Arcuate nucleus: difference between revisions
Diff·revision 4 → 5·20:33, 22 Oct 2024
Difference between revision 4 and revision 5 of Arcuate nucleus. 2 lines changed; the page grew by 353 bytes.
| Revision 4 — 16:07, 8 Oct 2024 DiagramDelphine (talk) give the magnitude of the incretin effect as a percentage of the insulin response 2,347 bytes ±0 | Revision 5 — 20:33, 22 Oct 2024 BetaCellBoyd (talk) expand §Access to circulating signals 2,700 bytes +353 | ||
|---|---|---|---|
| 10 | Its position adjacent to the median eminence, where the capillaries are fenestrated, gives it unusual access to circulating signals. Hormones that cannot cross an intact blood-brain barrier can nonetheless influence arcuate neurons, which is why the nucleus is a principal target for peripherally administered peptides including [[GLP-1 receptor agonist|GLP-1 receptor agonists]].{{r|schwartz2000}} | 10 | Its position adjacent to the median eminence, where the capillaries are fenestrated, gives it unusual access to circulating signals. Hormones that cannot cross an intact blood-brain barrier can nonetheless influence arcuate neurons, which is why the nucleus is a principal target for peripherally administered peptides including [[GLP-1 receptor agonist|GLP-1 receptor agonists]].{{r|schwartz2000}} |
| 11 | 11 | ||
| + | 12 | POMC and AgRP neurons project to the paraventricular nucleus and other second-order sites, where POMC-derived α-melanocyte-stimulating hormone acts at melanocortin-4 receptors and AgRP acts as an inverse agonist at the same receptors. This shared endpoint is what makes the two populations genuinely opposed rather than merely parallel.{{r|cone2005}} | |
| + | 13 | ||
| 12 | == Neuronal populations == | 14 | == Neuronal populations == |
| 13 | POMC neurons synthesise a precursor that is cleaved to α-melanocyte-stimulating hormone and other products. Released α-MSH acts at melanocortin-3 and melanocortin-4 receptors on downstream neurons to suppress food intake. These neurons are activated by leptin, insulin and [[Glucagon-like peptide-1|GLP-1]] receptor signalling.{{r|cone2005,woods2009}} | 15 | POMC neurons synthesise a precursor that is cleaved to α-melanocyte-stimulating hormone and other products. Released α-MSH acts at melanocortin-3 and melanocortin-4 receptors on downstream neurons to suppress food intake. These neurons are activated by leptin, insulin and [[Glucagon-like peptide-1|GLP-1]] receptor signalling.{{r|cone2005,woods2009}} |