Nucleus accumbens opioid, GABaergic, and dopaminergic modulation of palatable food motivation: contrasting effects revealed by a progressive ratio study in the rat.
The current studies were designed to evaluate whether incentive motivation for palatable food is altered after manipulations of opioid, GABAergic, and dopaminergic transmission within the nucleus accumbens. A progressive ratio schedule was used to measure lever-pressing for sugar pellets after microinfusion of drugs into the nucleus accumbens in non-food-deprived rats. The mu opioid agonist D-Ala2, NMe-Phe4, Glyo15-enkephalin and the indirect dopamine agonist amphetamine induced a marked increase in break point and correct lever-presses; the GABA(A) agonist muscimol did not affect breakpoint or lever-presses. The data suggest that opioid, dopaminergic, and GABAergic systems within the accumbens differentially modulate food-seeking behavior through mechanisms related to hedonic evaluation of food, incentive salience, and control of motor feeding circuits, respectively.
Zhang
Min
M
Department of Psychiatry, University of Wisconsin-Madison Medical School, 53715, USA.
Balmadrid
Christian
C
Kelley
Ann E
AE
D000701:Analgesics, Opioid / Q000494:pharmacology; D000818:Animals; D002241:Carbohydrates; D003913:Dextroamphetamine / Q000494:pharmacology; D004298:Dopamine / Q000502:physiology*; D018765:Dopamine Uptake Inhibitors / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)- / Q000494:pharmacology; D005247:Feeding Behavior / Q000187:drug effects / Q000502:physiology*; D018755:GABA Agonists / Q000494:pharmacology; D008297:Male; D009042:Motivation; D009118:Muscimol / Q000494:pharmacology; D009294:Narcotics / Q000378:metabolism*; D009714:Nucleus Accumbens / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012055:Reinforcement Schedule; D013997:Time Factors; D005680:gamma-Aminobutyric Acid / Q000502:physiology*
D000701:Analgesics, Opioid; D002241:Carbohydrates; D018765:Dopamine Uptake Inhibitors; D018755:GABA Agonists; D009294:Narcotics; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D009118:Muscimol; D005680:gamma-Aminobutyric Acid; D003913:Dextroamphetamine; D004298:Dopamine