Figure 7From: The Kv2.1 K+ channel targets to the axon initial segment of hippocampal and cortical neurons in culture and in situLocalization of Kv2.1 clusters to the AIS of hippocampal neurons in situ. Postnatal day 21 rat brains were formaldehyde-fixed, cryosectioned and immuno-stained with a polyclonal antibody against Kv2.1 and a monoclonal antibody against ankyrin G as described in Methods. The anti-Kv2.1 antibody was detected with Alexa 488-conjugated goat anti-rabbit secondary antibody (green) while the anti-AnkG monoclonal antibody was detected with Alexa 594-conjugated goat anti-mouse secondary (red). The top row of panels (A-E) illustrates the localization observed in the CA2 hippocampal layer. Single optical sections of either Kv2.1 or ankyrinG immuno-staining are shown in panels A and B, respectively. Panel C shows the overlay of these two images with the arrowhead pointing to an AIS domain with little or no Kv2.1 immuno-reactivity. However, as the insert containing a magnification of the boxed region indicates, Kv2.1 was most often found in the ankyrinG-positive AIS. Panel D shows a maximum projection image (Z-stack compression) and panel E the corresponding DIC image of the same field. The CA1 image represents a single optical section within the CA1 layer while the CA3 image is a maximum projection image of this hippocampal region. The arrows denote the expression of Kv2.1 within the AnkyrinG positive AIS domains.Back to article page