Temperature affects the development of central neurotransmitter systems of tilapia, Oreochromis mossambicus

The effects of temperature on the development of central neurotransmitter systems were investigated with tilapia, Oreochromis mossambicus. Zero-day-old (the hatching day) tilapia were kept at four different temperatures: 20 (lower), 24 (control), and 28 and 32 degrees C (elevated), respectively. On the 5th day, brain serotonin (5-HT), norepinephrine (NE), gamma-aminobutyric acid (GABA), and glutamate (Glu) contents were quantified by a high-performance liquid chromatograph with electrochemical detection. Similar experiments were performed on the 5-, 10-, 15-, 20-, and 25-day-olds. The results showed that aquatic temperature influenced brain 5-HT, NE, Glu, and GABA contents during its respective restricted period. The influence of both lower and elevated temperatures on the neurotransmitter content, either increasing or suppressing, is dependent on its developing stage. The facts provide an evidence that the development of central neurotransmitter systems is influenced by aquatic temperature during its specific effective period.