Notes
Basal Ganglia Nomenclature
CORPUS STRIATUM: Comprises the caudate, putamen, and globus pallidus.
CAUDATE NUCLEUS: Divides into a head, body, and tail.
GLOBUS PALLIDUS: Divides into external (lateral) and internal (medial) segments. Called the pallidum (aka paleostriatum) because of the myelinated fibers that traverse it. Dorsal pallidum - bulk of the globus pallidus. Ventral pallidum - anteromedial portion of the globus pallidus that lies below the anterior commissure.
STRIATUM (NEOSTRIATUM): The combined caudate and putamen. Further subdivides into dorsal and ventral divisions. Dorsal striatum - comprises the bulk of the caudate and putamen and is involved in a wide array of processes, including sensorimotor circuits. Ventral striatum - limited to the ventromedial caudate and putamen, nucleus accumbens, and select basal forebrain structures and is primarily involved in emotional and behavioral processes.
LENTIFORM NUCLEUS: The combined globus pallidus and putamen. Has a lens-shaped appearance.
CORPUS STRIATUM FIBER PATHWAYS: Pass between the globus pallidus and the subthalamic nucleus and thalamus and comprise white matter inferolateral to the thalamus called the fields of Forel (aka prerubral fields or Forel’s Field H) - the ansa lenticularis, lenticular fasciculus, subthalamic fasciculus, and thalamic fasciculus.