The cerebellum is a lobed structure located near the base of the brain that is primarily involved with the coordination of bodily movement and the development and recollection of physical skills, such as bike riding. The size of the cerebellum in mammal species is a fairly reliable gauge of their physical aptitude. Featured below is a low-resolution enlargement of the boxed area seen in the previous image of a rat cerebellum mid-saggital section.

Rat Cerebellum Mid-Saggital Section Enlargement Specimen: Fluorescently labeled thin section Technique: Two-Photon Microscopy

Divided by the central vermis, the surface of the cerebellum is composed of gray matter that surrounds a large mound of white matter. The structure, the name of which means “little brain” in Latin, is connected to the larger part of the central nervous system by the cerebellar peduncles, three wide bands of white matter. Injury to the cerebellum or cerebellar peduncles is often associated with ataxia, tremors, vertigo, muscle weakness, and dysarthria, an inability to coordinate the muscles needed for speech. Damage to the region is extremely common in cases of multiple sclerosis.

In order to fulfill its functions, the cerebellum must coordinate nerve impulses from a variety of sources. Based on input from the sensory organs, other areas of the brain, and the positional sensors in the muscles, cerebellar signals are able to make fine adjustments and create smooth, fluid movements. Some research suggests that there are actually two main information conduits in the cerebellum, which work together to efficiently synthesize the large amount of incoming information.