The lateral globus pallidus (or external GPe) is part of the globus pallidus. The globus pallidus, in turn, is part of the basal ganglia, a cluster of nerve cells (neurons) that plays a role in regulating movement. The lateral globus pallidus is located deep in the brain, near its center.
The lateral globus pallidus and the subthalamic nucleus form a particular system called a coupled pacemaker. Pacemakers control and maintain rhythmic physiological activities in the body. The axons of the external globus pallidum — the threadlike parts of the nerves cells that move signals through the cell — go essentially to the subthalamic nucleus. They go also to other elements of the basal ganglia system, including the striatum and the internal globus pallidus, where they release the neurotransmitter GABA. A neurotransmitter is a chemical substance that relays nerve impulses across the gaps (synapses) that separate nerves.
GPe serves as the main regulator of the basal ganglia system. It is sometimes used as a target for “deep brain stimulation,” which is one mode of treatment for Parkinson’s disease.