Tags

Type your tag names separated by a space and hit enter

Input- and subunit-specific AMPA receptor trafficking underlying long-term potentiation at hippocampal CA3 synapses.
Eur J Neurosci. 2004 Jul; 20(1):101-10.EJ

Abstract

Hippocampal CA3 pyramidal neurons receive synaptic inputs from both mossy fibres (MFs) and associational fibres (AFs). Long-term potentiation (LTP) at these synapses differs in its induction sites and N-methyl-D-aspartate receptor (NMDAR) dependence. Most evidence favours the presynaptic and postsynaptic mechanisms for induction of MF LTP and AF LTP, respectively. This implies that molecular and functional properties differ between MF and AF synapses at both presynaptic and postsynaptic sites. In this study, we focused on the difference in the postsynaptic trafficking of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) between these synapses. To trace the subunit-specific trafficking of AMPARs at each synapse, GluR1 and GluR2 subunits were introduced into CA3 pyramidal neurons in hippocampal organotypic cultures using the Sindbis viral expression system. The electrophysiologically-tagged GluR2 AMPARs, produced by the viral-mediated transfer of the unedited form of GluR2 (GluR2Q), were inserted into both MF and AF postsynaptic sites in a neuronal activity-independent manner. Endogenous Ca(2+)-impermeable AMPARs at these synapses were replaced with exogenous Ca(2+)-permeable receptors, and Ca(2+) influx via the newly expressed postsynaptic AMPARs induced NMDAR-independent LTP at AF synapses. In contrast, no GluR1 AMPAR produced by the gene transfer was constitutively incorporated into AF postsynaptic sites, and only a small amount into MF postsynaptic sites. The synaptic trafficking of GluR1 AMPARs was triggered by the activity of Ca(2+)/calmodulin-dependent kinase II or high-frequency stimulation to induce LTP at AF synapses, but not at MF synapses. These results indicate that MF and AF postsynaptic sites possess distinct properties for AMPAR trafficking in CA3 pyramidal neurons.

Authors+Show Affiliations

Department of Neurophysiology, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511, Japan. wkake@sc.itc.keio.ac.jpNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Comparative Study
Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

15245483

Citation

Kakegawa, Wataru, et al. "Input- and Subunit-specific AMPA Receptor Trafficking Underlying Long-term Potentiation at Hippocampal CA3 Synapses." The European Journal of Neuroscience, vol. 20, no. 1, 2004, pp. 101-10.
Kakegawa W, Tsuzuki K, Yoshida Y, et al. Input- and subunit-specific AMPA receptor trafficking underlying long-term potentiation at hippocampal CA3 synapses. Eur J Neurosci. 2004;20(1):101-10.
Kakegawa, W., Tsuzuki, K., Yoshida, Y., Kameyama, K., & Ozawa, S. (2004). Input- and subunit-specific AMPA receptor trafficking underlying long-term potentiation at hippocampal CA3 synapses. The European Journal of Neuroscience, 20(1), 101-10.
Kakegawa W, et al. Input- and Subunit-specific AMPA Receptor Trafficking Underlying Long-term Potentiation at Hippocampal CA3 Synapses. Eur J Neurosci. 2004;20(1):101-10. PubMed PMID: 15245483.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Input- and subunit-specific AMPA receptor trafficking underlying long-term potentiation at hippocampal CA3 synapses. AU - Kakegawa,Wataru, AU - Tsuzuki,Keisuke, AU - Yoshida,Yukari, AU - Kameyama,Kimihiko, AU - Ozawa,Seiji, PY - 2004/7/13/pubmed PY - 2004/9/8/medline PY - 2004/7/13/entrez SP - 101 EP - 10 JF - The European journal of neuroscience JO - Eur J Neurosci VL - 20 IS - 1 N2 - Hippocampal CA3 pyramidal neurons receive synaptic inputs from both mossy fibres (MFs) and associational fibres (AFs). Long-term potentiation (LTP) at these synapses differs in its induction sites and N-methyl-D-aspartate receptor (NMDAR) dependence. Most evidence favours the presynaptic and postsynaptic mechanisms for induction of MF LTP and AF LTP, respectively. This implies that molecular and functional properties differ between MF and AF synapses at both presynaptic and postsynaptic sites. In this study, we focused on the difference in the postsynaptic trafficking of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) between these synapses. To trace the subunit-specific trafficking of AMPARs at each synapse, GluR1 and GluR2 subunits were introduced into CA3 pyramidal neurons in hippocampal organotypic cultures using the Sindbis viral expression system. The electrophysiologically-tagged GluR2 AMPARs, produced by the viral-mediated transfer of the unedited form of GluR2 (GluR2Q), were inserted into both MF and AF postsynaptic sites in a neuronal activity-independent manner. Endogenous Ca(2+)-impermeable AMPARs at these synapses were replaced with exogenous Ca(2+)-permeable receptors, and Ca(2+) influx via the newly expressed postsynaptic AMPARs induced NMDAR-independent LTP at AF synapses. In contrast, no GluR1 AMPAR produced by the gene transfer was constitutively incorporated into AF postsynaptic sites, and only a small amount into MF postsynaptic sites. The synaptic trafficking of GluR1 AMPARs was triggered by the activity of Ca(2+)/calmodulin-dependent kinase II or high-frequency stimulation to induce LTP at AF synapses, but not at MF synapses. These results indicate that MF and AF postsynaptic sites possess distinct properties for AMPAR trafficking in CA3 pyramidal neurons. SN - 0953-816X UR - https://www.unboundmedicine.com/medline/citation/15245483/Input__and_subunit_specific_AMPA_receptor_trafficking_underlying_long_term_potentiation_at_hippocampal_CA3_synapses_ DB - PRIME DP - Unbound Medicine ER -