Distinct axo-somato-dendritic distributions of three potassium channels in CA1 hippocampal pyramidal cells.
Bottom Line: The Kv2.1 subunit was found in somatic, proximal dendritic and AIS plasma membranes at approximately the same densities.A quasi-linear increase in the Kir3.2 subunit density along the dendrites of PCs was detected, showing no significant difference between apical dendritic shafts, oblique dendrites or dendritic spines at the same distance from the soma.Our results demonstrate that each subunit has a unique cell-surface distribution pattern, and predict their differential involvement in synaptic integration and output generation at distinct subcellular compartments.
Affiliation: Laboratory of Cellular Neurophysiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Szigony Street 43, Budapest, Hungary.Show MeSH
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Mentions: Replicas were then incubated for 2 h in TBS containing 5% BSA and goat anti-rabbit IgGs coupled to 10- or 15-nm gold particles (1 : 100; British Biocell International Ltd., Cardiff, UK), or goat anti-mouse IgGs coupled to 10- or 15-nm gold particles (1 : 50 or 1 : 100; British Biocell). In most double-labelling reactions, a mixture of the two primary then a mixture of the two secondary antibodies was applied. However, we also performed sequential double-labelling reactions (e.g. for Kv1.1 and pan-NF as well as Kv1.1 and SNAP-25; see Fig. 2B and G, respectively) in which the anti-Kv1.1 primary antibody incubation was followed by the anti-rabbit secondary antibody incubation. After this the replicas were incubated with the anti-pan-NF or anti-SNAP-25 primary antibodies and then with the anti-mouse secondary antibodies. Finally, replicas were rinsed in TBS and distilled water before being picked up on copper parallel bar grids. Specimens were analysed with a transmission electron microscope (JEM-1011; JEOL Ltd., Tokyo, Japan).
Affiliation: Laboratory of Cellular Neurophysiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Szigony Street 43, Budapest, Hungary.