The striatum consists of the caudate nucleus and the putamen and is part of the basal ganglia. Most afferent axons between the cortex and the basal ganglia end in the striatum. The striatum is thus the main input structure of the basal ganglia. Within the basal ganglia, several complex networks exist in which the striatum plays an important role. Like the other parts of the basal ganglia, the striatum is also important for movement, in which dopamine plays an important role. For example, dopamine is released in the striatum after hitting a winning forehand in tennis. Because dopamine makes you feel good, this may lead you to choose a forehand again the next time you are in the same game situation. In other words, you have learned that in certain situations that move is successful!
Huntington's disease is an inherited disorder whose symptoms first appear after the age of 30 and increase with age. The disease is characterised by clumsy movements, balance problems and general restlessness. These involuntary movements are called chorea and are often very strange. However, the patient has no control over them. In the 17th century, Huntington's disease patients were even accused of witchcraft because the strange chorea made it seem as if they were possessed by an evil spirit.
It is not just movement that is affected. As the severity of the disease increases, symptoms also seen in Alzheimer's disease may develop, such as memory problems, difficulty speaking and agnosia (failure to recognise objects).
The brain of Huntington's disease patients shows widespread atrophy (shrinkage), which is most prominent in the striatum. However, abnormalities are also found in other parts of the basal ganglia.
Author: Bart Aben (translated by Melanie Smekal)