Figure 2.
Electrical stimulation of descending corticofugal (DCF) axons. (a) A connectivity distribution (blue) was used to predict the trajectories of DCF axons. Streamlines connected the brain stem (yellow) to the right motor cortex (green) and did not intersect the CSF, basal ganglia structures, or left hemisphere (red). Axes reflect radiological convention. (b) Contact 0 in a monopolar cathodic configuration was used to stimulate model axons at a stimulation amplitude of −2.5 V. (c) The stimulus waveform was a train of asymmetric rectangular pulses with a short cathodic 100 µs phase followed by a long 900 µs anodic phase at 130 Hz (inset). (d) The red streamlines denote model DCF axons that were activated by stimulation through contact 0. STN = subthalamic nucleus.
