Behavioral characterization of amygdala involvement in mediating intra-accumbens opioid-driven feeding behavior.
The present experiments were conducted to provide a more detailed behavioral analysis of the dissociable roles of the basolateral (BLA) and central nucleus (CeA) of the amygdala in mediating intra-accumbens (Acb) opioid-induced feeding of a high-fat diet. Confirming previous findings, temporary inactivation of the CeA with the GABAA agonist muscimol reduced DAMGO (D-Ala2-NMe-Phe4-Glyol5-enkephalin)-induced and baseline food intake, whereas intra-BLA muscimol selectively blocked only DAMGO-induced food intake, leaving baseline feeding intact. However, although inactivation of the BLA reduced DAMGO-induced food intake to control levels, this treatment led to exaggerated number and duration of food hopper entries after food intake had ended. A subsequent experiment under conditions of limited access to the diet found the identical pattern of behavior following intra-Acb administration of DAMGO, regardless of whether the BLA was inactivated. Last, BLA inactivation was shown to have no influence on feeding driven by a state of negative-energy balance (24-hr food deprivation), demonstrating a specific influence of the BLA on opioid-driven feeding. These findings suggest that BLA mediates palatability-driven feeding and that this influence is particular to the consummatory act of ingestion.
Will
Matthew J
MJ
Department of Psychological Sciences, University of Missouri-Columbia, Christopher Bond Life Sciences Center, 1201 Rollins St., Columbia, MO 65211, USA. willm@missouri.edu
Pritchett
Carolyn E
CE
Parker
Kyle E
KE
Sawani
A M
AM
Ma
H
H
Lai
Annie Y
AY
D000679:Amygdala / Q000187:drug effects* / Q000502:physiology; D000701:Analgesics, Opioid / Q000494:pharmacology*; D000704:Analysis of Variance; D000818:Animals; D004032:Diet; D004041:Dietary Fats / Q000008:administration & dosage; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)- / Q000494:pharmacology*; D005247:Feeding Behavior / Q000187:drug effects* / Q000502:physiology; D018755:GABA Agonists / Q000494:pharmacology; D058785:GABA-A Receptor Agonists; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D009118:Muscimol / Q000494:pharmacology; D009714:Nucleus Accumbens / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
D000701:Analgesics, Opioid; D004041:Dietary Fats; D018755:GABA Agonists; D058785:GABA-A Receptor Agonists; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D009118:Muscimol