Relationship between cerebral perfusion and EEG in the rat brain

Changes in cerebral blood flow (CBF) in the human cortex during seizures have been visually observed during surgery as early as the late 19th century. However, the study of continuous cerebral blood flow (CCBF) during seizures was not possible until the development of a subdural thermal-resistance cerebral blood-flow probe. The current experiment investigated cerebral perfusion (CP) in the rat neocortex using commercially available laser Doppler equipment. Epidural EEG of the rat brain was recorded simultaneously under anesthesia. A seizure was induced in the rat by intravenous injection of bicucullin. CP was measured continuously for a) baseline anaesthetized state, b) during the seizure induced by bicucullin, c) after arresting the seizure by injection of nembutal, and d) after return of the EEG to baseline anaesthetized state. We showed that the laser Doppler technique can be used for continuous recording of CP in the anesthetized rat brain, and also demonstrated the relationship between CP and epileptic discharges in the brain.