested once per week. For statistical analyses, the effect of compounds was initially analyzed by two-way ANOVA’s between-subjects factors lithium (vehicle or lithium) and compound (vehicle or compound). In addition, between-group analysis of separate cohorts of six mice per group was used in each separate experiment to test the effect of sulpiride pretreatment on AIH also in comparison with vehicle, lithium, and lithium plus sulpiride. For group allocation, there was no blinding and randomization.