title: Effect of acute L-tryptophan exposure on the brain serotonergic system and behavior in the male medaka.
abstract: The aim of this study was to investigate the effect of exposure to L-tryptophan (TRP) on the metabolism of 5-hydroxytryptamine (5HT) and behavior of medaka. In the first experiment, the fish were exposed to a 0, 1, 2 or 4 g/l of TRP solution for 24 hr. Although no significant difference in the brain 5HT content was detected, 5-hydroxyindoleacetic acid (5HIAA), a major 5HT metabolite, increased in a dose-dependent fashion. In the second experiment, the fish were maintained in a 0 or 4 g/l of TRP solution for 28 hr, and then their behaviors were monitored. The fish reared in under TRP solution were divided into two groups and transferred to either fresh water or a TRP solution. The locomotion of the TRP-treated group significantly increased compared to the control group irrespective of water conditions. It was suggested that TRP exposure activated the brain 5HTnergic systems and stimulated behavior of medaka.
authors.affiliation: Laboratory of Advanced Animal and Marine Bioresources, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Koutoku
authors.forename: Rong
authors.initials: R
authors.lastname: Zhang
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Tachibana
authors.forename: Yuji
authors.initials: Y
authors.lastname: Oshima
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Furuse
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D001921:Brain / Q000187:drug effects* / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D009990:Oryzias; D012701:Serotonin / Q000378:metabolism; D013997:Time Factors; D014364:Tryptophan / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D012701:Serotonin; D006897:Hydroxyindoleacetic Acid; D014364:Tryptophan