EEG in anaesthetized rats

The constancy of rat EEG during surgical anaesthesia induced by phenobarbital, cholorose, paraldehyde, and inactin was investigated. The results showed that intraindividual variations and spontaneity of EEG were not abolished in the anaestheized animals. However, at the higher of the two doses used, the EEG was less variable. Our findings thus indicate that in the study of drug actions on the EEG of anaesthetized animals, the results obtained not only represent the interaction of the anaesthetic and the drug on the animal EEG but is also a reflection of the dosage of the anaesthetic employed.