Ac. Ngai et al., SIMULTANEOUS MEASUREMENTS OF PIAL ARTERIOLAR DIAMETER AND LASER-DOPPLER FLOW DURING SOMATOSENSORY STIMULATION, Journal of cerebral blood flow and metabolism, 15(1), 1995, pp. 124-127
We simultaneously measured pial arteriolar diameter and changes in cor
tical blood flow during activation of the somatosensory cortex by scia
tic nerve stimulation. The pial vasculature was visualized with a clos
ed-cranial window technique in chloralose-anesthetized rats (n = 13).
Local blood flow was monitored with laser-Doppler flowmetry. During st
imulation of the sciatic nerve (0.2 V, 5 Hz, 20 s), vascular diameter
and laser-Doppler flow consistently displayed similar response profile
s. With 0.5-ms stimulation pulses, the responses showed an initial pea
k followed by a smaller but sustained plateau dilation. In contrast, 5
-ms pulses evoked a monotonically rising response. Our results support
the concept that pial arteriolar diameter changes reflect cortical bl
ood flow responses during somatosensory stimulation.