Three separate areas of ventral thalamus designated as H, H1, and H2. Field H, which is considered to be the area where H1 and H2 merge, lies rostral to red nucleus and medial to subthalamic nucleus and contains fibers from rubrothalamic, pallidofugal, and dentatothalamic tracts. Field H1 roughly comprises thalamic fasciculus, and field H2 is lenticular fasciculus and area where it merges with ventral zona incerta and dorsal subthalamic nucleus.