(GPi), and substantia nigra (SN). Latin nucleus subthalamicus Part of Basal ganglia NeuroNames hier-418 MeSH Subthalamic+Nucleus Dorlands/Elsevier n_11/14166739 The subthalamic nucleus is a small lens-shaped nucleus in the brain where it is a part of the basal ganglia system. As suggested by its name, the subthalamic nucleus is located ventral to