Summary

The vermis cerebelli, the middle part of the cerebellum, has been anatomically known and named since Galen (around 200 ce). As part of his work in physiology, which was based on the distribution of pneuma, Galen attributed to the worm a mechanical valve function for the flow of psychic pneuma (spiritus animalis) in the brain. This function was adopted and expanded by Arab scholars who translated Galen. In Costa ben Luca (around 900 ce), for example, the worm regulates memory and thinking, whereas Avicenna (ca. 1000) sticks to Galen’s ideas. In 1316, Mondino assigned this function within the cerebral ventricles to the worm-like choroid plexus; the cerebellar vermis is forgotten. Vesalius corrected Galen on several points in 1543/1555 and clarified that the vermis cerebelli has no mechanical function; he ignored Mondino’s new, different worm. However, this vermis survived the Middle Ages and was depicted in numerous illustrations until the 17th century.

Since Thomas Willis (1621-1675), the vermis remained an anatomically conspicuous part of the cerebellum but generally does not play a special role within the general function of the cerebellum, even if there are individual speculative assumptions about its function (e.g., respiration or coenesthesia). Since Rolando in the early 19th century, the cerebellum has been increasingly associated with motor activity, but any localized functions of the cerebellum were denied by Pierre Flourens (1794-1867) and even later by Luigi Luciani (1840-1919).

This attitude changed completely in the 20th century. Through the fundamental work of Bolk, Comolli, Edinger, Larsell, Jansen, and Brodal, the cerebellum and vermis were structured anatomically, phylogenetically, and functionally. At the same time, electrophysiological research led to the discovery of somatotopic representations in the cerebellar cortex. The second half of the 20th century was characterized by an expansion of functions. The vermis was recognized as a dynamic learning structure and as an important center of emotional control—the “limbic vermis.”

Research since the beginning of the 21st century relies much on functional neuroimaging and genetic expression patterns and may lead to a more integrated understanding of the cerebellum.