Coupled forebrain increases of local cerebral glucose utilization and blood flow during physiologic stimulation of a somatosensory pathway in the rat

To investigate the relationships of local cerebral glucose utilization (lCMRgl) and blood flow (lCBF) during physiologic activation, awake Wistar rats received unilateral stimulation of the large facial whiskers (vibrissae) and were studied by carbon-14 double-label autoradiography. Activation was followed by increased lCMRgl and lCBF in appropriate forebrain structures. There was an overall preservation of metabolism/blood flow coupling during periods of somatosensory activation despite small but significant increases (14 to 22%) in the coupling ratio of the barrel field. Prolonged activation may give rise to an intracortical redistribution of lCBF within the barrel field.