The basal ganglia are collections of nerve cells located deep within the brain. They include the following:

Caudate nucleus (a C-shaped structure that tapers to a thin tail)

Putamen

Globus pallidus (located next to the putamen)

Subthalamic nucleus

Substantia nigra

The basal ganglia help initiate and smooth out muscle movements, suppress involuntary movements, and coordinate changes in posture.