Fig. 3. Alteration of the Purkinje cell monolayer and dendritic formation in treated MBP-TK mice. (A,B) In situ hybridization using a zebrin-II antisense probe. (C-F) Immunofluorescence using an anti-calbindin antibody to visualize soma and dendritic extensions of Purkinje neurons. (A,B) Cerebellar coronal, and (C-F) sagittal sections of 3-week-old wild-type (A,C,E) and MBP-TK treated (B,D,F) (1-20d) mice. In wild type, Purkinje cell soma are aligned in a monolayer (A) and their dendritic tree extends throughout the ML (C). In MBP-TK cerebella, Purkinje cells form a multicellular layer (B) and the formation of their dendritic arborization is clearly altered (D). (E) Purkinje axons in wild type converge in the white matter tract to form bundles of myelinated fibers. (F) In MBP-TK mice, Purkinje axons are defasciculated. Scale bars: 75 µm (A,B); 25 µm (C-F).