Molecular layer thickness and Purkinje neuron number are dramatically reduced in anterior and central sagittal zones of 12-month-old Ank1 conditional knock-out mice. A, Sample sagittal cerebellum images from 12-month-old Ank1F/F, Ank1F/F;Nestin-Cre, and Ank1F/F;Pcp2-Cre mice immunostained for Calbindin. Cerebellar lobules labeled in Ank1F/F. Cerebellar zones illustrated in Ank1F/F inset. AZ (lobules I–V, blue), CZ (lobules VI–VII, green), PZ (lobules VIII–dorsal IX, purple), and NZ (ventral lobule IX–X, yellow). Scale bars shown in Ank1F/F;Pcp2-Cre, top 250 µm and bottom 50 µm. B, Quantification of molecular layer thickness by zone in 12-month-old mice. Ank1F/F (N = 3; AZ = 144 ± 2.7 µm; CZ = 150 ± 1.5 µm; PZ = 145 ± 6.8 µm; NZ = 125 ± 6.4 µm), Ank1F/F;Nestin-Cre (N = 3; AZ = 86 ± 4.0 µm; CZ = 112 ± 8.4 µm; PZ = 120 ± 1.2 µm; NZ = 105 ± 9.2 µm), and Ank1F/F;Pcp2-Cre (N = 3; AZ = 95 ± 3.0 µm; CZ = 111 ± 3.1 µm; PZ = 127 ± 8.6 µm; NZ = 110 ± 5.1 µm). C, Quantification of Purkinje neuron number using Calbindin by zone in 12-month-old mice. Ank1F/F (N = 3; AZ = 258 ± 8 cells; CZ = 147 ± 4 cells; PZ = 100 ± 5 cells; NZ = 122 ± 9 cells), Ank1F/F;Nestin-Cre (N = 3; AZ = 114 ± 19 cells; CZ = 108 ± 10 cells; PZ = 87 ± 12 cells; NZ = 96 ± 5 cells), and Ank1F/F;Pcp2-Cre (N = 3; AZ = 135 ± 6 cells; CZ = 91 ± 6 cells; PZ = 92 ± 4 cells; NZ = 113 ± 4 cells). D, Immunostaining of Purkinje neurons in coronal cerebellum with Calbindin in 12-month-old Ank1F/F and Ank1F/F;Nestin-Cre mice. Scale bars: 200 µm. Error bars indicate mean ± SEM.