Cerebellar granule cell
[2] Mutations that abnormally activate Sonic hedgehog signaling predispose to cancer of the cerebellum (medulloblastoma) in humans with Gorlin syndrome and in genetically engineered mouse models.Because granule cells are so small and so densely packed, it has been very difficult to record their spike activity in behaving animals, so there is little data to use as a basis of theorizing.This "combinatorial coding" scheme would potentially allow the cerebellum to make much finer distinctions between input patterns than the mossy fibers alone would permit.This genomic dynamic is modulated by cell type-specific genes, but not by CpG methylation at the global level and could be a cellular strategy to manage space and energy.Mutations in it lead to alterations in synaptogenesis, as a consequence of increased accessibility to genome-wide promoters and enhancers (which are repressed under physiological developmental conditions).