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Immunolocalization of BK channels in hippocampal pyramidal neurons
Author(s) -
Sailer Claudia A.,
Kaufmann Walter A.,
Kogler Michaela,
Chen Lie,
Sausbier Ulrike,
Ottersen Ole Petter,
Ruth Peter,
Shipston Michael J.,
Knaus HansGünther
Publication year - 2006
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/j.1460-9568.2006.04936.x
Subject(s) - postsynaptic potential , hippocampal formation , neuroscience , colocalization , immunocytochemistry , postsynaptic density , microbiology and biotechnology , hippocampus , chemistry , bk channel , biology , biophysics , membrane potential , excitatory postsynaptic potential , receptor , inhibitory postsynaptic potential , biochemistry , endocrinology
Neurons are highly specialized cells in which the integration and processing of electrical signals critically depends on the precise localization of ion channels. For large‐conductance Ca 2+ ‐ activated K + (BK) channels, targeting to presynaptic membranes in hippocampal pyramidal cells was reported; however, functional evidence also suggests a somatodendritic localization. Therefore we re‐examined the subcellular distribution of BK channels in mouse hippocampus using a panel of independent antibodies in a combined approach of conventional immunocytochemistry on cultured neurons, pre‐ and postembedding electron microscopy and immunoprecipitation. In cultured murine hippocampal neurons, the colocalization of BK channels with both pre‐ and postsynaptic marker proteins was observed. Electron microscopy confirmed targeting of BK channels to axonal as well as dendritic membranes of glutamatergic synapses in hippocampus. A postsynaptic localization of BK channels was also supported by the finding that the channel coimmunoprecipitated with PSD95, a protein solely expressed in the postsynaptic compartment. These results thus demonstrate that BK channels reside in both post‐ and presynaptic compartments of hippocampal pyramidal neurons.