RELATIONSHIP BETWEEN FLUCTUATIONS IN THE CEREBRAL HEMOGLOBIN OXYGENATION STATE AND NEURONAL-ACTIVITY UNDER RESTING CONDITIONS IN MAN

Simultaneous measurements by near-infrared spectroscopy and electroenc ephalography were performed during 15-min resting periods in nine heal thy adult brains. The peak frequencies of the frontal and occipital rh ythms varied with the time course like the hemoglobin oxygenation stat e. Changes in the amount of oxygenated hemoglobin in the frontal regio n by more than 50% of the maximum resting variation range were accompa nied by changes in peak frequency at the electrode position between tw o optodes. The results suggest that spontaneous neuronal activity is r esponsible for fluctuations in the hemoglobin oxygenation state in the resting state. (C) 1998 Elsevier Science Ireland Ltd.