Activation-Blood Flow Coupling During Direct Somatosensory Cortical Stimulation in Living Rat Brain

Laser Doppler flowmetry was used to characterize the cortical activation-blood flow coupling due to direct stimulation in somatosensory cortex of rat brain in vivo. Both amplitude and duration of the flow response increased along with the increases in stimulation current. Flow response became to saturate in a high-grade stimulation with the current above 0.3 mA. The flow response also featured a fast activation due to the stimulus and a slow recovery, which may imply an indirect coupling between neural activity and recruitment of local blood delivery