Amygdalar opioids modulate hypothalamic melanocortin-induced anorexia

Autor: Charles J. Billington, Tiffany R. Beckman, Qiuying Shi, Allen S. Levine
Rok vydání: 2009
Předmět:
Male
endocrine system
medicine.medical_specialty
media_common.quotation_subject
Receptors
Opioid
mu
Experimental and Cognitive Psychology
Peptides
Cyclic
Article
Naltrexone
Rats
Sprague-Dawley
Eating
Behavioral Neuroscience
chemistry.chemical_compound
Melanocortin receptor
Internal medicine
Orexigenic
Neural Pathways
medicine
Animals
Drug Interactions
Opioid peptide
media_common
Neurotransmitter Agents
Appetite Regulation
digestive
oral
and skin physiology
Appetite
Melanotan II
Enkephalin
Ala(2)-MePhe(4)-Gly(5)
Amygdala
Hormones
Melanocortins
Rats
Analgesics
Opioid
DAMGO
Endocrinology
nervous system
chemistry
alpha-MSH
Receptor
Melanocortin
Type 4
Melanocortin
Food Deprivation
Psychology
hormones
hormone substitutes
and hormone antagonists
Paraventricular Hypothalamic Nucleus
Receptor
Melanocortin
Type 3
medicine.drug
Zdroj: Physiology & Behavior. 96:568-573
ISSN: 0031-9384
DOI: 10.1016/j.physbeh.2008.12.007
Popis: We wanted to assess the possibility that opioid activity in the central amygdala (CeA) could modulate the feeding inhibition of melanocortin stimulation of the paraventricular hypothalamus (PVN). The melanocortin system is important in both the acute regulation of satiety and feeding behavior and in the integration of long-term appetite signals. Melanotan II (MTII) is a synthetic MC3R and MC4R agonist which reduces food intake when given intracerebroventricularly (ICV) and into the PVN. Tyr-D-Ala-Gly-(me) Phe-Gly-ol (DAMGO), a µ-opioid receptor agonist, increases food intake, while opioid antagonists, like naltrexone (NTX), inhibit food intake after injection into many brain sites involved in appetite regulation, including the CeA. In food-deprived male Sprague-Dawley rats, co-injected intra-PVN MTII partially blocked the orexigenic effect of co-injected intra-CeA DAMGO. Intra-CeA NTX co-injected with intra-PVN MTII reduced food intake significantly more than either alone. NTX administered intra-CeA reduced c-Fos-immunoreactivity (IR) in nucleus accumbens neurons significantly compared to the intra-PVN MTII treated animals, animals co-injected intra-PVN with MTII and intra-CeA with NTX animals, and control animals. Intra-PVN MTII induced c-Fos-IR in significantly more PVN neurons than observed in control animals. Intra-CeA NTX co-injected with intra-PVN MTII induced c-Fos-IR significantly in PVN neurons relative to control and intra-CeA NTX animals. Such data support the significance of opioid action within the CeA as a modulator of the feeding regulation action of melanocortins within the PVN, occurring within the context of a larger appetitive network.
Databáze: OpenAIRE
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