Figure 1.
Molecular organization of the cerebellar pinceau during postnatal development. Wild-type cerebellar sections from ages P10–P90 (indicated on left) and immunostained against Parv, Calb, pNfl, and KV1.2. A, B, At P10, very few basket neuron (b) collaterals have reached Purkinje neuron (P) AISs (arrows). C, D, At P12, a few basket neuron (b) collaterals have arrived at the Purkinje AIS (arrowhead) and faint traces of KV1.2 channels can be seen around the Purkinje AIS. E, F, By P16, more basket neuron (b) collaterals surround the Purkinje (P) AIS, and KV1.2 channels are enriched at the basket neuron terminals. G, H, At P20, the cone-shape of the pinceau is formed, as evident by Parv (Gb, arrow), pNfl (Hb, arrowhead; Hd, arrow), and KV1.2 clustering (Hc, arrowhead). I, J, At P30, the pinceau is fully mature (Ib, Jd, arrows; Jb, Jc arrowheads). K, L, At P90, the structure of the pinceau does not display major anatomical changes compared withP30 (Kb, Ld, arrows; Lb, Lc, arrowheads). M–Q, Cerebellar sections from Gad67-GFP BAC transgenic mice at ages P10 (M), P12 (N), P16 (O), P20 (P), and P30 (Q) immunostained against GFP (green) and Calb (red). The main basket axons (arrows) give off collaterals (arrowheads) that extend toward the Purkinje AIS begining at P10 (M, arrowhead) and form the cone-shape pinceau at P30 (Q, arrowhead). R, Representative drawings of each stage of pinceau development. Purkinje neurons (P) in green, basket neurons (b) in red and orange and potassium channels in blue. Scale bars: 10 μm.