@article{oai:iwate-u.repo.nii.ac.jp:00009799, author = {MATSUURA, Tetsuya and FUJITA, Hideaki and SEKI, Chie and KASHIKURA, Kenichi and YAMADA, Katsuya and KANNO, Iwao}, issue = {3}, journal = {The Japanese Journal of Physiology}, month = {Jan}, note = {The purpose of this study was to examine the timing and magnitude of neuronal activation. We measured the changes in local CBF(LCBF), red blood cell(RBC) velocity and RBC concentration by laser-Doppler flowmetry (LDF) as well as field potential recordings during activation of the somatosensory cortex of the rat in response to alactrical stimulation of the hind paw. Electrical stimuli, 0.1 ms pulses of 1-1.5 mA for 5 s, were applied at 0.2,0.5,5,10 and 50 Hz under α-chloralose anesthesia. LCBF showed the maximum increase at 5 Hz, and rose approximately 0.5 s after the onset of stimulation regardless of the frequency. The maximum freaquency of the filed potentials was also obtained at 5 Hz. During activation of the somatosensory cortex, the onset of rise in RBC concentration did not precede that of RBC velocity, and the peak RBC concentrasion was noted earlier than that both LCBF and RBC velocity, suggesting that both arteriolar diameter and active changes in the capillary contributed to the LCBF response.}, pages = {289--296}, title = {CBF Change Evoked by Somatosensory Activation Measured by Laser-Doppler Flowmetry: Independent Evaluation of RBC Velocity and RBC Concentration}, volume = {49}, year = {1999} }