Medullary c-fos activation in rats after ingestion of a satiating meal

• Published in: American journal of physiology. Regulatory, integrative and comparative physiology Vol. 275; no. 1; pp. 262 - R268
• Main Authors: Rinaman, L, Baker, E.A, Hoffman, G.E, Stricker, E.M, Verbalis, J.G
• Format: Journal Article
• Language: English
• Published: United States 01.07.1998
• Subjects: ANIMAL TISSUES; Animals; APETITO; APPETIT; APPETITE; BRAIN; Catecholamines - metabolism; Cerebral Ventricles - physiology; CEREBRO; COMPORTEMENT ALIMENTAIRE; Eating - physiology; ENCEPHALE; Energy Intake; FEEDING HABITS; Gastrointestinal Contents; Gene Expression Regulation; Genes, fos; HABITOS ALIMENTARIOS; HINDBRAIN; Male; NERF; NERVES; NERVIOS; NEURONS; Neurons - physiology; Organ Specificity; Proto-Oncogene Proteins c-fos - biosynthesis; Rats; Rats, Sprague-Dawley; Rhombencephalon - physiology; Satiation - physiology; SATIETY; Solitary Nucleus - physiology; STOMACH DISTENSION; TEJIDOS ANIMALES; TISSU ANIMAL
• ISSN: 0002-9513; 0363-6119; 2163-5773; 1522-1490
• DOI: 10.1152/ajpregu.1998.275.1.r262

1  Department of Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania 15260; 2  Department of Medicine, Georgetown University, Washington, District of Columbia 20007; and 3  Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261 The distribution and chemical phenotypes of hindbrain neurons that are activated in rats after food ingestion were examined. Rats were anesthetized and perfused with fixative 30 min after the end of 1-h meals of an unrestricted or rationed amount of food, or after no meal. Brain sections were processed for localization of the immediate-early gene product c-Fos, a marker of stimulus-induced neural activation. Hindbrain c-Fos expression was low in rats that ate a rationed meal or no meal. Conversely, c-Fos was prominent in the medial nucleus of the solitary tract (NST) and area postrema in rats that ate to satiety. There was a significant positive correlation between postmortem weight of gastric contents and the proportion of NST catecholaminergic neurons expressing c-Fos. Cells in the ventrolateral medulla (VLM) were not activated in rats after food ingestion, in contrast with previous findings that stimulation of gastric vagal afferents with anorexigenic doses of cholecystokinin activates c-Fos expression in both NST and VLM catecholaminergic cells. These findings indicate that anatomically distinct subsets of hindbrain catecholaminergic neurons are activated in rats after food ingestion and that activation of these cells is quantitatively related to the magnitude of feeding-induced gastric distension. feeding behavior; gastric distension; catecholamines; nucleus of the solitary tract