Study on the monoamine neurotransmitters change in rat striatum caused by γ-aminobutyric acid using liquid chromatography coupled with Pt/poly-3-methylthiophene modified electrode

γ-Aminobutyric acid (GABA) is the major inhibitory neurotransmitter in the nervous system. To study its effect on monoamine neurotransmitters and their metabolites, a novel Pt/poly-3-methylthiophene chemically modified electrode (Pt/P3MT/CME) was developed. The Pt/P3MT/CME was characterized by atomic force microscope (AFM). The electrochemical behaviors of monoamine neurotransmitters and their metabolites at the CME were investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The results showed that the CME had a prominent electrocatalytic effect, high sensitivity and excellent stability for the determination of monoamine neurotransmitters. When being applied as the liquid chromatographic detector, the CME exhibited a good linear relationship between the current responses and the analyte concentrations. The linear ranges were over three orders of magnitude and the detection limit was 2.0×10^-10 mol/L for norepinephrine (NE), 1. 0 × 10^-10 mol/L for dopamine (DA), 3. 0 × 10 ^-10 mol/L for 3, 4-dihydroxyphenylacetic acid (DOPAC) , 4. 0 × 10^-10 mol/L for 5-hydroxytryptamine(5-HT) and 7.0 × 10 ^-10 mol/L for 5 -hydroxyindoleacetic acid (5-HIAA). The application of this method coupled with microdialysis sampling for in vivo determination of monoamine neurotransmitters in rat striatum was satisfactory. The results demonstrated that GABA could substantially increase striatal concentration of monoamine neurotransmitters.