Amylin infusion into rat nucleus accumbens potently depresses motor activity and ingestive behavior.
Amylin, a calcitonin gene-related peptide-like peptide coreleased with insulin, exerts anorexic effects on central administration. Because previous studies revealed dense amylin binding in the nucleus accumbens (Acb), we investigated the behavioral effects of amylin infusions (10, 30, and 100 ng/side) into Acb subregions. Intra-Acb shell amylin infusions decreased ambulation, rearing, feeding, and drinking in either food-deprived rats or water-deprived rats; motor activity was affected more potently than ingestive behavior. Moreover, intra-Acb shell amylin reduced motor activity in nondeprived rats tested in the absence of food or water, indicating that the expression of amylin's effects is independent of drive or proximal incentives. Intra-Acb core amylin infusions in water-deprived rats also decreased ambulation and water intake, although anterior Acb placements were associated with smaller motor effects, regardless of Acb subregion. In contrast to amylin's effects, intra-Acb shell infusions of orexin-A (50, 100, and 500 ng/side) had no effects on motor activity, feeding, or drinking. Hence the Acb may be a target for behavioral regulation by satiety-related peptides like amylin.
Baldo
B A
BA
Department of Psychiatry, University of Wisconsin-Madison Medical School, Madison, Wisconsin 53719, USA. babaldo@facstaff.wisc.edu
Kelley
A E
AE
D000682:Amyloid / Q000008:administration & dosage*; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D002352:Carrier Proteins / Q000008:administration & dosage; D004305:Dose-Response Relationship, Drug; D004327:Drinking Behavior / Q000187:drug effects; D004435:Eating / Q000187:drug effects; D005247:Feeding Behavior / Q000187:drug effects*; D005508:Food Deprivation; D007263:Infusions, Parenteral; D047908:Intracellular Signaling Peptides and Proteins; D058228:Islet Amyloid Polypeptide; D008297:Male; D008845:Microinjections; D009043:Motor Activity / Q000187:drug effects*; D009479:Neuropeptides / Q000008:administration & dosage; D009714:Nucleus Accumbens / Q000033:anatomy & histology / Q000187:drug effects* / Q000502:physiology*; D000068797:Orexins; D051381:Rats; D017207:Rats, Sprague-Dawley; D014868:Water Deprivation
D000682:Amyloid; D002352:Carrier Proteins; D047908:Intracellular Signaling Peptides and Proteins; D058228:Islet Amyloid Polypeptide; D009479:Neuropeptides; D000068797:Orexins