Fields of Forel

• Field H₁, is the thalamic fasciculus, a horizontal white matter tract composed of the ansa lenticularis, lenticular fasciculus, and cerebellothalamic tracts between the subthalamus and the thalamus. These fibers are projections to the ventral anterior and ventral lateral thalamus from the basal ganglia and the cerebellum. H₁ is separated from H₂ by the zona incerta.
• Field H₂ is also made up of projections from the pallidum to the thalamus, but these course the subthalamic nucleus.
• Field H is a large zone of mixed grey and white matter from the pallidothalamic tracts of the lenticular fasciculus and the ansa lenticularis which combine in an area just in front of the red nucleus. The grey matter from this field is said to form a prerubral nucleus.

  Nuclei campi perizonalis

• Nucleus campi medialis: the nucleus of prerubral field
• Nucleus campi dorsalis: Neurons scattered along the thalamic fasciculi in field H1 of Forel
• Nucleus campi ventralis: Neurons scattered along the lenticular fasciculi in field H2 of Forel