INTERHEMISPHERIC SYNCHRONY OF SLOW OSCILLATIONS OF CORTICAL BLOOD-VOLUME AND CYTOCHROME AA(3) REDOX STATE IN UNANESTHETIZED RABBITS

In order to study spontaneous, slow oscillations of regional oxidative metabolism and blood flow in the normal, unanesthetized cortex, adult rabbits were implanted with bilateral cortical windows and electrodes for polysomnography. Relative changes in the cortical intramitochondr ial redox state of cytochrome aa(3) (CYT) and blood volume (CBV) were monitored by dual-wavelength reflectance spectrophotometry. Continuous , non-stationary oscillations (< 0.5 Hz) of both CYT and CBV were obse rved during waking and non-REM sleep. Cross-correlation analysis revea led a predominant interhemispheric synchrony of these oscillations whi ch were unrelated to the heart rate, breathing, or electrocorticogram pattern. These findings suggest a dynamic linkage of slowly varying me tabolic and vascular processes between unanesthetized cortical regions of 50 mm(2) surface area. (C) 1997 Elsevier Science B.V.