Title: | Abundant distribution of TARP γ-8 in synaptic and extrasynaptic surface of hippocampal neurons and its major role in AMPA receptor expression on spines and dendrites |
Authors: | Fukaya, Masahiro Browse this author |
Tsujita, Mika Browse this author |
Yamazaki, Maya Browse this author |
Kushiya, Etsuko Browse this author |
Abe, Manabu Browse this author |
Akashi, Kaori Browse this author |
Natsume, Rie Browse this author |
Kano, Masanobu Browse this author |
Kamiya, Haruyuki Browse this author |
Watanabe, Masahiko Browse this author →KAKEN DB |
Sakimura, Kenji Browse this author |
Keywords: | Hippocampus |
pyramidal cell |
transmembrane AMPA receptor regulatory protein |
immunohistochemistry |
immunoblot |
Issue Date: | Oct-2006 |
Publisher: | Blackwell Publishing |
Journal Title: | European Journal of Neuroscience |
Volume: | 24 |
Issue: | 8 |
Start Page: | 2177 |
End Page: | 2190 |
Publisher DOI: | 10.1111/j.1460-9568.2006.05081.x |
PMID: | 17074043 |
Abstract: | Transmembrane AMPA receptor regulatory proteins (TARPs) play pivotal roles in AMP A receptor trafficking and gating. Here we examined cellular and subcellular distribution of TARP γ-8 in the mouse brain. Immunoblot and immunofluorescence revealed the highest concentration of γ-8 in the hippocampus. Immunogold electron microscopy demonstrated dense distribution of γ-8 on the synaptic and extrasynaptic surface of hippocampal neurons with very low intracellular labeling. Of the neuronal surface, γ-8 was distributed at the highest level on asymmetrical synapses of pyramidal cells and interneurons, whereas their asymmetrical synapses selectively lacked immunogold labeling. Then, the role of γ-8 in AMPA receptor expression was pursued in the hippocampus using mutant mice defective in the γ-8 gene. In the mutant CA1 region, synaptic and extrasynaptic AMPA receptors on dendrites and spines were severely reduced to 35-37% of control levels, whereas reduction was mild for extrasynaptic receptors on somata (74%) and no significant decrease was seen for intracellular receptors within spines. In the mutant CA3 region, synaptic AMPA receptors were reduced mildly at asymmetrical synapses in the stratum radiatum (67% of control level), and showed no significant decrease at mossy fiber-CA3 synapses. Therefore, γ-8 is abundantly distributed on hippocampal excitatory synapses and extrasynaptic membranes, and plays an important role in increasing the number of synaptic and extrasynaptic AMPA receptors on dendrites and spines, particularly, in the CA1 region. Variable degrees of reduction further suggest that other TARPs may also mediate this function at different potencies depending on hippocampal subregions, input sources, and neuronal compartments. |
Rights: | The definitive version is available at www.blackwell-synergy.com |
Type: | article (author version) |
URI: | http://hdl.handle.net/2115/30133 |
Appears in Collections: | 医学院・医学研究院 (Graduate School of Medicine / Faculty of Medicine) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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