Fig. 2.

Identification of cerebellar cell types reveals distinct populations of olig2⁺ neurons organized alng the DV axis. (A–C) Sagital section through cerebellum of 48 hpf Tg(olig2:egfp) transgenic embryo showing EGFP⁺ cells expressed Hu (red). Arrowheads mark long axonal projections. (D) Dorsal view with anterior to left of one half of the cerebellum in living Tg(olig2:egfp) embryo at 56 hpf. Bracket and arrowheads mark EGFP⁺ axons extending from EGFP⁺ cells ventrally along midbrain-hindbrain boundary. (E) Dorsal view of cerebellum in living Tg(olig2:egfp) larva at 7 dpf, anterior is along the bottom. Bracket indicates extensive dendritic branches originating from EGFP⁺ cells. (F) 3-D reconstruction of 5 dpf sagital section of a Tg(olig2:egfp) larva illustrating DV organization of Zebrin II⁺ (green), EGFP⁺ (blue) and Calretinin⁺ (red) cells. Arrowhead marks ventrally extending EGFP⁺ axons. (G) Transverse section a 5 dpf Tg(olig2:egfp) larva showing Zebrin II, EGFP and Calretinin labeling of distinct populations and DV arrangement. (H–J) Sections of 14 dpf Tg(olig2:egfp) transgenic larvae labeled with Calretinin, Parvalbumin and Zebrin II antibodies. (H) Transverse hemisection shows EGFP⁺ cells dorsal to Calretinin⁺ eurydendroid cells. (I) Transverse hemisection showing EGFP⁺ cells intermixed with Zebrin II⁺ Purkinje neurons. Inset shows enlargement of area framed by dashed lines. (J) Sagital section showing distinct populations of Parvalbumin⁺ Purkinje neurons and EGFP⁺ neurons. Arrowheads mark EGFP⁺ axons extending toward deep brainstem. Inset shows enlargement of area framed by dashed lines. Scale bar = 20 µm for all panels except G, for which it represents 40 µm.