title: Roles of NMDA receptor NR2A and NR2B subtypes for long-term depression in the anterior cingulate cortex.
abstract: The anterior cingulate cortex (ACC) is thought to be important for the establishment, consolidation and retrieval of permanent memory. In many brain regions, including the hippocampus, it is suggested that long-term potentiation (LTP) and long-term depression (LTD), the cellular mechanisms for learning and memory, require the activation of glutamate N-methyl-D-aspartate receptors (NMDARs). In the hippocampus, the NR2A subunit is believed to be involved in the induction of LTP, whereas the NR2B subunit contributes to the formation of LTD. However, LTD has been less well studied in the ACC as compared with the hippocampus and little is known about the role of NMDA subtype receptors in cingulate LTD. Here we show that LTD can be induced by the combination of presynaptic stimulation with postsynaptic depolarization ('pairing training') in adult mouse ACC neurons. This form of LTD is an NMDAR- and voltage-dependent mechanism and a postsynaptic Ca2+ increase is required for the induction of LTD. Furthermore, our studies provide direct physiological evidence that both NR2A and NR2B subunits are involved in the induction of LTD in the ACC.
authors.affiliation: Department of Physiology, University of Toronto, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Toyoda
authors.forename: Ming-Gao
authors.initials: MG
authors.lastname: Zhao
authors.forename: Min
authors.initials: M
authors.lastname: Zhuo
mesh_terms: D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione / Q000494:pharmacology; D000818:Animals; D002614:Chelating Agents / Q000494:pharmacology; D004307:Dose-Response Relationship, Radiation; D004347:Drug Interactions; D004558:Electric Stimulation / Q000379:methods; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D006179:Gyrus Cinguli / Q000166:cytology* / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D066298:In Vitro Techniques; D036881:Long-Term Synaptic Depression / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D051379:Mice; D008810:Mice, Inbred C57BL; D009474:Neurons / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D018408:Patch-Clamp Techniques / Q000379:methods; D011810:Quinoxalines / Q000494:pharmacology; D016194:Receptors, N-Methyl-D-Aspartate / Q000819:agonists / Q000037:antagonists & inhibitors / Q000502:physiology*; D013997:Time Factors
chemical_list: C498554:5-(alpha-methyl-4-bromobenzylamino)phosphonomethyl-1,4-dihydroquinoxaline-2,3-dione; D002614:Chelating Agents; D018690:Excitatory Amino Acid Agonists; D018691:Excitatory Amino Acid Antagonists; C120997:NR2A NMDA receptor; C121001:NR2B NMDA receptor; D011810:Quinoxalines; D016194:Receptors, N-Methyl-D-Aspartate; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D015763:2-Amino-5-phosphonovalerate