rCBF dropped to 25% of baseline level within the first 1 minute in all pretreatment groups. Administration of the high dose CB1 antagonist (SR141716, 20mg/kg, i.p.) and CB2 agonist (O-1966, 1mg/kg, i.v.) together 1 hour prior to occlusion increased rCBF during the 1 hour occlusion period when compared with the vehicle-treated group (A); similarly, administration of low dose CB1 antagonist (SR141716, 5mg/kg, i.p.) and CB2 agonist (O-1966, 1mg/kg) by i.p. injection also increased rCBF, whereas other treatments failed to alter rCBF during MCAO (B). (*p<0.05 vs vehicle treated control group, n=8 in each group)