CP 55,940 protects against ischemia-induced electroencephalographic flattening and hyperlocomotion in Mongolian gerbils

The effect of CP 55,940, on electroencephalographic (EEG) spectral power decrease and hyperlocomotion induced by transient global ischemia in gerbils, was investigated. Animals were treated with CP 55,940 (4 mg/kg intraperitoneal (i.p.)) 5 min after bilateral carotid occlusion or SR 141716A (3 mg/kg i.p.) 5 min before or with both. Mean total and relative spectral power was evaluated for 1 h before (basal) and 1 and 24 h, 3 and 7 days after ischemia. Spontaneous locomotor activity was evaluated at the same times. CP 55,940 antagonized the reduction in mean total spectral power and the hyperlocomotion induced by ischemia, in comparison with vehicle group, starting from 24 h and lasting 7 days (P<0.001). Pretreatment with SR 141716A completely blocked the neuroprotective effect of CP 55,940. These findings suggest a potential therapeutic role of cannabinoids in cerebral ischemia.