Arcuate nucleus: difference between revisions
Diff·revision 8 → 9·04:18, 29 Dec 2024
Difference between revision 8 and revision 9 of Arcuate nucleus. 5 lines changed; the page grew by 704 bytes.
| Revision 8 — 01:54, 7 Dec 2024 LipidLedgerLou (talk) correct the second-messenger pathway named in the lead 3,033 bytes ±0 | Revision 9 — 04:18, 29 Dec 2024 CategoryBot (talk) bot: flag bare reference 3,737 bytes +704 | ||
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| 19 | The melanocortin-4 receptor is the convergence point, and loss-of-function mutations in it are the commonest known monogenic cause of severe early-onset obesity. Melanocortin agonists developed for other indications act on this same axis; see [[Melanotan II]] and [[Bremelanotide]].{{r|cone2005}} | 19 | The melanocortin-4 receptor is the convergence point, and loss-of-function mutations in it are the commonest known monogenic cause of severe early-onset obesity. Melanocortin agonists developed for other indications act on this same axis; see [[Melanotan II]] and [[Bremelanotide]].{{r|cone2005}} |
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| + | 21 | == Access to circulating signals == | |
| + | 22 | The median eminence is a circumventricular organ with fenestrated capillaries, and tanycytes lining the third ventricle provide a regulated route by which circulating molecules reach arcuate neurons. Access is not free — the tanycyte barrier is selective and its permeability changes with nutritional state — but it is far greater than across an intact blood-brain barrier.{{r|schwartz2000}} | |
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| + | 24 | This is the mechanistic basis for the central action of peripherally injected peptides that are far too large to cross the barrier elsewhere. It also explains why the area postrema, another circumventricular organ, is the site of the nausea produced by the same agents. | |
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| 21 | == References == | 26 | == References == |
| 22 | {{reflist}} | 27 | {{reflist}} |