title: Sodium appetite and Fos activation in serotonergic neurons.
abstract: We evaluated serotonergic hindbrain groups of cells for their involvement in the generation and inhibition of sodium appetite. For that purpose, we analyzed the number of Fos-immunoreactive (Fos-ir) cells and double-labeled Fos-serotonin (5-HT)-ir neurons within different nuclei of the hindbrain raphe system and the area postrema (AP). Sodium depletion and sodium appetite were induced by peritoneal dialysis. Twenty-four hours after peritoneal dialysis, a 2% NaCl solution intake test was given to peritoneal dialyzed animals [PD-with access (PD-A) group] and to control dialyzed animals [CD-with access (CD-A) group]. Two additional groups of animals received either peritoneal dialysis or control dialysis but were not given access to the 2% NaCl [CD-no access (CD-NA) group or PD-no access (PD-NA) group]. The number of Fos-ir neurons within different nuclei of the raphe system was increased in spontaneous and induced sodium ingestion of CD-A and PD-A groups compared with the CD-NA and PD-NA groups. The PD-NA group had significantly fewer double-labeled cells along the raphe system compared with the animals in near-normal sodium balance (CD-NA and CD-A) or in the process of restoring sodium balance by consuming NaCl (PD-A). The AP of the PD-A group showed a significant increase in the number of Fos-ir and Fos-5-HT-ir cells compared with the PD-NA and CD groups. Our results suggest that serotonergic pathways with cell bodies in the AP and the raphe system are involved in the control of sodium appetite.
authors.affiliation: Instituto de Investigación Médica Mercedes y Martin Ferreyra, 5000 Córdoba, Argentina.
authors.forename: Lucia F
authors.initials: LF
authors.lastname: Franchini
authors.forename: Alan Kim
authors.initials: AK
authors.lastname: Johnson
authors.forename: José
authors.initials: J
authors.lastname: de Olmos
authors.forename: Laura
authors.initials: L
authors.lastname: Vivas
mesh_terms: D000818:Animals; D000906:Antibodies; D001066:Appetite / Q000502:physiology*; D020546:Fourth Ventricle / Q000737:chemistry / Q000166:cytology; D007150:Immunohistochemistry; D008297:Male; D009474:Neurons / Q000737:chemistry* / Q000502:physiology; D016760:Proto-Oncogene Proteins c-fos / Q000032:analysis* / Q000276:immunology / Q000378:metabolism; D011903:Raphe Nuclei / Q000737:chemistry / Q000166:cytology; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000032:analysis* / Q000276:immunology / Q000378:metabolism; D012982:Sodium, Dietary / Q000494:pharmacology*
chemical_list: D000906:Antibodies; D016760:Proto-Oncogene Proteins c-fos; D012982:Sodium, Dietary; D012701:Serotonin