Fig. 2.

Key steps in glass plug implantation surgery. (a) Five aspirated cavities converge to form a larger ~1.5 mm diameter cavity centered within a 3 mm × 3 mm craniotomy. The craniotomy, in turn, is centered 2 mm below bregma and 1.5 mm to the right of midline. (b) A 1-20 µl pipette tip connected to a vacuum source is used to hold the glass plug and insert it into the excavated column of cortical tissue immediately above the hippocampus. (c) The plug is attached to a washer to facilitate attachment to the skull. A titanium head post is glued directly to the skull and can be attached to the gimbal mount assembly to immobilize the mouse during imaging.