title: Chronic fluoxetine treatment induces anxiolytic responses and altered social behaviors in medaka, Oryzias latipes.
abstract: Medaka (Oryzias latipes) is a small freshwater teleost that is an emerging model system for neurobehavioral research and toxicological testing. The selective serotonin reuptake inhibitor class of antidepressants such as fluoxetine is one of the widely prescribed drugs, but little is known about the effects of these drugs on medaka behaviors. To assess the behavioral effects of fluoxetine, we chronically administrated fluoxetine to medaka adult fish and analyzed the anxiety-related and social behaviors using five behavioral paradigms (diving, open-field, light-dark transition, mirror-biting, and social interaction) with an automated behavioral testing system. Fish chronically treated with fluoxetine exhibited anxiolytic responses such as an overall increased time spent in the top area in the diving test and an increased time spent in center area in the open-field test. Analysis of socially evoked behavior showed that chronic fluoxetine administration decreased the number of mirror biting times in the mirror-biting test and increased latency to first contact in the social interaction test. Additionally, chronic fluoxetine administration reduced the horizontal locomotor activity in the open-field test but not the vertical activity in the diving test. These investigations are mostly consistent with previous reports in the other teleost species and rodent models. These results indicate that behavioral assessment in medaka adult fish will become useful for screening of effects of pharmaceutical and toxicological compounds in animal behaviors.
authors.affiliation: Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan. Electronic address: ansai@kais.kyoto-u.ac.jp.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ansai
authors.affiliation: Department of Intelligence Science and Technology, Graduate School of Informatics, Kyoto University, Yoshida-Honmachi, Sakyo-ku, Kyoto 606-8501, Japan. Electronic address: hosokawa@i.kyoto-u.ac.jp.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hosokawa
authors.affiliation: Department of Intelligence Science and Technology, Graduate School of Informatics, Kyoto University, Yoshida-Honmachi, Sakyo-ku, Kyoto 606-8501, Japan.
authors.forename: Shingo
authors.initials: S
authors.lastname: Maegawa
authors.affiliation: Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Kinoshita
mesh_terms: D000818:Animals; D014151:Anti-Anxiety Agents / Q000008:administration & dosage*; D018687:Antidepressive Agents, Second-Generation / Q000008:administration & dosage*; D001007:Anxiety; D001522:Behavior, Animal / Q000187:drug effects*; D005473:Fluoxetine / Q000008:administration & dosage*; D009043:Motor Activity / Q000187:drug effects; D009990:Oryzias; D017367:Selective Serotonin Reuptake Inhibitors / Q000008:administration & dosage*; D012919:Social Behavior
chemical_list: D014151:Anti-Anxiety Agents; D018687:Antidepressive Agents, Second-Generation; D005473:Fluoxetine; D017367:Selective Serotonin Reuptake Inhibitors
keywords: Anxiety; Behavioral paradigms; Fluoxetine; Locomotor activity; Medaka; Social behavior