Figure 2. Basal ganglia circuitry involved in movement. GPe, globus pallidus
pars externa; GPi, globus pallidus pars interna; STN, subthalamic nucleus;
SNc, substantia nigra pars compacta; SNr, substantia nigra pars reticulata;
VL, ventrolateral thalamus; PPN, pedunculopontine nucleus [in colour
online]