Final answer:
The direct pathway is activated by dopamine, increasing cortical movement commands and resulting in increased motor activity. The indirect pathway is inhibited by dopamine, leading to decreased activity in the cerebral cortex and less motor activity.
Step-by-step explanation:
The direct and indirect pathways in the basal nuclei of the brain are modulated differently by dopamine (DA). The direct pathway is activated by DA, increasing cortical movement commands and resulting in increased motor activity. On the other hand, the indirect pathway is inhibited by DA, leading to decreased activity in the cerebral cortex and less motor activity.