Voltage-sensitive dye versus intrinsic signal optical imaging: comparison of optically determined functional maps from rat barrel cortex

Using intrinsic and voltage-sensitive dye optical imaging methods, somatose nsory-evoked neural activity and the consequent metabolic activity were vis ualized in the barrel cortex at high temporal and spatial resolution. We co mpared maps of neural and metabolic activity from the perspective of spatia l distribution in the cortex. There was good agreement between the two func tional maps, if the extent of metabolic activity before a prominent increas e in cerebral blood volume (CBV) was assessed. This result indicates that o xygen consumption occurs before CBV changes, in approximately the same cort ical area as that in which the preceding neural activity was evoked. This a lso suggests that the intrinsic signal reflects subthreshold synaptic activ ity, as well as spiking activity, which is similar to the dye-related signa ls. NeuroReport 12:2889-2894 (C) 2001 Lippincott Williams & Wilkins.