RRC ID 68694
著者 Niwa F, Bannai H, Arizono M, Fukatsu K, Triller A, Mikoshiba K.
タイトル Gephyrin-independent GABA(A)R mobility and clustering during plasticity.
ジャーナル PLoS One
Abstract The activity-dependent modulation of GABA-A receptor (GABA(A)R) clustering at synapses controls inhibitory synaptic transmission. Several lines of evidence suggest that gephyrin, an inhibitory synaptic scaffold protein, is a critical factor in the regulation of GABA(A)R clustering during inhibitory synaptic plasticity induced by neuronal excitation. In this study, we tested this hypothesis by studying relative gephyrin dynamics and GABA(A)R declustering during excitatory activity. Surprisingly, we found that gephyrin dispersal is not essential for GABA(A)R declustering during excitatory activity. In cultured hippocampal neurons, quantitative immunocytochemistry showed that the dispersal of synaptic GABA(A)Rs accompanied with neuronal excitation evoked by 4-aminopyridine (4AP) or N-methyl-D-aspartic acid (NMDA) precedes that of gephyrin. Single-particle tracking of quantum dot labeled-GABA(A)Rs revealed that excitation-induced enhancement of GABA(A)R lateral mobility also occurred before the shrinkage of gephyrin clusters. Physical inhibition of GABA(A)R lateral diffusion on the cell surface and inhibition of a Ca(2+) dependent phosphatase, calcineurin, completely eliminated the 4AP-induced decrease in gephyrin cluster size, but not the NMDA-induced decrease in cluster size, suggesting the existence of two different mechanisms of gephyrin declustering during activity-dependent plasticity, a GABA(A)R-dependent regulatory mechanism and a GABA(A)R-independent one. Our results also indicate that GABA(A)R mobility and clustering after sustained excitatory activity is independent of gephyrin.
巻・号 7(4)
ページ e36148
公開日 2012-1-1
DOI 10.1371/journal.pone.0036148
PII PONE-D-11-25262
PMID 22563445
PMC PMC3338568
MeSH 4-Aminopyridine / pharmacology Animals Astrocytes / cytology Astrocytes / drug effects Astrocytes / metabolism Carrier Proteins / metabolism* Cells, Cultured Cluster Analysis HeLa Cells Hippocampus / cytology Hippocampus / drug effects Hippocampus / metabolism Humans Immunohistochemistry Membrane Proteins / metabolism* N-Methylaspartate / pharmacology Quantum Dots Rats Rats, Wistar Receptors, GABA-A / metabolism* Synapses / drug effects Synapses / metabolism
IF 2.74
リソース情報
ヒト・動物細胞 HeLa(RCB0007)