All animals were between 8-15 weeks old at the time of behavioral testing. Mice had free access to food and water and lights were maintained on a 12:12 h light/dark cycle, with all behavioral testing performed during the light portion of the cycle. All experiments were conducted according to National Institutes of Health guidelines for animal care and use and were approved by the Institutional Animal Care and Use Committee of the University of California, Irvine. All animals were group housed and backcrossed at least five generations to C57BL/6 (Jackson Labs). Official Mouse Genome Database strain name for BAF53b Δ HD mutant mice: B6J.CB6-Tg(CamK2α-Actl6b*)Mwood.