Effects of gonadal steroids on the GABA and glutamate contents of the early developing tilapia brain.
The effects of gonadal steroids on the gamma-aminobutyric acid (GABA) and glutamate (Glu) contents of the early developing brain were investigated. Seven-day-old (7 days post-hatch) tilapia were divided into three groups which were continuously treated with 100 mg/kg diet 17beta-estradiol (E2), 100 mg/kg diet methyltestosterone (MT), and a normal diet, respectively. Until 10, 20, and 30 days old, the GABA and Glu contents of the brains were detected by HPLC-ECD. The brain GABA and Glu contents, before 30 days old, significantly increased with age. These results demonstrate that before 30 days old is a developing period of both GABA and Glu systems in the tilapia brain. During this period, both E2 and MT have a facilitative effect on the GABAergic and Gluergic system during a restricted effective period.
D000818:Animals; D001921:Brain / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism; D004958:Estradiol / Q000494:pharmacology*; D018698:Glutamic Acid / Q000494:pharmacology*; D008777:Methyltestosterone / Q000494:pharmacology*; D012016:Reference Values; D017210:Tilapia; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*