title: The endocannabinoid system modulates the valence of the emotion associated to food ingestion.
abstract: Endocannabinoids (eCBs) are mediators of the homeostatic and hedonic systems that modulate food ingestion. Hence, eCBs, by regulating the hedonic system, may be modulating the valence of the emotion associated to food ingestion (positive: pleasant or negative: unpleasant). Our first goal was to demonstrate that palatable food induces conditioned place preference (CPP), hence a positive-valence emotion. Additionally, we analyzed if this CPP is blocked by AM251, inducing a negative valence emotion, meaning avoiding the otherwise pursued compartment. The second goal was to demonstrate that CPP induced by regular food would be strengthened by the simultaneous administration of anandamide or oleamide, and if such, CPP is blocked by AM251. Finally, we tested the capacity of eCBs (without food) to induce CPP. Our results indicate that rats readily developed CPP to palatable food, which was blocked by AM251. The CPP induced by regular food was strengthened by eCBs and blocked by AM251. Finally, oleamide, unlike anandamide, induced CPP. These results showed that eCBs mediate the positive valence (CPP) of the emotion associated to food ingestion. It was also observed that the blockade of the CB1 receptor causes a loss of correlation between food and CPP (negative valence: avoidance). These data further support the role of eCBs as regulators of the hedonic value of food.
authors.affiliation: Grupo de Neurociencias, Laboratorio de Canabinoides, Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico. mendezm@unam.mx
authors.forename: Mónica
authors.initials: M
authors.lastname: Méndez-Díaz
authors.forename: Pavel Ernesto
authors.initials: PE
authors.lastname: Rueda-Orozco
authors.forename: Alejandra Evelyn
authors.initials: AE
authors.lastname: Ruiz-Contreras
authors.forename: Oscar
authors.initials: O
authors.lastname: Prospéro-García
mesh_terms: D000818:Animals; D001095:Arachidonic Acids / Q000494:pharmacology; D063385:Cannabinoid Receptor Modulators / Q000502:physiology*; D004435:Eating / Q000523:psychology*; D004644:Emotions / Q000187:drug effects*; D063388:Endocannabinoids; D009829:Oleic Acids / Q000494:pharmacology; D010880:Piperidines / Q000494:pharmacology; D053284:Polyunsaturated Alkamides / Q000494:pharmacology; D011597:Psychomotor Performance / Q000187:drug effects; D011720:Pyrazoles / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar
chemical_list: D001095:Arachidonic Acids; D063385:Cannabinoid Receptor Modulators; D063388:Endocannabinoids; D009829:Oleic Acids; D010880:Piperidines; D053284:Polyunsaturated Alkamides; D011720:Pyrazoles; C103505:AM 251; C029407:oleylamide; C078814:anandamide