Short official Latin term

Libelle of note

Traditionally, the Mesencephalon was subdivided into the Tectum (the Colliculi) and the Pedunculus (the Crus cerebri, the Substantia.VTA complex and the Tegmentum mesencephali). Here it is advocated to use the term Pedunculus only for what it actually is: a large bundle of fibres from the Telencephalon to the Brain stem and Spinal cord.

The Pars compacta may be further subdivided into two parts or tiers, each with subnuclei (Braak H, Braak E 1986 Nuclear configuration and neuronal types of the nucleus niger in the brain of the human adult. Human Neurobiol 5:71-82; van Domburg PHMF, ten Donkelaar HJ 1991 The human substantia nigra and ventral tegmental area. Adv Anat Embryol Cell Biol 121:1-130); here, the subdivision by Halliday G, Reyes S, Double K (2012 Substantia nigra, ventral tegmental area and retrorubral fields. In: Mai JK, Paxinos G, eds: The Human Nervous System, 3rd ed. Elsevier, Amsterdam, pp 439-455) is used. The various subnuclei partly correspond to the subdivision into Nigrosomes and Matrix (Damier P, Hirsch EC, Agid Y, Graybiel AM 1999 The substantia nigra of the human brain. I. Nigrosomes and the nigral matrix, a compartmental organization based on calbindin D28k immunohistochemistry. Brain 122:1421-1436).

The Nucleus externus is a laminar structure; in Amunts K, Morosan P, Hilbig H, Zilles K (2012 Auditory system. In: Mai JK, Paxinos G, eds: The Human Nervous System, 3rd ed. Elsevier, Amsterdam, pp 1270-1300) described as External cortex of Inferior colliculus (ECIC) to replace the TA term Nucleus lateralis. In TH, the Nucleus pericentralis is described as Dorsal cortex with Layers I-IV, based on: Geniec P, Morest DK (1971) The neuronal architecture of the human posterior colliculus; Acta Oto-Laryngol 295:(Suppl):1-33; supported by immunohistochemical data in rhesus monkeys by Amunts et al. (2012; their Dorsal cortex of inferior colliculus).

See note # 5672

The Tractus vestibulomesencephalici include (Büttner-Ennever JA, Gerrits NM 2004 Vestibular system. In: Paxinos G, Mai JK, eds. The Human Nervous System, 2nd ed. Elsevier, Amsterdam, pp 1213-1240): the Tractus vestibulomesencephalicus medialis, containing fibres from Vestibular nuclei to Oculomotor nuclei, passing via the MLF; the Tractus vestibulomesencephalicus lateralis, with fibres from the Lateral vestibular nucleus to Oculomotor nuclei, passing just lateral to the MLF (eponym: Ascending tract of Deiters; the Tractus vestibulomesencephalicus ventralis, with fibres from the Y group and the Superior vestibular nucleus crossing in the Ventral tegmentum either within or below the Brachium conjunctivum.

(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 two 'Olfactory gyri' in TA suggested their presence as clearly identifiable structures; this is not true. These terms remained from the classic description of the Rhinencephalon (see Gastaut H, Lammers HJ 1961 Anatomie du rhinencéphale. Masson, Paris) and have been deleted. The Cortex piriformis or Cortex olfactorius primarius is the real Olfactory cortex, and can be divided into Frontal and Temporal parts (Allison AC 1954 The secondary olfactory areas in the human brain. J Anat (Lond) 88:481-488; Heimer L, de Olmos J, Alheid GF, et al. 1999 The human basal forebrain, Part 2. Handb Chem Neuroanat 15:57-226).