Habenula
From Wikipedia, the free encyclopedia
| Brain: Habenula | ||
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| Mesal aspect of a brain sectioned in the median sagittal plane. Habenula is not labeled directly, but after expanding, look to region with 'habenular commissure', 'pineal body', and 'posterior commissure' | ||
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| 1. Taenia choroidea (and lateral: Lamina affixa, Stria terminalis) 2. Thalamus, Pulvinar thalami 3. Third ventricle 4. Stalk of pineal gland 5. Habenula 6. Stria medullaris 7. Superior colliculus 8. Brachium of superior colliculus 9. Inferior colliculus 10. Brachium of inferior colliculus 11. Medial geniculate nucleus 12. Sulcus medianus 13. Superior cerebellar peduncles 14. Inferior cerebellar peduncle 15. Middle cerebellar peduncles 16. Tuberculum anterius thalami 17. Obex, Area postrema |
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| NeuroNames | hier-277 | |
| MeSH | habenula | |
| Dorlands/Elsevier | h_01/12405682 | |
In neuroanatomy, habenula originally denoted the stalk of the pineal gland (pineal habenula; pedunculus of pineal body), but gradually came to refer to a neighboring group of nerve cells with which the pineal gland was believed to be associated, the habenular nucleus. Currently, the Terminologia Anatomica term refers exclusively to this separate cell mass in the caudal and dorsal aspect of the dorsal thalamus, the epithalamus, embedded in the posterior end of the medullary stria from which it receives most of its afferent fibers. By way of the retroflex fasciculus (habenulointerpeduncular tract) it projects to the interpeduncular nucleus and other paramedian cell groups of the midbrain tegmentum. Despite its proximity to the pineal stalk, no connecting tissue is known to exist.
The habenula is involved in receiving input from the brain via the stria medullaris thalami and output to many midbrain areas involved in releasing personality-related neurotransmitters and neuromodulators, such as dopamine, norepinephrine, and serotonin (from the ventral tegmental area, locus coeruleus and raphe nucleus respectively.)
The habenula is the only nucleus of the epithalamus.
