PCP2 and Ataxia: Similar changes in Purkinje neuron activity were observed in another ataxia animal model, the ataxin 2 (Atxn2) mouse carrying a mutation of ataxin 2 [ATXN2Q127: Tg(Pcp2-ATXN2*127Q)#Plt/0] found in patients with spinocerebellar ataxia type 2.