TRPM2 and bipolar disorder: Under physiological conditions, a comprehensive behavioral test battery has shown that Trpm2 KO mice exhibit no behavioral phenotypes in light/dark transition, rotarod, elevated plus maze, social interaction, prepulse inhibition, Y-maze, forced swim, cued and contextual fear conditioning, and tail suspension tests (Andoh et al., 2019), whereas Trpm2 KO mice were also reported to exhibit bipolar disorder-related behaviors (Jang et al., 2015) (Table 2).