Effects of halothane on the synthesis of neurotransmitter amino acids in mouse brain

The effects of halothane on the synthesis of the three major neuroactive amino acids (gamma-aminobutyric acid, aspartate and glutamate) and glutamine, which is closely related metabolically, were investigated in mouse brain using a labelled precursor ([13C]glucose) and a gas chromatography-mass spectrometry system. The ratios of newly synthesized amino acids were increased relative to baseline values when animals were exposed to 1% halothane, and decreased when they were exposed to 2% halothane. These findings suggest that halothane affects the synthesis of neurotransmitter amino acids in a concentration-dependent manner, without discrimination between excitatory and inhibitory amino acids.