31At first, cerebellar differentiation from mouse ESCs (mESC) has accomplished a
combinatory treatment of positional signals (Salero and Hatten 2007 ; Su et al.
2006 ). In this culture, mESCs were treated sequentially with secreted factors (Fgf8,
Wnt1 and RA) known to initiate cerebellar primordium; BMPs and Gdf7, which
induce granule cell progenitors; and mitogens (Shh and Jagged 1). While Atoh1+
granule cell progenitors were differentiated from mESCs at relatively high effi-
ciency (>15%), the generation of Purkinje cells was extremely low (less than 1% of
the total). A similar approach, exposing a series of inductive signals, was applied in
hESC culture (Erceg et al. 2010 ). Although this protocol somewhat improves the
Fig. 2.4 Schematic of the organization the embryonic cerebellar plate. Sagittal view of cerebellar
plate (a) and coronal view of neural tube (b). EGL external granular layer, is isthmus. mb midbrain,
NTZ nuclear transitory zone, r1 rhombomere 1, RL rhombic lip, SVZ subventricular zone, VZ ven-
tricular zone, rp roof plate, ap alar plate, bp basal plate, fp floor plate, and cp cerebellar plate
(Modified from Muguruma et al. 2015 )
2 Self-Organized Cerebellar Tissue fromfiHuman Pluripotent Stem Cells andfiIts...