(A) Overview of the experimental preparation, AAV stereotaxic injection in the dorsal hippocampus followed by intraperitoneal biotin injection (left), and field recordings of LTP in CA1 evoked by HFS (3 × 1-s trains, 100 Hz) of Schaffer collaterals in acute slices (right). (B) Representative tiled wide-field images of 300-μm frontal brain sections from KI mice injected with eGFP control or BirAER-eGFP AAV, live-labeled with 100 nM NA conjugated to DyLight 633. Scale bars, 500 μm. (C and D) HFS-induced LTP in acute slices from KI and WT mice (KI in red; WT in blue), representative voltage traces and summary time courses (C), and cumulative histograms (D) of mean normalized fEPSP/FV slope 35 to 40 min after HFS induction (shaded gray). N ≥ 16. P = 0.8580 (unpaired t test). Statistical comparison of LTP was 35 to 40 min after HFS. Number of slices is indicated in brackets. (E and F) HFS-induced LTP in acute slices from KI mice injected in CA1 with eGFP control or BirAER-eGFP AAV (eGFP + NA in gray, BirAER without NA in red, and BirAER + NA in orange); slices were incubated with 100 nM NA and then continuously perfused with 10 pM NA, as in (C) and (D). N ≥ 8. *P ≤ 0.0365 (Kruskal-Wallis test; F = 8.812, P = 0.0122; Dunn’s post hoc test). Error bars, SEM. See also fig. S20 for basal transmission controls.