Fig. 8. Cntn1 is required for axo-axonic innervation of Purkinje neuron AIS.

a Illustration of a Purkinje neuron (black) with a basket cell (red) forming the cerebellar pinceau on the AIS. b Immunostaining of P17 cerebellar pinceau in control and Cntn1 −/− mouse brain using antibodies against Kv1.2 (red) and PSD95 (green) to label the pinceau, and Nfasc (blue) to label the Purkinje neuron AIS. Scale bar, 10 µm. N = 3 control and 2 Cntn1 −/− mice. c Violin plot of the mean Kv1.2 intensity of the cerebellar pinceau in control and Cntn1 −/− mice. N = 3 control and 2 Cntn1 −/− mice. The number of pinceau analyzed is indicated. In the violin plot the dashed lines indicate the median, while the dotted lines represent the first and third quartiles. P values were calculated using a nonparametric two-sided T-test; no adjustments were made for multiple comparisons; (t = 14.41, df = 156) p = 1.8 × 10⁻³⁰.