Schematic of the cerebellar cortex organization. Excitatory and inhibitory synapses are distinguished with solid and dotted lines respectively. PF, Parallel fibers; DCN, deep cerebellar nuclei; IO, inferior olive; CF, climbing fibers; G, Golgi cells; P, Purkinje cells. Small gray circles represent granule cells and the other undefined symbols represent other interneurons found in the granular and molecular layers.