title: Improvement by low doses of nociceptin on scopolamine-induced impairment of learning and/or memory.
abstract: The effects of fmol doses of nociceptin/orphanin FQ on scopolamine-induced impairment of learning and/or memory were examined using spontaneous alternation of Y-maze and step-down type passive avoidance tasks. While fmol doses of nociceptin alone had no effect on spontaneous alternation or passive avoidance behavior in normal mice, administration of nociceptin (10 and/or 100 fmol/mouse) 30 min before spontaneous alternation performance or the training session of the passive avoidance task, significantly improved the scopolamine-induced impairment of spontaneous alternation and passive avoidance behavior. This ameliorating effect was not antagonized by nocistatin (0.5 and 5.0 nmol/mouse, i.c.v.), naloxone benzoylhydrazone (2.3, 11.2, and 56.1 micromol/kg, s.c.) or nor-binaltorphimine (4.9 nmol/mouse, i.c.v.). These results indicated that very low doses of nociceptin ameliorate impairments of spontaneous alternation and passive avoidance induced by scopolamine, and suggested that this peptide has bidirectional modulatory effects on learning and memory; impairment at high doses and amelioration at low doses.
authors.affiliation: Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Meijo University, 150 Yagotoyama, Tenpaku-ku, Nagoya, Japan. mhiramt@meijo-u.ac.jp
authors.forename: M
authors.initials: M
authors.lastname: Hiramatsu
authors.forename: K
authors.initials: K
authors.lastname: Inoue
mesh_terms: D000701:Analgesics, Opioid / Q000494:pharmacology / Q000627:therapeutic use; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects; D004195:Disease Models, Animal; D016291:Dizocilpine Maleate / Q000494:pharmacology / Q000627:therapeutic use; D007859:Learning Disabilities / Q000139:chemically induced / Q000188:drug therapy*; D008297:Male; D018782:Maze Learning / Q000187:drug effects; D008569:Memory Disorders / Q000139:chemically induced / Q000188:drug therapy*; D051379:Mice; D009270:Naloxone / Q000031:analogs & derivatives / Q000494:pharmacology / Q000627:therapeutic use; D009271:Naltrexone / Q000031:analogs & derivatives / Q000494:pharmacology / Q000627:therapeutic use; D009292:Narcotic Antagonists / Q000494:pharmacology / Q000627:therapeutic use; D018696:Neuroprotective Agents / Q000494:pharmacology / Q000627:therapeutic use; D018847:Opioid Peptides / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D011597:Psychomotor Performance / Q000187:drug effects; D051381:Rats; D012601:Scopolamine; D000097629:Nociceptin
chemical_list: D000701:Analgesics, Opioid; D016291:Dizocilpine Maleate; D009270:Naloxone; D009271:Naltrexone; D009292:Narcotic Antagonists; D018696:Neuroprotective Agents; D018847:Opioid Peptides; D012601:Scopolamine; D000097629:Nociceptin; C111148:nocistatin; C058380:naloxone benzoylhydrazone; C051844:norbinaltorphimine