Figure 3.

Long term imaging with repeated dye loading. Repeated bright field imaging of blood vessels during a 7 week period (A) starting 1 week after mounting of the chronic cranial window with access port. Regrowth of bone and gradual hardening of the dura but not infection terminated the time course. The decreasing diameter of the craniotomy due to regrowth of bone can be seen from left to right. During this period eight injections of the calcium dye OGB-1 AM-ester were performed, four of which are shown in (B). Functional signals imaged with two-photon microscopy at a depth of 250 µm below the dura in a lightly anesthetized mouse (0.5% isoflurane) are shown in two recordings after repeated injection of AM-ester dye to the same location, indicated in (A) by squares, three (C) and five (D) weeks after mounting the window.