Measurement of glutamate and aspartate in Planaria

IntroductionThe major excitatory neurotransmitters in the mammalian central nervous system are glutamate and aspartate. We developed a rapid and efficient method for the extraction and measurement of these amino acids in Planaria—a valuable model for mammalian processes because of their simple, centralized nervous system and similar neurotransmitter systems.MethodThe method utilized buffer extraction (perchloric acid containing 0.025% of l-cystine and Na2EDTA), simple derivatization, high-pressure liquid chromatography (HPLC), and fluorescence detection.ResultsThe mean ± S.E.M. amounts of glutamate and aspartate were 322.6 ± 43.6 and 188.6 ± 27.6 pmol/mg-planarian, respectively.DiscussionThe method provides the ability to investigate changes in glutamate and aspartate in response to drug administration or withdrawal.