title: Roux-en-Y gastric bypass in rats increases sucrose taste-related motivated behavior independent of pharmacological GLP-1-receptor modulation.
abstract: Roux-en-Y gastric bypass (RYGB) surgery has been shown to decrease consummatory responsiveness of rats to high sucrose concentrations, and genetic deletion of glucagon-like peptide-1 receptors (GLP-1R) has been shown to decrease consummatory responsiveness of mice to low-sucrose concentrations. Here we assessed the effects of RYGB and pharmacological GLP-1R modulation on sucrose licking by chow-fed rats in a brief-access test that assessed consummatory and appetitive behaviors. Rats were tested while fasted presurgically and postsurgically and while nondeprived postsurgically and 5 h after intraperitoneal injections with the GLP-1R antagonist exendin-3(9-39) (30 μg/kg), agonist exendin-4 (1 μg/kg), and vehicle in 30-min sessions during which a sucrose concentration series (0.01-1.0 M) was presented in 10-s trials. Other rats were tested postsurgically or 15 min after peptide or vehicle injection while fasted and while nondeprived. Independent of food-deprivation state, sucrose experience, or GLP-1R modulation, RYGB rats took 1.5-3× as many trials as sham-operated rats, indicating increased appetitive behavior. Under nondeprived conditions, RYGB rats with presurgical sucrose experience licked more to sucrose relative to water compared with sham-operated rats. Exendin-4 and exendin-3(9-39) impacted 0.3 M sucrose intake in a one-bottle test, but never interacted with surgical group to affect brief-access responding. Unlike prior reports in both clearly obese and relatively leaner rats given RYGB and in GLP-1R knockout mice, we found that neither RYGB nor GLP-1R blockade decreased consummatory responsiveness to sucrose in our less obese chow-fed rats. Collectively, these results highlight the fact that changes in taste-driven motivated behavior to sucrose after RYGB and/or GLP-1R modulation are very model and measure dependent.
authors.affiliation: Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, Florida 32306-4301,USA.
authors.forename: C M
authors.initials: CM
authors.lastname: Mathes
authors.forename: M
authors.initials: M
authors.lastname: Bueter
authors.forename: K R
authors.initials: KR
authors.lastname: Smith
authors.forename: T A
authors.initials: TA
authors.lastname: Lutz
authors.forename: C W
authors.initials: CW
authors.lastname: le Roux
authors.forename: A C
authors.initials: AC
authors.lastname: Spector
mesh_terms: D000818:Animals; D001066:Appetite / Q000187:drug effects / Q000502:physiology; D001522:Behavior, Animal / Q000187:drug effects* / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D004326:Drinking / Q000502:physiology; D004435:Eating / Q000187:drug effects / Q000502:physiology; D000077270:Exenatide; D015390:Gastric Bypass; D000067757:Glucagon-Like Peptide-1 Receptor; D007274:Injections, Intraperitoneal; D008297:Male; D023421:Models, Animal; D010446:Peptide Fragments / Q000008:administration & dosage / Q000494:pharmacology*; D010455:Peptides / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D018027:Receptors, Glucagon / Q000819:agonists / Q000037:antagonists & inhibitors / Q000187:drug effects*; D013395:Sucrose / Q000494:pharmacology*; D013997:Time Factors; D014688:Venoms / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: C000593834:Glp1r protein, mouse; C000593835:Glp1r protein, rat; D000067757:Glucagon-Like Peptide-1 Receptor; D010446:Peptide Fragments; D010455:Peptides; D018027:Receptors, Glucagon; D014688:Venoms; C083773:exendin (9-39); D013395:Sucrose; D000077270:Exenatide