Molecular Pain

official impact factor 4.15

Open Access Research

Roles of the AMPA receptor subunit GluA1 but not GluA2 in synaptic potentiation and activation of ERK in the anterior cingulate cortex

Hiroki Toyoda1, Ming-Gao Zhao1, Bettina Ulzhöfer2, Long-Jun Wu1, Hui Xu1, Peter H Seeburg3, Rolf Sprengel3, Rohini Kuner2 and Min Zhuo1,4*

Author Affiliations

1 Department of Physiology, Faculty of Medicine, University of Toronto, University of Toronto Centre for the Study of Pain, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada

2 Institute for Pharmacology, University of Heidelberg, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany

3 Department of Molecular Neurobiology, Max-Planck Institute for Medical Research, Jahnstrasse 29, 69120 Heidelberg, Germany

4 Department of Brain and Cognitive Sciences, Seoul National University, Seoul 151-746, Korea

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Molecular Pain 2009, 5:46 doi:10.1186/1744-8069-5-46

Published: 10 August 2009

Abstract

Cortical areas including the anterior cingulate cortex (ACC) are important for pain and pleasure. Recent studies using genetic and physiological approaches have demonstrated that the investigation of basic mechanism for long-term potentiation (LTP) in the ACC may reveal key cellular and molecular mechanisms for chronic pain in the cortex. Glutamate N-methyl D-aspartate (NMDA) receptors in the ACC are critical for the induction of LTP, including both NR2A and NR2B subunits. However, cellular and molecular mechanisms for the expression of ACC LTP have been less investigated. Here, we report that the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor subunit, GluA1 but not GluA2 contributes to LTP in the ACC using genetic manipulated mice lacking GluA1 or GluA2 gene. Furthermore, GluA1 knockout mice showed decreased extracellular signal-regulated kinase (ERK) phosphorylation in the ACC in inflammatory pain models in vivo. Our results demonstrate that AMPA receptor subunit GluA1 is a key mechanism for the expression of ACC LTP and inflammation-induced long-term plastic changes in the ACC.