title: Kainic acid stimulates uptake of divalent cations in postnatal cochlear neurons.
abstract: Excitatory amino acids were tested for their ability to induce cobalt uptake in cochlear explants of spiral ganglion neurons. Explants were taken from postnatal day 5 hamsters. Compared with NMDA and quisqualate, kainic acid (KA) stimulated the greatest amount of Co2+ uptake within spiral ganglion neurons as indicated by precipitation of the Co2+ accumulation and relative optical density measurements. Both L-glutamate and KA stimulation were blocked by non-NMDA receptor antagonists kynurenate and DNQX. Nifedipine, a dihydropyridine-sensitive calcium channel blocker, also partially inhibited Co2+ uptake. These data suggest that a mixed population of NMDA and non-NMDA receptors are present. Additionally non-NMDA receptors may have a role in cochlear synaptic maturation.
authors.affiliation: Department of Biology, UCLA 90024-1606.
authors.forename: D D
authors.initials: DD
authors.lastname: Simmons
authors.forename: C
authors.initials: C
authors.lastname: Song
authors.forename: P
authors.initials: P
authors.lastname: Giboney
mesh_terms: D000818:Animals; D002413:Cations, Divalent; D003035:Cobalt / Q000378:metabolism*; D003051:Cochlea / Q000294:innervation*; D006224:Cricetinae; D004305:Dose-Response Relationship, Drug; D018698:Glutamic Acid / Q000494:pharmacology; D007608:Kainic Acid / Q000494:pharmacology*; D016202:N-Methylaspartate / Q000494:pharmacology; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D009924:Organ Culture Techniques; D011810:Quinoxalines / Q000494:pharmacology; D016318:Quisqualic Acid / Q000494:pharmacology; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors
chemical_list: D002413:Cations, Divalent; D011810:Quinoxalines; D016194:Receptors, N-Methyl-D-Aspartate; D003035:Cobalt; D018698:Glutamic Acid; C056723:FG 9041; D016202:N-Methylaspartate; D016318:Quisqualic Acid; D007608:Kainic Acid