title: Contrasting effects of 5-HT3receptor stimulation of the nucleus accumbens or ventral tegmentum on food intake in the rat.
abstract: Although serotonin (5-HT) signaling is known to regulate food intake and energy homeostasis, the roles of the 5-HT3receptor in feeding processes have been elusive. 5-HT3receptors are found throughout mesolimbic circuitry that promote feeding not only in response to hunger, but also to the palatable and rewarding properties of food. These experiments examined if stimulation or blockade of the 5-HT3receptor of the nucleus accumbens (NAcc) or ventral tegmentum affected food intake in the rat in response to hunger or the presence of a palatable diet. Rats (N=6-9/group) received bilateral injections of the 5-HT3agonist m-chlorophenylbiguanide hydrochloride (mCPBG; at 0.0, 10.0, or 20.0μg/0.5μl/side) or the 5-HT3antagonist ondansetron hydrochloride (at 0.0, 1.0, 2.0, or 5.0μg/0.5μl/side) into either the NAcc or the ventral tegmentum. NAcc 5-HT3receptor stimulation significantly increased 2-h food intake in food-deprived animals offered rat chow and in a separate group of unrestricted rats offered a sweetened fat diet. In contrast to the feeding increase seen with NAcc treatments, stimulation of 5-HT3receptors of the ventral tegmentum significantly reduced food and water intake in food-restricted animals; reductions of intake in non-restricted rats offered the palatable diet did not approach significance. Blockade of the 5-HT3receptor had no effect on feeding in either brain region. These data support a functional role for serotonergic signaling in the mesolimbic pathway on motivated behavior, and demonstrate that 5-HT3receptors differentially modulate food consumption in a region-dependent manner.
authors.affiliation: Department of Psychology, Wake Forest University, Winston-Salem, NC, United States. Electronic address: prattwe@wfu.edu.
authors.forename: Wayne E
authors.initials: WE
authors.lastname: Pratt
authors.affiliation: Department of Psychology, Wake Forest University, Winston-Salem, NC, United States. Electronic address: linp182@gmail.com.
authors.forename: Peagan
authors.initials: P
authors.lastname: Lin
authors.affiliation: Department of Psychology, Wake Forest University, Winston-Salem, NC, United States. Electronic address: harmonicr@gmail.com.
authors.forename: Zachary
authors.initials: Z
authors.lastname: Pierce-Messick
authors.affiliation: Department of Psychology, Wake Forest University, Winston-Salem, NC, United States. Electronic address: ade.ilesanmi@gmail.com.
authors.forename: Adeolu O
authors.initials: AO
authors.lastname: Ilesanmi
authors.affiliation: Department of Psychology, Wake Forest University, Winston-Salem, NC, United States. Electronic address: kaclissold@gmail.com.
authors.forename: Kara A
authors.initials: KA
authors.lastname: Clissold
mesh_terms: D000818:Animals; D001645:Biguanides / Q000008:administration & dosage; D004326:Drinking; D004435:Eating; D008124:Locomotion / Q000187:drug effects; D008297:Male; D009714:Nucleus Accumbens / Q000187:drug effects / Q000502:physiology*; D017294:Ondansetron / Q000008:administration & dosage; D017207:Rats, Sprague-Dawley; D044406:Receptors, Serotonin, 5-HT3 / Q000502:physiology*; D058827:Serotonin 5-HT3 Receptor Agonists / Q000008:administration & dosage; D058831:Serotonin 5-HT3 Receptor Antagonists / Q000008:administration & dosage; D017557:Ventral Tegmental Area / Q000187:drug effects / Q000502:physiology*
chemical_list: D001645:Biguanides; D044406:Receptors, Serotonin, 5-HT3; D058827:Serotonin 5-HT3 Receptor Agonists; D058831:Serotonin 5-HT3 Receptor Antagonists; D017294:Ondansetron; C065734:1-(3-chlorophenyl)biguanide
keywords: 5-HT(3); Food intake; Motivation; Nucleus accumbens; Serotonin; Ventral tegmental area