title: Antagonistic effects of S 22153, a new mt1 and MT2 receptor ligand, on the neophobia-reducing properties of melatonin in BALB/c mice.
abstract: When exposed to a free-exploratory situation, BALB/c mice are well known to exhibit strong avoidance responses toward unfamiliar places (neophobia). Because melatonin was found to significantly reduce neophobia in BALB/c mice, it seemed interesting to examine potential antagonistic effects of S 22153, a new melatonin mt1 and MT2 receptor ligand, on the neophobia-reducing properties of melatonin in BALB/c mice confronted with the free-exploratory paradigm. S 22153 was able to block, in a dose-dependent manner, the anxiolytic-like properties of melatonin when it was administered 5 min before melatonin. The antagonistic effects of S 22153 persisted when the drug was administered 2 or 4 h before melatonin, and were almost abolished when it was administered 6 h before melatonin. These results suggest that the anxiolytic-like effects of melatonin on the neophobic responses in BALB/c mice are mediated by mt1 and/or MT2 receptors.
authors.affiliation: Laboratoire d'Ethologie et de Neurobiologie, Strasbourg, France.
authors.forename: C
authors.initials: C
authors.lastname: Kopp
authors.forename: E
authors.initials: E
authors.lastname: Vogel
authors.forename: M C
authors.initials: MC
authors.lastname: Rettori
authors.forename: P
authors.initials: P
authors.lastname: Delagrange
authors.forename: P
authors.initials: P
authors.lastname: Renard
authors.forename: D
authors.initials: D
authors.lastname: Lesieur
authors.forename: R
authors.initials: R
authors.lastname: Misslin
mesh_terms: D000818:Animals; D014151:Anti-Anxiety Agents / Q000494:pharmacology*; D001007:Anxiety / Q000188:drug therapy* / Q000523:psychology; D004305:Dose-Response Relationship, Drug; D005106:Exploratory Behavior / Q000187:drug effects; D008024:Ligands; D008297:Male; D008550:Melatonin / Q000037:antagonists & inhibitors* / Q000494:pharmacology*; D051379:Mice; D008807:Mice, Inbred BALB C; D009043:Motor Activity / Q000187:drug effects; D011956:Receptors, Cell Surface / Q000187:drug effects*; D018160:Receptors, Cytoplasmic and Nuclear / Q000187:drug effects*; D044094:Receptors, Melatonin; D013876:Thiophenes / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D014151:Anti-Anxiety Agents; D008024:Ligands; D011956:Receptors, Cell Surface; D018160:Receptors, Cytoplasmic and Nuclear; D044094:Receptors, Melatonin; C120267:S 22153; D013876:Thiophenes; D008550:Melatonin