Short official Latin term

Libelle of note

The Diencephalon in its classic, columnar view was divided into four dorsoventrally arranged columns separated by ventricular sulci: the Epithalamus, the Dorsal thalamus, the Ventral thalamus and the Hypothalamus. Extensive embryological studies made it clear that the thalamic 'columns' are derived from transversely oriented zones, the Prosomeres (see TE). Currently, the (Caudal) Diencephalon is subdivided into three segmental units, which from caudal to rostral, contain in their alar domains the Pretectum (prosomere 1 or P1), the Epithalamus and the Thalamus (P2) and the Ventral thalamus or Prethalamus (P3). The diencephalic basal plate contains the rostral part of the Substantia nigra-VTA complex and some other nuclei, collectively forming the Diencephalic or Prerubral tegmentum between the Mesencephalon and the Hypothalamus. The entire Hypothalamus or Rostral diencephalon arises from the alar and basal components of the secondary prosencephalon. The Preoptic area is one of the subpallial developmental domains (Puelles L, Harrison M, Paxinos G, Watson C 2013 A developmental ontology for the mammalian brain based on the prosomeric model. Trends Neurosci 36:570-578).

For the Thalamic nuclei, a new subdivision based on Hirai T, Jones EG (1989 A new parcellation of the human thalamus on the basis of histochemical staining. Brain Res Rev 14:1-34) and updated by Morel A, Magnin M, Jeanmonod D (1997 Multiarchitectonic and stereotactic atlas of the human thalamus. J Comp Neurol 387:618-677) is used to replace the list of terms in TA (14.1.08.603-14.1.08.658), largely a matter of a more practical grouping of nuclei. As Latin synonym the term Regio is adopted from Percheron G (2004 Thalamus. In: Paxinos G, Mai JK, eds: The Human Nervous System, 2nd ed. Elsevier, Amsterdam, pp 592-675).

New term, described by Horn, AKE, Büttner-Ennever, JA (1998 Premotor neurons for vertical eye-movements in the rostral mesencephalon of monkey and man: The histological identification by parvalbumin immunostaining. J Comp Neurol 392:413-427) as a premotor nucleus for vertical eye movements.

See note # 8641

(Tractus trigeminothalamici): The Tractus trigeminothalamicus anterior arises in the Spinal trigeminal nucleus and joins the Medial lemniscus, whereas the Tractus trigeminothalamicus lateralis arises in the Caudal part of the Spinal trigeminal nucleus and joins the Anterolateral tract.

(Tractus vestibulothalamicus): In monkeys, Vestibulothalamic projections pass via both the FLM and the Ascending tract of Deiters (Lang W, Büttner-Ennever JA, Büttner U 1979 Vestibular projections to the monkey thalamus: An autoradiographic study. Brain Res 177:3-17). Zwergal et al. (2008) demonstrated a Vestibulothalamic tract adjacent to the Medial lemniscus in humans (Zwergal A, Büttner-Ennever JA, Brandt T, Strupp M 2008 An ipsilateral vestibulothalamic tract adjacent to the medial lemniscus in humans. Brain 131:2928-2935).

The basal parts of the prosomeres P1-P3 form several nuclei, previously included in the Mesencephalon (see General footnote). The rostral parts of the Substantia nigra/VTA-complex also derive from P1-P3. The term Tegmentum prerubrale is preferred as topographic term over Tegmentum diencephali.

The Nucleus ventromedialis posterior (Ventromedial posterior nucleus; VMpo) is a newly discovered nucleus involved in pain perception as part of the Ventromedial nucleus (Blomqvist A, Zhang ET, Craig AD 2000 Cytoarchitectonic and immunohistochemical characterization of a specific pain and tempearature relay, the posterior portion of the ventral medial nucleus, in the human thalamus. Brain 123:601-619).

Replaced from Mesencephalon; for the subdivision of this nucleus, Principal and Magnocellular parts are adopted, following Olszewski and Baxter3. The Ventral division is renamed as Nucleus ellipticus (coming from Cetacea and Proboscidea) or Nucleus of Darkschewitsch, not part of the Nucleus of the posterior commissure.