Transient Middle Cerebral Artery Occlusion

Focal cerebral ischemia was induced by transient MCAo in the right hemisphere. The animals were anesthetized with inhaled 1.0–2.0% isoflurane and 5.0% isoflurane (Baxter International) in air through the use of a mask. Body temperature was preserved at 37 °C with a heating pad and was supervised via an intrarectal type T thermocouple (Harvard, Kent, UK). The animals were located in a stereotaxic system (Kopf). Middle cerebral artery (MCA) occlusion was provided by introducing a 4–0 nylon monofilament (Ethilon; Johnson & Johnson, Somerville, NJ, USA), precoated with silicone (Xantopren; Heraeus Kulzer, Germany) via the external carotid artery into the internal carotid artery to occlude the MCA [89 (link),90 (link),91 (link)]. Sham animals were subjected to the same procedure, but the filament was introduced into the internal carotid artery and suddenly withdrawn. At the end of the procedure, anesthesia was discontinued, and the rats were returned to a prone position. Laser Doppler flowmetry (PeriFlux System 5000; Perimed AB, Stockholm, Sweden) with a flexible probe over the skull was used to monitor regional cerebral blood flow (rCBF), as previously described [92 (link)].