Abstract
Kainate, an agonist at non-NMDA glutamate receptors, evoked strong concentration-dependent cobalt accumulation in the chick brain stem auditory nuclei angularis, laminaris (NL) and magnocellularis (NM). This effect could be blocked completely by the AMPA/kainate receptor antagonist CNQX and the AMPA antagonist GYKI 53655 but not by antagonists of NMDA receptors or voltage-sensitive calcium channels. Kainate (30 microM) evoked cobalt uptake from embryonic day (E)9 through E21, with a peak intensity at E15. Before E13, uptake occurred mainly in NL but declined markedly in NM after E15 and ceased in NL by E21. We conclude that calcium-permeable non-NMDA receptors are transiently expressed at the time when mature neuronal number, form and synaptic connectivity are established.
Publication types
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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6-Cyano-7-nitroquinoxaline-2,3-dione / pharmacology
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Acoustic Stimulation
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Animals
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Auditory Pathways / embryology
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Auditory Pathways / metabolism*
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Benzodiazepines / pharmacology
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Brain Stem / drug effects
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Brain Stem / embryology
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Brain Stem / metabolism*
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Cell Membrane Permeability
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Chick Embryo
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Cobalt / metabolism*
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Evoked Potentials, Auditory, Brain Stem / physiology
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Excitatory Amino Acid Agonists / pharmacology
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Excitatory Amino Acid Antagonists / pharmacology
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Kainic Acid / antagonists & inhibitors
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Kainic Acid / pharmacology
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Neurons / metabolism*
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Receptors, N-Methyl-D-Aspartate / drug effects
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Receptors, N-Methyl-D-Aspartate / metabolism*
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alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / antagonists & inhibitors
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alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / pharmacology
Substances
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Excitatory Amino Acid Agonists
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Excitatory Amino Acid Antagonists
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Receptors, N-Methyl-D-Aspartate
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Benzodiazepines
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GYKI 53655
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Cobalt
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6-Cyano-7-nitroquinoxaline-2,3-dione
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alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid
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Kainic Acid