Which nucleus is part of the direct pathway in the basal ganglia?

The internal globus pallidus is crucial in the direct pathway of the basal ganglia, which facilitates movement. In this pathway, excitatory inputs from the cortex stimulate the putamen, which in turn inhibits the internal globus pallidus. This inhibition reduces the inhibitory output of the internal globus pallidus to the thalamus, resulting in increased thalamic excitation of the motor cortex, thereby promoting movement.

Understanding the role of the internal globus pallidus within this pathway highlights its importance in the regulation of voluntary movement. The balance of activity between the direct and indirect pathways of the basal ganglia is essential for smooth and coordinated motor activity, and the internal globus pallidus plays a key role in this balance by modulating the output to the thalamus.