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The habenular nuclei: a conserved asymmetric relay station in the vertebrate brain.

Bianco IH, Wilson SW - Philos. Trans. R. Soc. Lond., B, Biol. Sci. (2009)

Bottom Line: The habenulae form part of the dorsal diencephalic conduction (DDC) system, a highly conserved pathway found in all vertebrates.In this review, we shall describe the neuroanatomy of the DDC, consider its physiology and behavioural involvement, and discuss examples of neural asymmetries within both habenular circuitry and the pineal complex.We will discuss studies in zebrafish, which have examined the organization and development of this circuit, uncovered how asymmetry is represented at the level of individual neurons and determined how such left-right differences arise during development.

View Article: PubMed Central - PubMed

Affiliation: Department of Cell and Developmental Biology, University College London, London, UK. ibianco@mcb.harvard.edu

ABSTRACT
The dorsal diencephalon, or epithalamus, contains the bilaterally paired habenular nuclei and the pineal complex. The habenulae form part of the dorsal diencephalic conduction (DDC) system, a highly conserved pathway found in all vertebrates. In this review, we shall describe the neuroanatomy of the DDC, consider its physiology and behavioural involvement, and discuss examples of neural asymmetries within both habenular circuitry and the pineal complex. We will discuss studies in zebrafish, which have examined the organization and development of this circuit, uncovered how asymmetry is represented at the level of individual neurons and determined how such left-right differences arise during development.

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Connectivity of the DDC. This schematic shows the principal connections of the medial and lateral habenulae and interpeduncular nucleus as described in mammals, in particular the rat. Thick arrows highlight the septum–MHb–IPN axis and the convergence of limbic and striatal inputs into the lateral habenula. Notably, there are very limited data regarding the relative functional importance of the various connections shown here. Acb, nucleus accumbens; Circad., potential sources of circadian information; CPu, caudate/putamen; Dors. Teg. region, dorsal tegmental region; DBB, nucleus of diagonal band; DTN, ventral tegmental nucleus of Güdden; EP, entopeduncular nucleus; FrCx, frontal cortex; HippoF, hippocampal formation; IPN, interpeduncular nucleus; LC, locus coeruleus; LH, lateral hypothalamic area; LHb, lateral habenula; LPO, lateral preoptic area; MHb, medial habenula; NI, nucleus incerta; P, pineal; SC, superior colliculus; SCN, suprachiasmatic nucleus; SNc, substantia nigra pars compacta; sf, septofimbrial nucleus; Thal, thalamic nuclei; tr, nucleus triangularis; VTA, ventral tegmental area; VTN, ventral tegmental nucleus of Güdden.
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fig1: Connectivity of the DDC. This schematic shows the principal connections of the medial and lateral habenulae and interpeduncular nucleus as described in mammals, in particular the rat. Thick arrows highlight the septum–MHb–IPN axis and the convergence of limbic and striatal inputs into the lateral habenula. Notably, there are very limited data regarding the relative functional importance of the various connections shown here. Acb, nucleus accumbens; Circad., potential sources of circadian information; CPu, caudate/putamen; Dors. Teg. region, dorsal tegmental region; DBB, nucleus of diagonal band; DTN, ventral tegmental nucleus of Güdden; EP, entopeduncular nucleus; FrCx, frontal cortex; HippoF, hippocampal formation; IPN, interpeduncular nucleus; LC, locus coeruleus; LH, lateral hypothalamic area; LHb, lateral habenula; LPO, lateral preoptic area; MHb, medial habenula; NI, nucleus incerta; P, pineal; SC, superior colliculus; SCN, suprachiasmatic nucleus; SNc, substantia nigra pars compacta; sf, septofimbrial nucleus; Thal, thalamic nuclei; tr, nucleus triangularis; VTA, ventral tegmental area; VTN, ventral tegmental nucleus of Güdden.

Mentions: In mammals, the habenular complex comprises two separate nuclei on each side: the ‘medial’ (MHb) and ‘lateral’ (LHb) habenulae. The LHb is further subdivided into principal medial and lateral subdivisions. Despite sharing some sources of afferent inputs and efferent targets, the medial and lateral habenulae appear to represent largely distinct subcircuits within the DDC (Herkenham & Nauta 1977, 1979; Kim & Chang 2005). In outlining the anatomy of this circuit, we shall focus primarily on the patterns of connectivity in the rat, which have been well studied (figure 1). Some species differences will also be mentioned, where relevant, but we will not attempt a description of the comparative neuroanatomy of the DDC in any detail.


