Figure 2

Schematic drawings of the tMCAo model and the study schedule. A and B are schematic drawings modified according to Longa et al. [17] of the sham and tMCAo procedure. The occluding filament (microloader) was advanced to the bifurcation of the PA and ICA in sham animals. In tMCAo rats the tip of the microloader was advanced 22 mm beyond the carotid bifurcation. Note that the PA was ligated permanently, and the ipsilateral CCA clamped temporarily during the ischemic challenge. C shows the time course of the surgical procedures. Each animal was on average anesthetized for 160 minutes with isoflurane, and subjected to either 90 minutes of sham surgery or tMCAo. All rats received an intramuscular injection of 50 μg/kg bodyweight atropine (Atropin SAD 1 mg/ml; Denmark) to reduce mucus production while the animals breathed spontaneously in isoflurane anesthesia. Bupivacaine (Bupivacain SAD 2.5 mg/ml; Denmark) was administered subcutaneously at the incision sites in the neck and left femoral region to avoid increase in blood pressure during surgery and to ease postoperative pain. Arterial blood gasses were obtained before, during and after surgery. D represents the schedule of buprenorphine (30 μg/kg BW) and BrdU (50 mg/kg BW) administration. Buprenorphine was administered as a painkiller IM twice daily within the first 48 hours after surgery. BrdU was given IP twice each day on Day 4 to Day 7. All animals were euthanized after one week. BrdU, 5-bromo-2'-deoxy-uridine; BW, bodyweight; CCA, common carotid artery; ICA, internal carotid artery; IM, intramuscularly; IP, intraperitoneally; PA, pterygopalatine artery; tMCAo, transient middle cerebral artery occlusion.