Glutamate receptor agonist-induced inward currents in spinal dorsal horn neurons dissociated from the adult rats.
Inward currents to glutamate receptor agonists, quisqualate (QA), kainate (KA) and N-methyl-D-aspartate (NMDA) were examined in spinal dorsal horn neurons by whole-cell voltage-clamp techniques after acute dissociation. Neurons were dissociated from the superficial dorsal horn (laminae I/II) of the adult rat (8-16 weeks old) spinal cords by enzymatic and mechanical treatment. The KA-induced current was sustained during KA application, while the QA- and NMDA-induced currents were attenuated. The NMDA response was augmented dose-dependently by addition of glycine (10(-7)-5 X 10(-6) M) and became obscure in the absence of glycine. The NMDA current was depressed by D-2-amino-5-phosphonovaleric acid (APV). Analyses of dose-response curves of these inward currents indicate that both the QA and KA currents were competitively blocked by 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX), while the NMDA current was blocked non-competitively.
Yoshimura
M
M
Center for Neurobiology and Behavior, Columbia University, New York, NY.
Murase
K
K
Arancio
O
O
MacDermott
A B
AB
D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D000818:Animals; D000831:Animals, Newborn / Q000502:physiology; D007473:Ion Channels / Q000502:physiology*; D007608:Kainic Acid / Q000494:pharmacology; D016202:N-Methylaspartate / Q000494:pharmacology; D009412:Nerve Fibers / Q000378:metabolism / Q000502:physiology; D009474:Neurons / Q000378:metabolism*; D011810:Quinoxalines / Q000494:pharmacology; D016318:Quisqualic Acid / Q000494:pharmacology; D051381:Rats; D017470:Receptors, Glutamate; D017981:Receptors, Neurotransmitter / Q000502:physiology*; D013116:Spinal Cord / Q000166:cytology*
D007473:Ion Channels; D011810:Quinoxalines; D017470:Receptors, Glutamate; D017981:Receptors, Neurotransmitter; D016202:N-Methylaspartate; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D015763:2-Amino-5-phosphonovalerate; D016318:Quisqualic Acid; D007608:Kainic Acid