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Activation of mesolimbic dopamine neurons during novel and daily limited access to palatable food is blocked by the opioid antagonist LY255582.
- Source :
-
American journal of physiology. Regulatory, integrative and comparative physiology [Am J Physiol Regul Integr Comp Physiol] 2008 Aug; Vol. 295 (2), pp. R463-71. Date of Electronic Publication: 2008 Jun 04. - Publication Year :
- 2008
-
Abstract
- An analog of the trans-3,4-dimethyl-4-(3-hydroxyphenyl)piperidine series (LY255582) exhibits high in vitro binding affinity and antagonist potency for the mu-, delta-, and kappa-opioid receptors. In vivo, LY255582 exhibits potent effects in reducing food intake and body weight in several rodent models of obesity. In the present study, we evaluated the effects of LY255582 to prevent the consumption of a highly palatable (HP) diet (a high-fat/high-carbohydrate diet) both when the food was novel and following daily limited access to the HP diet. Additionally, we examined the effects of consumption of the HP diet and of LY255582 treatment on mesolimbic dopamine (DA) signaling by in vivo microdialysis. Consumption of the HP diet increased extracellular DA levels within the nucleus accumbens (NAc) shell. Increased DA in the NAc shell was not related to the quantity of the HP diet consumed, and the DA response did not habituate following daily scheduled access to the HP diet. Interestingly, treatment with LY255582 inhibited consumption of the HP diet and the HP diet-associated increase in NAc shell DA levels. Moreover, the increased HP diet consumption observed following daily limited access to the HP diet was completely prevented by LY255582 treatment. LY255582 may be a useful tool in understanding the neural mechanisms involved in the reinforcement mechanisms regulating food intake.
- Subjects :
- Animals
Eating drug effects
Food Preferences
Male
Microdialysis
Neurons metabolism
Nucleus Accumbens cytology
Nucleus Accumbens metabolism
Rats
Rats, Sprague-Dawley
Receptors, Opioid metabolism
Reinforcement, Psychology
Time Factors
Appetite Regulation drug effects
Behavior, Animal drug effects
Cyclohexanes pharmacology
Dopamine metabolism
Narcotic Antagonists pharmacology
Neurons drug effects
Nucleus Accumbens drug effects
Piperidines pharmacology
Subjects
Details
- Language :
- English
- ISSN :
- 0363-6119
- Volume :
- 295
- Issue :
- 2
- Database :
- MEDLINE
- Journal :
- American journal of physiology. Regulatory, integrative and comparative physiology
- Publication Type :
- Academic Journal
- Accession number :
- 18525013
- Full Text :
- https://doi.org/10.1152/ajpregu.00390.2007