The fields of Forel is a complex region in the posterior

subthalamus The subthalamus or ventral thalamus is a part of the diencephalon. Its most prominent structure is the subthalamic nucleus. The subthalamus connects to the globus pallidus, a subcortical nucleus of the basal ganglia. Structure The subthalamus ...

, consisting of a concentrated collection of bundles of

fibers Fiber (spelled fibre in British English; from ) is a natural or artificial substance that is significantly longer than it is wide. Fibers are often used in the manufacture of other materials. The strongest engineering materials often inco ...

. The

tracts Tract may refer to: Geography and real estate * Housing tract, an area of land that is subdivided into smaller individual lots * Land lot or tract, a section of land * Census tract, a geographic region defined for the purpose of taking a census ...

formed include the thalamic fasciculus that includes the

ansa lenticularis The ansa lenticularis (''ansa lentiformis'' in older texts) is a part of the brain, making up the superior layer of the substantia innominata. Its fibers, derived from the medullary lamina of the lentiform nucleus, pass medially to end in the thal ...

and lenticular fasciculus, cerebellothalamic tracts, and pallidothalamic tracts. Other included fibers connect to other brain regions. These tracts are described in regions known as ''H fields''.

H fields

*Field H₁, is the thalamic fasciculus, a horizontal white matter tract composed of the

, 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 The basal ganglia (BG) or basal nuclei are a group of subcortical Nucleus (neuroanatomy), nuclei found in the brains of vertebrates. In humans and other primates, differences exist, primarily in the division of the globus pallidus into externa ...

(

globus pallidus The globus pallidus (GP), also known as paleostriatum or dorsal pallidum, is a major component of the Cerebral cortex, subcortical basal ganglia in the brain. It consists of two adjacent segments, one external (or lateral), known in rodents simpl ...

) and the

cerebellum The cerebellum (: cerebella or cerebellums; Latin for 'little brain') is a major feature of the hindbrain of all vertebrates. Although usually smaller than the cerebrum, in some animals such as the mormyrid fishes it may be as large as it or eve ...

. H₁ is separated from H₂ by the

zona incerta The zona incerta (ZI) is a horizontally elongated small Nucleus (neuroanatomy), nucleus that separates the larger subthalamic nucleus from the thalamus. Its connections project extensively over the brain from the cerebral cortex down into the spin ...

. *Field H₂ (synonymous with lenticular fasciculus) is also made up of projections from the

pallidum The globus pallidus (GP), also known as paleostriatum or dorsal pallidum, is a major component of the subcortical basal ganglia in the brain. It consists of two adjacent segments, one external (or lateral), known in rodents simply as the globus p ...

to the thalamus, but these course the subthalamic nucleus (dorsal). *Field H (sometimes called field H₃) is a large zone of mixed

grey Grey (more frequent in British English) or gray (more frequent in American English) is an intermediate color between black and white. It is a neutral or achromatic color, meaning that it has no chroma. It is the color of a cloud-covered s ...

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 red nucleus or nucleus ruber is a structure in the rostral midbrain involved in motor coordination. The red nucleus is pale pink, which is believed to be due to the presence of iron in at least two different forms: hemoglobin and ferritin. ...

. The grey matter from this field is said to form a ''prerubral'' nucleus.

Nuclei campi perizonalis

Nuclei campi perizonalis or the nuclei of the perizonal fields (of Forel) are a group of nuclei in the

, (or ventral thalamus).They comprise 3 groups of nuclei arranged as follows: *Nucleus campi medialis: the nucleus of prerubral field (field H) *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

External links

Fields of Forel - Biology Online Dictionary
*Forel, A. (1877). "Untersuchungen über die Haubenregion und ihre oberen Verknüpfungen im Gehirne des Menschen und einiger Säugethiere, mit Beiträgen zu den Methoden der Gehirnuntersuchung". Archiv für Psychiatrie und Nervenkrankheiten 7: 393–495. .

References

{{Diencephalon Subthalamus