Electrophysiology of the Olivo-Cerebellar Loop

In animals, motor function and muscle control are critical for an organisms ability to interact with and react to its environment. This behavior can have many different functions, from finding food to defending themselves against enemies. In general, we can subdivide movements into two categories: 1) involuntary movements, like reflexes, and 2) voluntary movements. From an evolutionary point of view, the more efficient these movements are, the higher the chance of survival. In vertebrates, the cerebellum controls movement and monitors its efficiency by collecting sensory information, such as limb position, balance information and vision. All this information is evaluated to control and correct our intended movements . The cerebellum is located just above the brainstem at the lower back of the brain. In humans, it is the size of a fist and has a very high nerve cell (neuron) density. The outer layer of the cerebellum, also known as the cerebellar cortex, consists of grey matter and the inner layer consists of white matter. The neurons in the cerebellum are arranged in remarkably homogeneous and repetitive structural patterns with little variation in organization across species.