PCP2 and Ataxia: We generated the Lhx1/5 double knockout mice (ataxia mice) by crossing Purkinje cell protein (Pcp)2-Cre mice with Lhx1 floxed (fl) and Lhx5 fl mice, to obtain adult littermates (Pcp2-Cre−/−/Lhx1fl/fl/Lhx5fl/fl) and ataxia mice (Pcp2-Cre+/−/Lhx1fl/fl/Lhx5fl/fl) for subsequent experiments23 (Fig. 1b).