Publisher Summary This chapter discusses that mossy fiber input to the cerebellum is coded primarily in spatial patterns, as reflected by the fractured: somatotopy of the receptive fields in the granular layer. A new theory of how information is coded along the parallel fibers in the cerebellar cortex is explained in the chapter. Feedback inhibition by Golgi cells loosely synchronizes granule cell firing along the parallel fiber beam. Simultaneous activation of granular layer patches causes synchronized firing of the activated granule cells and transforms the spatial code into a temporal code onto the parallel fiber beam. The corticopontine projection contributes by distributing a renormalized copy of cortical activity to multiple patches and possibly by equalizing activity across fibers.