SCA1 mice show reduced threshold to evoke calcium spikes.

(A) Representative traces where dendritic calcium spikes were evoked with somatic current injection (injected current amount indicated on the trace) from five week old wild-type Purkinje neurons (left) and ATXN1[82Q] Purkinje neurons (right) in the presence of 1 μM TTX. ATXN1[82Q] Purkinje neurons require less injected current to elicit a dendritic calcium spike than wild-type Purkinje neurons, summarized in (B). (C) At five weeks of age, the input resistances of wild-type and ATXN1[82Q] Purkinje neurons do not differ when measured in normal aCSF with 1 μm TTX. In (B and C) N = 4–6 mice were utilized per genotype. Throughout, data are mean ± SEM. *** = P<0.001; NS = Not significant.