Cerebellum structure. Fluorescent light micrograph of a section through the cerebellum of the brain. The cerebellum comprises three main layers. The outer grey matter (cortex) comprises the molecular layer (green) and the granular layer (blue). The molecular layer is largely made up of the highly branched dendrites of Purkinje nerve cells (green), the large round bodies of which are found at the junction between the molecular and granular layers. Within the grey matter is the white matter (red), largely made up of the axons of the grey matters nerve cells. The cerebellum is involved in motor control, sensory perception and learning. Magnification: x20 when printed 10cm wide.