We showed that 302 of 840 EEG parameters in old Wistar rats significantly change 3 h after bilateral carotid artery ligation. All animals (n=7) died 250+/-47 min after ligation. EEG power spectra had signs of suppression (increased d-activity, decreased t-activity, and increased low-frequency alpha-activity) or activation of CNS (decreased high-frequency alpha-activity and paroxysmal increase in beta-activity). The coherence, synchrony, and entropy of potentials were reduced in the majority of brain regions. This method and scheme of experiments are suitable for the search and study of anti-stroke drugs.