Distribution of NMDA and AMPA receptor subunits at thalamo-amygdaloid dendritic spines

Radley, Jason J., Farb, Claudia R., He, Yong, Janssen, William G.M., Rodrigues, Sarina M., Johnson, Luke R., Hof, Patrick R., LeDoux, Joseph E., & Morrison, John H. (2007) Distribution of NMDA and AMPA receptor subunits at thalamo-amygdaloid dendritic spines. Brain Research, 1134, pp. 87-94.

View at publisher

Abstract

Synapses onto dendritic spines in the lateral amygdala formed by afferents from the auditory thalamus represent a site of plasticity in Pavlovian fear conditioning. Previous work has demonstrated that thalamic afferents synapse onto LA spines expressing glutamate receptor (GluR) subunits, but the GluR subunit distribution at the synapse and within the cytoplasm has not been characterized. Therefore, we performed a quantitative analysis for α-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) receptor subunits GluR2 and GluR3 and N-methyl-D-aspartate (NMDA) receptor subunits NR1 and NR2B by combining anterograde labeling of thalamo-amygdaloid afferents with postembedding immunoelectron microscopy for the GluRs in adult rats. A high percentage of thalamo- amygdaloid spines was immunoreactive for GluR2 (80%), GluR3 (83%), and NR1 (83%), while a smaller proportion of spines expressed NR2B (59%). To compare across the various subunits, the cytoplasmic to synaptic ratios of GluRs were measured within thalamo-amygdaloid spines. Analyses revealed that the cytoplasmic pool of GluR2 receptors was twice as large compared to the GluR3, NR1, and NR2B subunits. Our data also show that in the adult brain, the NR2B subunit is expressed in the majority of in thalamo-amygdaloid spines and that within these spines, the various GluRs are differentially distributed between synaptic and non-synaptic sites. The prevalence of the NR2B subunit in thalamo-amygdaloid spines provides morphological evidence supporting its role in the fear conditioning circuit while the differential distribution of the GluR subtypes may reflect distinct roles for their involvement in this circuitry and synaptic plasticity.

Impact and interest:

37 citations in Scopus
Search Google Scholar™
35 citations in Web of Science®

Citation counts are sourced monthly from Scopus and Web of Science® citation databases.

These databases contain citations from different subsets of available publications and different time periods and thus the citation count from each is usually different. Some works are not in either database and no count is displayed. Scopus includes citations from articles published in 1996 onwards, and Web of Science® generally from 1980 onwards.

Citations counts from the Google Scholar™ indexing service can be viewed at the linked Google Scholar™ search.

ID Code: 67965
Item Type: Journal Article
Refereed: Yes
Keywords: GluR2, GluR3, Excitatory amino acid, Immunogold, NR1, NR2B, Postembedding, Immunohistochemistry, Tracing, Electron microscopy
DOI: 10.1016/j.brainres.2006.11.045
ISSN: 0006-8993
Subjects: Australian and New Zealand Standard Research Classification > MEDICAL AND HEALTH SCIENCES (110000) > NEUROSCIENCES (110900)
Divisions: Current > QUT Faculties and Divisions > Faculty of Health
Current > Institutes > Institute of Health and Biomedical Innovation
Current > Schools > School of Psychology & Counselling
Deposited On: 03 Mar 2014 00:55
Last Modified: 03 Mar 2014 00:55

Export: EndNote | Dublin Core | BibTeX

Repository Staff Only: item control page