Hippocampal slices were cultured as previously described35 (link). Briefly, P3–4 Sprague–Dawley rat pups of both genders were fully anaesthetised and decapitated. Their brains were rapidly sectioned in cold sterile slicing media with a tissue slicer (model HA752, Campden Instruments, Lafayette, IN). Serial coronal slices (300 μm) of the hippocampal CA1 regions were prepared. The slices were separated under a dissecting microscope and halved at the midline. For each experiment, at least 18 slices from3 animals were used. Six hippocampal slices were transferred onto a 0.4-μm Millicell-CM membrane insert (Millipore) in a 6-well plate. The slices were maintained in culture media (1 mL, 50% MEM media, 25% horse serum, and 25% Hanks’ balanced salt solution; Gibco-BRL system, Thermo-Fisher) supplemented with D-glucose (5 mg/mL) and L-glutamine (2 mm) at 37 °C. The media was changed thrice weekly.
We injected virus solution (0.1–0.2 μL) into the extracellular space of the cultured slices’ pyramidal cell layers 3 days after the start of cultivation. Electrophysiological recordings were performed after the slices had been cultured for 8 days.
We injected virus solution (0.1–0.2 μL) into the extracellular space of the cultured slices’ pyramidal cell layers 3 days after the start of cultivation. Electrophysiological recordings were performed after the slices had been cultured for 8 days.