Loss of AnkR results in progressive cerebellar Purkinje neuron degeneration. Immunostaining of Purkinje neurons with Calbindin in the cerebellar cortex of Ank1F/F, Ank1F/F;Nestin-Cre, and Ank1F/F;Pcp2-Cre in (A) one-month-old, (D) six-month-old, and (G) 12-month-old mice of the indicated genotypes. Arrowheads in D, G show examples of axonal torpedoes present in six-month and 12-month Ank1F/F;Nestin-Cre and Ank1F/F;Pcp2-Cre. Scale bars: 50 µm. ML, molecular layer; PCL, Purkinje neuron layer; GCL, granule cell layer. Quantification of molecular layer thickness at (B) one month, Ank1F/F (N = 5; 143.0 ± 0.83 µm), Ank1F/F;Nestin-Cre (N = 4; 137.8 ± 4.43 µm), and Ank1F/F;Pcp2-Cre (N = 3; 136.1 ± 3.44 µm); (E) six months, Ank1F/F (N = 4; 142.1 ± 1.51 µm), Ank1F/F;Nestin-Cre (N = 5; 118.3 ± 2.57 µm), and Ank1F/F;Pcp2-Cre (N = 3; 129.3 ± 4.29 µm); and (H) 12 months, Ank1F/F (N = 3; 141.7 ± 2.58 µm), Ank1F/F;Nestin-Cre (N = 3; 100.5 ± 1.96 µm), and Ank1F/F;Pcp2-Cre (N = 3; 106.44 ± 0.64 µm). Normalized quantification of Purkinje neuron density at (C) one month, Ank1F/F (N = 3; 1.0 ± 0.03), Ank1F/F;Nestin-Cre (N = 3; 0.98 ± 0.03), and Ank1F/F;Pcp2-Cre (N = 3; 1.04 ± 0.02); (F) six months, Ank1F/F (N = 3; 1.0 ± 0.04), Ank1F/F;Nestin-Cre (N = 3; 0.84 ± 0.02), and Ank1F/F;Pcp2-Cre (N = 3; 0.92 ± 0.02); and (I) 12 months, Ank1F/F (N = 4; 1.0 ± 0.02), Ank1F/F;Nestin-Cre (N = 4; 0.57 ± 0.03), and Ank1F/F;Pcp2-Cre (N = 3; 0.68 ± 0.03).