TY - JOUR
T1 - Effects of hydrostatic pressure on monoaminergic activity in the brain of a tropical wrasse, Halicoeres trimaculatus
T2 - Possible implication for controlling tidal-related reproductive activity
AU - Takemura, Akihiro
AU - Shibata, Yoriko
AU - Takeuchi, Yuki
AU - Hur, Sung Pyo
AU - Sugama, Nozomi
AU - Badruzzaman, Md
PY - 2012/1/1
Y1 - 2012/1/1
N2 - 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.
AB - 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.
KW - Brain
KW - Dopamine
KW - Hydrostatic pressure
KW - Ovary
KW - Sex steroids
KW - Tide
KW - Wrasse
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U2 - 10.1016/j.ygcen.2011.11.019
DO - 10.1016/j.ygcen.2011.11.019
M3 - Article
C2 - 22134178
AN - SCOPUS:84855187447
SN - 0016-6480
VL - 175
SP - 173
EP - 179
JO - General and Comparative Endocrinology
JF - General and Comparative Endocrinology
IS - 1
ER -