structure and functions of the globus pallidus
Structure and Functions of the Globus Pallidus
Inhibiting excitatory output of the cerebellum and regulating voluntary movements are the important functions of the globus pallidus. The following Buzzle article elaborates more on this important part of the basal ganglia.
Did You Know?
Nerve impulses between different neural structures of the brain can travel as fast as 260 mph.- Regulating voluntary movements is the main function of the globus pallidus. So any issues with this neural structure are likely to cause difficulty in movement. In short, impaired motor activity is the result of damage to the globus pallidus.
- Disorders of the basal ganglia involving the globus pallidus can cause slowness in movement. As a damaged globus pallidus cannot perform its muscle regulatory function, it can cause involuntary movement such as tremors while taking rest.
- In movement disorders like Parkinson's disease, the globus pallidus is found to be hyperactive. Hence, patients suffer from lack of muscle control, which is typically marked by stiff and inflexible muscles and trembling. In such circumstances, surgical procedures such as pallidotomy may be recommended, in which a small portion of the globus pallidus is eliminated.
- Huntington's disease that is marked by substantial neuronal loss in the globus pallidus can also cause abnormal, uncontrolled movements in different regions of the body.
- The cerebellum sends its output to the motor cortex, which in turn transmits it to the basal ganglia. It is observed that the output of the cerebellum is excitatory, which needs to be curbed in order to ensure a coordinated movement. This is done by the Gpi of the basal ganglia, which provides inhibitory action.
- This balance between the excitatory and inhibitory signals is necessary for smooth controlled movement. Imbalance in excitatory and inhibitory neurotransmitters results in purposeless movements that manifest in the form of tremors. Some of the inhibitory output of GPI is also sent to the neural structures lying in the midbrain, which supposedly provides better stability to our back.
- The globus pallidus in the basal ganglia essentially applies brakes on one movement so as to properly execute other motor activities. For instance, in order to stand straight in one position, the global pallidus withholds all unnecessary movements, barring one that is required for a stable erect posture.