Where did the motor function of the cerebellum come from?
Until the end of 18th century, the role of the cerebellum remained obscure. The turning point occurred when Luigi Galvani showed that muscle contraction is due to electricity and Alessandro Volta produced the battery, an apparatus based on the pairing of silver and zinc plates separated by brine soaked paper disks, capable to generate electricity. Luigi Rolando, at beginning of 19th century, was impressed by these two observations. He thought that, since the brain generates the movement, it must contain a device generating electricity. As a battery, it should be formed by overlapping disks and the cerebellum for Rolando seemed to be the right structure for such a characteristic laminar organization. He argued that, if the cerebellum is the battery that produces electricity for muscle activity, its removal would produce paralysis. Consequently, Rolando removed the cerebellum in a young goat and observed that the animal, before dying, could no longer stand up. He concluded that the cerebellum is a motor structure as it generates the electricity which produces the movement. The conclusions of Rolando were criticized by Marie-Jean-Pierre Flourens who observed that animals undergoing cerebellectomy were still able to move, even if with problems of balance. Flourens concluded that the role of the cerebellum "is to put in order or to coordinate movements wanted by certain parts of the nervous system, excited by others". It was necessary to wait up to 1891 when Luigi Luciani, observing a dog survived the cerebellectomy, described a triad of symptoms (asthenia, atony and astasis), unquestionably of cerebellar origin.
Department of Biomedical and Biotechnological Sciences, Section of Physiology, University of Catania, Via Santa Sofia 64, 95125 Catania, Italy.
Marinella
M
Coco
Department of Biomedical and Biotechnological Sciences, Section of Physiology, University of Catania, Via Santa Sofia 64, 95125 Catania, Italy.
Vincenzo
V
Perciavalle
Cerebellum; History; Motor control