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This Article Full Text Full Text (PDF) All Versions of this Article: 586/10/2539    most recent jphysiol.2007.147652v1 Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Miwa, H. Articles by Manabe, T. Search for Related Content PubMed PubMed Citation Articles by Miwa, H. Articles by Manabe, T. Related Collections Neuroscience

¹ Division of Neuronal Network, Department of Basic Medical Sciences, Institute of Medical Science, University of Tokyo, Tokyo, 108-8639, Japan
² Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Kawaguchi, 332-0012, Japan
³ Department of Anatomy, Hokkaido University School of Medicine, Sapporo, 060-8638, Japan

The NMDA-type glutamate receptor is a heteromeric complex composed of the NR1 and at least one of the NR2 subunits. Switching from the NR2B to the NR2A subunit is thought to underlie functional alteration of the NMDA receptor during synaptic maturation, and it is generally believed that it results in preferential localization of NR2A subunits on the synaptic site and that of NR2B subunits on the extracellular site in the mature brain. It has also been proposed that activation of the NR2A and NR2B subunits results in long-term potentiation (LTP) and long-term depression (LTD), respectively. Furthermore, recent reports suggest that synaptic and extrasynaptic receptors may have distinct roles in synaptic plasticity as well as in gene expression associated with neuronal death. Here, we have investigated whether NR2B subunit-containing receptors are present and functional at mature synapses in the lateral nucleus of the amygdala (LA) and the CA1 region of the hippocampus, comparing their properties between the two brain regions. We have found, in contrast to the above hypotheses, that the NR2B subunit significantly contributes to synaptic transmission as well as LTP induction. Furthermore, its contribution is greater in the LA than in the CA1 region, and biophysical properties of NMDA receptors and the NR2B/NR2A ratio are different between the two brain regions. These results indicate that NR2B subunit-containing NMDA receptors accumulate on the synaptic site and are responsible for the unique properties of synaptic function and plasticity in the amygdala.

(Received 28 February 2008; accepted after revision 26 March 2008; first published online 27 March 2008)
Corresponding author T. Manabe: Division of Neuronal Network, Department of Basic Medical Sciences, Institute of Medical Science, University of Tokyo, Tokyo, 108-8639, Japan. Email: tmanabe-tky{at}umin.ac.jp