Alexa 594 conjugated streptavidin directed against biocytin

Superficial and deep CA1 pyramidal neurons used for morphological analysis were filled with a solution containing 0.1–0.5% biocytin (Sigma‐Aldrich) through the patch pipette while recording. Acute slices were fixed in 4% Histofix (Carl Roth) after recording. After 2–10 days, the slices were washed in 1× PBS (phosphate‐buffered saline) for 3× 10 min. Permeabilization was performed for 1 h in 0.2% PBST (0.2% Triton X‐100 in 1× PBS). Slices were stained overnight with Alexa 594‐conjugated Streptavidin directed against biocytin (Life Technologies). On the next day, the slices were washed again for 3× 10 min in 1× PBS. After air‐drying the slices at RT for 1 h, they were mounted with a coverslip in ProLong Gold Antifade (Life Technologies).

CA1 pyramidal neurons used for morphological analysis were filled with a solution containing 0.1–0.5% biocytin (Sigma Aldrich) through a patch pipette. Acute slices were fixed in 4% Histofix (Carl Roth). After 2–10 days, the slices were washed in 1x PBS (phosphate-buffered saline) for 3× 10 min. Permeabilization was performed for 1 h in 0.2% PBST (0.2% Triton X-100 in 1x PBS). Slices were stained overnight with Alexa 594-conjugated Streptavidin directed against biocytin (Life Technologies). On the next day, the slices were washed again for 3× 10 min in 1x PBS. After air-drying the slices at RT for 1 h, they were mounted with a coverslip in ProLong Gold Antifade (Life Technologies).