Effects of hydrostatic pressure on monoaminergic activity in the brain of a tropical wrasse, Halicoeres trimaculatus: Possible implication for controlling tidal-related reproductive activity

Akihiro Takemura, Yoriko Shibata, Yuki Takeuchi, Sung Pyo Hur, Nozomi Sugama, Md Badruzzaman

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

Most wrasse species in tropical waters exhibit daily spawning synchrony with a preference for high tide. Fish perceive tidal rhythm cues through sensory organs and activate the brain-pituitary-gonadal endocrine axis for synchronous gonadal maturation, although how the tidal-related spawning cycle is controlled endogenously is not known. The purpose of this study was to examine whether hydrostatic pressure has an impact on brain monoamine levels and reproductive activities in the threespot wrasse Halichoeres trimaculatus. The contents of dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC), serotonin (5-HT), and 5-hydroxyindoleacetic acid (5-HIAA) in the brain were measured using high-performance liquid chromatography and an electrochemical detection system. Exposing the fish to hydrostatic pressure occurring at a 3-m depth (~30. kPa) resulted in an increase in 5-HIAA/5-HT over 3. h and a decrease in DOPAC/DA over 6. h. No changes in gonadosomatic index or oocyte diameter were observed between the groups when female fish were reared at 0-m and 3-m depth for 3. h. Hydrostatic pressure did not alter pituitary mRNA abundance of follicle stimulating hormone-β or luteinizing hormone-β. However, in vitro culture of ovaries from pressurized fish in the presence of human chorionic gonadotropin resulted in an increase in 17α,20β-dihydroxy-4-pregnen-3-one in the medium. These results suggest that hydrostatic pressure activates oocyte maturation through brain monoaminergic activity in this tropical wrasse species.

Original languageEnglish
Pages (from-to)173-179
Number of pages7
JournalGeneral and Comparative Endocrinology
Volume175
Issue number1
DOIs
Publication statusPublished - 2012 Jan 1
Externally publishedYes

    Fingerprint

Keywords

  • Brain
  • Dopamine
  • Hydrostatic pressure
  • Ovary
  • Sex steroids
  • Tide
  • Wrasse

ASJC Scopus subject areas

  • Endocrinology

Cite this