What are the basal ganglia?
The basal ganglia are a group of nuclei within the brain that, despite having different origins, are capable of working together. These nuclei are well connected with several areas of the brain, such as the cerebral cortex and the thalamus and they are structured similarly to an earpiece. Unlike other parts of the brain, that use neurotransmitters that act in a stimulating or accelerating manner, the basal ganglia use GABA as a neurotransmitter: this puts on the brakes. The only exception to this rule is on the subthalamic nuclei.
What are the parts of the basal ganglia?
There are five parts of the basal ganglia, and they include the following:
- Globus pallidus
- Substantia nigra
- Nucleus accumbens
- Subthalamic nucleus
What are the functions of each of these parts?
The striatum is the largest component of the basal ganglia, and this has two sections: the caudate nucleus and the putamen. This is the receptionist at the front of house: the striatum receives information from the other sections of the brain, but only transmits information internally (to other parts of the basal ganglia).
The globus palldius literally translates to a ‘pale globe’ and the main function of this area is to inhibit motor functions of the brain via information from the striatum. This is due to the GABA receptors on the neurons located here.
The substantia nigra has two functions: inhibiting the functions of the thalamus, and the production of the pleasure hormone dopamine.
The subthalamic nuclei are the only part of the basal ganglia that produces a stimulating hormone. In this case, it produces glutamate. It receives information from the cerebral cortex and the striatum, and sends information to the globus pallidus.
Disorders Associated with Basal Ganglia
There are several key disorders of the brain associated with the basal ganglia: Huntington’s disease, movement disorders, OCD (obsessive-compulsive disorder) and Parkinson’s disease.