The ventral posteromedial nucleus (VPM) is a nucleus within the ventral posterior nucleus of the thalamus and serves an analogous somatosensory relay role for the ascending trigeminothalamic tracts as its lateral neighbour the ventral posterolateral nucleus serves for dorsal column–medial lemniscus pathway 2nd-order neurons.[1]
| Ventral posteromedial nucleus | |
|---|---|
 Thalamic nuclei: MNG = Midline nuclear group AN = Anterior nuclear group MD = Medial dorsal nucleus VNG = Ventral nuclear group VA = Ventral anterior nucleus VL = Ventral lateral nucleus VPL = Ventral posterolateral nucleus VPM = Ventral posteromedial nucleus LNG = Lateral nuclear group PUL = Pulvinar MTh = Metathalamus LG = Lateral geniculate nucleus MG = Medial geniculate nucleus | |
 Thalamic nuclei | |
| Details | |
| Identifiers | |
| Latin | nucleus ventralis posteromedialis |
| NeuroNames | 347 |
| NeuroLex ID | birnlex_743 |
| TA98 | A14.1.08.642 |
| TA2 | 5693 |
| FMA | 62202 |
| Anatomical terms of neuroanatomy | |
The term "ventral posteromedial nucleus" was introduced by Le Gros Clark in 1930.[2][3]
Afferents and efferents
editOrofacial somatosensory
editThe VPM receives second-order general somatic afferent fibers from the ventral trigeminal tract and the dorsal trigeminal tract which convey general somatic sensory information from the face and oral cavity (including touch, pressure, temperature, pain, and propriception). Proprioceptive synapses are situated anteriorly, ones mediating touch in the middle, and nociceptive ones posteriorly.[4]
Third-order neurons in turn project to the somatosensory cortex in the postcentral gyrus.
Taste
editThe VPM receives second-order taste special visceral afferents from the solitary nucleus.[4] These synapse in the medial-most portion of the VPM,[5] which is sometimes referred to as the accessory arcuate nucleus.[6]
Third-order neurons in turn project to the gustatory cortex.
Visceral sensations
editThe VPM likely also receives some general visceral afferents from the solitary tract conveying non-nociceptive visceral conscious sensations.[7]
Subareas
editVPMpc
editThe VPMpc is the parvicellular part of the ventral posteromedial nucleus. The VPMpc receives ipsilateral projection inputs from the medial parabrachial nucleus, the "gustatory responsive waist region" of the parabrachial nucleus (which has inputs from the solitary nucleus). The axons of these VPMpc relay neurons make synapses with neurons in all layers of the gustatory cortex.[8]
The VPMpc is argued by some as not actually a part of the VPM, because it does not project to the somatosensory cortex as the remainder of the VPM does, and therefore should be called the basal ventromedial (or ventral medial) nucleus (VMb) instead.[9][10] However, later authors have retained the VPMpc abbreviation, meaning the parvicellular part of the VPM.[11][12]
See also
edit- Ventral posterolateral nucleus — relays somatosensory afferents from the rest of the body (dorsal column–medial lemniscus pathway, and spinothalamic tract).
- Ventrobasal complex
- List of thalamic nuclei
References
edit- ^ Sheridan, Nicholas; Tadi, Prasanna (2023), "Neuroanatomy, Thalamic Nuclei", StatPearls, Treasure Island (FL): StatPearls Publishing, PMID 31751098, retrieved 2023-09-17
- ^ Jones, Edward G (1985). The Thalamus. New York: Springer. p. 327. doi:10.1007/978-1-4615-1749-8. ISBN 978-1-4613-5704-9. S2CID 41337319.
- ^ Le Gros Clark, W. E. (1930). "The Thalamus of Tarsius". Journal of Anatomy. 64 (4): 371–414. PMC 1250146. PMID 17104288.
- ^ a b Patestas, Maria A.; Gartner, Leslie P. (2016). A Textbook of Neuroanatomy (2nd ed.). Hoboken, New Jersey: Wiley-Blackwell. p. 473. ISBN 978-1-118-67746-9.
- ^ Hall, Michael E.; Hall, John E. (2021). Guyton and Hall textbook of medical physiology (14th ed.). Philadelphia, PA: Elsevier. p. 678. ISBN 978-0-323-59712-8.
- ^ Standring, Susan (2020). Gray's Anatomy: The Anatomical Basis of Clinical Practice (42th ed.). New York: Elsevier. p. 449. ISBN 978-0-7020-7707-4. OCLC 1201341621.
- ^ Kiernan, John A.; Rajakumar, Nagalingam (2013). Barr's The Human Nervous System: An Anatomical Viewpoint (10th ed.). Philadelphia: Wolters Kluwer Lippincott Williams & Wilkins. p. 137. ISBN 978-1-4511-7327-7.
- ^ Courtiol, Emmanuelle; Maffei, Arianna; Fontanini, Alfredo (2024). "Thalamocortical contributions to chemical senses". In Usrey, W. Martin; Sherman, S. Murray (eds.). The cerebral cortex and thalamus. New York: Oxford University Press. pp. 300–302. ISBN 978-0-19-767615-8.
- ^ Craig, A.D. (2002). "How do you feel? Interoception: the sense of the physiological condition of the body". Nature Reviews Neuroscience. 3 (8): 655–666. doi:10.1038/nrn894. PMID 12154366. S2CID 17829407.
- ^ Jones 1985, pp. 327, 420.
- ^ Courtiol, Maffei & Fontanini 2024, p. 297.
- ^ BrainInfo NeuroName 349
Additional images
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Thalamus
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