PMID- 20875839
OWN - NLM
STAT- MEDLINE
DCOM- 20111031
LR  - 20101118
IS  - 1873-7544 (Electronic)
IS  - 0306-4522 (Linking)
VI  - 171
IP  - 3
DP  - 2010 Dec 15
TI  - Dopamine D1 receptor gene expression decreases in the nucleus accumbens upon 
      long-term exposure to palatable food and differs depending on diet-induced 
      obesity phenotype in rats.
PG  - 779-87
LID - 10.1016/j.neuroscience.2010.09.046 [doi]
AB  - The nucleus accumbens (NAcc) mediates feeding reward; its activity reflects 
      tastants' hedonic value. NAcc dopamine guides immediate responses to reward, 
      however, its involvement in establishing long-term responses after a period of 
      exposure to palatable foods has not been defined. Furthermore, reward-driven 
      overeating propels weight increase, but the scale of weight gain depends on 
      animals' obesity-prone (OP) or -resistant (OR) phenotype. It is unclear whether 
      the NAcc dopamine response to palatable food depends on obesity susceptibility. 
      We investigated the effect of unrestricted extended access to high-fat high-sugar 
      (HFHS) diet on expression of genes encoding dopamine receptors in the NAcc of OP 
      and OR rats. We examined persistence of HFHS diet-induced changes in D(1) and 
      D(2) gene expression in OP and OR rats subjected to HFHS withdrawal (bland chow 
      for 18 days). Effects of restricted access to HFHS by pair-feeding were also 
      studied. Using reverse transcriptase PCR (RT-PCR), we found that NAcc D(1) mRNA 
      was downregulated after long-term HFHS access in OP vs. OR animals. The effect 
      was also observed after 18 days of HFHS withdrawal. Furthermore, restricted HFHS 
      led to downregulation of D(1) as well as of D(2) mRNA levels compared to chow-fed 
      controls. A difference in the expression of mu opioid receptor in the NAcc was 
      also detected between the OP and OR rats during access to palatable food but not 
      after withdrawal. We conclude that exposure to HFHS diets has lasting 
      consequences for the NAcc dopamine system, perhaps modifying the motivation to 
      search for food reward. The fact that the NAcc D(1) expression changes in OP 
      animals after long-term exposure to palatable food and that this effect extends 
      well into the reward discontinuation phase, implicates the D(1) receptor in the 
      propensity to overeat and, in effect, gain weight in obesity prone individuals.
CI  - Copyright (c) 2010 IBRO. Published by Elsevier Ltd. All rights reserved.
FAU - Alsio, J
AU  - Alsio J
AD  - Department of Neuroscience, Functional Pharmacology, Uppsala University, 
      Biomedical Center, Box 593, SE-751 24, Uppsala, Sweden. johan.alsio@neuro.uu.se
FAU - Olszewski, P K
AU  - Olszewski PK
FAU - Norback, A H
AU  - Norback AH
FAU - Gunnarsson, Z E A
AU  - Gunnarsson ZE
FAU - Levine, A S
AU  - Levine AS
FAU - Pickering, C
AU  - Pickering C
FAU - Schioth, H B
AU  - Schioth HB
LA  - eng
PT  - Comparative Study
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20100926
PL  - United States
TA  - Neuroscience
JT  - Neuroscience
JID - 7605074
RN  - 0 (Receptors, Dopamine D1)
SB  - IM
MH  - Animals
MH  - Appetite Regulation/*genetics
MH  - Disease Models, Animal
MH  - Down-Regulation/*genetics/physiology
MH  - Eating/*genetics
MH  - Male
MH  - Nucleus Accumbens/*metabolism/physiopathology
MH  - Obesity/*genetics/metabolism/physiopathology
MH  - *Phenotype
MH  - Rats
MH  - Rats, Sprague-Dawley
MH  - Receptors, Dopamine D1/*antagonists & inhibitors/*genetics/physiology
MH  - Time Factors
MH  - Weight Gain/genetics
EDAT- 2010/09/30 06:00
MHDA- 2011/11/01 06:00
CRDT- 2010/09/30 06:00
PHST- 2010/03/05 00:00 [received]
PHST- 2010/09/14 00:00 [revised]
PHST- 2010/09/27 00:00 [accepted]
PHST- 2010/09/30 06:00 [entrez]
PHST- 2010/09/30 06:00 [pubmed]
PHST- 2011/11/01 06:00 [medline]
AID - S0306-4522(10)01294-7 [pii]
AID - 10.1016/j.neuroscience.2010.09.046 [doi]
PST - ppublish
SO  - Neuroscience. 2010 Dec 15;171(3):779-87. doi: 10.1016/j.neuroscience.2010.09.046. 
      Epub 2010 Sep 26.