Figure 2

Presence and distribution of Kir6.2, SUR1, and SUR2 subunits in DRG neurons and satellite glial cells from control rats. Samples of DRG slices were co-labeled with DAPI, which stains nuclei (blue), and the antibody against each individual subunit (red) (A-D). A. Kir6.1 immunofluorescence was absent in DRG. In contrast the same antibody revealed immunostaining in positive controls (rat brain and aorta smooth muscle; not shown). B. Immunofluorescence against Kir6.2 is identified on plasma membranes (yellow arrowheads) and cytosol (white arrow). Most satellite glial cells also stained positive for Kir6.2. C. Immunofluorescence against SUR1 is observed in the plasma (yellow arrowheads) and nuclear membranes (purple color), as well as along the axons (single yellow arrowhead). Satellite glial cells also stained positive. D. Staining against the SUR2 subunit is observed in the plasma membrane (yellow arrowheads), nuclear membrane (purple color), and the cytosol (white arrow). Satellite glial cells also stained positive. In order to confirm the localization of staining in the plasmalemmal membrane of neurons versus the satellite cell membrane, we examined dissociated DRG cells, stained with the same antibodies, using confocal microscopy. These images clearly showed that neuronal plasmalemmal membrane stained positive for SUR1 (E), Kir6.2 (F), and SUR2 (G). Nuclear envelops also stained positive (E and G, single yellow arrowhead). Distinct positive staining was also observed in satellite cells (G). In E, images correspond to 5 sequential confocal images of z-projections (with spacing increments of 1 μm).