The habenular nuclei: a conserved asymmetric relay station in the vertebrate brain.

Bianco IH, Wilson SW - Philos. Trans. R. Soc. Lond., B, Biol. Sci. (2009)

Connectivity of the DDC. This schematic shows the principal connections of the medial and lateral habenulae and interpeduncular nucleus as described in mammals, in particular the rat. Thick arrows highlight the septum–MHb–IPN axis and the convergence of limbic and striatal inputs into the lateral habenula. Notably, there are very limited data regarding the relative functional importance of the various connections shown here. Acb, nucleus accumbens; Circad., potential sources of circadian information; CPu, caudate/putamen; Dors. Teg. region, dorsal tegmental region; DBB, nucleus of diagonal band; DTN, ventral tegmental nucleus of Güdden; EP, entopeduncular nucleus; FrCx, frontal cortex; HippoF, hippocampal formation; IPN, interpeduncular nucleus; LC, locus coeruleus; LH, lateral hypothalamic area; LHb, lateral habenula; LPO, lateral preoptic area; MHb, medial habenula; NI, nucleus incerta; P, pineal; SC, superior colliculus; SCN, suprachiasmatic nucleus; SNc, substantia nigra pars compacta; sf, septofimbrial nucleus; Thal, thalamic nuclei; tr, nucleus triangularis; VTA, ventral tegmental area; VTN, ventral tegmental nucleus of Güdden.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2666075&req=5

fig1: Connectivity of the DDC. This schematic shows the principal connections of the medial and lateral habenulae and interpeduncular nucleus as described in mammals, in particular the rat. Thick arrows highlight the septum–MHb–IPN axis and the convergence of limbic and striatal inputs into the lateral habenula. Notably, there are very limited data regarding the relative functional importance of the various connections shown here. Acb, nucleus accumbens; Circad., potential sources of circadian information; CPu, caudate/putamen; Dors. Teg. region, dorsal tegmental region; DBB, nucleus of diagonal band; DTN, ventral tegmental nucleus of Güdden; EP, entopeduncular nucleus; FrCx, frontal cortex; HippoF, hippocampal formation; IPN, interpeduncular nucleus; LC, locus coeruleus; LH, lateral hypothalamic area; LHb, lateral habenula; LPO, lateral preoptic area; MHb, medial habenula; NI, nucleus incerta; P, pineal; SC, superior colliculus; SCN, suprachiasmatic nucleus; SNc, substantia nigra pars compacta; sf, septofimbrial nucleus; Thal, thalamic nuclei; tr, nucleus triangularis; VTA, ventral tegmental area; VTN, ventral tegmental nucleus of Güdden.
Mentions: In mammals, the habenular complex comprises two separate nuclei on each side: the ‘medial’ (MHb) and ‘lateral’ (LHb) habenulae. The LHb is further subdivided into principal medial and lateral subdivisions. Despite sharing some sources of afferent inputs and efferent targets, the medial and lateral habenulae appear to represent largely distinct subcircuits within the DDC (Herkenham & Nauta 1977, 1979; Kim & Chang 2005). In outlining the anatomy of this circuit, we shall focus primarily on the patterns of connectivity in the rat, which have been well studied (figure 1). Some species differences will also be mentioned, where relevant, but we will not attempt a description of the comparative neuroanatomy of the DDC in any detail.

Bottom Line: The habenulae form part of the dorsal diencephalic conduction (DDC) system, a highly conserved pathway found in all vertebrates.In this review, we shall describe the neuroanatomy of the DDC, consider its physiology and behavioural involvement, and discuss examples of neural asymmetries within both habenular circuitry and the pineal complex.We will discuss studies in zebrafish, which have examined the organization and development of this circuit, uncovered how asymmetry is represented at the level of individual neurons and determined how such left-right differences arise during development.

View Article: PubMed Central - PubMed

Affiliation: Department of Cell and Developmental Biology, University College London, London, UK. ibianco@mcb.harvard.edu

ABSTRACT
The dorsal diencephalon, or epithalamus, contains the bilaterally paired habenular nuclei and the pineal complex. The habenulae form part of the dorsal diencephalic conduction (DDC) system, a highly conserved pathway found in all vertebrates. In this review, we shall describe the neuroanatomy of the DDC, consider its physiology and behavioural involvement, and discuss examples of neural asymmetries within both habenular circuitry and the pineal complex. We will discuss studies in zebrafish, which have examined the organization and development of this circuit, uncovered how asymmetry is represented at the level of individual neurons and determined how such left-right differences arise during development.

Show MeSH