title: Stress-induced anorexia in rats mediated by serotonergic mechanisms in the hypothalamus.
abstract: The effects of stress on food intake and on neural activity in the lateral hypothalamic area (LHA) were investigated. Significant reduction of daily food intake was observed after 2 hr immobilization. The reduction of body weight was also significant during experimental days. Duplicate injections of methysergide (5 mg/kg, IP) antagonized the immobilization-induced anorexia for 3 hr and injection of naloxone had no effect. Single neuron activity was recorded from a chronically implanted electrode. Activity of 80% of LHA neurons was significantly decreased by immobilization stress. Methysergide significantly attenuated the suppressive effect of immobilization. Further, direct effects of 5-HT on LHA neurons were examined in anesthetized rats. Of 43 LHA neurons tested, the activity of 35 was inhibited by electrophoretic application of 5-HT. These results suggest that immobilization-induced anorexia is mediated at least in part through serotonergic mechanisms in the LHA.
authors.affiliation: Department of Physiology, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Shimizu
authors.forename: Y
authors.initials: Y
authors.lastname: Oomura
authors.forename: Y
authors.initials: Y
authors.lastname: Kai
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects / Q000502:physiology; D005247:Feeding Behavior / Q000187:drug effects / Q000502:physiology*; D007026:Hypothalamic Area, Lateral / Q000187:drug effects / Q000503:physiopathology*; D007478:Iontophoresis; D008297:Male; D008784:Methysergide / Q000494:pharmacology; D009270:Naloxone / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D012149:Restraint, Physical; D012701:Serotonin / Q000494:pharmacology* / Q000502:physiology; D013312:Stress, Physiological / Q000503:physiopathology / Q000523:psychology*; D015430:Weight Gain / Q000502:physiology
chemical_list: D012701:Serotonin; D009270:Naloxone; D008784:Methysergide