title: Differential role of the accumbens Shell and Core subterritories in food-entrained rhythms of rats.
abstract: Restricted feeding schedules (RFS) entrain behavioral and physiological rhythms even in suprachiasmatic nucleus ablated animals, suggesting the existence of a food-entrained oscillator. The nucleus accumbens is an important structure for the expression of motivational behaviors and because its anatomical subterritories, Shell (Acc-Sh) and Core (Acc-Co) establish connections with different functional systems, they may participate in a differential way in food-entrainment. A first experiment, explored the role of Acc-Sh and Acc-Co in food-entrainment using the immunohistochemical detection of the protein c-Fos as a transcriptional activation marker. Experiment 2 tested the differential effect of Acc-Sh and Acc-Co, NMDA excitotoxic lesions. Lesioned rats were entrained to RFS and locomotor activity and free fatty acids (FFA) concentrations were evaluated. Results data show that in the Acc-Sh there is an increase of c-Fos immunoreactivity in food-entrained rats principally during feeding, whereas c-Fos expression in the Acc-Co region was increased during feeding and also anticipating mealtime. FFA were entrained in both lesioned groups, but the basal level was lower in Core-lesion rats. All rats exhibited food anticipatory activity (FAA). However, FAA was increased in Shell-lesioned animals and was almost abolished in the Core-lesion rats. These data indicate that the accumbens nucleus is involved with behavioral and metabolic food-entrainment, and that there is a differential role between both subregions.
authors.affiliation: Departamento de Anatomía, Facultad de Medicina, Edificio B 4 Piso, Universidad Nacional Autónoma de México, México DF 04510, México.
authors.forename: Jorge
authors.initials: J
authors.lastname: Mendoza
authors.forename: Manuel
authors.initials: M
authors.lastname: Angeles-Castellanos
authors.forename: Carolina
authors.initials: C
authors.lastname: Escobar
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D001835:Body Weight / Q000502:physiology; D002452:Cell Count / Q000379:methods; D002940:Circadian Rhythm / Q000502:physiology*; D004435:Eating / Q000502:physiology; D018690:Excitatory Amino Acid Agonists / Q000633:toxicity; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005247:Feeding Behavior / Q000502:physiology*; D005508:Food Deprivation / Q000502:physiology*; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D009043:Motor Activity / Q000502:physiology; D016202:N-Methylaspartate / Q000633:toxicity; D009714:Nucleus Accumbens / Q000033:anatomy & histology / Q000502:physiology*; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors
chemical_list: D018690:Excitatory Amino Acid Agonists; D005230:Fatty Acids, Nonesterified; D016760:Proto-Oncogene Proteins c-fos; D016202:N-Methylaspartate