Evidence for motivational effects elicited by activation of GABA-A or dopamine receptors in the nucleus accumbens shell.
Microinjections of the inhibitory GABA-A receptor agonist muscimol into the shell region of the nucleus accumbens (AcbSh) have been reported to induce large increases in food intake, but the effect of these injections on motivational processes is less clear. In the current study, bilateral injections of saline, muscimol (50ng/side) or d-amphetamine (10mug/side) were made into the AcbSh of rats trained to lever press on a progressive ratio schedule for food reward. Injections of both muscimol and amphetamine were found to produce a large increase in the breaking point relative to saline injections. This result suggests that inactivation of the AcbSh does not simply drive ingestive behavior, but also affects motivational processes assessed by the progressive ratio schedule. Breaking points were also increased by injections of amphetamine into the AcbSh.
Wirtshafter
David
D
Laboratory of Integrative Neuroscience, Department of Psychology (m/c 285), University of Illinois at Chicago, 1007 West Harrison Street, Chicago, IL 60607-7137, USA.
Stratford
Thomas R
TR
D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D001921:Brain; D003216:Conditioning, Operant / Q000187:drug effects; D003913:Dextroamphetamine / Q000008:administration & dosage / Q000494:pharmacology; D018491:Dopamine Agonists / Q000008:administration & dosage / Q000494:pharmacology*; D018765:Dopamine Uptake Inhibitors / Q000008:administration & dosage / Q000494:pharmacology; D005502:Food; D018755:GABA Agonists / Q000008:administration & dosage / Q000494:pharmacology*; D007267:Injections; D008297:Male; D009042:Motivation / Q000187:drug effects*; D009118:Muscimol / Q000008:administration & dosage / Q000494:pharmacology; D009714:Nucleus Accumbens / Q000033:anatomy & histology / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011954:Receptors, Dopamine / Q000187:drug effects*; D011963:Receptors, GABA-A / Q000187:drug effects*; D012055:Reinforcement Schedule; D012054:Reinforcement, Psychology
D018491:Dopamine Agonists; D018765:Dopamine Uptake Inhibitors; D018755:GABA Agonists; D011954:Receptors, Dopamine; D011963:Receptors, GABA-A; D009118:Muscimol; D003913:Dextroamphetamine