Back to Search Start Over

Downregulation of GluA2 AMPA receptor subunits reduces the dendritic arborization of developing spinal motoneurons.

Authors :
Yone J Yoon
Sheryl L White
Xianglian Ni
Alexander P Gokin
Miguel Martin-Caraballo
Source :
PLoS ONE, Vol 7, Iss 11, p e49879 (2012)
Publication Year :
2012
Publisher :
Public Library of Science (PLoS), 2012.

Abstract

AMPA receptors lacking the GluA2 subunit allow a significant influx of Ca(2+) ions. Although Ca(2+)-permeable AMPA receptors are a familiar feature at early stages of development, the functional significance of these receptors during the maturation of the nervous system remains to be established. Chicken lumbar motoneurons express Ca(2+)-permeable AMPA receptors at E6 but the Ca(2+) permeability of AMPA receptors decreases ∼3-fold by E11. Considering that activity-dependent changes in intracellular Ca(2+) regulates dendritic outgrowth, in this study we investigated whether downregulation of GluA2 expression during a critical period of development alters the dendritic arborization of spinal motoneurons in ovo. We use an avian replication-competent retroviral vector RCASBP (B) carrying the marker red fluorescent protein (RFP) and a GluA2 RNAi construct to downregulate GluA2 expression. Chicken embryos were infected at E2 with one of the following constructs: RCASBP(B)-RFP, RCASBP(B)-RFP-scrambled RNAi, or RCASBP(B)-RFP-GluA2 RNAi. Infection of chicken embryos at E2 resulted in widespread expression of RFP throughout the spinal cord with ≥60% of Islet1/2-positive motoneurons infected, resulting in a significant reduction in GluA2 protein expression. Downregulation of GluA2 expression had no effect on the dendritic arborization of E6 motoneurons. However, downregulation of GluA2 expression caused a significant reduction in the dendritic arborization of E11 motoneurons. Neither motoneuron survival nor maturation of network activity was affected by changes in GluA2 expression. These findings demonstrate that increased GluA2 expression and changes in the Ca(2+) permeability of AMPA receptors regulate the dendritic arborization of spinal cord motoneurons during a critical period of development.

Subjects

Subjects :
Medicine
Science

Details

Language :
English
ISSN :
19326203
Volume :
7
Issue :
11
Database :
Directory of Open Access Journals
Journal :
PLoS ONE
Publication Type :
Academic Journal
Accession number :
edsdoj.47237bdfc0439cb85ff5befa7d7327
Document Type :
article
Full Text :
https://doi.org/10.1371/journal.pone.0049879