@misc{oai:ir.soken.ac.jp:00001165, author = {春日井, 雄 and カスガイ, ユウ and KASUGAI, Yu}, month = {2016-02-17, 2016-02-17}, note = {Pyramidal cells in he hippocampal CA1 area express at least 14 subunits of the
GABA-A receptor, and receive GABAergic input from interneurons, which make
synapses on the soma,dendrites and the axon initial segment(AIS).Here,they used
the SDS-digested freeze-fracture replica labelling method to visualize the cell surface
distribution of the alpha1,alpha2,and beta2/3 subunits quantitatively on distinct
subcellular compartments of pyramidal cells. Immunogold particles for these subunits
were accumulated over clusters of intramembrane particles(IMP) on the protoplasmic
face(P-face) of the plasma membrane, indicating that many IMP clusters of a certain
size represent GABAergic synapses.
The sizes of labelled synapses were not different on the somata and the main apical
dendritic trunks.However,the synaptic areas on AISs were significantly smaller than
those on the soma and apical dendrites. Axon initial segments were identified by
immunogold Labelling for the Nav1.6 subunit of sodium channels. The synaptic
receptor labelling densities for GABA-A receptor subunits were not significantly
different on the tested areas of the cells. A high proportion of receptor labelling was on
the extrasynaptic membrane of the pyramidal cell soma and dendrites. To examine the
co-localization of different GABA-A receptor subunits in single synapses on the soma,
double labelling was performed with antibodies raised in different species. These
experiments showed that the majority of synapses contains alpha1,alpha2,and beta2/3
subunits. Future experiments aim at testing whether distinct synapese populations
differing in the relative proportions of different subunits can be detected with freeze
fracture replica immunogold labelling., application/pdf, 総研大甲第963号}, title = {Quantitative localization of GABAA receptor subunits on hippocampal pyramidal cells by SDS-digested freeze fracture replica labeling(SDS-FRL)}, year = {} }