For biocytin visualization of recorded neurons, 1% biocytin (Jackson ImmunoResearch) was included in the internal patch solution. After termination of the experiment (30–60 min), slices were placed in 4% paraformaldahyde for 24 h. Sections were then washed in PBS for 30 min and incubated in Cy-3-conjugated streptavidin (Jackson ImmunoResearch) at 1:500 dilution for 2 h at room temperature. Sections were washed and mounted on slides using Aquamount and visualized using confocal microscopy.
