Developmental changes in the effects of drugs acting at NMDA or non-NMDA receptors on synaptic transmission in the chick cochlear nucleus (nuc. magnocellularis).
The developmental pharmacology of excitatory amino acid (EAA) receptors in the chick cochlear nucleus (nucleus magnocellularis, NM) was studied by means of bath application of drugs and recording of synaptically-evoked field potentials in brain slices taken from chicks aged embryonic day (E) 14 through hatching (E21). The abilities of various EAA agonists (N-methyl-D-aspartate [NMDA], kainic acid, and alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid [AMPA]) to suppress postsynaptic responses by depolarization block and of EAA antagonists ((3-[RS]-2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid [CCP], dizocilpine [MK-801], 6-nitro-7-sulfamoyl-benzo(F)quinoxaline-2,3 dione [NBQX], 6-cyano-7-nitroquinoxaline-2,3-dione [CNQX] and 6,7-dinitroquinoxaline-2,3-dione [DNQX]) to suppress these responses directly were assessed quantitatively. The results support the existence of NMDA receptors in NM and suggest that the ability of these receptors to influence synaptically-evoked responses declines dramatically during the last week of embryonic life. The results similarly suggest that the non-NMDA receptors in NM undergo changes in density and/or function during a period of development when the cochlear nucleus is undergoing a variety of morphological and functional transformations.
Zhou
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Department of Anatomy, University of Utah School of Medicine, Salt Lake City 84132.
Parks
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TN
D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D000818:Animals; D000927:Anticonvulsants / Q000494:pharmacology; D002642:Chick Embryo; D003056:Cochlear Nerve / Q000187:drug effects / Q000196:embryology / Q000502:physiology*; D016291:Dizocilpine Maleate / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D005314:Embryonic and Fetal Development; D005071:Evoked Potentials / Q000187:drug effects; D007051:Ibotenic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D016202:N-Methylaspartate / Q000494:pharmacology*; D010879:Piperazines / Q000494:pharmacology; D017378:Quinolinic Acid; D011805:Quinolinic Acids / Q000494:pharmacology; D011810:Quinoxalines / Q000494:pharmacology; D016194:Receptors, N-Methyl-D-Aspartate / Q000187:drug effects / Q000502:physiology*; D017981:Receptors, Neurotransmitter / Q000187:drug effects / Q000502:physiology*; D013569:Synapses / Q000187:drug effects / Q000502:physiology*; D009435:Synaptic Transmission / Q000187:drug effects*; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid
D000927:Anticonvulsants; D010879:Piperazines; D011805:Quinolinic Acids; D011810:Quinoxalines; D016194:Receptors, N-Methyl-D-Aspartate; D017981:Receptors, Neurotransmitter; C062865:2,3-dioxo-6-nitro-7-sulfamoylbenzo(f)quinoxaline; C065286:SDZ EAA 494; D007051:Ibotenic Acid; D016202:N-Methylaspartate; D016291:Dizocilpine Maleate; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid; D017378:Quinolinic Acid