Vascular organ of lamina terminalis
The vascular organ of lamina terminalis (VOLT), organum vasculosum of the lamina terminalis (OVLT), or supraoptic crest[1] is one of the four sensory circumventricular organs of the brain, the others being the subfornical organ, the median eminence, and the area postrema in the brainstem.[2]
| Vascular organ of lamina terminalis | |
|---|---|
| Details | |
| Identifiers | |
| Latin | organum vasculosum laminae terminalis |
| MeSH | D066278 |
| NeuroNames | 383 |
| NeuroLex ID | nlx_anat_100313 |
| TA98 | A14.1.08.940 |
| TA2 | 5781 |
| FMA | 62315 |
| Anatomical terms of neuroanatomy | |
Anteroventral third ventricle region
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 "AV3V" region.[2][3][4] This region functions in the regulation of fluid and electrolyte balance by controlling thirst, sodium excretion, blood volume regulation, and vasopressin secretion.[3][5]
Function
The VOLT is one of the four sensory circumventricular organs providing information to other brain regions (others are median eminence, subfornical organ, and area postrema).[2][6][7]
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.[2][5]
Neurons in the VOLT are osmoreceptors sensitive to the sodium content and osmotic pressure of blood.[3] Neurons of the lamina terminalis project to the supraoptic nucleus and paraventricular nucleus to regulate the activity of vasopressin-secreting neurons.[5] 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.[5][8][9] These neurons also project to the median preoptic nucleus which is involved in controlling thirst.[2][5][8]
References
- "Organum vasculosum". BrainInfo, University of Washington, Seattle.
- 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.
- 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.
- 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.
- 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.
- Shaver, S. W; Pang, J. J; Wainman, D. S; Wall, K. M; Gross, P. M (1992). "Morphology and function of capillary networks in subregions of the rat tuber cinereum". Cell and Tissue Research. 267 (3): 437–48. doi:10.1007/bf00319366. PMID 1571958. S2CID 27789146.
- Fry Mark, Ferguson Alastair V., (2007) The sensory circumventricular organs: Brain targets for circulating signals controlling ingestive behavior, Physiology & Behavior, Volume 91, Issue 4, 24 July 2007, Pages 413-423, ISSN 0031-9384, doi:10.1016/j.physbeh.2007.04.003.
- 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.
- Fitzgerald, M J Turlough (2012). Clinical Neuroanatomy and Neuroscience. Philadelphia: Saunders Elsevier. p. 281. ISBN 978-0-7020-3738-2.