(anatomy) Stalk of the pineal body. A ribbonlike structure.
Habenula
| Sci-Tech Dictionary: habenula |
(hə′ben·yə·lə)
| 5min Related Video: Habenula |
| Medical Dictionary: ha·ben·u·la |
(hă-bĕn'yə-lə)
n., pl. -lae (-lē').
n., pl. -lae (-lē').
- A frenulum.
- The stalk of the pineal gland. No longer in technical use.
- A circumscript cell mass embedded in the posterior end of the medullary stria of the thalamus, from which it receives most of its afferent fibers. Also called habena, pedunculus of pineal body.
| Veterinary Dictionary: habenula |
Pl. habenulae [L.]
1. any frenulum, especially one of a series of structures in the cochlea.
2. a triangular area in the dorsomedial aspect of the thalamus rostral to the pineal gland.
| Wikipedia: Habenula |
| 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 | |
| NeuroLex ID | birnlex_1611 | |
In neuroanatomy, habenula (diminutive of Latin habena meaning rein) 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. The habenular nucleus is a set of well conserved structures in all vertebrate animals.[1]
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.
The habenula receives input from the brain via the stria medullaris thalami and outputs to many midbrain areas involved in releasing neuromodulators, such as dopamine, norepinephrine, and serotonin.
Contents |
Anatomy
The habenula was traditionally divided into lateral (limbic) and medial (motor) parts.[2] Detailed examination of the region in the rat, however, suggested that the lateral part should be further divided into ten distinct subnuclei and the medial into five distinct subnuclei.[2]
Lateral habenula
The primary input regions to the lateral habenula are the lateral preoptic area (bringing input from the hippocampus and lateral septum), the ventral pallidum (bringing input from the nucleus accumbens and mediodorsal nucleus of the thalamus), the lateral hypothalamus, and the internal segment of the globus pallidus (bringing input from other basal ganglia structures).[3].
Neurons in the lateral habenula are ‘reward-negative’ as they are activated by stimulus associated with unpleasant events, the absence of the reward or punishment especially when this is unpredictable.[4] Reward information to the lateral habenula comes from the internal part of the globus pallidus.[5]
The outputs of the lateral habenula target dopaminergic regions (substantia nigra pars compacta and the
Medial habenula
Input to the medial hebanula comes from a variety of regions and carries a number of different chemicals. Input regions include septal nuclei (the fimbrialis septi and triangularis septi nuclei), dopaminergic inputs from the interfascicular nucleus of the ventral tegmental area, noradrenergic inputs from the locus ceruleus, and GABAergic inputs from the diagonal band of Broca.[7]
The medial habenula sends outputs of substance P and acetylcholine to the interpeduncular nucleus as well as to the pineal gland.[7]
Functions
The habenular nuclei have been shown to be involved in many functions, including pain processing, reproductive behavior, nutrition, sleep-wake cycles, stress responses, and learning.[1] Recent demonstrations using fMRI[8] and single unit electrophysiology[9] have closely linked the function of the lateral habenula with reward processing, in particular with regard to encoding negative feedback or negative rewards. Matsumoto and Hikosaka suggested in 2007 that this reward and reward-negative information in the brain might "be elaborated through the interplay among the lateral habenula, the basal ganglia, and monoaminergic (dopaminergic and serotonergic) systems" and that the lateral habenula may play a pivotal role in this "integrative function".[9]
External links
References
- ^ a b Andres et al. 1999
- ^ a b Iwahori 1977
- ^ a b Geisler 2008
- ^ Matsumoto M, Hikosaka O. (2009). Representation of negative motivational value in the primate lateral habenula. Nat Neurosci. 12(1):77-84. PMID 19043410
- ^ Hong S, Hikosaka O. (2008). The globus pallidus sends reward-related signals to the lateral habenula. Neuron. 60(4):720-9. PMID 19038227
- ^ Matsumoto M, Hikosaka O. (2007). Lateral habenula as a source of negative reward signals in dopamine neurons. Nature. 447(7148):1111-5. PMID 17522629
- ^ a b Lecourtier and Kelly 2007
- ^ Ullsperger and von Cramon 2003
- ^ a b Matsumoto and Hikosaka 2007
- Andres, KH; During MV, Veh RW (1999). "Subnuclear organization of the rat habenular complexes.". Journal of Comparative Neurology 407: 130-150. PMID 10213193.
- Geisler, S (2008). "The lateral habenula: no longer neglected.". CNS Spectrums 13: 484-489.
- Iwahori, N (1977). "A Golgi study on the habenular nucleus of the cat.". Journal of Comparative Neurology 72: 319-344.
- Lecourtier, L; Kelly PH (2007). "A conductor hidden in the orchestra? Role of the habenular complex in monoamine transmission and cognition". Neuroscience & Biobehavioral Reviews 31: 658-672. doi:. PMID 17379307.
- Matsumoto, M; Hikosaka O (2007). "Lateral habenula as a source of negative reward signals in dopamine neurons.". Nature 447: 1111-1115. doi:.
- Ullsperger, M; von Cramon, DY (2003). "Error monitoring using external feedback: Specific roles of the habenular complex, the reward system, and the cingulate motor area revealed by functional magnetic resonance imaging". Journal of Neuroscience 23: 4308-4314.
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 | epithalamus (anatomy) |
| peduncle |
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