Three weeks after the viral infection, anesthetize and fix the mouse with a head plate on a stereotaxic frame. Soak a gel foam in saline to stop potential bleeding. Use a micro-drill to create a three by two millimeter oval, centered at 0.5 millimeter posterior to the lambda.
Thin the boundary of the oval until it cracks, then thin the skull before the oval recording window to close the cover slip to the SC.Using fine forceps, take off the bone flaps. Make a cut down the dura, posterior to the transverse sinus and remove the piece of dura. Dry the skull and the recording window with gel foam and cotton swabs.
Then deposit a drop of silicone adhesive into the recording window. Use the suction cup to hold the plug with negative pressure, and use a motorized micro-manipulator to move the suction cup and lower the plug into the silicone adhesive until the cover slip touches the skull. Once the head plate is cleaned, apply butyl cyanoacrylate and resin cement around the boundary of the plug to fix it to the head plate and proceed with imaging.