Fig. 3.

The depth of all cells studied based on microdrive measurements was referenced to the dorsal surface of the STN determined from the microelectrode recordings. The recorded neurons were distributed throughout the dorso-ventral extent of the nucleus. Because of the physical arrangement of the microelectrode anterior to the DBS electrode, the cells were recorded from the anterior portion of the nucleus. IC, internal capsule; SNr, substantia nigra pars reticularis; STN, subthalamic nucleus; ZI, zona incerta.