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

Jason J Radley; Claudia R Farb; Yong He; William G M Janssen; Sarina M Rodrigues; Luke R Johnson; Patrick R Hof; Joseph E LeDoux; John H Morrison

doi:10.1016/j.brainres.2006.11.045

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

Journal article

Peer reviewed

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

Jason J Radley, Claudia R Farb, Yong He, William G M Janssen, Sarina M Rodrigues, Luke R Johnson, Patrick R Hof, Joseph E LeDoux and John H Morrison

Brain research, Vol.1134(1), pp.87-94

02/23/2007

DOI: 10.1016/j.brainres.2006.11.045

PMCID: PMC2359729

PMID: 17207780

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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 alpha-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.

Synaptic Transmission - physiology

Conditioning (Psychology) - physiology

Geniculate Bodies - metabolism

Amygdala - metabolism

Geniculate Bodies - ultrastructure

Receptors, N-Methyl-D-Aspartate - metabolism

Rats

Male

Dendritic Spines - metabolism

Presynaptic Terminals - ultrastructure

Fear - physiology

Auditory Pathways - ultrastructure

Rats, Sprague-Dawley

Microscopy, Immunoelectron

Amygdala - ultrastructure

Animals

Synapses - metabolism

Presynaptic Terminals - metabolism

Auditory Pathways - metabolism

Receptors, AMPA - metabolism

Dendritic Spines - ultrastructure

Details

Title: Subtitle: Distribution of NMDA and AMPA receptor subunits at thalamo-amygdaloid dendritic spines
Creators: Jason J Radley - Department of Neuroscience, Mount Sinai School of Medicine, New York, NY 10029, USA. radley@salk.edu
Claudia R Farb
Yong He
William G M Janssen
Sarina M Rodrigues
Luke R Johnson
Patrick R Hof
Joseph E LeDoux
John H Morrison
Resource Type: Journal article
Publication Details: Brain research, Vol.1134(1), pp.87-94
Publisher: Netherlands
DOI: 10.1016/j.brainres.2006.11.045
PMID: 17207780
PMCID: PMC2359729
ISSN: 0006-8993
eISSN: 1872-6240
Grant note: MH58911 / NIMH NIH HHS P50 MH058911 / NIMH NIH HHS
Language: English
Date published: 02/23/2007
Academic Unit: Psychological and Brain Sciences; Iowa Neuroscience Institute
Record Identifier: 9984070303702771

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