PMID- 21543633
OWN - NLM
STAT- MEDLINE
DCOM- 20110908
LR  - 20211020
IS  - 1522-1490 (Electronic)
IS  - 0363-6119 (Print)
IS  - 0363-6119 (Linking)
VI  - 301
IP  - 1
DP  - 2011 Jul
TI  - mu-Opioid receptor stimulation in the nucleus accumbens elevates fatty tastant 
      intake by increasing palatability and suppressing satiety signals.
PG  - R244-54
LID - 10.1152/ajpregu.00406.2010 [doi]
AB  - Infusion of a mu-opioid receptor (MOR) agonist into the nucleus accumbens (NAcc) 
      drives voracious food intake, an effect hypothesized to occur through increased 
      tastant palatability. While intake of many palatable foods is elevated by MOR 
      stimulation, this manipulation has a preferential effect on fatty food ingestion. 
      Consumption of high-fat foods is increased by NAcc MOR stimulation even in rats 
      that prefer a carbohydrate-rich alternative under baseline conditions. This 
      suggests that NAcc MOR stimulation may not simply potentiate palatability signals 
      and raises the possibility that mechanisms mediating fat intake may be distinct 
      from those underlying intake of other tastants. The present study was conducted 
      to investigate the physiological mechanisms underlying the effects of NAcc MOR 
      stimulation on fatty food intake. In experiment 1, we analyzed lick 
      microstructure in rats ingesting Intralipid to identify the changes underlying 
      feeding induced by infusion of a MOR-specific agonist into the NAcc. MOR 
      stimulation in the NAcc core, but not shell, increased burst duration and 
      first-minute licks, while simultaneously increasing the rate and duration of 
      Intralipid ingestion. These results suggest that MOR activation in the core 
      increases Intralipid palatability and attenuates inhibitory postingestive 
      feedback. In experiment 2, we measured the effects of MOR stimulation in the NAcc 
      core on consumption of nonnutritive olestra. A MOR-specific agonist dose 
      dependently increased olestra intake, demonstrating that caloric signaling is not 
      required for hyperphagia induced by NAcc MOR stimulation. Feeding induced by drug 
      infusion in both experiments 1 and 2 was blocked by a MOR antagonist. In 
      experiment 3, we determined whether MOR activation in the NAcc core could 
      attenuate satiety-related signaling caused by infusion of the melanocortin 
      agonist MTII into the third ventricle. Suppression of intake caused by MTII was 
      reversed by MOR stimulation. Together, our results suggest that MOR stimulation 
      in the NAcc core elevates fatty food intake through palatability mechanisms 
      dependent on orosensory cues and suppression of satiety signals inhibiting food 
      intake.
FAU - Katsuura, Yoshihiro
AU  - Katsuura Y
AD  - Department of Physiology, University of Utah School of Medicine, Salt Lake City, 
      Utah, USA.
FAU - Heckmann, Jennifer A
AU  - Heckmann JA
FAU - Taha, Sharif A
AU  - Taha SA
LA  - eng
GR  - R21 MH082325/MH/NIMH NIH HHS/United States
GR  - MH-082325/MH/NIMH NIH HHS/United States
PT  - Journal Article
PT  - Research Support, N.I.H., Extramural
PT  - Research Support, Non-U.S. Gov't
DEP - 20110504
PL  - United States
TA  - Am J Physiol Regul Integr Comp Physiol
JT  - American journal of physiology. Regulatory, integrative and comparative 
      physiology
JID - 100901230
RN  - 0 (Analgesics, Opioid)
RN  - 0 (Dietary Fats)
RN  - 0 (Fatty Acids)
RN  - 0 (Melanocortins)
RN  - 0 (Receptors, Opioid, mu)
RN  - 100929-53-1 (Enkephalin, Ala(2)-MePhe(4)-Gly(5)-)
RN  - 57-50-1 (Sucrose)
RN  - 6742Y30KGK (sucrose polyester)
SB  - IM
MH  - Analgesics, Opioid/adverse effects
MH  - Animals
MH  - Behavior, Animal/physiology
MH  - Dietary Fats/*metabolism
MH  - Eating/*physiology
MH  - Enkephalin, Ala(2)-MePhe(4)-Gly(5)-/adverse effects
MH  - Fatty Acids/metabolism
MH  - Feeding Behavior/physiology
MH  - Hyperphagia/chemically induced/physiopathology
MH  - Male
MH  - Melanocortins/physiology
MH  - Models, Animal
MH  - Nucleus Accumbens/*physiology
MH  - Rats
MH  - Rats, Sprague-Dawley
MH  - Receptors, Opioid, mu/*physiology
MH  - Satiety Response/*physiology
MH  - Signal Transduction/*physiology
MH  - Sucrose/analogs & derivatives/metabolism
MH  - Taste Perception/*physiology
PMC - PMC3129872
EDAT- 2011/05/06 06:00
MHDA- 2011/09/09 06:00
PMCR- 2012/07/01
CRDT- 2011/05/06 06:00
PHST- 2011/05/06 06:00 [entrez]
PHST- 2011/05/06 06:00 [pubmed]
PHST- 2011/09/09 06:00 [medline]
PHST- 2012/07/01 00:00 [pmc-release]
AID - ajpregu.00406.2010 [pii]
AID - R-00406-2010 [pii]
AID - 10.1152/ajpregu.00406.2010 [doi]
PST - ppublish
SO  - Am J Physiol Regul Integr Comp Physiol. 2011 Jul;301(1):R244-54. doi: 
      10.1152/ajpregu.00406.2010. Epub 2011 May 4.