Layer-specific distribution and expression pattern of AMPA- and NMDA-type glutamate receptors in the barrel field of the adult rat somatosensory cortex: a quantitative electron microscopic analysis

Cerebral Cortex, vol. 33, pp. 2342–2360

Abstract

AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) and NMDA (N-methyl-d-aspartate) glutamate receptors are driving forces for synaptic transmission and plasticity at neocortical synapses. However, their distribution pattern in the adult rat neocortex is largely unknown and was quantified using freeze fracture replication combined with postimmunogold-labeling. Both receptors were co-localized at layer (L)4 and L5 postsynaptic densities (PSDs). At L4 dendritic shaft and spine PSDs, the number of gold grains detecting AMPA was similar, whereas at L5 shaft PSDs AMPA-receptors outnumbered those on spine PSDs. Their number was significantly higher at L5 vs. L4 PSDs. At L4 and L5 dendritic shaft PSDs, the number of gold grains detecting GluN1 was ~2-fold higher than at spine PSDs. The number of gold grains detecting the GluN1-subunit was higher for both shaft and spine PSDs in L5 vs. L4. Both receptors showed a large variability in L4 and L5. A high correlation between the number of gold grains and PSD size for both receptors and targets was observed. Both receptors were distributed over the entire PSD but showed a layer- and target-specific distribution pattern. The layer- and target-specific distribution of AMPA and GluN1 glutamate receptors partially contribute to the observed functional differences in synaptic transmission and plasticity in the neocortex.

Authors 7

1. Astrid Rollenhagen

   Forschungszentrum Jülich

   Affiliation as printed

   Institute of Neuroscience and Medicine INM-10, Research Centre Jülich GmbH , Leo Brandt Str., Jülich 52425, Germany

2. Max Anstötz

   Forschungszentrum Jülich · Düsseldorf University Hospital · Heinrich Heine University Düsseldorf

   Affiliation as printed

   Institute of Anatomy II, Medical Faculty, University Hospital Düsseldorf, Heinrich-Heine-University , Universitätsstr. 1, Düsseldorf 40001, Germany

   Institute of Neuroscience and Medicine INM-10, Research Centre Jülich GmbH , Leo Brandt Str., Jülich 52425, Germany

3. Yu Kasugai

   Innsbruck Medical University · Universität Innsbruck

   Affiliation as printed

   Department of Pharmacology, Medical University of Innsbruck , Peter Mayr Strasse 1a, Innsbruck A-6020, Austria

4. Kurt Sätzler

   University of Ulster

   Affiliation as printed

   School of Biomedical Sciences, University of Ulster , Cromore Rd., Londonderry BT52 1SA, United Kingdom

5. Elek Molnár

   University of Bristol

   Affiliation as printed

   School of Physiology, Pharmacology and Neuroscience, University of Bristol, University Walk , Bristol BS8 1TD, United Kingdom

6. Francesco Ferraguti

   Innsbruck Medical University · Universität Innsbruck

   Affiliation as printed

   Department of Pharmacology, Medical University of Innsbruck , Peter Mayr Strasse 1a, Innsbruck A-6020, Austria

7. Joachim H. R. Lübke corresponding Aachen Department of Psychiatry, Psychotherapy and Psychosomatics

   Forschungszentrum Jülich · Jülich Aachen Research Alliance · RWTH Aachen University

   Affiliation as printed

   Department of Psychiatry , Psychotherapy and Psychosomatics, , Pauwelstr. 30, Aachen 52074, Germany

   Institute of Neuroscience and Medicine INM-10, Research Centre Jülich GmbH , Leo Brandt Str., Jülich 52425, Germany

   JARA Translational Medicine Jülich/Aachen , Germany

   RWTH/Medical University Aachen , Psychotherapy and Psychosomatics, , Pauwelstr. 30, Aachen 52074, Germany

   Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH/Medical University Aachen, Pauwelstr. 30, Aachen 52074, Germany