posterior tuberculum — Zebrafish UCL

Schematic showing the position of the posterior tuberculum split into dorsal and ventral regions in sagittal, horizontal and coronal sections through the zebrafish brain. Based on the anatomical segmentation of 3 day old zebrafish larval brain by T… — Schematic showing the position of the posterior tuberculum split into dorsal and ventral regions in sagittal, horizontal and coronal sections through the zebrafish brain.
Based on the anatomical segmentation of 3 day old zebrafish larval brain by Thomas Müller, Olaf Ronneberger, Wolfgang Driever and colleagues. For details see Ronneberger et al., Nat. Meth. 2012 and http://vibez.informatik.uni-freiburg.de
Abbreviations: Ce, cerebellar plate; D, dorsal telencephalon/pallium; E, epiphysis; EmT, eminentia thalami; Hb, habenula; Hyp, hypothalamus; MO, medulla oblongata; OB, olfactory bulb; OT, optic tectum; PG, preglomerular complex; PO, preoptic area;PrT, pretectum; PTd, posterior tuberculum dorsal part; PTh, prethalamus; PTv posterior tuberculum ventral part; Teg, tegmentum; Th, thalamus; TS, torus semicircularis; V, ventral telencephalon/subpallium; Va, valvula cerebelli.

Description

“The posterior tuberculum and the preglomerular complex are two dominant structures in the basal diencephalon of zebrafish, which also have no apparent counterparts in amniote tetrapods like birds and mammals. Yet, a large posterior tuberculum is present in jawless vertebrates (lampreys), cartilaginous fishes (sharks and manta rays), lungfish, and amphibians (Nieuwenhuys et al., 1998). In mammals, the basal plate derivatives of prosomere two and three are homologous to the dorsal and ventral posterior tubercular fields of developing zebrafish (Wullimann and Puelles, 1999). In the mature zebrafish brain, the posterior tuberculum comprises the periventricular nucleus of the posterior tuberculum with its characteristic large pear-shaped dopaminergic cells, the paraventricular organ, and the posterior tuberal nucleus. All of them are intercalated between prethalamus and hypothalamus (Rupp et al., 1996; Wullimann et al., 1996). Some of these dopaminergic neurons found in the posterior tuberculum of zebrafish project to the subpallium and have been compared and homologized with an anteriormost diencephalic, not mesencephalic, division of the mammalian ascending mesodiencephalic dopaminergic groups A8–A10 in mammals (Wullimann and Rink, 2001; Rink and Wullimann 2002).” (Mueller, 2012).

Schematic adapted from Mueller 2012 showing the nuclei that comprise the wider thalamus.

Abbreviations: A, anterior thalamic nucleus; CPo, centroposterior thalamic nucleus; D, dorsal telencephalon (pallium); DP, dorsoposterior thalamic nucleus; EmT, eminentia thalami; Hyp, hypothalamus; Hb, habenula; I, intermediate thalamic nucleus; IC, intercalated thalamic nucleus; OB, olfactory bulb; OT, optic tectum; P, posterior thalamic (preglomerular) nucleus; PG, preglomerular complex; PGa, anterior preglomerular nucleus; PGc, caudal preglomerular nucleus; PGl, lateral preglomerular nucleus; PGm, medial preglomerular nucleus; PO, preoptic region; PrT, pretectum; PVO, paraventricular organ; SG, subglomerular nucleus; TGN, tertiary gustatory nucleus; TPp, periventricular nucleus of posterior tuberculum; TPm, migrated nucleus of posterior tuberculum; V,ventral telencephalon (subpallium); VL, ventrolateral thalamic nucleus; VM, ventromedial thalamic nucleus.