The excitation of frog motoneurones in vitro by the glutamate analogue, DI-alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA), and the effect of amino acid antagonists.
Intracellular recordings were made from motoneurones of the frog spinal cord in vitro and the excitatory effects of the glutamate analogue DL-alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) examined. AMPA (25-100 microM) depolarized motoneurones with an increase in input conductance and an increase in spontaneous cell firing. The time-course of the AMPA response was prolonged compared to L-glutamate. D-Aminophosphonovalerate (1 microM) and D-aminoadipate (100 microM) did not antagonize AMPA-induced excitations while depressing L-glutamate responses. Glutamate diethylester up to 1 mM was not found to be a useful amino acid antagonist since it did not significantly reduce the depolarizations to quisqualate, L-glutamate and AMPA. The results are compatible with an action of AMPA on receptors distinct from those to N-methyl-D-aspartate and shared by quisqualate.
King
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Nistri
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Rovira
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D015763:2-Amino-5-phosphonovalerate; D015074:2-Aminoadipic Acid / Q000494:pharmacology*; D000600:Amino Acids, Dicarboxylic / Q000494:pharmacology*; D000818:Animals; D005971:Glutamates / Q000494:pharmacology; D018698:Glutamic Acid; D007051:Ibotenic Acid / Q000031:analogs & derivatives / Q000494:pharmacology*; D008564:Membrane Potentials / Q000187:drug effects; D009046:Motor Neurons / Q000187:drug effects*; D010069:Oxadiazoles / Q000494:pharmacology; D010080:Oxazoles / Q000494:pharmacology*; D016318:Quisqualic Acid; D011896:Rana temporaria; D018091:Receptors, AMPA; D011955:Receptors, Drug / Q000187:drug effects; D013116:Spinal Cord / Q000187:drug effects*; D013569:Synapses / Q000187:drug effects; D009435:Synaptic Transmission / Q000187:drug effects*; D014633:Valine / Q000031:analogs & derivatives* / Q000494:pharmacology; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid
D000600:Amino Acids, Dicarboxylic; D005971:Glutamates; D010069:Oxadiazoles; D010080:Oxazoles; D018091:Receptors, AMPA; D011955:Receptors, Drug; C011829:glutamic acid diethyl ester; D015074:2-Aminoadipic Acid; D007051:Ibotenic Acid; D018698:Glutamic Acid; D015763:2-Amino-5-phosphonovalerate; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid; D016318:Quisqualic Acid; D014633:Valine