Cortical blood flow through individual capillaries in rat vibrissa S1 cortex: Stimulus induced changes in flow are comparable to the underlying fluctuations in flow.

摘要: Abstract Cortical blood flow was probed via the motion of red cells (RBCs) in individual capillaries that lay as much 600 μm below pia matter primary somatosensory cortex rat. The quite variable, with a speed 0.8±0.5 mm/s (mean±S.D.) and flux 60±40 RBC/s, averaged over all time. fluctuations were dominated by spectral band near 0.1 Hz. This coincides previously seen across whole capillary beds optical [Neuroimage 4 (1996) 183] f MRI [Mag. Reson. Med. 37 (1997) 511] imaging techniques. Time-locked increases within observed response to stimulation multiple vibrissae at natural levels deflection. magnitude stimulus-evoked change was, most, equal 20% basal speed. is comparable level single capillaries. Thus, changes evoked stimuli are largely masked fluctuations. In toto, results our study suggest microvasculature limit sensitivity brain techniques, least low frequencies.