ON THE WAY TO UNDERSTANDING PHARMACO-EEG PHENOMENA

In animal studies (outbred albino rats with different types of conflic t behaviour, cottontail rats, inbred mice) it was established that the anxiolytic effects of benzodiazepine and atypical tranquilizers inclu ding buspirone are associated only with EEG theta-rhythm slowing. At t he same time, anxiogenic drugs caused an increase in frequency of the theta-activity and (in large doses) increase of low-frequency spindles . These EEG-changes are close to the patterns of EEG induced by stress . These results suggest that increase in the beta-activity, especially , owing to high-frequence spindles, which has been reported to be a co mmon feature of all tranquilizers, might be connected with adaptive me chanisms of the brain preventing from lesions by psychotropic drugs. I t is possible that some abnormal EEG activity of epileptic humans and animals (spike slow wave, spindles) also is a reflection of these adap tive mechanisms of the brain.