Skip to main content
. Author manuscript; available in PMC: 2009 Jul 29.
Published in final edited form as: Neuron. 2003 Dec 18;40(6):1119–1131. doi: 10.1016/s0896-6273(03)00769-4

Figure 8. A model for reciprocal signaling in Purkinje and granule cell differentiation.

Figure 8

(A) Speculative model for sequential intercellular signaling events surrounding RORα-stimulated gene expression. Wnt1 is expressed by migratory granule cell precursors (GCPs) at the rhombic lip (RL). WNT expression may influence the nuclear accumulation of β-catenin in Purkinje cells (PC). Nuclear β-catenin acts as a cofactor on RORα-regulated promoters, including Shh. Purkinje cell SHH stimulates proliferation of GCPs in the external granule cell layer (EGL). Granule cells in the internal granule cell layer (IGL) make glutamatergic synapses on Purkinje cells, where RORα also regulates expression of signal transduction molecules to receive and process this input.

(B) Model for RORα-dependent gene expression in Purkinje cells. In Purkinje cell nuclei, RORα (red) recruits promoter-specific sets of coactivators (light red) to target genes in the context of additional, independent factors (gray). The products of known direct and potentially direct target genes are involved in receiving signals from afferent cells (blue), processing those signals via calcium release (orange), and the stimulation of proliferation of GCPs in the EGL (SHH).