Neural basis of orexigenic effects of ghrelin acting within lateral hypothalamus.
Ghrelin stimulates feeding when administered centrally and peripherally. The lateral hypothalamus (LH) is thought to mediate ghrelin-induced hyperphagia. Thus, we examined central mechanisms underlying feeding generated by LH ghrelin. We determined that 0.3nmol of LH-injected ghrelin was the lowest dose increasing food consumption and it induced Fos immunoreactivity (IR; a marker of neuronal activation) in feeding-related brain areas, including the hypothalamic paraventricular, arcuate, and dorsomedial nuclei, amygdala, and nucleus of the solitary tract. Also, LH ghrelin induced Fos IR in LH orexin neurons. We conclude that the LH, as part of larger central circuitry, integrates orexigenic properties of ghrelin.
Olszewski
Pawel K
PK
Veterans Affairs Medical Center, Research Service 151, Minneapolis, MN 55417, USA.
Li
Dehong
D
Grace
Martha K
MK
Billington
Charles J
CJ
Kotz
Catherine M
CM
Levine
Allen S
AS
D000679:Amygdala / Q000187:drug effects / Q000473:pathology; D000818:Animals; D001921:Brain / Q000473:pathology; D002352:Carrier Proteins / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D054439:Ghrelin; D007031:Hypothalamus / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology*; D007150:Immunohistochemistry; D047908:Intracellular Signaling Peptides and Proteins; D008024:Ligands; D008297:Male; D009474:Neurons / Q000378:metabolism*; D009479:Neuropeptides / Q000378:metabolism; D016761:Oncogene Proteins v-fos / Q000378:metabolism; D064446:Orexin Receptors; D000068797:Orexins; D036361:Peptide Hormones / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D043562:Receptors, G-Protein-Coupled / Q000737:chemistry; D054440:Receptors, Ghrelin; D018013:Receptors, Neuropeptide; D013997:Time Factors
D002352:Carrier Proteins; D054439:Ghrelin; D047908:Intracellular Signaling Peptides and Proteins; D008024:Ligands; D009479:Neuropeptides; D016761:Oncogene Proteins v-fos; D064446:Orexin Receptors; D000068797:Orexins; D036361:Peptide Hormones; D043562:Receptors, G-Protein-Coupled; D054440:Receptors, Ghrelin; D018013:Receptors, Neuropeptide