Premium
Differential subcellular localization of SK3‐containing channels in the hippocampus
Author(s) -
BallesterosMerino Carmen,
Watanabe Masahiko,
Shigemoto Ryuichi,
Fukazawa Yugo,
Adelman John P.,
Luján Rafael
Publication year - 2014
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1111/ejn.12474
Subject(s) - dentate gyrus , hippocampal formation , neuroscience , hippocampus , postsynaptic potential , postsynaptic density , biology , dendritic spine , synaptic plasticity , microbiology and biotechnology , excitatory postsynaptic potential , chemistry , receptor , inhibitory postsynaptic potential , biochemistry
Small‐conductance, Ca 2+ ‐activated K + (SK) channels are expressed in the hippocampus where they regulate synaptic responses, plasticity, and learning and memory. To investigate the expression of SK3 (KCNN3) subunits, we determined the developmental profile and subcellular distribution of SK3 in the developing mouse hippocampus using western blots, immunohistochemistry and high‐resolution immunoelectron microscopy. The results showed that SK3 expression increased during postnatal development, and that the localization of SK3 changed from being mainly associated with the endoplasmic reticulum and intracellular sites during the first postnatal week to being progressively concentrated in dendritic spines during later stages. In the adult, SK3 was localized mainly in postsynaptic compartments, both at extrasynaptic sites and along the postsynaptic density of excitatory synapses. Double labelling showed that SK3 co‐localized with SK2 (KCNN2) and with N ‐methyl‐D‐aspartate receptors. Finally, quantitative analysis of SK3 density revealed two subcellular distribution patterns in different hippocampal layers, with SK3 being unevenly distributed in CA1 region of the hippocampus pyramidal cells and homogeneously distributed in dentate gyrus granule cells. Our results revealed a complex cell surface distribution of SK3‐containing channels and a distinct developmental program that may influence different hippocampal functions.