Diet selection following area postrema/nucleus of the solitary tract lesions

Ten adult Long-Evans male rats were offered access to fat, protein and carbohydrate from separate sources. After adaptation to this diet, 5 animals received thermal lesions of the area postrema and adjacent caudal-medial portion of the nucleus of the solitary tract (AP/cmNTS). The remainder were sham-operated. AP/cmNTS lesioned rats ate significantly less and lost more weight than controls during the first postsurgery measurement period (Days 4-13 after lesioning). The decrease of food intake of AP/cmNTS lesioned rats was due to reduced fat consumption. Carbohydrate and protein intakes of lesioned animals did not differ from those of controls. Food intakes and weight changes of lesioned rats did not differ from those of controls during days 14-23 after lesioning. Intake of fat by lesioned animals remained low but was no longer significantly different from that of controls. Carbohydrate and protein intakes of lesioned rats increased slightly but did not differ significantly from those of nonlesioned controls.