The basal ganglia are a group of brain structures linked together, handling complex processes that affect your entire body. While best known for their role in controlling your body’s ability to move, experts now know they also play a role in several other functions, such as learning, emotional processing and more.
The basal ganglia (pronounced “bay-sal” “gang-lee-uh”) are a group of structures near the center of your brain that form important connections. These connections allow different areas of your brain to work together. The basal ganglia manage the signals your brain sends that help you move your muscles.
The basal ganglia are best known for how they help your brain control your body’s movements. However, ongoing research continues to uncover other ways that the basal ganglia interact with other parts of your brain. Though experts continue to uncover more about the inner workings of the basal ganglia, there’s much about them that remains unknown.
The basal ganglia are a key part of the network of brain cells and nerves that control your body’s voluntary movements. They can approve or reject movement signals that your brain sends, filtering out unnecessary or incorrect signals. This lets you control certain muscles without also using other muscles that are nearby.
If the basal ganglia approve a signal, it continues to the motor pathways, the nerves that eventually carry the signal down your spinal cord and nerves to their destination muscle. If they don’t approve the signal, they redirect it into an area where other brain cells dampen those signals until they stop.
The parts of your brain that process information from your senses, namely sight, sound, smell, taste and touch, also send that information to your basal ganglia. That sensory information helps the basal ganglia refine your movements further.
Another job of the basal ganglia is processing how you evaluate goals and risks. It also processes signals that affect your emotions and your motivation. That means it also plays a role in learning and forming habits, planning and carrying out tasks, and more.
Because the basal ganglia involve processes like emotions, motivation and habits, they also affect how you learn and how you feel in response to things happening around you. That includes feeling good (reward) about something you do, or feeling the need to avoid something. Because of the involvement of your brain’s processes with rewards, habits and motivation, the basal ganglia also have a role in illnesses like addiction.
The basal ganglia aren’t a single structure in your brain. Instead, they include several structures, ganglia and nuclei alike, found at the center of your brain.
The parts of the basal ganglia include:
The basal ganglia are separate structures that link up in various ways. One way to think of the basal ganglia is like a circuit board found in an electronic device. The ganglia form connections and circuits with different parts of your brain, allowing them to send signals back and forth. Some parts of the basal ganglia can also relay signals from different areas.
There are also different kinds of connections that happen throughout the basal ganglia. Some of these connections are “excitatory,” meaning they cause something to happen. Others are “inhibitory,” meaning they stop signals from continuing. Some connections trigger the release of other neurotransmitter chemicals, which your body uses for communication and activating or deactivating certain processes and systems.
The basal ganglia take up about 10 cubic centimeters of space, which is a volume that’s about the same as a standard gumball.
The basal ganglia aren’t actually all ganglia. Some of the structures are nuclei, but experts still group them under the name. The definition of nuclei and ganglia are as follows:
Making up the nuclei and ganglia are the following:
Neurons are the cells that send and relay signals through your nervous system, using both electrical and chemical signals. Each neuron consists of the following:
Neuron connections are incredibly complex, and the dendrites on a single neuron may connect to thousands of other synapses. Some neurons are longer or shorter, depending on their location in your body and what they do.
Glial (pronounced “glee-uhl”) cells have many different purposes, helping develop and maintain neurons when you’re young, and managing how the neurons work throughout your entire life. They also protect your nervous system from infections, control the chemical balance in your nervous system and create the myelin coating on the neurons’ axons. Your nervous system has 10 times more glial cells than neurons.
Conditions that affect the basal ganglia include, but aren’t limited to:
The symptoms that can happen with conditions that affect the basal ganglia depend strongly on the type of condition. Movement disorders like Parkinson’s disease or Huntington’s disease will have different effects from carbon monoxide poisoning or heavy metal poisoning.
Several types of diagnostic tests are possible with conditions that affect the basal ganglia. Some of the most common tests include, but aren’t limited to:
The treatments for conditions that affect your basal ganglia can vary depending on the condition in question. There’s no one-treatment-fits-all approach to conditions that affect your brain, and treatments that help one condition can make others worse. Some conditions are treatable with medication only, while others require surgery or other treatments. In some cases, the condition isn’t treatable, so healthcare providers will focus on treating the symptoms.
Many — but not all — conditions that affect the basal ganglia are preventable. Protecting the basal ganglia is very similar to taking care of your entire brain, as well as your body overall. Some of the most important things you can do include:
A note from Cleveland Clinic
The basal ganglia have a critical job in your brain, and experts are working to understand even more about what they do. While there’s still a lot that experts don’t yet understand, advances in medical knowledge and technology are helping change that. As understanding of the basal ganglia grows, healthcare providers will have even more ways to diagnose and treat the conditions that affect them.
Last reviewed by a Cleveland Clinic medical professional on 08/05/2022.
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