Vascular organ of lamina terminalis

The vascular organ of lamina terminalis (VOLT), organum vasculosum of the lamina terminalis (OVLT), or supraoptic crest[1] is a sensory organ, one of the circumventricular organs of the third ventricle within the lamina terminalis. It is covered with pia mater, and lined with ependyma.[2][3] It overlies the paraventricular nucleus of hypothalamus,[4] and is involved in the secretion of vasopressin.[2] The VOLT monitors the presence of peptides and macromolecules in the bloodstream, and conveys the information to the hypothalamus.[3]

Vascular organ of lamina terminalis
Details
Identifiers
Latinorganum vasculosum laminae terminalis
MeSHD066278
NeuroNames383
NeuroLex IDnlx_anat_100313
TA98A14.1.08.940
TA25781
FMA62315
Anatomical terms of neuroanatomy

It is one of the three sensory circumventricular organs of the brain.[5] The other four are secretory.[6]

Anteroventral third ventricle region

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The VOLT, median eminence, and subfornical organ are interconnected with the mid-ventral hypothalamus, and together these three structures surround the third ventricle, a complex often called the anteroventral region of the third ventricle ("AV3V" region).[7][8] This region functions in the regulation of fluid and electrolyte balance by controlling thirst, sodium excretion, blood volume regulation, and vasopressin secretion.[7][9]

Function

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The VOLT is one of the three sensory circumventricular organs providing information to other brain regions.[6][10]

VOLT capillaries do not have a blood–brain barrier, and so neurons in this region can respond to circulating factors present in the systemic circulation.[11][9]

Neurons in the VOLT are osmoreceptors sensitive to the sodium content and osmotic pressure of blood.[7] Neurons of the lamina terminalis project to the supraoptic nucleus and paraventricular nucleus to regulate the activity of vasopressin-secreting neurons.[9] In a situation of lowered blood volume, secretion of renin by the kidneys results in the production of angiotensin II, which stimulates receptors in the VOLT and subfornical organ to complete a positive feedback loop.[9][12][13] These neurons also project to the median preoptic nucleus which is involved in controlling thirst.[11][9][12]

References

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  1. ^ "Organum vasculosum". BrainInfo, University of Washington, Seattle.
  2. ^ a b Naganawa S, Taoka T, Kawai H, Yamazaki M, Suzuki K (April 2018). "Appearance of the Organum Vasculosum of the Lamina Terminalis on Contrast-enhanced MR Imaging". Magn Reson Med Sci. 17 (2): 132–137. doi:10.2463/mrms.mp.2017-0088. PMC 5891338. PMID 28966303.
  3. ^ a b Patestas, Maria A.; Gartner, Leslie P. (2016). A Textbook of Neuroanatomy (2nd ed.). Hoboken, New Jersey: Wiley-Blackwell. ISBN 978-1-118-67746-9.
  4. ^ "organe vasculaire de la lame terminale l.m. - Dictionnaire médical de l'Académie de Médecine". www.academie-medecine.fr. Retrieved 2024-05-24.
  5. ^ Kaur, C; Ling, EA (September 2017). "The circumventricular organs". Histology and Histopathology. 32 (9): 879–892. doi:10.14670/HH-11-881. PMID 28177105.
  6. ^ a b Whyte, DG; Johnson, AK (May 2005). "Thermoregulatory role of periventricular tissue surrounding the anteroventral third ventricle (AV3V) during acute heat stress in the rat". Clinical and Experimental Pharmacology & Physiology. 32 (5–6): 457–61. doi:10.1111/j.1440-1681.2005.04211.x. PMID 15854158.
  7. ^ a b c Johnson, A. K (1985). "The periventricular anteroventral third ventricle (AV3V): Its relationship with the subfornical organ and neural systems involved in maintaining body fluid homeostasis". Brain Research Bulletin. 15 (6): 595–601. doi:10.1016/0361-9230(85)90209-6. PMID 3910170. S2CID 4781981.
  8. ^ Miyata, S (2015). "New aspects in fenestrated capillary and tissue dynamics in the sensory circumventricular organs of adult brains". Frontiers in Neuroscience. 9: 390. doi:10.3389/fnins.2015.00390. PMC 4621430. PMID 26578857.
  9. ^ a b c d e Johnson, A. K; Gross, P. M (1993). "Sensory circumventricular organs and brain homeostatic pathways". FASEB Journal. 7 (8): 678–86. doi:10.1096/fasebj.7.8.8500693. PMID 8500693. S2CID 13339562.
  10. ^ Fry, Mark; Ferguson, Alastair V. (July 2007). "The sensory circumventricular organs: Brain targets for circulating signals controlling ingestive behavior". Physiology & Behavior. 91 (4): 413–423. doi:10.1016/j.physbeh.2007.04.003. PMID 17531276.
  11. ^ a b Gross, P. M; Weindl, A (1987). "Peering through the windows of the brain (review)". Journal of Cerebral Blood Flow & Metabolism. 7 (6): 663–72. doi:10.1038/jcbfm.1987.120. PMID 2891718. S2CID 18748366.
  12. ^ a b McKinley, M. J; Allen, A. M; May, C. N; McAllen, R. M; Oldfield, B. J; Sly, D; Mendelsohn, F. A (2001). "Neural pathways from the lamina terminalis influencing cardiovascular and body fluid homeostasis". Clinical and Experimental Pharmacology and Physiology. 28 (12): 990–2. doi:10.1046/j.1440-1681.2001.03592.x. PMID 11903300. S2CID 43091000.
  13. ^ Fitzgerald, M J Turlough (2012). Clinical Neuroanatomy and Neuroscience. Philadelphia: Saunders Elsevier. p. 281. ISBN 978-0-7020-3738-2.