Effects of D-alpha-aminoadipate on excitation of afferent fibers in the lateral line of Xenopus laevis.
The effects of D-alpha-aminoadipate (D alpha AA) on excitation of afferent nerve fibers in the Xenopus laevis lateral line were studied in vitro. D alpha AA reversibly suppressed spontaneous activity and excitation induced by water motion at concentrations as low as 0.25-0.5 mM. Higher concentrations (up to 10 mM) caused a greater suppression that was rapidly and fully reversible. L-alpha-Aminoadipate at 0.25-1.0 mM had no suppressive effects. Responses elicited by NMDA (1.0-2.0 mM) were the most sensitive to D alpha AA (0.25-0.5 mM), those elicited by L-aspartate and L-glutamate (1.0-2.0 mM) were less sensitive and similar, and those elicited by kainate (5-15 muM) were the least sensitive. The results provide evidence that the transmitter released by hair cells in the Xenopus lateral line interacts postsynaptically with NMDA-preferring receptors and that the transmitter is an excitatory amino acid, possibly L-glutamate or L-aspartate.
D015074:2-Aminoadipic Acid / Q000494:pharmacology*; D000344:Afferent Pathways / Q000187:drug effects; D000600:Amino Acids, Dicarboxylic / Q000494:pharmacology*; D000818:Animals; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D005260:Female; D005971:Glutamates / Q000494:pharmacology; D018698:Glutamic Acid; D006198:Hair Cells, Auditory / Q000187:drug effects*; D007608:Kainic Acid / Q000494:pharmacology; D008297:Male; D008465:Mechanoreceptors / Q000187:drug effects; D009043:Motor Activity / Q000187:drug effects; D016202:N-Methylaspartate; D009435:Synaptic Transmission / Q000187:drug effects*; D014982:Xenopus laevis
D000600:Amino Acids, Dicarboxylic; D005971:Glutamates; D015074:2-Aminoadipic Acid; D001224:Aspartic Acid; D018698:Glutamic Acid; D016202:N-Methylaspartate; D007608:Kainic Acid